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ISBN 978-951-42-6371-2 (Paperback)ISBN 978-951-42-6372-9 (PDF)ISSN 0355-3221 (Print)ISSN 1796-2234 (Online)

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Jarmo R

eponen

OULU 2010

D 1077

Jarmo Reponen

TELERADIOLOGY—CHANGING RADIOLOGICAL SERVICE PROCESSES FROM LOCAL TO REGIONAL, INTERNATIONAL AND MOBILE ENVIRONMENT

UNIVERSITY OF OULU,FACULTY OF MEDICINE,INSTITUTE OF DIAGNOSTICS,DEPARTMENT OF DIAGNOSTIC RADIOLOGY;UNIVERSITY OF OULU,FACULTY OF MEDICINE,INSTITUTE OF BIOMEDICINE,DEPARTMENT OF MEDICAL TECHNOLOGY

A C T A U N I V E R S I T A T I S O U L U E N S I SD M e d i c a 1 0 7 7

JARMO REPONEN

TELERADIOLOGY—CHANGING RADIOLOGICAL SERVICE PROCESSES FROM LOCAL TO REGIONAL, INTERNATIONALAND MOBILE ENVIRONMENT

Academic dissertation to be presented with the assent ofthe Faculty of Medicine of the University of Oulu forpublic defence in Auditorium 7 of Oulu UniversityHospital, on 10 December 2010, at 12 noon

UNIVERSITY OF OULU, OULU 2010

Copyright © 2010Acta Univ. Oul. D 1077, 2010

Supervised byProfessor Osmo Tervonen

Reviewed byDocent Tomi KauppinenProfessor Timo Paakkala

ISBN 978-951-42-6371-2 (Paperback)ISBN 978-951-42-6372-9 (PDF)http://herkules.oulu.fi/isbn9789514263729/ISSN 0355-3221 (Printed)ISSN 1796-2234 (Online)http://herkules.oulu.fi/issn03553221/

Cover DesignRaimo Ahonen

JUVENES PRINTTAMPERE 2010

Reponen, Jarmo, Teleradiology—changing radiological service processes fromlocal to regional, international and mobile environmentUniversity of Oulu, Faculty of Medicine, Institute of Diagnostics, Department of DiagnosticRadiology, P.O.Box 5000, FI-90014 University of Oulu, Finland; University of Oulu, Faculty ofMedicine, Institute of Biomedicine, Department of Medical Technology, P.O.Box 5000, FI-90014 University of Oulu, FinlandActa Univ. Oul. D 1077, 2010Oulu, Finland

AbstractThe possibilities of teleradiology to modify the radiological service process in a regional,international and mobile setting were investigated by building new types of technical connectionsand then by evaluating their feasibility.

First a teleradiology link based on low-end technology was built for primary care and hospitalsettings. On evaluation, the total diagnostic agreement between the transmitted images and theoriginal films was 98%.

Then, a work practice-oriented approach was used to gain an understanding of the relationshipbetween the emerging teleradiology work practice and the newly implemented technology.Ethnographically informed fieldwork and cooperative workshops were utilized. According tofindings, articulation work that supports the key tasks is mostly conducted at the receiving site,and radiologists have to rely on much less information in image interpretation. The decisions madeat the sending site influence the outcome.

To study the idea of consultations between different countries, a connection utilizing theInternet was built between university hospitals in Oulu, Reykjavik and Tromsø. After 131 images,a suitable image compression ratio was selected. Image quality and transfer time of the 80 clinicalcase readings were found to be adequate for teleradiology.

A wireless image consultation system for radiological sub-specialist consultations based on aportable computer and a mobile phone with secure access to the hospital network was set up andtested. The transmitted images of 68 patients were acceptable for final diagnosis in 72% of thecases. The wireless link saved the senior radiologist a hospital visit in 24% of the cases.

A smartphone was then used to communicate computed tomography scans in a feasibility studyof 21 patient cases of brain attacks. All transmitted image series were suitable for giving apreliminary consultation to the clinic, and in one case even a final report could be made. In a reallife clinical setting of the study with neuroradiological and neurosurgical emergencies, twodifferent smartphone platforms with electronic patient record integration were built in Europeanresearch projects and evaluated with sets of 115 and 150 patient cases. They were good for finaldiagnosis in 38% and 40% of the cases, respectively. The concept was found to be ready forclinical use.

Finally a survey was made showing the status and trends of the usage of eHealth applicationsin Finland. The results from all the public health care providers and a representative sample ofprivate providers showed that in 2005, teleradiology services were used by 18/21 hospital districtsand the usage of all eHealth applications has progressed throughout the entire health care deliverysystem. Teleradiology services have become an integrated part of eHealth.

Keywords: computer-supported cooperative work, eHealth, radiography technology,telemedicine, teleradiology, wireless systems, work practice

To my family

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7

Acknowledgements

This study was carried out at the Department of Diagnostic Radiology, Oulu

University Hospital, in collaboration with the Department of Medical Technology,

Institute of Biomedicine, University of Oulu, during the years 1995–2010.

I owe my deepest gratitude to my supervisor, Professor Osmo Tervonen,

M.D., Head of the Department of Diagnostic Radiology, for his encouragement

during this work. He provided me with the opportunity and positive atmosphere

to accomplish this work. He was always supportive in assuring that the work

would be finished when the time was right.

I wish to acknowledge Professor Emeritus Ilkka Suramo, M.D., the former

Head of the Department of Diagnostic Radiology, who believed in my research

topic and encouraged me to seek international collaborators and contacts early on

in an emerging cross-discipline research field.

I wish to express my gratitude to Professor Timo Jämsä, Ph.D. Head of

Department of Medical Technology, who has enabled me to extend my studies

into new research fields within his department.

I also wish to express my particular gratitude to Docent Ilkka Winblad, M.D.,

my friend and closest co-worker in the past years. In addition to generously

providing me with a lot of research knowledge, he has always kept reminding me

how important it is to accomplish tasks once they are started.

I wish to extend my warmest thanks to the official reviewers, Professor Timo

Paakkala, M.D., and Docent Tomi Kauppinen, Ph.D., for their constructive

criticism. Their efficient work and suggestions have markedly improved the

outcome.

This study would have not been possible without extensive teamwork. I wish

to thank Antero Rahtu, M.Sc. (Engineering), for showing me the basics of

teleradiology, as well as Thorgeir Palsson, M.Sc. (Engineering), Head of Clinical

Engineering and Physics at Landspitalinn, Reykjavik, Iceland, and Torbjörn Sund,

M.Sc. (Engineering), Telenor, Oslo, Norway, for showing me the possibilities of

international data networks.

I am grateful to Docent Eero Ilkko, M.D., and Docent Jaakko Niinimäki,

M.D., who have always been open for new ideas and given the best of their

knowledge and time for both scientific thinking and practical work in this study.

My sincere thanks belong to Professor Seppo Lähde, M.D., and Juhani

Laitinen, M.D., who besides taking part of this study, have been great clinical

teachers in radiology.

8

All the other collaborators deserve my sincere thanks. From the Oulu team

Professor Helena Karasti, Ph.D., Virpi Karhula, M.Sc., Docent Ari Karttunen,

M.D., Docent Antero Koivula, Ph.D., Docent Timo Kumpulainen, M.D.,

Professor Kari Kuutti, Ph.D., Pekka Jartti, M.D., Ph.D., Lasse Jyrkinen, M.Sc.

(Engineering), Eeva-Liisa Leisti, M.D., Ph.D., Professor Juhani Pyhtinen, M.D.,

Docent Markku Päivänsalo, M.D., and Docent Tarja Rissanen, M.D., Ph.D., have

taken part in various new experiments without counting their working hours.

I am grateful to Anna Vuolteenaho M.A., for the careful revision of the

language of this thesis. I would also like to thank Professor Roberto Blanco, M.D.,

and Professor Miika Nieminen, Ph.D., for taking part in the follow-up group of

this work. I also wish to thank Mrs Kaisa Punakivi, Mrs Marja-Liisa Raipola, Mrs

Leila Salo and Ms Arja Väisänen for their kind assistance with practical matters.

I express my gratitude to Virpi Honkala, M.D., chief physician at Raahe

Hospital, who has been an inspiring clinical superior and done her best to

guarantee possibilities to convert theories into practice.

The board of the Finnish Society of Telemedicine and eHealth has made up

an excellent atmosphere for discussing recent developments in eHealth. Many

thanks to all the collaborators, especially to Sinikka Salo, DDS, Ph.D., and

Principal Lecturer Anja Henner, Ph.D., for their support towards a scientific

approach, and to Arto Holopainen, M.Sc. (Engineering), for technical support.

A group of former photography enthusiasts, the Hemmos, has provided a

yearly escape from formal activities. Special thanks are due to all of them,

without forgetting Pertti Saloheimo, M.D., Ph.D., who also gave his editorial

experience for the benefit of this work.

Finally, I wish to express my warmest gratitude to my dear wife Jaana for her

support throughout the years. Without her patiently taking care of daily

responsibilities I would not have been able to concentrate on this work. My

beloved children Tiina, Tuomo and Taneli have brought delight into my life and

their music has carried me during the lonely evenings spent preparing these texts.

I also give my dearest thanks to my parents, Laura and Paavo Reponen, for their

support and guidance from early on. I am deeply sorry my mother was not able to

see the finished work.

The research was financially supported by European Commission R&D

framework programmes IV (Health Telematics) and V (Information Society

Technologies) and also by a grant from the Radiological Society of Finland, all of

which are gratefully acknowledged.

9

Abbreviations

3G third-generation mobile networks

4G fourth-generation mobile networks

AAPM American Association of Physicists in Medicine

ACR American College of Radiology

ANSI American National Standards Institute

bit/s bits per second, used with prefixes like kbit/s, Mbit/s, Gbit/s

CCD charge coupled device

CDMA code division multiple access

CE conformité européenne, marking for European conformity

CEN Comité Européen de Normalisation

CR computed radiography

CSCW computer supported cooperative work

DCT discrete cosine transform

DPI dots per inch

CT computed tomography, computerized tomography

DICOM digital imaging and communication in medicine

DF digital fluoroscopy

DM digital mammography

DR digital radiography

DSA digital subtraction angiography

EDGE enhanced data rates for GSM Evolution

EPR electronic patient record

EU European Union

EVDO evolution data optimized

Funet Finnish University and Research Network

FTP file transfer protocol

GPRS general packet radio service

GSM global system for mobile communications

HIS hospital information system

HL7 health level 7

HSCSD high-speed circuit-switched data

HTTP hypertext transfer protocol

ICT information and communication technology

IEEE Institute of Electrical and Electronics Engineers

ISDN integrated services digital network

10

JIF JPEG interchange format

JIRA Japan Industries Association of Radiological Systems

JPEG Joint Photographers Expert Group

bit/s bits per second

LAN local area network

LCD liquid crystal display

LTE long time evolution

LZW Lempel–Ziv–Welch

Mhz megahertz

MDD Medical Devices Directive

MR magnetic resonance

MRI magnetic resonance imaging

MS-DOS MicroSoft Disk Operating System

NEMA National Electrical Manufactures Association

NM nuclear medicine

NMT nordic mobile telephone

NORDUnet Nordic Infrastructure for Research & Education

PACS picture archiving and communication systems

PC personal computer

PDA personal digital assistant

PPP point-to-point protocol

QoS quality of service

OSI open systems interconnect

RIS radiology information system

ROC receiver operating characteristic

SSL secure sockets layer

SMS short message service

TCP/IP transmission control protocol /Internet protocol

TIFF tagged image file format

TDMA time division multiple access

UMTS universal mobile telecommunications system

US ultrasound

Unix a computer operating system (mainly for efficient workstations)

VPN virtual private network

WAN wide area network

WLAN wireless local area network

WWW World Wide Web

11

List of original publications

This thesis is based on the following original articles, which are referred to in the

text by their Roman numerals:

I Reponen J, Lähde S, Tervonen O, Ilkko E, Rissanen T & Suramo I (1995) Low-cost Digital Teleradiology. Eur J Radiol 19: 226–231.

II Karasti H, Reponen J, Tervonen O & Kuutti K (1998) The teleradiology system and changes in work practices. Comput Methods Programs Biomed 57(1–2): 69–78.

III Reponen J, Palsson T, Kjartansson O, Ilkko E, Störmer J, Päivänsalo M, Pyhtinen J, Laitinen J, Eiriksson A & Brekkan A (1995) Nordic Telemedicine Consultation Network Using Internet. Proceedings of CAR ´95 Computer Assisted Radiology and Surgery. Berlin, Springer Verlag: 723–728.

IV Reponen J, Ilkko E, Jyrkinen L, Karhula V, Tervonen O, Laitinen J, Leisti E-L, Koivula A & Suramo I (1998) Wireless radiological consultation with portable computers. J Telemed Telecare 4: 201–205.

V Reponen J, Ilkko E, Jyrkinen L, Tervonen O, Niinimaki J, Karhula V & Koivula A (2000) Initial experience with a wireless personal digital assistant as a teleradiology terminal for reporting emergency computerized tomography scans. J Telemed Telecare 6(1): 45–9.

VI Reponen J, Niinimäki J, Kumpulainen T, Ilkko E, Karttunen A & Jartti P (2005) Mobile teleradiology with smartphone terminals as a part of a multimedia electronic patient record. Int Congr Ser 1281: 916–921.

VII Reponen J, Winblad I & Hämäläinen P (2008) Current status of national eHealth and telemedicine development in Finland. Stud Health Technol Inform 134: 199–208.

12

13

Contents

Abstract Acknowledgements 7 Abbreviations 9 List of original publications 11 Contents 13 1 Introduction 15 2 Review of the literature 17

2.1 Definition and development of teleradiology .......................................... 17 2.2 Change of paradigm: the digital image ................................................... 20 2.3 Required components of a teleradiology system ..................................... 21

2.3.1 Image-sending station ................................................................... 21 2.3.2 Transmission network ................................................................... 22 2.3.3 Image review station..................................................................... 23 2.3.4 Development of workstation and digitizer technology ................. 23

2.4 Recent communication technology developments .................................. 24 2.4.1 Wired connections ........................................................................ 24 2.4.2 Connection of networks; the Internet ........................................... 25 2.4.3 Mobile communication ................................................................. 26

2.5 DICOM-standard .................................................................................... 27 2.5.1 IHE integration profiles ................................................................ 28

2.6 Medical Devices Directive ...................................................................... 30 2.7 Image compression ................................................................................. 30 2.8 Data safety .............................................................................................. 32 2.9 Work process ........................................................................................... 33 2.10 Motivation of teleradiology..................................................................... 33

2.10.1 Effectiveness of teleradiology ...................................................... 33 2.10.2 Quality aspects ............................................................................. 35

2.11 Use of teleradiology ................................................................................ 36 2.11.1 Point to point consultations .......................................................... 36 2.11.2 Regional service concept .............................................................. 36 2.11.3 Mobile teleradiology .................................................................... 37 2.11.4 International teleradiology consultations ...................................... 38

2.12 Concept of eHealth .................................................................................. 39 2.12.1 National initiatives for electronic patient documents ................... 40 2.12.2 EU cross border telemedicine initiatives ...................................... 40

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2.12.3 Teleradiology as a part of eHealth services .................................. 41 3 Purpose of the study 43 4 Subjects and methods 45

4.1 Low-end technology teleradiology .......................................................... 45 4.2 Work practise analysis ............................................................................. 46 4.3 Internet teleradiology .............................................................................. 49 4.4 Mobile PC teleradiology ......................................................................... 50 4.5 Smartphone teleradiology ....................................................................... 54

4.5.1 Feasibility study ............................................................................ 54 4.5.2 Clinical study ................................................................................ 55

4.6 Integration of teleradiology as a part of eHealth services ....................... 57 5 Results 59

5.1 Low-end technology teleradiology .......................................................... 59 5.2 Work practice analysis ............................................................................ 60 5.3 Internet teleradiology .............................................................................. 64 5.4 Mobile PC teleradiology ......................................................................... 66 5.5 Smartphone teleradiology ....................................................................... 67

5.5.1 Feasibility study ............................................................................ 67 5.5.2 Clinical study ................................................................................ 68

5.6 Integration of teleradiology as a part of eHealth services ....................... 70 6 Discussion 75

6.1 Low-end technology teleradiology .......................................................... 76 6.2 Work practise analysis ............................................................................. 79 6.3 Internet teleradiology .............................................................................. 81 6.4 Mobile PC teleradiology ......................................................................... 83 6.5 Smartphone teleradiology ....................................................................... 85

6.5.1 Feasibility study ............................................................................ 85 6.5.2 Clinical study ................................................................................ 89

6.6 Integration of teleradiology as a part of eHealth services ....................... 93 6.7 General discussion – from teleradiology to eHealth and beyond ............ 97

7 Summary and Conclusions 101 8 References 103 Original publications 119

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1 Introduction

Teleradiology services have long been performed with special solutions (Gitlin

1986, Batnitzky et al. 1990, Dwyer et al. 1991, Goldberg et al. 1993), but

gradually connections came to be established with far less effort and cost than

before (Dohrmann 1991, Yamamoto et al. 1996, Berry & Barry 1998, Engelmann et al. 2002). The advances in telecommunication and computer technology have

given us widely standardized tools, which can be applied into clinical practice

(Henri et al. 1997, Hussein et al. 2004).

Teleradiology started as point-to-point connections using either telephone or

dedicated data network connections (Thrall 2007a, Huang 2010). Two major

advances forward have been the Internet (Caramella 1996) and mobile

communication technology (Yamamoto 1995). They pose new challenges by

linking experts quickly with patient information and breaking the barriers of time

and physical hospital buildings. The Internet has even the potential to link

international institutions to obtain secondary opinion (Kovalerchuk et al. 1998,

Wagner 2002). Mobile phones have the potential of bringing a radiology

workstation to a radiologist’s pocket (Yamamoto & Williams 2000). However, the

technical feasibility of the Internet and mobile communication technology for

clinical radiology practice needs to be assessed. New concepts have to be

developed both in order to connect these tools to the hospital information systems

(HIS) in an applicable and secure manner and to find the target medical areas and

workflows that will benefit the most from these advances (Arenson et al. 2000,

Benjamin et al. 2010). This means combining both engineering and medical

knowledge in an effective way.

The work process in a radiological department even within one institution is

complicated by many successive steps (Siegel & Reiner 2002), and the utilization

of the new telemedical workflow in this environment can therefore be

problematic. The amount of teamwork needed to establish the final radiological

report is extensive (Siegel & Reiner 2002). There are many challenges when we

progress from an analogue to a digital environment (Reiner et al. 1996). These are

related to technical, practical and quality aspects (Protopapas et al. 1996, Siegel et al. 1997, Soegner et al. 2003b). A work practice analysis can reveal aspects,

otherwise hidden, that can be used to develop the teleradiology process chain

(Abbot & Sarin 1994, Karasti 1997).

When health care information processing turns digital, teleradiology becomes

a natural part of eHealth (Harno 2004, Reponen 2008), which by definition

16

combines local and distant information and communication solutions in health

care, such as electronic patient records (EPR), HIS, picture archiving and

communication systems (PACS) and direct services for citizens under one

umbrella (World Health Organization 2010). Before this study, the situation and

the progression rate of digital image transfer in Finland has not been well known.

Better knowledge of the present state also gives us tools to take the next logical

steps and develop even international cross-border links (Ross et al. 2010) for

consultations.

The purpose of this study is to evaluate the use and implementation of

teleradiology, more precisely the following: whether low-end technology could

combine acceptable image quality and reasonable costs for primary care centres

and local hospitals, whether there will be noticeable changes in the work

processes when two different institutions start to work together, whether

international teleconsultations using data networks could link together different

institutions in a feasible manner, whether new ubiquitous communication tools,

such as mobile data communication, are suitable for radiological purposes,

whether smartphones could be used for image interpretations, and finally, to chart

the usage status of teleradiology and digital radiology in the electronic health care

(eHealth) domain in Finland in general.

This study will discuss important research steps and achievements from

traditional point-to-point teleradiology to mobile and internationally networked

services over a time span of more than ten years. As some of the sub-topics in this

study were among the earliest published work in this field, the results will draw a

natural development path and summarize the newest trends in the rapidly

developing field of teleradiology as part of the present electronic health care

environment.

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2 Review of the literature

2.1 Definition and development of teleradiology

Teleradiology is one of the most established and most widely used forms of a

larger entity called telemedicine (Wootton 1996, Roine et al. 2001, Ruotsalainen

2010). One of the early comprehensive definitions of telemedicine is that of

Dripps et al. (1992), stating that telemedicine is the investigation, monitoring and

management of patients and staff using systems which allow ready access to

expert advice no matter where the patient is located.

Telemedicine is actually an umbrella term that encompasses any medical

activity involving an element of distance (Wootton 2001). A few years ago the

term telemedicine began to be supplemented by the term telehealth (Watanabe et al. 1999, Krupinski et al. 2002), which was thought to be more “politically

correct”, but since the year 2000 or thereabouts this too has been overtaken by

even more fashionable terms, such as online health and e-health (or eHealth)

(Wootton 2001).

In a narrow definition, teleradiology has been defined as obtaining a

specialist opinion by transmission of digital x-ray images to a radiologist

elsewhere (often in a tertiary centre) (Wootton 2001).

A wider definition by the Canadian Association of Radiologists (2008) says

that teleradiology is the electronic transmission of diagnostic imaging studies

from one location to another for the purposes of interpretation and/or consultation.

It is mentioned that this definition covers both interfacility PACS networks as

well as remote teleradiology.

American College of Radiology (ACR) definition (2002) adds educational

aspects by saying that teleradiology may allow even more timely interpretation of

radiological images and give greater access to secondary consultations and

improved continuing education. Images may be viewed simultaneously by users

in different locations. According to ACR, when appropriately utilized,

teleradiology can improve access to high-quality radiological interpretations and

thus significantly improve patient care.

The following is a short practical definition suitable for most purposes:

Teleradiology is the ability to obtain images in one location, transmit them over a

distance, and view them remotely for diagnostic or consultative purposes (Thrall

2007a).

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The earliest mention of teleradiology dates back to 1929, when two dental

radiographs were transmitted in the USA with the help of telegraph to a distant

location. The image quality was cited to be good enough for dental fillings to be

seen, according to an anonymous article published in the Journal of Dental

Radiography and Photography (1929). This realized the hopes raised by an earlier

anonymous article in published in the the New York Times (1907) describing the

pioneering telephotograph work of professor Arthur Korn from Munich and

predicting the coming wonders: “Lovers conversing at a great distance will

behold each other as in the flesh. Doctors will examine patients’ tongues in

another city, and the poor will enjoy visual trips wherever their fancy inclines.”

The earliest generation of clinical teleradiology starting from the late 1950s

was based on the transmission of analogue TV images with either close circuit or

broadcast technology, using either real time or videotaped images (Jutras 1959,

Murphy & Bird 1974, Murphy et al. 1970, Andrus et al. 1975a, Andrus et al. 1975b). However, the image quality was inadequate compared with the quality of

film images (Page et al. 1981, Curtis et al. 1983). In addition, the working

logistics were not optimal, as the images had to be sent one by one and the cost of

a dedicated installation was high. Once these limitations were recognized, most of

the pioneering projects of clinical teleradiology were terminated (Thrall 2007a).

Then, in the early 1980s, attention turned to computer-based approaches to

telemedicine, with a shift in interest from real-time television applications to

“store-and-foreward” methods, in which data are collected in digital form at an

initiating site and aggregated and stored for subsequent transmission to a

receiving site (Gayler et al. 1981, Lufkin et al. 1983, Gitlin 1986, Thrall 2007a).

Teleradiology systems became commercially available in the 1980s from a

number of vendors, but in retrospect, they were very limited in terms of quality

and scalability (Markivee & Chenoweth 1990, Thrall 2007a). So-called camera-

on-a-stick systems enjoyed a brief period of popularity mostly for hospital-to-

home applications to provide “after-hours” coverage (Bradley 2008). The

approach entailed photographing or videographing selected hard-copy images for

subsequent digitization and image transfer (Mun et al. 1995, Thrall 2007a).

In the Nordic countries the first clinical teleradiology connection was

established in Sweden in the early 1980s. A digital system for transmission of

images over telephone lines using a 256 × 256 and 6 bit deep matrix from a video

camera providing communication between a county hospital and a university

hospital was presented. Transmission of computed tomography (CT) images was

performed without significant degradation of image quality while deterioration of

19

image quality was noticed when conventional films were transmitted. The

consultations gave clinically valuable information to the transmitting radiologist

in approximately 50 percent of the cases. (Nilsson et al. 1986.) However, the

limited image quality and relatively slow image transmission prevented the

diffusion of this method (Olsson 1991).

In Finland, distance teleradiology using the national television broadcasting

network was tested briefly in 1969 (Soila 1970), but the results were only

published in a non-scientific newspaper and magazine articles (Reponen 2004).

Clinical teleradiology started when a videocamera-based photophone device with

a 529 × 440 pixel and 8 bit deep matrix was taken into use between Jyväskylä

central hospital and Kuopio University Hospital in 1989. CT images of

neurosurgical emergencies were sent; each scanned image was transmitted over

telephone lines in 30 seconds. According to users, the equipment saved its

purchasing costs because transportation of patients could be avoided. (Vuorela &

Puranen 1994.) More capable teleradiology, with film scanners and Unix

computer workstations with a 1024 × 1024 and 2048 × 2048 pixel matrix that

were still expensive at that time, was launched in Finland in the early 1990s

(Viitanen et al. 1992) and evaluation results showed acceptable quality for chest

images (Kormano et al. 1994, Korsoff et al. 1995). Lower resolution

microcomputer-based teleradiology with a 512 × 512 pixel and 8-bit image matrix

was also evaluated and found sufficient for consultation with most conventional

radiographs in daily practice (Paakkala et al. 1991). In this study, images from

372 conventional roentgen examinations were digitized and transmitted via a 64

Kbits/s telephone line from a rural health centre to a university hospital, where

they were interpreted by two radiologists. Slight deterioration of image quality

was noticed, although the images were non-diagnostic only in a few cases.

According to the authors, a system based on a 1024 × 1024 pixel matrix is

desirable, however.

Modern teleradiology thus began to develop after the introduction of digitized

images. The early digitized systems captured video images with a 256 × 256 to

512 × 512 pixel matrix and a 6- to 8-bit dynamic range, while more sophisticated

laser scanners enabled resolution of up to 4096 × 4096 pixel and 12 bit- grey

scale (Jelaso et al. 1978, Goldberg et al. 1993). However, the approaches were

cumbersome, and images were still handled one at a time (Thrall 2007a).

Other obstacles for widespread use of teleradiology were the relatively low

performance and high cost of computer systems available (Batnitzky et al. 1990),

high costs of data transmission (Dwyer et al. 1991), and lack of practical and

20

affordable digital image handling systems including high-resolution workstations

at originating and receiving sites (Thrall 2007a).

2.2 Change of paradigm: the digital image

One of the key enabling factors for teleradiology has been the change in the

overall paradigm of how radiological images are made and used. Since the

invention of new X-rays (Röntgen 1895), the imaging process was for nearly a

hundred years based on photographic chemistry and physical images. These

images had to then be copied or transmitted via courier if their presence at another

local was needed.

New imaging modalities, like tomographic nuclear medicine (NM) imaging

with computerized image display and storage in the 1960s and CT in 1971, were

digital from the beginning and paved way to a digital medical image, which

consisted of computer-made measurement results and had only a representation as

a physical image (Langan & Wagner 1969, Thrall 2005, Beckmann 2006).

Magnetic resonance imaging (MRI or MR), digital subtraction angiography

(DSA), digital fluoroscopy (DF), ultrasound (US) with digital image capture

followed soon after, and finally computed radiography (CR), digital radiography

(DR) and digital mammography (DM) signalled the start of the digital age,

making the computerized image commonplace (Kiuru et al. 1991b, Thrall 2005).

First, these digital modalities revolutionalized image acquisition, resulting

gradually in digital storage and transmission of images in everyday practice.

PACS took care of the images (Huang et al. 1988, Taira et al. 1988, Kiuru et al. 1991a, Viitanen et al. 1991), while radiology information systems (RIS) managed

the radiological workflow and information exchange with the other components

in the HIS (Kotter & Langer 1998, Kinsey et al. 2000). As radiologists’ working

environment has moved away from a lightbox to a computer workstation,

teleradiology is no longer an extraordinary task; it is actually one of the normal

instruments of conducting radiological work. The parallel development of digital

imaging and PACS has thus given a push forward for teleradiology, too

(Benjamin et al. 2010).

21

2.3 Required components of a teleradiology system

A basic teleradiology system consists of three major components:

1. An image-sending station

2. A transmission network

3. A receiving/image review station.

Patient images are electronically encoded in a digital format at the sending station,

sent via the transmission network, and received, viewed and possibly stored at the

review station. (Kumar S., 2008.) A generic teleradiology set-up is shown in

figure 1.

Fig. 1. Generic Teleradiology component set-up (Huang 2010, Kalyanpur et al. 2004,

Kumar 2008, Lee et al. 1999). The components are explained in more detail in the

adjacent text.

2.3.1 Image-sending station

At the image-sending station images are captured into digital format with a

digitizer, if originally stored on x-ray film. A laser film digitizer or a CCD (charge

coupled device) film scanner is usually used for this purpose. Today, with most of

the images already in digital DICOM (digital imaging and communication in

Satellite

Microwaves

Mobiledata

WAN

DSL

Phone

ISDN

Internet

FilmDigitizer,(Video, Laser, CCD)

DICOMImages,orDirectDigitalCapture

HIS/RIS/EPR

Images

Patient-relatedinformation

Formatedimage data / transmission system

Networkaccesscontroller

SecurityController

Fax/Phone

Reporttransmitter

ManagementSoftware

Fax/Phone

Reportreceiver

Storage/ PACS

Teleradiology workstation

Phone line

SENDING SITE DATA NETWORK RECEIVING SITE

Networkaccesscontroller

SecurityController

Links: billing, HIS, RIS

TXT

22

medicine) format, a direct digital output from digital modalities (CR, CT, DF, DM,

DR, DSA, MR, US) is utilized. (Huang 2010.) For older devices, also video frame

grabbers are used (Kroeker et al. 2000).

If a digital connection to HIS and RIS exists, this information is also

combined with relevant images and sent to the receiving site (Huang 2010).

Otherwise a fax connection or even a telephone connection can be used to

communicate the relevant patient information (Dunne & Dunne 2004). For image

and related data communication, it is advantageous to convert the data to the

industry standard because multiple vendors’ equipment is used in the

teleradiology chain. Specifically, the DICOM and TCP/IP (Transmission control

protocol/Internet protocol) standards should be used for image data

communication. (Huang 2010.)

2.3.2 Transmission network

Communication networks are essential for teleradiology. The networks can

basically be wired or wireless. The simplest wired solutions are telephone lines or

digital ISDN (integrated services digital network) lines that can be used as point-

to-point connections with the help of a modem. They are also known as dial-up

connections, because they are established as need arises. Their security

requirements are less stringent, because there are no other partners in the

communication pathway. Their usable speed starts from 9.6 kbit/s for a modem

connection and 64 kbit/s for a one-channel ISDN connection. ISDN connections

can be multiplied; a typical setting uses 2 to 6 parallel channels with a speed of

128 to 384 kbits/s. (Lear et al. 1989, Stewart et al. 1992, Huang 2010.)

Wide area network (WAN) connections are fixed connections between local

area networks (LAN) in different institutions. They typically provide higher

speeds and more reliable connections. A lower-cost solution to WAN connection

is using DSL (Digital Subscriber Line) at the customer site of the connection. A

specific type of WAN connection is the Internet, which technically in most cases

uses WAN backbone, but includes the possibility to establish connections more

easily, even on an ad hoc basis. (Arenson et al. 2000, Huang 2010.)

Wireless network connections for teleradiology include satellite transmission,

microwave transmission and mobile phones connections. Satellite connections are

used directly or as part of WAN connections. Microwave transmission usually

involves direct point-to-point connections. Mobile phone network connections are

23

based on the data transfer capability of the operator lines and are usually

connected to LAN at the sending site. (Lamminen 1999, Huang 2010.)

The recent developments of WAN and mobile phone networks are discussed

in more detail in the next chapter.

2.3.3 Image review station

For a teleradiology review system, workstations with high-end 1024 × 1024 pixel

resolution (1 K) monitors for cross-sectional images and workstations with

multiple 2048 × 2048 pixel resolution (2 K) monitors have been recommended

for CR and DR (digital radiography) primary diagnosis (Huang 2010). As the

radiology workflow has turned digital, the American Association of Physicists in

Medicine (AAPM) has published requirements for image reading displays in

general PACS environment, and the current recommendations include not only

definitions of display resolution, but also definitions of other display

characteristics, such as luminance, as well as recommendations for image reading

environments and quality assurance including DICOM calibration of the displays

(Samei et al. 2005a, Samei et al. 2005b). The AAPM recommendations make no

difference between teleradiology or local reading, but they do distinguish quality

requirements between displays used for primary diagnosis and secondary

consultation. In Finland, the Radiation and Nuclear Safety Authority (STUK) has

published a Guide for Quality Control of X-ray equipment in Health Care (2008)

which covers also image display monitors and required steps in quality

maintenance. More recently, Liukkonen has published a thesis (2010) which can

be used as a primer for display requirements.

The workstation should include local storage for images and user-friendly

software to manage and display the images and relevant patient data if available.

Ideally, the teleradiology workstation should be connected to the local PACS for

image store and comparison image retrieval. For the expert centre, administrative

tools for reporting and billing are also necessary. (Huang 2010.)

2.3.4 Development of workstation and digitizer technology

In the early days of digital medical images, the concept of high-quality

teleradiology consisted of laser film scanners with large scanning matrix like

2048 × 2048 pixel resolution and high-end computer workstations together with

fast connection lines. (Batnitzky et al. 1990, Stewart et al. 1992, Goldberg et al.

24

1993.) The costs of such a system could be considerable up to the level of USD

200,000. (Dwyer et al. 1991).

The development of computer and software technology made it possible to

achieve acceptable computational power with more commonly available personal

computers (PC) and to substitute dedicated software with more general

components (Yamamoto et al. 1993, O'Sullivan et al. 1997). CCD film scanner

technology has also progressed so as to produce image quality that is getting close

to the quality of the more expensive laser film scanners (Boland 1998, Calder et al. 1999).

2.4 Recent communication technology developments

Teleradiology requires efficient and affordable communication networks. The

access to fast computer networks is now easier than before, and interestingly

enough, open networks like the Internet as well as mobile data communication

provide new possibilities.

2.4.1 Wired connections

Teleradiology connections first started with modem-based telephone lines, after

which they developed into digital ISDN connections and the high-capacity digital

networks that are readily available today (Kumar 2008).

Institutions can hire fast WAN connections speeds in the magnitude of 1 to

155 Mbit/s and more between their local networks. The costs rise in proportion to

network speed. These WAN connections are established together with a telecom

operator, and appropriate security measures are taken. There is a possibility to

purchase a guaranteed bandwidth or quality of service (QoS) in order to have a

constant transfer speed. (Huang 2010.) These high-capacity networks are mostly

used for image traffic between PACS archives and also for regional teleradiology

and image transfer networks (Bradley 2008).

Private persons can also lease DSL (Digital Subscriber Line) or optic cable

connections to their homes with capacities from 256 kbit/s to 20 Mbit/s. Even

though the costs are lower, these lines are still suitable for teleradiology. (Huang

2010.)

25

2.4.2 Connection of networks; the Internet

The Internet is a global system of interconnected computer networks that use the

standard Internet Protocol Suite (TCP/IP) to serve billions of users worldwide. It

is a network of networks that consists of millions of private, public, academic,

business and government networks of local to global scope that are linked by a

broad array of electronic and optical networking technologies. The Internet carries

a vast array of information resources and services, most notably the inter-linked

hypertext documents of the World Wide Web (WWW) originally developed in

1989 at CERN, the European Organization for Nuclear Research, and the

infrastructure to support electronic mail. (Ahonen 2008, Bergh et al. 2000.)

Started as the US military network Arpanet in the late 1960s, the Internet with

its protocols has now achieved a global position. In Finland, university networks

were started in the 1970s, and in 1983 the Finnish University and Research

Network (Funet) project was founded. The Nordic countries were forerunners in

Europe by establishing a joint NORDUnet research network in 1985. The

NORDUnet network had the benefit of being neutral to networking protocols,

which enabled researchers to use the Internet ahead of central European countries

like Germany, England, France or the Netherlands. In 1988, NORDunet was

actually the first network outside the USA to have a connection to Internet.

Researches in the Nordic countries had thus better opportunities for international

collaboration. (Ahonen 2008.)

After the Internet was made publicly available outside the research

community as well in the mid-1990s, there was increasing interest in its use for

medical information transfer. For teleradiology, the possible benefits of the

Internet are related to the ease of making connections, even internationally

(Boland 1998). There is however no QoS on Internet connections (Huang 2010).

Because of slow speeds and security concerns, the Internet and more specifically,

WWW, was seen a tool for educational material delivery and discussion

(Scarsbrook et al. 2005). Patient treatment over the network was considered to

require more advanced secured tunnelling protocols and more efficient ways of

forwarding large amounts of data (Bergh et al. 2003).

26

2.4.3 Mobile communication

Mobile data networks

Wireless networks became meaningful for medical purposes after they covered a

reasonably large area. The Nordic Mobile Telephone (NMT) network was the first

fully automatic wireless network that provided multinational roaming from

country to country and could be used for data transfer (Ali-Yrkkö & Hermans

2004, Reponen & Niinimäki 2006). One of the benefits of the NMT network was

that its 450 Mhz variant also covered more distant areas of Finland (Judén &

Kuokkanen 2000).

Although the GSM (global system for mobile communications) developed in

Europe is the most widely distributed second-generation mobile network,

different technologies are used in the US and Japan, making them incompatible

(Istepanian et al. 1998, Istepanian et al. 1999). Interestingly, the first GSM call

ever was made in Finland in 1991 (Elisa Oyj 2004, GSM Association 2010). One

benefit of GSM for medical use is that digital data transfer was defined as one of

its basic functions from the beginning. The main limitation of circuit switched

GSM data networks is the data transfer speed, which is realized in commercial

services in the magnitude of 9.6 to 14.4 kbit/s (high-speed), although data rates up

to 57.6 kbit/s would be theoretically possible (Joutjärvi et al. 2000, Tachakra

2003).

The next generation of data networks, the so-called 2.5 generation, namely

packet-switched GPRS (general packet radio service) and its variant EDGE

(enhanced data rates for GSM evolution), provide theoretical maximum data

transmission speeds of up to 114 and 473.6 kbit/s, respectively. In practice, the

effective speed is lower. The increase in speed is substantial compared to original

GSM data transfer, enabling much faster data transmission. Another benefit of

these packet-switched networks is that they allow the usage of Internet protocols

in data transmission, which makes system design much easier for mobile data

applications. Finally, third-generation (3G) UMTS (universal mobile

telecommunications system) networks have developed data transfer speeds to a

level that makes mobile Internet usage feasible. (Ericsson 2009.)

All these variants of data networks are currently available, GPRS coverage

being available practically in all parts of Finland and in most European countries,

its faster EDGE variant having a slightly more limited coverage. Fast 3G

27

networks, even though available world-wide, are still concentrated in the most

densely populated regions. (GSM Association 2009.)

Handheld terminal devices

Thanks to advances in processor and display technology, handheld computers or

personal digital assistants (PDAs) gained a market in the 1990s (Yamamoto 2000,

Pyrros & Yaghmai 2008). Mostly equipped with a black and white display and a

slow processor, they were capable of displaying elementary images. The variants

included devices from manufactures like Psion, Ericsson, Palm and Sharp.

Networking capacity was added to some of the devices via a cable modem or a

network card, or with a GSM data card or a cable connection to a mobile phone

(Tachakra 2003). The concept thus resembled that of a laptop computer with

networking capabilities.

A revolution took place in 1996 when Nokia Corporation introduced the first

integrated communicator device, which had a handheld PDA-type computer and a

GSM phone with digital data transfer capabilities in one package (PDAdb.net

2007). The phone functions included advanced SMS messaging, and the PDA

functions included office solutions as well as typical PDA applications like

calendar and voice recording. The most important factor was the possibility to

make new software applications for the device and also to guide it remotely. This

opened the possibility of using it as a terminal device for various computer and

data network applications. The display was sharp and larger than in ordinary

mobile phones. The limitation was its grey scale, but with proper software to

compensate for this, it was possible to use it for displaying grey-scale images.

2.5 DICOM-standard

Radiology has the benefit of standing in the crossroads of medicine and

technology. The cost of equipment is high, so the investments should be

economically feasible. In the digital imaging domain, it was very soon noticed

that no single vendor could provide a comprehensive imaging system for

customers. The integration of different imaging systems is expensive and time-

consuming and the business prognosis was poor if customers could not trust the

vendors. This prompted the ACR and the National Electrical Manufacturers

Association (NEMA), with input from various vendors, academia, and industry

groups, to work together to come up with standards of interoperability in medical

28

imaging from 1983 on, and published finally the DICOM standard in 1993

(NEMA 2010).

DICOM is a standard that is a framework for medical-imaging

communication. Based on the open system interconnect (OSI) reference model,

which defines a 7-layer protocol, DICOM is an application-level standard,

meaning that it exists inside layer 7 (the uppermost layer). It is referred to as

“version 3.0” because it replaces versions 1.0 (published in 1985) and 2.0 of the

standard (published in 1988) previously issued by ACR and NEMA known as the

“ACR-NEMA” standard (Kiuru 1993, NEMA 2010).

DICOM provides standardized formats for images, a common information

model, application service definitions and protocols for communication in

medical imaging in general, not only in radiology (NEMA 2009).

DICOM is a cornerstone standard in medical imaging, and very rapidly after

its launch in 1993 it replaced local European and Japanese standardization

initiatives. It is now developed in liaison with other standardization organizations

including CEN TC251 (European Committee for Standardization, Technical

Committee 251) in Europe and JIRA (Japan Industries Association of

Radiological Systems) in Japan, with review input from other organizations

including the IEEE (Institute of Electrical and Electronics Engineers), HL7

(Health level 7) and ANSI (American National Standards Institute) in the USA.

(NEMA 2009.)

One of the factors leading to rapid implementation of the DICOM standard

was commitment on the part of end-users. When DICOM became a requirement

in released calls for tender, new equipment and software soon complied with the

standard and made more complicated integration possible after the latter half of

the 1990s. (Kotter & Langer 1998, Kinsey et al. 2000.)

Because the standard enabled various vendors to work together, the medical

imaging sector has been a forerunner in digital patient data usage. A common

standard has increased the market sector and has made it possible for so-called

third party vendors to enter the market with new innovations.

2.5.1 IHE integration profiles

DICOM is in no way perfect; there is quite a lot of freedom in its implementation,

which is why a new initiative called IHE (Integrating the Healthcare Enterprise)

has been established (Oosterwijk 2004). The purpose of IHE is not to create a

new standard, but to develop further so-called integration profiles, which describe

29

how everyday tasks are best performed with existing equipment and available

standards, such as the imaging standard DICOM and the medical record

messaging standard HL7 (Channin 2001). IHE has reached a critical mass in

product support, enabling a significantly higher level of interoperability compared

to former system installations. Integration profiles in particular allow broad

implementation and useful extension of existing and newly developed IT systems

in healthcare (Wein et al. 2005).

IHE is organized across a growing number of clinical and operational

domains. Each domain produces its own set of Technical Framework documents,

in close coordination with other IHE domains. Currently in 2010 there are nine

different domains. In the radiology domain there are 19 IHE profiles that have

been published in trial implementation or final text versions. For example a

profile called Cross-enterprise Document Sharing for Imaging (XDS-I) extends

XDS-profile (which registers and shares electronic health record documents

between healthcare enterprises) to share images, diagnostic reports and related

information across a group of care sites (IHE 2010). Titles of the radiology

domain profiles are presented in Table 1.

Table 1. Titles of the published radiology domain IHE integration and interoperability

profiles in 2010. Detailed up-to-date description of the functions of each profile can be

found at http://www.ihe.net/Profiles/.

Content Profiles Workflow and Infrastructure Profiles

Consistent Presentation of Images (CPI) Scheduled Workflow (SWF)

Key Image Note (KIN) Patient Information Reconciliation (PIR)

Nuclear Medicine Image (NM) Post-Processing Workflow (PWF)

Mammography Image (MAMMO) Reporting Workflow (RWF)

Evidence Documents (ED) Cross-enterprise Document Sharing for Imaging (XDS-I)

Simple Image and Numeric Report (SINR) Portable Data for Imaging (PDI)

Teaching File and Clinical Trial Export (TCE) Import Reconciliation Workflow (IRWF)

Image Fusion (FUS) Presentation of Grouped Procedures (PGP)

Charge Posting (CHG)

Access to Radiology Information (ARI)

Audit Trail and Node Authentication (ATNA)

Product vendors test the interoperability of their products in so called

Connectathon events. The results are then published in an open database (IHE

Europe 2010).

30

Development of these standards and integration profiles has been important

in also making teleradiology an extension of existing imaging networks, thus

helping its distribution as a health care service (Hussein et al. 2004).

2.6 Medical Devices Directive

Another form of coordinating regulation, which will in the future have an impact

on software used for teleradiology is the Medical Devices Directive (MDD). It is

a safety regulation that discusses the responsibilities of the manufacturer, the user

and the authorities. More recently, Directive 2007/47/EC (2007) amended the

definition of the term “medical device” used in Directives 90/385/EEC (1990)

and 93/42/EEC (1993). Recital 6 of Directive 2007/47/EC (2007) states that “it is

necessary to clarify that software in its own right, when specifically intended by

the manufacturer to be used for one or more of the medical purposes set out in the

definition of a medical device, is a medical device”. In Finland, the corresponding

update in legislation of medical devices came into effect on 1st July 2010

(L 629/2010).

An important implication of these above mentioned regulations is that

software products in medical device categories should fulfil the essential

requirements and their risk class has to be classified. Depending on risk class,

there are different evaluation steps before the product can receive a CE mark

(European conformance marking) and enter the market. The regulations promote

the safety and quality of the products and give users a mechanism to report any

serious problems.

The Swedish Medical Products Agency has published a guidance report

(Läkemedelsverket 2009) on how to classify various IT systems. This report has

been a basis for the work of the European Union (EU) Medical Devices Expert

Group, which is preparing European guidelines on this topic. According to the

guidance report, telemedicine programs, including teleradiology programs, are

considered to be not less than risk class I medical devices. The same implies to

software products running PACS when images are viewed and transmitted and to

RIS when information is used for treatment planning of individual patients.

2.7 Image compression

Digital images can be compressed in order to decrease the file size. This has the

benefit of decreasing either the storage space or the bandwidth needed. The latter

31

aspect is related to required network capacity and image transfer times. The

general rule is that the more capacity is needed, the more it costs and the more

time image transfer takes. (Logeswaran 2008.)

As access to affordable bandwidth has increased, the importance of image

compression has decreased in normal consultation settings. In most the cases, a

full uncompressed DICOM radiographic image can be sent for a consultation.

However, image compression is still an issue if wireless networks are used for

mobile terminals and if images are sent over otherwise narrow bandwidths, such

as satellite connections. In addition, new modalities like multislice CT, MRI and

DM produce image packages that are transmitted slowly if uncompressed.

(Logeswaran 2008.)

There are basically two types of compression, lossless and lossy (Kajiwara

1992). The first typically results in 1:2 or 1:3 gain in image size, while lossy

compression for medical purposes can be used without noticeable visual loss with

resolutions such as 1:7 to 1:40, depending on the modality and type of images

(Savcenko et al. 1998, Savcenko et al. 2000).

For lossy compression, the most widely used are JPEG (Joint Photographers

Expert Group) compression and wavelett compression. Fractal compression is not

commonly used for medical purposes because of its inferior performance. (Ricke et al. 1998, Kotter et al. 2003.) The artefacts generated with compression types

vary, and according to reports, influence their suitability for different types of

clinical images. Even though wavelet compression usually enables a higher

compression rate compared to JPEG compression, this is not always true in

clinical settings. (Sung et al. 2002, Schulze et al. 2008.)

Many studies have shown that properly chosen lossy compression has no

effect on diagnostic quality (Lo & Huang 1986, Ishigaki et al. 1990, MacMahon et al. 1991). In practice, PACS vendors have implemented compression in their

clinical viewer software in order to decrease bandwidth requirements for in-house

networks (Logeswaran 2008).

New recommendations on the use of image compression have been published

by three radiological societies over the last two years 2008–2009:

– Royal College of Radiologists (RCR, UK) “The adoption of lossy data

compression for the purpose of clinical interpretation” (RCR 2008)

– German Röntgen Society (DRG, Germany) “Compression of Digital Images

in Radiology - Results of a Consensus Conference” (Loose et al. 2009)

32

– Canadian Association of Radiologists (CAR, Canada) “Pan-Canadian

Evaluation of Irreversible Compression Ratios (“Lossy” Compression) for

Development of National Guidelines” (Koff et al. 2009)

These recommendations have some similarities, e.g. the use of image

compression is possible without losing relevant clinical informations. There are

slight differences in accepted compression ratios. Based on these papers, users

should be able to implement workflows using “lossy” image compression.

However, that there are still some concerns due to different aspects, e.g.

responsibility, algorithms, post processing. Therefore ESR has initiated a process

to discuss these open issues including well recognized international experts in this

field. The estimated outcome is an official ESR recommendation (ESR 2010).

This activity has been coordinated by the ESR subcommittee for “Information

and Communication”.

2.8 Data safety

Patient information should be kept secret and unmodified, but the data should be

available when needed in patient care. The privacy policy means that only

authorized persons are allowed to see personal health data. (Ruotsalainen 2010.)

These requirements are common in any type of teleradiology.

Telemedicine widens the access to sensitive data and therefore data security

development is an essential part of telemedicine projects. Publicly available

security evaluation methods provide a good starting point for security work. A

systematic approach to data security development facilitates the process, but does

not give answers to all practical questions. (Niinimäki et al. 2001.)

The security and privacy protection of any teleradiology system must be

planned in advance, and the necessary security and privacy enhancing tools

should be selected based on risk analysis and requirements set down by

legislation (Ruotsalainen 2010). There is, however, a trade-off between security

measures and system performance (Engelmann 1999, Zhang 2007).

Wireless security specifically has three goals: (1) restricting wireless access

to authorized users, (2) controlling which devices are allowed access to the host

network, and (3) encrypting wireless data transmission to prevent eavesdropping,

modification or insertion of data with respect to the wireless data stream. Server

and client security (including PCs, laptops, PDAs etc) is a separate, but equally

important, security objective. (Pyrros & Yaghmai 2008).

33

2.9 Work process

As mentioned earlier, the first clinical teleradiology experiments were based on

television technology, which mostly required simultaneous presence of the

participants. A major logistic step forward was the store-and-forward approach,

which simplified operation by eliminating the need for all parties – patients,

providers and other support staff – to be present simultaneously at both sites

(Thrall 2007a).

In terms of systems design, teleradiology can be seen as one application area

of interactive or computer-supported cooperative work (CSCW) systems. Within

systems design, it is quite common to view such systems in terms of workflow,

often accompanied by a chain of tasks view of work (Abbot & Sarin 1994).

These identifiable, usually system use-related tasks make up only part of the

teleradiology service and the time spent on making it work. It is not sufficient to

study only these isolated tasks, however; an investigation of actual, everyday

routine activities is needed in order to understand the contextual details of work

and interaction in ways that support the usability of the system. Even though

technical (Uldal et al. 1997, Glinkowski & Kornacki 2002, Struber & Tichon

2003), clinical (Goh et al. 1997a, Goh et al. 1997b, Kiuru et al. 2002, Stranzinger et al. 2003, Daucourt et al. 2005) and economic (Bergmo 1996, Halvorsen &

Kristiansen 1996, Johansen & Breivik 2004, Daucourt et al. 2006, Kreutzer et al. 2008, Plathow et al. 2005) aspects of teleradiology have been investigated

intensively, there are not many studies with a work practice-oriented focus

describing real-life teleradiology work between primary and secondary care

(Karasti 1997, Karasti 2001).

2.10 Motivation of teleradiology

2.10.1 Effectiveness of teleradiology

Teleradiology has been seen as being economically feasible in Norway in a

situation where it replaced a visiting radiology service to a remote hospital, the

examinations consisting of plain radiographs (8,000 examinations per year)

(Bergmo 1996).

Another early example from Austria showed that teleradiology of emergency

CT examinations from a regional hospital to a university hospital was

economically feasible compared to patient transportation even with a reasonable

34

low number of examinations (121 examinations over a period of 13 months)

(Stoeger et al. 1997).

Similar benefits have been reported by Goh et al. (Goh et al. 1997a) on the

role of teleradiology in the management of inter-hospital transfer of neurosurgical

patients. They found that for patients referred with teleradiologic images,

unnecessary transfers were reduced by 21%.

In a large prospective series from Aquitaine France, all teleradiology

transmissions in 15 hospitals and over a period of one year were examined. There

were 664 (90%) transmissions that met the inclusion criteria. Of these, 562 (85%)

were for emergency care and 102 (15%) for non-emergency care. In emergency

care, the pathologies most often associated with a remote consultation were

cerebral pathologies (88%) and traumatic spinal pathologies (8%); the proportion

of avoided transfers was 48%. In non-emergency care, the specialties most often

concerned with remote consultations were neurology/neurosurgery (36%),

cardiology and pulmonary diseases (17%) and gastroenterology (14%). Transfer

was avoided for 37% and hospitalization for 12% of the patients. An additional

consultation occurred after remote consultation for 2% of the patients (Daucourt et al. 2005). A cost-minimization study enabled a comparison of care procedures

following the use of the network with those that would have been implemented

without the network. Annual savings can be estimated at EUR 102,779 for the

Aquitaine area (Daucourt et al. 2006). The results confirm the effectiveness of an

inter-hospital teleradiology network. (Daucourt et al. 2005.)

In a primary care setting, a teleradiology service linking a general practice in

rural Norway with the local hospital in the nearest town was evaluated, and

savings on travelling expenditure were registered for all patients who underwent

elective examinations during the first year of service. Over a four-month period in

2002, it was recorded whether patients undergoing emergency examinations were

taken in at the local general practice or referred to the hospital. The method

employed was a cost-minimization analysis in which the costs of teleradiology

are compared to the costs incurred when patients go to hospital for a radiological

examination. On the basis of data for 3,006 patients, the analysis showed that on

an annual basis the service resulted in savings of NOK 1 million (USD 160,000).

According to the authors, teleradiology is most likely to be cost-effective when

annual patient load and travel costs are high, together with relatively low

investment costs. (Johansen & Breivik 2004.)

In Finland, the clinical effectiveness of primary care teleradiology has been

well demonstrated (Kiuru et al. 2002). In the study, 685 plain film examinations

35

were sent from a primary care centre to a university hospital via an ISDN

connection for a radiological report. The study was conducted in two phases:

during phase 1 (446 cases), general practitioners (GPs) selected the examinations,

and during phase 2 (239 cases), all consecutive examinations were transmitted. In

at least one-third of all cases, teleradiology helped with the diagnosis, although

completely new diagnoses were less common. An effect on treatment was noted

in 15% and on prognosis in 5% of the cases. However, an appropriate

consultation level is required for these positive effects. Adequate accuracy and

patient safety cannot be achieved if the examinations sent for radiological

reporting are preselected by a GP.

In their systematic review of telemedicine articles Roine at al. were able to

show that one the strongest pieces of evidence of the effectiveness of

telemedicine is within teleradiology, especially teleneuroradiology (Roine et al. 2001).

2.10.2 Quality aspects

A proper quality assessment should be included in teleradiology service in order

to assure users that remote interpretation is as accurate and fluent as local image

reading (Wong et al. 2005, Branstetter 2007).

A Tyrolean ‘four-column model of quality management in telemedicine’ was

introduced to ensure a global view of the project and to avoid mistakes. In

teleradiology, a 12-step workflow was developed, describing the medical

responsibilities at each stage. The investigators found that the defined

teleradiology workflow and the technical equipment for data security and data

exchange worked without problems in over 79% of a total of 424 cases. To ensure

continuous quality assurance, the whole teleradiology workflow was ISO

9001:2000 certified. (Soegner et al. 2003b.)

In another study, careful analysis of errors resulted in reduction of the number

of mistakes (mostly minor workflow errors), from 23 errors per month in January

2002 to 9 errors per month in January 2003. The authors concluded that

continuous cross-checking of the workflow and training of the employees

involved guaranteed a better standard of teleradiology. (Soegner et al. 2003a.)

36

2.11 Use of teleradiology

Several factors – including the prevailing shortage of radiologists, the increasing

use of advanced imaging methods, the consolidation of hospitals into regional

delivery systems, and heightened expectations of patients and referring physicians

for timely service – have fostered the increasing use of teleradiology. These

factors have also helped underwrite the creation of new and potentially disruptive

business models for service delivery that can be viewed as threats, opportunities,

or both, but which cannot be ignored. (Thrall 2007a.)

2.11.1 Point to point consultations

Teleradiology has traditionally been used for secondary opinion or for off-hours

emergency consultations (DeCorato et al. 1995, Wilson 1996). It has also been

proposed for educational purposes (Thrall 2007a, Canadian Association of

Radiologists 2008). A rather new aspect in teleradiology is outsourcing the

workload, where a major part of the service is given away from regular staff to an

external expertise centre. In the US, a new term, “nighthawking” has been coined,

because off-hour consultations by external experts are such a common practice.

(Boland 2008.) At the 2007 meeting of the Radiological Society of North America

there were 41 teleradiology companies that provided nighttime coverage, daytime

coverage, or all of the above (Bradley 2008). According to another study, 44% of

all radiology practices in the United States reported using external off-hours

teleradiology services in 2007. These practices included 45% of all U.S.

radiologists. Out-of-practice teleradiology had been used by 15% of practices in

2003, so the amount has tripled. (Lewis 2009.) In the EU area there is service

provider based in Spain that provides local as well as international services (Eklof et al. 2007).

2.11.2 Regional service concept

Regional access to a joint PACS archive actually means teleradiology workflow,

if the images are interpreted in a different location from the imaging site. This

concept makes it possible to build up a virtual hospital, where even small sites

can enjoy sub-specialist consultations or where sub-specialist expertise can be

used more efficiently without physical boundaries. Primary health care centres

can have access to radiology consultation as if they had this service on their own

37

premises. An additional benefit is access to older images and thus avoidance of

excess radiation exposure. (Harno et al. 2002, Harno 2004, Vogl 2005.) For image

interpretation it is also important to have comparison images from other sites

available; this allows physicians to follow up pathologic changes over time,

which results in more accurate diagnosis.

One major regional PACS installation in Finland is HUSpacs, consisting of

the images of 21 hospitals and related primary health care centres (Pohjonen et al. 2004). In Austria, the Insbruck region has built a comprehensive telemedicine

installation connecting the university clinic with a district hospital (Soegner et al. 2003b). Both of these examples implement remote interpretation of images.

Integrating primary health care centres to secondary care via information

systems can create a virtual electronic health record and change service models

(Harno et al. 2002). When associated with viewing of patient data through the

link directory, interactive eConsultations enable supervised care leading to the

reduction of outpatient visits and more timely appointments. In the HUSpacs

information system the link directory is an interface containing links pointing to

the actual patient data located in remote information systems. The original data

including images can be viewed with a web browser, but data can be accessed

only with the patient's informed consent. This means that the citizen has an active

role in deciding on the use of his medical information (Harno 2004). In this

manner the link directory system has implemented the European data protection

directive (Directive 95/46/EC 1995).

An interesting idea has been proposed by Wootton, stating that one advantage

of teleradiology would be omitting the need to maintain specialist staff in

hospitals where the volume of radiology may not justify it (Wootton 2001).

2.11.3 Mobile teleradiology

Wireless transfer of radiology images to a portable computer was reported early

in emergency medicine using analogue cellphone technology (Yamamoto 1995).

With the advance of digital cellular phones and worldwide digital networks image

transmission has been extended to major catastrophe sites and for purposes such

as delivering information needed in post mortem recognition of bodies (Salo et al. 2007).

Wireless technology is identical to conventional teleradiology, with the

obvious difference of using a radiofrequency wireless network for the digital

communication of radiographic images. There are four major disadvantages with

38

wireless technologies: reliability, cost, security and speed. The obvious major

advantage of such technology is the ability to view images virtually anywhere,

from a hospital patient room to the quagmire of the battlefield. In addition, the

costs of wireless networks and their speed have become insignificant issues:

many would in fact argue that deploying a wireless network saves costs, as it does

not require the expense of cabling. (Pyrros & Yaghmai 2008, Thrall 2007a, Thrall

2007b.)

Wireless devices have been utilized with wireless broadband technology

within the hospital environment in ward rounds. In a Finnish study a mobile

Tablet-PC/Webpad- based system with WLAN (Wireless Local Area Network)

connectivity was used to access both textual and image data in the wards. The

data access was fast and comparable with terminals connected to the ordinary

hospital network. The main limitation of WLAN was that outside the hospital

campus area it was only available at so-called service points, “hot spots”. WLAN-

based image review was thus not considered suitable for health professionals who

are on duty and have to be able to connect to the hospital at any time. (Pagani et al. 2003.)

A new type of equipment class entered the market when pocket computers

emerged, and to demonstrate the feasibility of wireless pocket teleradiology, brain

CT scan images of five neurosurgical emergency cases were received on a pocket

computer via a wireless modem link (Yamamoto & Williams 2000).

2.11.4 International teleradiology consultations

International teleradiology was first developed in a military setting. The first

published article describes how an US army team lead by Lt. Col. Fred Goeringer,

MSC, deployed a CT scanner to a transportable hospital in the Saudi Arabian

desert during the first Gulf War in 1991. The images were transmitted via satellite

and telephone links to Brooke Army Medical Center in San Antonio, Texas, for

specialist radiology consultations. Another objective was to validate the concept

of distant interpretation of images obtained on the battlefield. According to the

report, the scan quality was excellent and the scans proved clinically important in

patient management. (Cawthon et al. 1991.) This pilot showed great promise for

both combat and civilian teleradiology and led to further development (Mun et al. 1998).

The Internet opened up new possibilities for international consultation

possibilities. The Nordic countries were among the forerunners in utilizing

39

Internet connections (Ahonen 2008). The new route was at that time tested for

medical purposes. Data safety was a concern at the beginning, but patient data

anonymization, secured network connections like VPN (virtual private network)

and SLL (secure socket layer) technology or data encryption were gradually

adopted in public network connections and international connections as well.

(Wunderbaldinger et al. 1999, Seibel et al. 2000, Niinimäki et al. 2001, Alaoui et al. 2003, Bergh et al. 2004.)

Today, technical aspects do not necessarily restrict international image

transfer. Images are stored in DICOM format and can thus be transferred with

DICOM command to capable destinations. What is more complicated is the

transfer of equally important RIS information and EPR information. This is

related both to lack of commonly used standards in this area as well as possible

language issues. (Arenson et al. 2000, Siegel & Reiner 2002, ESR 2004.)

2.12 Concept of eHealth

Utilization of ICT (information and communication technology) in health care has

moved from individual projects and services to a more comprehensive model.

Instead of telemedicine, terms like telehealth, eHealth, on-line health and most

recently connected health (Microsoft Corporation 2009) have emerged.

eHealth is an umbrella term that gathers together ICT usage in health care

(World Health Organization 2010). It includes major infrastructure services and at

the other end also services targeted to individual citizens. According to the EU

eEurope action plan “An information society for all” eHealth could also seen as a

derivative of eServices, in line with similar terms like eCommerce or

eGovernance (COM/2002/0263 final). The main political goal is to deliver more

accessible and better services to citizens.

eHealth has been strongly emphasized by the European Commission since

2003, when the first eHealth ministerial meeting was held and the first Ministerial

Declaration (2003) on the topic was given. Since then, the European Commission

has encouraged member states to include eHealth in their national health policies.

The WHO has also created its own world wide eHealth strategy (World Health

Organization 2010).

40

2.12.1 National initiatives for electronic patient documents

Finland is a good example of a country that has been an early adopter of eHealth

policies. The information management infrastructure of Finnish health care on a

national level will be based on an internationally unique centralized electronic

archive. The operative use of EPRs will take place on a regional or local level.

(Hämäläinen et al. 2009, Winblad et al. 2010.)

The core of the national Finnish health ICT infrastructure will reside in the

national digital archive for patient documents. It is since 2007 based on

legislation (L 159/2007) and its implementation will be mandatory for all health

care providers in the public sector. For private providers of physician services the

implementation will be mandatory for those using electronic documentation of

patient data.

The national architecture consists of local EPRs using a common data

structure and technical standards, the national eArchive in which all EPRs are

made available online subject to patients’ consent (L 159/2007 2007). In addition,

the archive will include a national ePrescription database based on act on

electronic prescription (L 61/2007 2007), and an eView for citizens, enabling

them to access their own patient data and log data (L 159/2007 2007).

There are several challenges to be overcome with the national archiving

system. It is a technologically complex system that has to be implemented

alongside the everyday service routines of health care. In order to work on a

nationwide level, interoperability of systems is crucial. In addition, the volumes

of information transfer, for instance in radiology, may be very large and overload

the data networks. The system requires that health care employees use an

electronic signature and learn new ways to work, such as documenting patient

information in a structured manner. (Winblad et al. 2010.)

2.12.2 EU cross border telemedicine initiatives

Since the beginning of 2000s, the European Commission has become interested in

the possibilities of cross-border telemedicine. The topic has been discussed in the

EU-funded projects Baltic eHealth and R-Bay (Ross et al. 2010). In the Baltic

eHealth project teleradiology was utilized between the Baltic states and Denmark.

The image interpretation results were dictated in the native languages of the

radiologists and translated into Danish with a computer-based structured form.

Legal issues concerning cross-border telemedicine were also investigated in the

41

project. In the R-Bay project a more general concept of an international

teleradiology marketplace was studied.

More recently, the EU has initiated the epSOS project (Smart Open Services

for European Patients), where interoperability issues are investigated between the

electronic patient record systems of various European countries in a more general

setting of cross-border telemedicine (epSOS 2008). The EU Commission has

promoted cross-border telemedicine and eHealth in ministerial meetings, given

out various statements: a Commission Recommendation on cross-border

interoperability of electronic health record systems (C(2008)3282), a Commission

Communication on telemedicine for the benefit of patients, healthcare systems

and society (COM/2008/0689 final) and a Ministerial declaration (2010) on

European co-operation on eHealth. The EU parliament has been also discussing

incorporating definitions of cross-border telemedicine into the directives on the

mobility of services (Commission Proposal for a directive 2008/0142) which will

be voted in January 2011.

The European Society of Radiology (ESR) has published two guideline

“white papers” concerning teleradiology (ESR 2004, ESR 2006). In these papers,

teleradiology is seen as a feasible opportunity, but ESR stresses the quality

aspects. In relation to directives discussing cross-border telemedicine, ESR

reminds that teleradiology is a medical act and should be treated accordingly.

2.12.3 Teleradiology as a part of eHealth services

In the future health care environment teleradiology has a strong role as one of the

services given (Shieh et al. 2008). It is a means of delivering care, but not a

medical discipline in itself. One key issue is the well-established integration to

other health information systems, especially RIS (Roberson & Shieh 1998). From

the point of view of users, usability and reliable functionality are key issues

(Shieh & Roberson 1999).

Health care services are becoming more ubiquitous (Kyriacou et al. 2009).

Experts need to be reachable anytime and anywhere, and they require the same

amount of information they rely on while working within hospitals. For

teleradiology, the technological possibilities with more capable handheld devices

and even faster wireless networks are no longer an obstacle. Mobile health care

systems (mHealth) have been said to be the next major step forward in

telemedicine. (Voskarides et al. 2002, Herscovici et al. 2007, Waegemann 2010.)

42

Virtual hospital is already a existing possibility (Jones 2000, Graschew et al. 2006). Various institutions can be linked together and workflows can be

synchronized (Bradley 2008). This requires hard work, however, as integration

standards are not well developed or not adopted to a satisfactory degree in other

HIS compared to medical imaging systems. For teleradiology purposes, the

existing infrastructure is for the most part sufficient if RIS and HIS information

can be transmitted. A common regional information system could help solve

many of the problems that exist today. (Harno et al. 2002, Harno 2004.)

Outsourcing of work is a solution to distribute the burden of excess workload

and perhaps a tool to connect sub-specialist radiologists with their own patients

(Bradley 2008). A new structure for the radiology department is also needed. The

risks are also obvious – how to cope with quality issues and keep up interest also

in the boring, bulk-type interpretation work?

43

3 Purpose of the study

The purpose of this study was to evaluate the use and implementation of

teleradiology, namely:

1. whether a low-end technology teleradiology system could combine

acceptable image quality with reasonable costs and serve primary health

centres and local hospitals for image consultation

2. whether there will be noticeable changes in work processes and what are the

most important work practice issues when two different institutions start to

work together,

3. whether international teleconsultations using data networks could link

together different institutions in a feasible manner,

4. whether new ubiquitous communication tools, such as mobile data

communication, are suitable for radiological purposes,

5. whether smartphones could be used for image interpretations, and finally,

6. to chart the usage status of teleradiology and digital radiology in the

electronic health care (eHealth) domain in Finland in general.

44

45

4 Subjects and methods

4.1 Low-end technology teleradiology

The hardware consisted of a standard PC computer with an Intel (Santa Clara,

USA) processor. The images were scanned using a 300 dots per inch (DPI) flat-

bed charged coupled device (CCD) image scanner (model XRS CX3 by X-Ray

Scanner Corporation, Torrance, USA) with a 21 × 35 cm scanning area, giving a

maximum of a 2478 × 4130 pixel matrix. In practice the image digitization matrix

sizes varied from 512 × 512 to 2048 × 2048 pixels depending on the selected

resolution and image size. Each pixel had a 256-step (8 bits) grey scale. Large

images (e.g. 35 cm × 35 cm films) were scanned in two parts and connected

together. A commercial image-processing program was used for scanning and

viewing (PhotoStyler by Aldus Corporation, Seattle, USA). The computer screen

was 47 cm in diameter. Its resolution was 1024 × 768 pixels, but the image

zooming and scrolling functions in the viewing program made it possible to

interpret larger digitized images.

The image data were transmitted via a dial-up digital 64 kilobits per second

(kbit/s) one-channel ISDN telephone line with the help of a communication

program (TeleImage by Telecom Finland). The procedure of sending the images

consisted of the following steps: (1) selecting the images, (2) prescanning and

setting up parameters for the first image, (3) scanning, (4) saving the files, (5)

making a connection, (6) sending the images. Image receiving was automatic.

Both the on-line sending time and the total image transmission time were

recorded.

The PC-based teleradiology system was tested in three different system

configurations (phases). The software interface and the use of compression

differed in these three phases. In the first and second phases, all the programs had

to be used separately and the scanning parameters were adjusted manually. No

common user interface was used. In the first and second phases, all the images

were sent uncompressed. Before the actual clinical cases, a small pilot series of

10 images was made to determine appropriate settings for image digitalization.

In the third phase, the effect of data compression and a new easier graphical

user interface (programmed with Microsoft Visual Basic) on the total transfer

time was tested. All the programs operated in a Microsoft Windows environment.

No more than five buttons were available at each screen. Presets for the scanning

46

parameters were used for different images. These presets included a possibility to

decrease excessive contrast in chest and bone images. Image resolution for chest

and bone images was now set to the same level as in the commercial image plate

system Fuji AC-1 (Fuji Corporation, Tokyo, Japan). In this series, images were

sent using lossy DCT (discrete cosine transform) image compression with

approximately 1:10 compression results (Joint Photographer Experts Group,

JPEG compression). (In literature, DCT compression methods with slight

compression between 1:10 and 1: 25 depending on the quality of the original have

given acceptable results with no statistical difference in diagnostic quality (Lo &

Huang 1986, Ishigaki et al. 1990, MacMahon et al. 1991). JPEG compression has

been proposed for use in PACS environments (Kajiwara 1992). The requests and

reports were written with the Windows Write program (Microsoft Corporation,

Seattle, USA) in a separate program window on the same terminal.

A total of 254 films were sent, all to a university hospital. In the first phase 48

uncompressed images were sent from a rural health centre, and in the second

phase 126 sets of uncompressed images were sent from a central hospital. In the

third phase, 80 compressed images were sent from a regional hospital.

The selection of patients was made so as to simulate as accurately as possible

real teleconsultation needs when radiological expertise is not locally available. At

the health centre the images were scanned and sent by a computer operator, while

in the central hospital and the regional hospital this was done by x-ray technicians.

At the university hospital, the images were interpreted by two staff

radiologists on a computer screen. They first scored the images as acceptable or

unacceptable in the technical respect. After that, a consensus diagnosis was made

from the technically acceptable images. A report was given and returned to the

sender via telefax in phases 1 and 2 and as a computer file in phase 3. The same

radiologists inspected the original images two weeks later and again made a

consensus diagnosis. The diagnoses were compared for possible differences.

4.2 Work practise analysis

The study

The work practice study consisting of fieldwork (from October of 1995 to January

1996) and workshops (March and May of 1996) was carried out in connection

with the implementation and clinical use of the new teleradiology system, which

47

was designed to answer many shortcomings found in the first paper. Especially a

new 12 bit gray scale full film area CCD-scanner (Pinja by Finnelpro, Tampere,

Finland), a new archiver and communication software (Medilink by Acta Systems,

Oulu, Finland) and a new networked teleradiology review workstation with a

high-resolution 1600 x 1280 pixel screen and software developed for the purpose

(Pinjaview by Finnelpro, Tampere, Finland) with an adjacent electronic text

messaging service for referrals and reports were integrated together. The database

combining images and text made it possible to follow the status of consultation

tasks. For an overview of the teleradiology system configuration, see figure 2.

Fig. 2. Teleradiology set-up between Kuusamo primary care health centre and Oulu

University hospital. Technical details are explained in the original paper (Paper II,

published by permission of Elsevier).

The common purpose was to achieve a high usability with an iterative

development process after the initial launch of the system. The experimental stage

lasted from October 1995 to April 1997. During this period, a total of 375 image

packages consisting of several images were transferred. Parallel to the fieldwork,

user questionaires were collected of 108 consecutive cases, with questions asking

the case distribution and the image processing tools used by the physicians. In the

study the reseachers from the Department of Information Processing Science took

48

care of conducting the fieldwork and workshops while the researchers from the

Department of Diagnostic Radiology took care of the development and use of the

teleradiology system itself, the user questionaires, and expert participation at the

workshops. Both teams then contributed to the multidisciplinary presentation of

the results with an emphasis on image interpretation.

The fieldwork

Interviews with design team members and participants on the use of the

teleradiology system were conducted during the fieldwork (Karasti 1997) with

total of 12 interviews. Emphasis was, however, on studying the actually occurring

clinical practice of teleradiology in everyday settings in both locations

(approximately 15 working days) by observation, contextual interviews and

videotaping. A total of 21 system use-related instances of work were recorded (11

image interpretation sessions, 4 instances of typing out reports and sending them,

6 instances of scanning and sending images). Stimulated recall interviews

(Engeström 1996) were carried out with the radiologists whose interpretation

work had been recorded (7 patient cases). The interviewees and researchers

watched the tapes together, questioning and commenting on the events recorded.

Analysis of work practice started already during the fieldwork as the fieldworkers’

interpretations and formulations of the phenomena were continuously challenged

by new observations. The stimulated recall interviews also served as collaborative

analyses. After the fieldwork more focused and detailed video analyses were

conducted with special attention on the unfolding of work: interaction and use of

materials, skills and knowledge employed in work.

The workshops

Based on the fieldwork and the analyses of work two workshops were organized

(Karasti 1997). The communities of work practice, design and research were

brought together to collaboratively evaluate and redesign the system so as to

support the established and contingent practices through which the work is

accomplished and to address issues relevant to developing the teleradiology work

practice. Participation of all occupational groups involved in the teleradiology

practice was required. A video collage of actual work situations was edited to

present the entire teleradiology work practice in parallel to corresponding

traditional ways of working. The video collage served as a shared object of

49

interest and helped provide a basis for the cooperative analysis of actual work

practice. The participants were able to compare practices and share their

experiences. They built a common understanding of the teleradiology work

practice. System usability was evaluated based on cooperatively produced

emergent practical criteria. Moving on from evaluation to envisioning future use

situations they started to raise informed issues relevant to both system redesign

and development of work procedures.

4.3 Internet teleradiology

An experimental consultation system was tested between Oulu University Central

Hospital in Finland, University Hospital of Reykjavik in Iceland and University

Hospital of Tromsø in Norway. The hospitals provided a gateway access (firewall

policy) to the NORDUnet network and workstations for image viewing and

interpretation. Access to digitized images occurred either by network connection

to image sources or by film digitization with a CCD scanner. Digitized images

were converted to common TIFF (tagged image file format) or JIF (JPEG

interchange format) file formats and sent using Internet FTP (file transfer protocol)

protocol. Technical details of the hardware are summarized in Table 2.

Table 2. Technical details of the hardware used in multicentre Internet teleradiology

(Paper III, published by permission of Springer).

Hardware

components Oulu Reykjavik Tromsø 1 Tromsø 21

Digitizer CCD CCD CCD CCD

Pixel size 85 µm 170 µm 85 µn 85 µm

Grey scale 8 bits 8 bits 12 bits2 8 bits

Gateway Unix/HP3 Unix/Sun4 Unix/HP/Sun Unix/HP

Viewing station PC 486 PC 486 Unix/HP/Sun Unix/HP

Display pixels 1280x1024 1280x1024 1280x1024 1280x865 1 Tromsø used two different hardware constellations, 2 only for digitalization, image display grey scale was

always 8 bits. 3 HP is a trade mark of Hewlett-Packard. 4 Sun is a trade mark of Sun Microsystems.

In the first study, 131 randomly selected neuroradiological CT and MRI images

plus skeletal x-rays were sent between Oulu and Reykjavik. Different

compression methods (lossless LZW (Lempel–Ziv–Welch) with compression up

to 1:2.4 and lossy JPEG compression up to 1:10) and image resolutions were

50

tested and transmission times recorded. The images were compared with originals

for possible differences in quality or diagnosis.

In the second study MRI studies of pituitary glands were sent between each

institution. Laser-printed images were digitized and compressed according to the

results of a previous study with lossy JPEG-compression with quality factor 85,

giving approximately 1:10 compression. Twenty pituitary cases were sent from

Iceland both to Norway and Finland. In the same manner, 20 cases were sent from

Finland to Iceland and Norway. These four sets made a total of 80 cases. The

clinical information given was always the same: suspected enlargement of sellar

contents or suspicion of microadenoma. In every institution three

neuroradiologists interpreted the digital images on the screen and indicated each

abnormality according to a 5-point confidence scale: 1= definitely not present,

2=probably not present, 3=cannot be decided, 4=probably present, 5=definitely

present. The interpreters used grey-scale windowing and zooming functions on

the workstation. The original analogue radiographs were interpreted in the same

manner two weeks after the workstation session. The actual diagnosis was

determined by consensus of two neuroradiologists in the sending site using all the

patient information available. Receiver operating characteristic (ROC) curves

were produced and the area below them and statistics calculated by using methods

described in radiological literature (Hanley & McNeil 1982, Hanley & McNeil

1983).

In connection with this study 12 clinical consultation cases were sent from

Iceland to Finland, recording the time of sending, viewing and reporting. These

cases included both images and the request for examination. For data safety

reasons, patient identification data were removed from all the material sent.

4.4 Mobile PC teleradiology

Portable terminal

The neuroradiologist was supplied with a portable terminal capable of receiving

and viewing images. The terminal was constructed from a notebook computer

(Contura 430cx, Compaq Computer Corp., USA) equipped with an active matrix

display of 640 × 480 pixel resolution. The display was capable of showing 256

colours. The computer weighed 1.7 kg, measured 23 × 30 cm and cost about EUR

51

3150. The computer had a 16 MByte random access memory and an 800 MByte

hard disk.

MS Windows (Microsoft Corp, Seattle, USA) was used as the operating

system. Images were viewed with a shareware program (Polyview, Polybytes,

Cedar Rapids, USA).

The notebook computer was equipped with a PCMCIA digital cellular data

card (Nokia Mobile Phones, Salo, Finland). This was used to interface the

computer to a GSM telephone (Nokia 2110i, Nokia Mobile Phones, Salo,

Finland). When the neuroradiologist was not in the hospital, the data connection

to the hospital was established through the GSM network. A commercial GSM

data service (Telecom Finland, Helsinki, Finland) was used for the wireless

connection. The nominal data transmission rate was 9.6 kbit/s.

The telecommunication software used was the Microsoft remote access

service of Windows 95. The remote access service included PPP (point-to-point

protocol) client software that could be used to connect to a PPP server at the

hospital over a modem line. Microsoft’s implementation of the TCP/IP was used

over the PPP connection. PPP is the certified Internet standard protocol that

extends the LAN protocols to function over a modem line. When the TCP/IP

connection was established, a data transmission connection was formed and the

images were transferred using an FTP program (WS-FTP, Ipswitch Inc, Lexington,

USA).

Dial-up server

To provide a dial-in connection to the LAN of the Department of Radiology, a

PPP server was set up. The server accepted incoming modem calls and, after user

authentication, provided a connection to the LAN. When the connection was

active the server routed network packets between the modem line and the LAN.

In the present study, the server was used to provide a TCP/IP connection between

the LAN and the portable terminal.

Initially the PPP server was based on a Unix workstation (Indigo, Silicon

Graphics, Mountain View, USA). Subsequently, it was changed to a standard Intel

Pentium (Santa Clara, USA) personal computer. The computer used Linux, a

freely distributable implementation of Unix, as the operating system.

52

Imaging device interface

The patients were imaged with a CT scanner (GE HiSpeed Advantage or GE

Sytec 3000, GE, Milwaukee, USA). The images were routinely transferred to a

visualization workstation (SUN Microsystems, Mountain View, USA) via the

LAN.

The visualization workstation used a diagnostic visualization program

(Advantage Windows, GEMS, Buc, France). The visualization workstation had a

display with 8 bit/pixel colour depth, which was able to show 256 colours

simultaneously. The contrast window and the brightness level of the images were

set to make the images suitable for diagnosing from the monitor. For the technical

set-up, see figure 3.

Fig. 3. The technical configuration of the wireless image consultation chain. The

portable terminal connects to a private dial-up server for a secure image consultation

(Paper IV, published by permission of RSM press).

After manipulation, the images were captured from the screen using public

domain xv software with a special script. This was performed by an X-ray

technician who had detailed instructions to manipulate the images to look the

same as if printed on film. The capturing took on average 7 min per patient. The

colour depth used was the full dynamic range of the display, i.e. 8 bits/pixel. The

images were captured at the original 512 × 512 pixel resolution. The captured

image size was 256 kBytes in size. All the captured images from the visualization

workstation were stored in a network directory that was physically mounted on

the dial-up server.

53

To reduce the bandwidth required for transmission, the images were

compressed with a JPEG algorithm and stored in 8 bits/pixel greyscale format.

The JPEG quality factor used was 75%, resulting in an approximate compression

ratio of 8:1. This yielded an average image size of 40 kBytes. The images were

then automatically transferred in patient folders to the dial-in server.

Patients and interpretation

The material consisted of 68 consecutive neuroradiological emergency patients

(36 males and 32 females). The mean age was 59 years, range 1–90. There were

63 head, 1 lumbar spine, 2 sinus, 1 orbital and 1 neck CT examinations.

Two series of scans were examined. In the first series, a neuroradiologist

interpreted the CT scans of 47 patients on a portable computer during working

hours. Later, the same neuroradiologist reviewed the images on film. In the first

series, all the CT slices obtained in each examination were transmitted. The

experience was used to define the second part of the study.

In the second series, the images of 21 patients were sent by a junior

radiologist for a neuroradiologist consultation after normal working hours. Three

senior neuroradiologists gave their advice in turn. These results were also

compared to the film interpretation the next morning. In the second series, the

junior radiologist either sent all slices or only those slices covering the area

requiring consultation. In the re-evaluation, the images of all patients were

viewed in the manner used by the radiologists to interpret CT-images in daily

work. A written report was made for both transmitted and comparison images.

The images of patients were transferred to the portable terminal by GSM. The

image transfer times (both FTP connection time and total time) were recorded.

After receiving the images, the radiologists evaluated them for diagnostic quality,

scoring them as: 1=suitable for final diagnosis, 2=suitable for preliminary

diagnosis only or, 3=not suitable for diagnosis. The reasons for inadequacy were

recorded. The neuroradiologist also evaluated each image consultation on a five-

point scale indicating whether the image consultation was beneficial compared to

an ordinary telephone discussion. The scale was: 1= no need for consultation,

2=no benefits over a telephone conversation, 3=minor benefit, 4=beneficial for

diagnosis, 5=gave essential information. The neuroradiologst also decided and

recorded whether a hospital visit would have been necessary without the image

transfer.

54

4.5 Smartphone teleradiology

4.5.1 Feasibility study

PDA terminal

The PDA terminal device for image reception and viewing was a Nokia 9000

Communicator (Nokia Ltd, Helsinki, Finland), which was a combined digital

phone and messaging device with short message service (SMS), telefax and even

Internet/intranet capability. It could be called an intelligent phone (smartphone) or

personal digital assistant with GSM phone capabilities. It weighted 397g and its

dimensions were 173 × 64 × 38 mm. The LCD (Liquid Crystal Display) display

area was capable of showing graphics of 600 × 200 pixels with 8 grey levels, and

the contrast was adjustable. Larger images could be viewed using zooming and

scrolling functions. It had 8 megabytes (MB) total memory, 4 MB for operating

system and applications, 2 MB for program execution and 2 MB for user data

storage. The cost of the terminal device was 1,000 Euros. As an extra capability,

the phone was equipped with Celesta MDO Mobile Data Organiser (CCC Mobile

Ltd, Oulunsalo, Finland) file transfer software.

Hospital teleradiology server and image acquisition

To provide a dial-in connection to the LAN of the Department of Diagnostic

Radiology, a private PPP server using a Microsoft remote access service (RAS) of

Windows NT (Microsoft Corp., Seattle, USA) was set up. PAP (Password

Authentication Protocol) was used as an authentication mechanism for PPP

connection. After user authentication a TCP/IP connection between the PDA

terminal and teleradiology server of the hospital was established using

commercial GSM data service. Internet standard protocol FTP was used for

transferring the images from the teleradiology server to the PDA terminal.

The patients were imaged with a CT scanner (CT HiSpeed Advantage or CT

Sytec 3000, GE, Milwaukee, USA) and the image capture arrangement was the

same as reported in the previous work on mobile PC teleradiology and described

in the previous chapter.

55

Patients and interpretation

A junior radiologist at the hospital selected either all the CT slices or slices

containing the area requiring consultation to be stored in the teleradiology server.

After notification of an emergency case, a senior neuroradiologist at home made a

data call, logged into the server and downloaded and viewed each of the 21

patient cases. Twenty of these were head scans and one was a sinus scan. There

were 12 female and 9 male patients, their mean age being 62 years (range 1–87).

Image transmission, file handling and image interpretation times were

recorded as well as any technical remarks. The neuroradiologist rated the images

for image quality; the scoring was as follows: 1. suitable for final diagnosis; 2.

suitable for preliminary diagnosis only, or 3. not suitable for diagnosis. The

reasons for inadequacy were recorded. After that the neuroradiologist gave a

written report. These reports were compared to the original report given at the

hospital and to a reference reading from the original films the following day. The

neuroradiologist also scored each image consultation on whether it was beneficial

compared to a telephone discussion. The scale was: 1. no need for consultation; 2.

no benefits over a telephone conversation; 3. minor benefit; 4. beneficial for

diagnosis; 5. gave essential information. The neuroradiologist also recorded

whether a hospital visit would have been necessary without the image transfer.

4.5.2 Clinical study

MOMEDA

According to the concept, a Mobile Medical Data server was established in the

hospital intranet. In the case of consultation, the server received the DICOM

images and sent them together with relevant narratives retrieved from the hospital

EPR system. After an automatic SMS initiation, data connection was established

with a secure call-back method and connections were authenticated with a double

security verification (both at the PPP server and at the communication software).

The terminal device was a Nokia 9110 communicator device (Nokia Ltd, Helsinki,

Finland) which was smaller (158 × 56 × 27 millimetres) and more lightweight

(253 grams) than the original model, yet having still monochromatic display with

640 × 200 pixels and data transfer with GSM data technology (PDAdb.net 2007b).

The developed client image viewer software (Celesta Ltd, Oulu Finland), was a

light-weight version of diagnostic image workstation viewer software, and was

56

capable of full diagnostic manipulation of data. Additional information requests

could be made from the hospital EPR system using a WWW-browser client over a

secure connection. Finally, a consultation phone call could be made to the hospital

with an embedded hands-free phone while reading the images. For the mobile

terminal functions, see figure 4.

Fig. 4. The radiology workflow and security oriented software components realized in

the integrated mobile image and electronic patient record terminal.

PROMODAS

The Professional Mobile Data Systems project developed the ideas further to 2.5

generation wireless networks and platforms. GPRS technology with IP-protocol

facilitated the fast development of the system because the amount of device-

specific programming decreased. Improved image manipulation functions were

developed for the mobile client software. This first Microsoft Pocket-PC platform

smartphone device O2 XDA (HTC Corporation, Taiwan) was even more

lightweight with 201 grams, yet the processor was more powerful (PDAdb.net

2005). The colour display (240 × 320 pixels, 4096 colours) in this combined PDA

and GPRS mobile phone was larger in vertical direction and capable of showing

more grey levels. The security of the data transfer was also improved, and VPN

tunnelling with strong encryption was utilized. The system architecture is shown

in figure 5.

Secure Mobile Terminal Access after Local User Authentication

Radiology Workflow Functions EPR Functions Communication

Secure Call-back with AuthenticatedServer Access and Image Transfer

ErrorRecovery

Image and TextUnpackager

SMS-Receiver/Listener

RIS Worklist / Patient Information

Referral Text Display

Image Overview/ Thumbnail Display

Full Image Display

Image Processing/Window/Level, Zoom,

Scroll, Flip, Turn

WWW-Browser/EPR Query

EPR Display

EPR Text Input

Hands-freePhone

Telefax

Basic Office Tools:Notetaker, Spreadsheet,

Calender, Calculator, Clock

57

Fig. 5. Schematic architecture of the PROMODAS system (Paper VI, published by

permission of Elsevier).

Evaluation

The clinical feasibility of the MOMEDA and PROMODAS systems was tested in

two different evaluations with real CT and MRI on-duty scans sent to the mobile

terminals. In the first clinical evaluation, 115 CT and MRI scan series were read

with the MOMEDA terminal. In the second evaluation 150 CT and MRI scan

series were read with the PROMODAS terminal. Before the evaluation phase a

short educational pilot was conducted. The reading radiologists, neuroradiologists

and neurosurgeons also had the full examination request coming from the EPR

available at the mobile terminal and were able to use image processing tools at

each of the mobile terminals. Detailed reports were made of each examination,

and after a time interval compared to reports made using the full-size

workstations at the department of radiology. In addition to the results of image

interpretation also the amount of time needed for image transmission and

reviewing the cases was recorded.

4.6 Integration of teleradiology as a part of eHealth services

The structured web-based questionnaire of eHealth usage was distributed by e-

mail to all public health service providers or hospital districts and health care

centres, and to a sampling of private health care providers. The survey was

conducted for the first time by FinnTelemedicum in 2003 (Kiviaho et al. 2004)

and repeated in 2005. In this study, data from the year 2005 are presented with

comparison to data from the year 2003 where appropriate. The questionnaire

58

consisted of: the identification of the responding organisation and the respondent;

questions about the adaptation of EPR systems; systems or applications used to

transfer/exchange patient information between organizations during care

processes and the standards in use for the migration of patient information;

methods of authentication, identification, and informed consent of patients; the

usage of different eEducation systems for staff education; the types of human and

material resources needed; systems supporting quality control and service

delivery; and the adaptation of different eServices for patients.

The total number of questions was 97. Most of them also included further

questions on how old the system or application concerned was and the intensity of

use. The questions for hospitals, health care centres and private health care

providers differed to some extent, depending on the nature of the services they

provided.

The intensity of use told about the amount (%) of the action or function being

carried out by electronic means. For example, if a service provider used EPR for

the documentation of patient data in half of the cases and a paper-based record for

others, the intensity of use of the EPR was 50%. Several of the questions in the

year 2005 survey were the same as the questions in the FinnTelemedicum survey

conducted in late 2003, using the same web-based data collection methods.

The questionnaire was emailed between October and November 2005 to all

public service providers, i.e. to 21 hospital districts and 251 health care centres.

The questionnaire was also emailed to a sample of 65 private health care service

providers including 30 of the largest service providers, and 35 who had responded

to the 2003 survey. Additional information was obtained by telephone interviews

from those health care sites where not all information in the returned

questionnaires was complete. Also PACS vendors were interviewed for their

reference sites in primary care. A full report with a detailed description of the

method has been published in Finnish (Winblad et al. 2006) and an English

version with edited information has been published by Hämäläinen et al (2007).

59

5 Results

5.1 Low-end technology teleradiology

Time factor

The average total image transfer procedure time in phase one (from the health

centre) was 15 min 50 sec (range 15 min to 18 min 20 sec) for an uncompressed

single chest x-ray image (average size 3897 bytes). The longest single task in the

transmission process was the on-line sending of image (average 10 min 50 sec),

followed by scanning (64 sec, range 55–74 sec) and saving the images on a hard

disk (57 sec, range 53 to 83 sec). The average throughput of the digital line was

60 kbit/s (range 56 to 61 kbit/s) per second.

The average total image transfer procedure time for a CT film (4 to 6 images

on each film) with an average size of 840 kbytes in phase two (from the central

hospital) was 6 min 20 sec (range 5 min 10 sec to 7 min 20 sec) per

uncompressed film. The longest single step was sending the film (2 min 20 sec),

the next longest step was scanning (35 sec, range 23–42 sec), followed by saving

the films on a hard disk (26 sec, range 19 to 35 sec).

The average total image transfer procedure time for a 1:10 compressed chest

x-ray film in phase three (from the regional hospital) was 5 min for a single view

(36–49% of the time for uncompressed images). Of this, only 30 sec on average

was on-line time (5–9% of that for uncompressed images). The average time

required for the preparatory steps preceding the scanning had decreased from 3

min to 2 min 30 sec.

Technical quality

Of the 48 uncompressed films transmitted in phase one (from the health centre),

two chest x-rays and five bone images were considered technically unacceptable.

This was due to faulty scanner settings; one chest x-ray had an excessively small

scanning area and the other was initially digitized too light. Two thoracic and

three cervical spine images were scanned with excessive contrast settings, with

details lost in both light and dark areas.

All the uncompressed transmitted images in phase two (from the central

hospital) were considered technically high-quality.

60

Of the 80 compressed films sent in phase three (from the regional hospital),

the only low-quality film was an image of the thoracic spine, which was digitized

with excessive contrast settings, with loss of detail in the highlight parts as a

consequence.

Diagnostic ability

Diagnostic agreement between the transmitted and original images was

determined on all of the technically acceptable chest (n=8) and bone (n=33)

images transmitted uncompressed in phase one (from the health centre).

A lesion was missed in two cases of the 126 image sets (2%) transmitted

uncompressed in phase two (from the central hospital). Both cases were brain CT

scans (n=55): The first was a small infarction in the cerebral pons (diameter under

5mm), while the second was a thickening of the right nervus opticus (difference

of 5 mm compared to the other side). All the 38 body CT sets as well as all the 25

angiography film sets, 4 mammographies and 4 ultrasound images were correctly

interpreted from the transmitted images.

A discrepant finding was made in four (5%) out of 79 image sets

satisfactorily transmitted in compressed form in phase three (from the regional

hospital). All of them were mammography images (n=40). After interpreting the

original images, an enlargement mammography was considered necessary in two

cases, while in two cases no further examinations were considered necessary even

though an enlargement mammography was suggested after reading the

transmitted images. All the twenty chest images and all the nineteen bone images

were interpreted correctly from the transmissions.

Total diagnostic agreement between the transmitted images and the original

films was 98% in the technically acceptable image transmissions.

5.2 Work practice analysis

Moulding two previously separate communities to work together

From the point of view of the Kuusamo Primary Health Care Centre,

teleradiology became a question of integrating and scheduling expert consultation

into the other constituents of patients’ care trajectory (Strauss et al. 1985). The

two previously separate communities of radiological work practice began to

61

cooperate in a distributed fashion. They had to revise their local ways of working

and establish new commonly agreed work procedures. The teleradiology system

replaced the peripheral awareness and face-to-face communication of local work

communities by asynchronous computer-mediated image transfer, request-report

exchange, and occasional phone calls on critical cases. Interactive cooperation

was replaced by distribution of tasks performed in geographically separate

locations at sequentially ordered times. The new teleradiology work practice is

depicted in figure 6.

Fig. 6. The teleradiology work practice between primary care and secondary care

consultant centre. (Co-author Helena Karasti is thanked for designing this figure.

Paper II, published by permission of Elsevier.)

The chain of tasks

After radiological examination of a patient and initial interpretation of images, the

attending physician in Kuusamo decides whether an expert consultation is

necessary, in which case he or she dictates a request for a consult. An X-ray

technician or secretary scans the films, enters the patient information, types the

request into the system and then sends them to the University Hospital. The

teleradiologist on duty at Oulu University Hospital checks once a day whether

images to be interpreted have been received. The radiologist then interprets the

62

images of each patient case on a computer screen and dictates reports. She or he

hands over the tape to the departmental secretary who types the report into the

system and sends the file back to Kuusamo Primary Health Care Centre. The

reports are received by an X-ray technician who prints them out to be delivered to

the attending physicians.

Activities aimed at ensuring a smooth flow of work

A great deal of work was carried out by the personnel in addition to the chain of

tasks directly related to using the teleradiology system. A continuous stream of

contingent support work was needed in “making the system work” (Bowers et al. 1995) as the patient case was taken through the consultation service. This

articulation work (Strauss et al. 1985) was carried out both in individual tasks and

on the level of cooperating the entire process. For example, prior to the image

transfer, the X-ray technician on duty prepares the patient folder. Films of the

patient’s previous radiology examinations are acquired, relevant films selected,

any missing information is checked and the patient material is organized. The

technician carries out all these measures to ensure a smooth flow of work in the

system while scanning, entering and sending information. Another set of

examples is of activities carried out to sustain an account of the service as a

formal sequential operation. The participants routinely checked whether they had

a task to carry out and after “completing their bit” made sure the next step was

completed, i.e., a sender in Kuusamo made a phone call to Oulu to inform about a

critical case, a radiologist handed over the dictation tape to a secretary, who in

turn, after typing out and sending the report, checked whether it was received at

the Kuusamo end.

The changed script of image interpretation work

In the film-based image reading practice, smooth flow of work for image

interpretation is ensured by a great deal of support work performed by other

occupations and easy-to-use technology in the form of films on autoalternator

light screens.

Radiologists are accustomed to interpreting images as sequentially ordered

processes of cases in series. The alternator supports this with its magazine for

light screens that are used for the temporary storage of organized films. In

traditional image interpretation sessions, the radiologists are accustomed to

63

reading the request concerning the following patient to determine the problem

formulation while the light screens are swiftly changed between the cases. As the

next patient’s pair of light screens appears, they take a quick overall glance at the

films and then proceed to a more detailed interpretation process and dictation of a

report. In a similar fashion, in a typical teleradiology image interpretation session,

a report was first displayed on the screen followed by images. The radiologist

would, however, have to wait idly while the images appeared slowly on the screen

one by one in blown-out-size and were then reduced to fit the pre-set frame for

each image. Then the radiologist would have to reorganize and resize the images

to suit the more detailed interpretation process. The system caused disruptions

and breakdowns in the smooth organization of work by imposing a new script for

image interpretation.

Dispersion of the patient records and the examination process

The radiologists are used to having a patient folder easily accessible on the

alternator’s desk during image interpretation. Should a need for more information

arise it can be referred to, at least for images of previous examinations with

accompanying reports and on occasion also for the patient’s medical record.

Material transferred via teleradiology from the primary health care centre is less

comprehensive than radiologists are accustomed to, being minimal (“it’s like the

patient was to a radiological examination for the first time”, “there is no history”)

or not sufficient (occasionally more images had to be requested to enable

comparison).

Dispersion of the examination process led to situations where the

teleradiologists did not have access to knowledge that is self-evident when the

examination is performed within close proximity of a department. They may miss

the locally produced knowledge related to the patient’s examination, patient-

related information (the patient’s physical appearance, conduct and behaviour,

and answers to the questions posed during examinations), and even recollections

of the patient’s previous examinations.

Dispersion of image articulation work

The radiologists need to be able to concentrate on the image interpretation work

during the sessions. To ensure an efficient flow of image interpretation, all image-

related articulation work is carried out prior to the session. In the film-based work

64

practice at the Oulu University Hospital, the retrieval, checking, organization,

arrangement and layout of films on the alternator’s light screens was done by a

special assistant. With the studied new teleradiology system, the tasks

corresponding to the assistants’ work were dispersed into four aspects of the

teleradiology system-related work practice: 1) the scanning of films and

transmission of images in Kuusamo – which affects the final display order and

orientation, 2) the image display system – how it displays a series of images on

the computer screen, 3) how the radiologist arranges the images on the computer

screen at the beginning of a session and 4) the continuous image organization and

processing by the radiologist during the interpretation process.

In the teleradiology experiment, the radiologists ended up doing a great deal

of image-related articulation work both at the beginning of each case and during

the interpretation process itself. One factor contributing to the latter are the

enhanced image processing functions. During the study they were used as follows:

zoom function (enlargement) in 71% of the cases, image windowing and levelling

(brightness contrast adjustment) in 70% of the cases, image rotation (correct side

up) in 25% of the cases and image enhancement (unsharp mask function) in 3%

of the cases. Another contributing factor is the lack of system support for an easy

way of laying out images for juxtaposition on the screen. The radiologists’ part of

the system was designed based on the assumption that the transferred cases would

mostly be acute ones with few images. It turned out that 25% of the cases were

acute ones (report needed in less than an hour) while the rest were urgent ones

(75%, report needed in less than 24 hours). However, many of these were control

cases with numerous images (19% of the total number of cases), and even in the

acute cases comparison of images side-by-side was central to image interpretation.

To a great extent, the professional expertise of radiologists lies in being able to

follow a change through a series of images. This is traditionally done by

comparing films side-by-side on large light screens.

5.3 Internet teleradiology

Image quality, transmission time and interpretation time

In the first phase, image quality was found to be adequate with both

uncompressed and compressed images. Network transfers occurred without errors

or data loss. Data conversion between MS-DOS and Unix computer platforms

65

also occurred without problems. Image transfer times between Iceland and

Finland ranged from 2.5 minutes (compressed JIF file size 140 kbytes) to 43

minutes (uncompressed TIFF file size 2480 kbytes).

In the second phase, where only JPEG compressed images were sent, the

average image transfer time between Finland and Iceland was 3 minutes 45

seconds for an average image size of 270 kbytes. The average image transfer time

between Finland and Norway was 55 seconds for an average image size of 317

kbytes. As each study case needed two to three images, total on-line transfer times

ranged from 7.5 to 11 minutes (Finland-Iceland) and from one to three minutes

(Finland-Norway).

The average radiologist’s working time at the receiving site for the clinical

consultation cases was 8.5 min (range 5 to 14 min). This covered time from the

opening of images on screen to the end of the dictation session.

Comparison of screen and film readings in sellar pathology

The results of each group of three neuroradiologists and their combined reading

results in the second phase as analysed by the ROC study are summarized in

Table 3 and combined ROC curves are presented graphically in figures 7 and 8.

Table 3. Area under ROC curve derived from the analysis of the enlargement of sellar

contents and from the analysis of possible presence of microadenoma (III, published

by permission of Springer).

Evaluation of sellar enlargement Evaluation of presence of microadenoma

Reader group

Area under ROC curve

Reader group

Area under ROC curve

Screen Film Screen Film

Group 1 ISFI 0.874 0.869 Group 1 ISFI 0.762 0.803

Group 2 ISNO 0.884 0.933 Group 2 ISNO 0.755 0.823

Group 3 FINO 0.799 0.820 Group 3 FINO 0.613 0.590

Group 4 FIIS 0.848 0.848 Group 4 FIIS 0.758 0.738

Total 1-4 0.842 0.863 Total 1-4 0.758 0.717

ISFI = Sending Iceland -> Finland, ISNO=Sending Iceland -> Norway,

FINO = Sending Finland ->Norway, FIIS = Sending Finland ->Iceland.

There were no significant differences in readers’ performance between

teleradiology screen readings and film readings of the images either in each

individual reading group or in combined reading results for each study question.

66

Fig. 7. The combined ROC curves of all the readers evaluating the possible

enlargement of sellar contents. The area under the curve for teleradiology screen

reading is 0.842 and for reference film reading 0.863 (III, published by permission of

Springer).

Fig. 8. The combined ROC curves of all the readers evaluating the presence of

pituitary microadenoma. The area under the curve for teleradiology screen reading is

0.719 and for reference film reading 0.717 (III, published by permission of Springer).

5.4 Mobile PC teleradiology

In the final evaluation of the 68 consecutive neuroradiological emergency patients,

there were 22 normal cases and 46 pathological cases. The most common

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pathological findings were brain infarction (16), haemorrhage (12) and atrophy

(7).

In all cases the consultations succeeded technically. The average data transfer

time (i.e. the FTP connection time) for a single compressed CT slice via GSM

was 55 s (total connection time one min). The transfer of an ordinary head CT

examination took 18 min on average.

The transmitted images were considered suitable for final diagnosis in 49 of

the 68 cases (72%) and suitable for preliminary diagnosis only in 19 of them

(28%). None of them were considered not suitable for diagnosis. The reasons for

suitability for preliminary diagnosis only were: the need to use a different window

and level (n=10), the need to compare to previous studies (n=7), or the need to see

more images than those selected for consultation by the junior radiologist (n=2).

The diagnosis from the transmitted images was the same as that from the

original images in 66 cases (97%) and slightly different (although no effect on

patient care) in two (3%). A small brain infarction in the posterior fossa region

remained undiagnosed and an artefact 2 mm in diameter was misdiagnosed as a

pons infarction.

Compared to an ordinary telephone discussion, the transmitted images gave

essential information in 55 cases (81%), beneficial information in eight cases

(12%) and minor benefit in five cases (7%).

According to the consulting radiologist’s opinion, the mobile image

consultation saved him a hospital visit for image interpretation in 16 cases (24%).

5.5 Smartphone teleradiology

5.5.1 Feasibility study

The 21 patient cases contained on average 14 images (range 3–20 images) per

case. The distribution of the diagnoses in original images was: 11 brain

infarctions, 2 atrophies, 4 haemorrhages, 1 aneurysm, 1 infection and 2 tumours.

Connection to the server was in all cases established with the first attempt.

The connection initializing time was on average 1 min 20 s (range 1 to 2 min). In

three cases the data connection was lost before all the images were transferred,

but a new connection was established after notification of an error message. There

was on average 2 min 40 s time (range 1 min to 6 min 50 s) to select the correct

images from the server. Image transmission to the terminal took 1 min 30 s per

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image (including image transmission and file management time). The average net

transmission time for a head CT-scan was thus 21 min (range 4 min 30 s to 30

min). After the connection was closed the local interpretation of the images took

on average 15 min (range 7 to 23 min); the mean total working time on one case

was thus 40 min. There were no changes in the data contents of the transferred

data.

In one of the cases the image quality was good enough for a “final report”

and in 20 cases the quality was suitable for a “preliminary report”. There were no

cases in the category “not suitable for diagnosis”. The reasons for categorizing

images suitable for “preliminary report” were neuroradiologist’s doubts about the

suitability of image quality for interpreting small changes in 18 cases and need to

window and level the grey scale of the images in 2 cases.

The report given from the transmitted images was identical with the reference

film reading in 18 cases (86%) and not totally identical in 3 cases (14%). The

differences were: 1) a possible density loss at nucleus lentiformis was not seen, 2)

a small lacuna infarction at the right capsula interna region was not found, 3) a

pineal cyst was not found. In one case a pons infarction observed on the PDA

terminal by the neuroradiologist had not been noticed by a junior radiologist in

the original film report.

According to the neuroradiologist, the transmitted images gave essential

information in 5 cases (24%), beneficial information in 13 cases (62%) and minor

benefit in three cases (14%) compared to an ordinary telephone discussion. The

neuroradiologist considered that the image consultation saved a hospital visit in

15 cases (71%).

5.5.2 Clinical study

MOMEDA

With the second generation MOMEDA GSM terminal the sending time of a CT

scan series over the GSM network ranged from 15 to 20 min. The reading time

for a series of CT scans was 20 to 30 min for radiologists and less than 10 min for

neurosurgeons. The reading time for MRI scan series was longer, more than 35

min. This is mainly explained by the larger number of images in MRI

examination of the head compared to head CT. The image quality was sufficient

for final diagnosis in 38% of the 115 cases and for preliminary consultation in

69

62% of the cases. The diagnostic quality was considered adequate and user

acceptance for emergency service was high. The costs of the transmission were

related to the transfer time. The demonstrator in this study showed that it is

medically sensible to use pocket-sized teleradiology terminals for consultation

purposes in neurosurgery and with limitations in radiology. This meant that the

final product was adopted for clinical use by the neurosurgeons of Oulu

University Hospital in June 2000.

PROMODAS

With the 2.5 generation PROMODAS GPRS terminal the transmission time was

cut down to 5 to 10 min depending on the network load. The image viewer

application had similar functionalities as the earlier terminal, but there were

considerable changes in the responsiveness of the system in favour of the

PROMODAS system, so user acceptance was high. New portable terminal

devices with faster processors enabled a more efficient processing and display of

patient information and the reading times were reduced to 5 to 10 min per scan

series. The confidence in image quality was somewhat higher than in the

MOMEDA project; now, image quality was considered good enough for final

diagnosis in 40% of the 150 cases, and in 60% good enough for preliminary

consultation. Telecom operators had now implemented a monthly flat fee work

for data, which made it possible to stay connected at a lower cost than previously.

In practice, the PROMODAS terminal replaced the earlier generation in clinical

use by neurosurgeons in June 2003.

The functional differences influencing the performance of MOMEDA and

PROMODAS are summarized in Table 4.

Table 4. Main functional differences between the two mobile teleradiology systems

(Paper VI, published by permission of Elsevier).

Parameter MOMEDA PROMODAS

Network GSM GPRS

Access method Private Internet access point Mobile IP via operator

Pricing scheme Per second Flat monthly fee

Average download time less than 60 s / image less than 20 s / image

Terminal display size 640x200 pixels 320x240 pixels

Image decompression time more than 10 s / image less than 1 s /image

70

5.6 Integration of teleradiology as a part of eHealth services

Coverage

Responses to the year 2005 questionnaire were obtained from all hospital districts

(100%, n=21). A total of 179 (71.3%) of 251 health care centres responded to the

questionnaire. The responses covered 88.2% of the whole population of Finland.

Additional data were also obtained from 27 health care centres that had not

responded to the present survey, but had responded to the 2003 survey.

Results were obtained from 28 private service providers, about half (n=13)

from the biggest private service providers and about half (n=15) from those

companies that had responded to the 2003 survey. The private providers included

enterprises, from conglomerates with hospital and operative services to small

part-time general practices. Because the private providers are a heterogeneous

group, the results concerning them can only be regarded as indicative.

The health care centres which did not respond were smaller in size than those

who did, covering only 12% of the population of the country. Therefore, the

answers obtained can be regarded as representative in terms of primary and

secondary health care. Because the public sector covers 85% of all health services,

the results can be regarded as representative for the whole country.

Electronic Patient Record

In specialized health care EPR was in use in all but one of the 21 hospital districts.

In one hospital district, EPR was in the planning stage at the end of 2005. Among

17 of the 20 users of EPR the intensity of use was over 90%. One hospital district

had intensity of use between 50–90%, and two between 25–49% In the year 2003

survey, 13 of the 21 hospital districts had EPR in use. In 2005, 18 hospital

districts indicated that the usage of EPR covered at least three out of four main

medical responsibility areas (conservative, operative, emergency care and

psychiatric care), while only 5 hospital districts had achieved this level in 2003.

In primary health care centres, EPR was in use in 240 (95.6%) of the 251

health care centres, three of them had it at testing stage, and eight at a planning

stage. In 2003 the coverage was 93.6% in heath centres. The 11 health care

centres lacking EPR in 2005 were small and remote, and some of them were

planning on converging with a larger neighbouring health care centre. The

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intensity of use was very high: at 91% of the health care centres using EPR, the

rate was over 90%, while among the rest it was 50–90%.

Of the 28 responders of the private health care service providers, 25 (89%)

used EPR. Compared to the 2003 surveys the figures seem to be similar. The

intensity of use was high: three out of four providers had an intensity of use of

more than 90%.

Picture Archiving and Communication Systems

The results of the PACS survey for secondary care (hospital districts) in 2003 and

2005 are presented in Table 5. The progress has been fast during the two years.

Fifteen out of 21 hospital districts had a PACS in production in 2005. What is

more important is that they were practically filmless (over 90% of the medical

images were utilized only in digital form). The rest of the hospitals planned to

have their PACS in production towards the end of the year 2007. After that, all the

hospital districts in Finland have been totally filmless.

Table 5. PACS installations in 21 Finnish hospital districts in 2003 and 2005 (Reponen

et al. 2008, published by permission of IOS press).

Measure 2003 2005

PACS in production phase 10/21 15/21

PACS in pilot phase 1/21 2/21

PACS in installation phase 10/21 4/21

PACS usage > 90% 6/21 15/21

PACS usage 50–90% 3/21 1/21

PACS usage < 50% 4/21 1/21

Concerning primary care, in the year 2005 full picture archiving and

communication systems or system components were in use in 95 out of 179

health care centres (53%), based on the information provided by the vendors. In

the previous survey conducted in 2003, PACS usage information was obtained

directly from the primary health care centres; at that time, it was reported that

PACS components were used in 27 (17%) primary health care centres. Even

though the methodology is different, this information reveals that the use of PACS

at primary health care level has increased in Finland.

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Results of regional services

Before presenting the results of many different and yet at the same time partially

overlapping forms of interorganizational data exchange, a couple of definitions

are needed. Electronic referrals are basically sent to another institution in order to

transfer the responsibility of patient care. Electronic discharge letters are then

returned to the sending institution once the patient’s treatment is finished. The

referral can evolve to an electronic consultation letter, if neither responsibility for

the patient nor the actual patient is transferred, but professional advice for

treatment is sought or professional opinions are given. Consultations can also take

place with a help of videoconferencing (televideo consultations). There are special

cases like teleradiology, which can be used for consultation but also for

information distribution; the same also applies to telelaboratory. Regional patient data repositories or exchanges can serve many purposes: they can provide a

source of reference information for past treatment, a basis for current patient data

distribution in a geographically distributed health care environment, as well as a

data depository for consultation services and workload distribution. In a normal

medical practice, the various forms of data distribution complement each other.

e-Referral and e-Discharge letters

In 2005, the e-Referral letter and e-Discharge letter service was provided by 16 of

the 21 hospital districts. Rapid progress was made over a period of a few years,

because in 2003 the service was available in about half of the hospital districts.

In primary care, 45% of the health care centres made use of the service in

2005, while the figure was 24% in 2003.

Electronic and Televideo Consultations

Electronic consultation was provided by 11 of the 21 hospital districts, and it was

at testing or planning stages in the rest of the hospital districts, with the exception

of one hospital district.

About one third (36%) of the 174 health care centres purchased electronic

consultations from hospitals. Another third reported planning or having even

tested it. The health care centres purchasing electronic consultations seemed to be

very active with its use: in 70% of the 49 health care centres which answered the

question it was their principal mode for consultation.

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In 2005, videoconferencing service was provided regularly by 10 of the 21

hospital districts, while five were in the testing or piloting phase.

Among 179 health care centres that answered the questionnaire, 21 (12%)

purchased video conferencing in order to consult a specialist at a hospital. In

addition, ten health care centres had been planning or were testing it. Although

specialist consultations by video conferencing were in 2005 provided by more

hospitals than earlier, the number of health care centres purchasing the service

had not increased from the 21 in 2003.

Regional Data Exchange Systems

According to the year 2005 survey, nine out of 21 hospital districts had a regional

patient data repository in clinical use for the exchange of patient data and six

districts were running pilot projects. There is no single closed network dedicated

to healthcare in Finland; technically, the connections are provided through the use

of commercial high-speed public data networks and secure tunnelling such as

VPN over the public network.

Teleradiology and Image Distribution through a Regional Archive

The results from the surveys conducted in 2003 and 2005 on teleradiology and

regional image distribution/archive services for secondary care (hospital districts)

are presented in Table 6. The usage percentage is also given, if available. Since

teleradiology services could be independent of local PACS or a regional archive, a

combined look at image transfer services is given. The key information is that in

2005, 18 out of 21 (86%) hospital districts utilized some form of electronic

distribution of radiological images.

Table 6. Teleradiology and regional image distribution services in Finnish hospital

districts in 2003 and 2005 (Paper VII, published by permission of IOS press).

Measure 2003 2005

Teleradiology in production phase 13/21 16/21

Teleradiology in pilot phase 4/21 2/21

Teleradiology usage > 90% 2/21 5/21

Regional archive in production 3/21 10/21

Regional archive in pilot phase 0/21 3/21

Regional archive usage > 90% 0/21 3/21

Either teleradiology or regional archive in use 13/21 18/21

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In the primary health care sector, the combined results show that 52 primary

health care centres out of 179 (29%) had some method of teleradiological image

delivery in production. This is a remarkable increase compared to 2003, when 15

primary health care centres were using teleradiological image delivery.

Telelaboratory

In 2005, regional distribution of laboratory results through a regional archive was

utilized by 11 out of 21 Finnish hospital districts, one was at the pilot-project

stage and three were planning to provide such a service in the near future. In

addition, 16 out of 21 hospital districts utilized some other form of electronic

transmission of laboratory results to the primary health care centres in their region.

These other services were partially overlapping with the usage of the regional

archives. The combined results showed that a total of 19 out of 21 (90%) hospital

districts had some method for the electronic distribution of laboratory results in

2005. This figure has nearly doubled from 2003, when 10 hospital districts used

telelaboratory services.

In the primary health care sector, 48 health care centres out of 179 (27%)

reported in 2005 that they received daily laboratory results electronically through

a regional database, while 71 informed that they were either at testing or planning

stage.

Information Exchange between Health Care Organizations and Patients

Twenty hospital districts and 79% of all the health care centres maintained their

own websites. The hospital district and half of the health care centres who did not

have an individual website were running pilot projects or were planning the

implementation of their own website.

Information exchange with patients by SMS messaging was used by one and

tested by three of the hospital districts. It was used by nine (5%) health care

centres and tested by 11 (6%) of the 179 health care centres. With private

providers information exchange with patients by SMS was used by three (11%)

and tested by five (18%) of the 28 private providers.

Only one health care centre used secure e-mail in information networks,

while 15% used conventional e-mail. Remote browsing of EPR by the patient was

not in use anywhere, but was planned to be implemented by two hospital districts,

three health care centres, and one private care provider.

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6 Discussion

This work was conducted during a time period when teleradiology technology

advanced in great leaps. Therefore, the discussion topics touch a wide variety of

implementation issues, both technical and clinical.

The feasibility of commercial off-the-shelf technology for medical purposes

is related to the clinically acceptable image quality level, but also to investment

costs at that particular time. Radiological work practices have changed

considerably because of teleradiology, but also because of the digital radiology

environment in general. The Internet and mobile networks continuously give rise

to questions of adequate transmission speed and required compression ratio of

images. Likewise, portable terminals and even smaller smartphones challenge our

attitude towards display characteristics acceptable for different purposes. Security,

standardization and integration issues are crucial for all the implementations.

Because radiology as a medical speciality is serving other disciplines,

teleradiology should be investigated in relation to regulations and other digital

and remote medical services in the eHealth domain. The keywords of the most

common challenges are presented in table 7.

Table 7. Common challenges when building a teleradiology service presented as

keywords.

Hardware and software related Communications related Teleradiology service related

Cost of the equipment Availability of connections Work practice issues

Quality of the images Speed of the network Medical quality of the service

Usability of the equipment Quality of Service Liability, other legal aspects

Image compression rate Cost of the network Patient´s consent

Display characteristics Security of connections Reimbursement

Integration and interoperability Mobility of the terminal devices Language issues

It is interesting to note that these issues will come up again and again as

teleradiology is finding new frontiers from point-to-point to an international and

mobile setting.

Because of the time span and different technologies used, each of the

problems investigated in this study is first discussed separately in relation to the

work where it first appeared, after which common findings and development

trends are discussed.

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6.1 Low-end technology teleradiology

In the case of high-standard film scanning teleradiology systems with resolution

equal to the original films and full 12-bit (4096 steps) grey scale with instant

image transmission, the price for a single-site unit at the time of this study could

be as high as USD 196,000 and a central referral unit may cost as much as USD

343,000. Network services make for additional costs if permanent connections are

used (Batnitzky et al. 1990, Dwyer et al. 1991, Templeton et al. 1991). The cost

of the equipment in this study was USD 20,000 for the transmitter and USD

15,000 for the receiver unit. This cost level made film-based teleradiology

feasible for health centres and smaller hospitals. The kind of dial-up ISDN lines

used in this study are available in all parts of Finland. Their fixed monthly costs

are only USD 20 to 100, depending on the amount of simultaneous channels used,

and the connections are paid by use, the price being that of normal long-distance

calls.

In their report on the use of low-cost, low-end digital teleradiology Lear et al. (Lear et al. 1989) built a system based on a prototype high-resolution CCD

camera, a personal computer and an ISDN link. Their equipment and software

were however proprietary and not commercially available. Dohrmann et al. (Dohrmann 1991) used personal computers to establish a low-cost teleradiology

link in Australia. They used a video camera and a frame grabber to capture the

images from printed films, however. A slow-speed (2,400 bit/s) ordinary

telephone line modem was used to transfer images. This solution limits maximum

resolution and transfer speed and is mostly suited for CT images. Yamamoto et al. (Yamamoto et al. 1992) built their low-cost teleradiology equipment out of

personal computers and handheld scanners. Their scanning area was limited to 6.1

× 7.0 centimetres, and an ordinary telephone line was used for transmission.

The on-line sending time for a 10:1 compressed chest image (size before

compression less than 4 megabytes) in this study was at the same 30 sec level as

reported by Goldberg et al. (Goldberg et al. 1993) for an uncompressed 7

megabyte image over a fast 1.544 Mbit/s network. If efficient compression can be

used, even ISDN networks can serve effectively for this purpose. Only a few

studies, however, discuss the total procedure time for teleradiology (Carey et al. 1989, Lear et al. 1989, Slovis & Guzzardo-Dobson 1991). In the present study,

when efficient compression was used, film digitization together with other

preparations took up more of the total procedure time than the actual sending.

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The transmitted images were scored as technically acceptable with 8

exceptions (3%). In seven cases the inadequacy was due to improper scanner

settings or insufficient grey scale dynamics. Because the scanner in the present

study limited the image grey scale to 8 bits (256 levels), parameters such as

brightness and contrast were critical for good image quality. If the original images

present excessive contrast, details in both the dark and the light areas may be lost.

This means that such images should be sent in duplicate for the dark and light

areas. Another solution is an image scanning program which can decrease image

contrast by making the highlights darker and the shadows lighter (thus modifying

the response curve in the digitalization process). This method was used in phase

three (from the regional hospital). True 12-bit (4096 levels) scanners that are not

so operator-dependent are three to four times more expensive than the unit in this

study.

Image spatial resolution was sufficient, except in mammograms. The

maximum scanning density of the tested system is 300 DPI, which equals 11.8

pixels per mm. This exceeded the scanning density of the Fuji AC-1 CR image

plate system, for example. In practice, in the present study the scanning density

was finally set to the same level as in the CR image plate system for chest (129

DPI = 5.1 pixels/mm) and bone (165 DPI = 6.5 pixels/mm) images. If the

maximum scanning density of the tested scanner had been used all the time, the

image sizes would have been too large for the equipment in this study. A 35 × 35

cm chest x-ray with 300 DPI (11.8 pixels/mm) resolution would require more

than 17 megabytes and could not be loaded into the 8-megabyte memory of the

computer.

There were no significant differences in the diagnoses of technically

acceptable chest or bone images. In two CT images, a small pons infarction and a

slight thickening of the nervus opticus were missed in the original screen reading.

In retrospect, however, these lesions were detected. It seems that the errors were

due to the reader’s unfamiliarity with the computer screen. The opportunity of

film printing might have been an advantage, but on the other hand, when picture

archiving and communication systems are taken into use, computer workstations

become a common workplace for radiologists. In mammograms, the error

frequency was markedly greater, 10%, suggesting that the scanning resolution

used in this study was not sufficient for transmission of the most detailed films.

The results of this study, with their total 98% agreement on the technically

acceptable images, correspond well to the results by Carey et al. (Carey et al. 1989), who sent 489 laser-digitized conventional and US examinations with 98%

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agreement between the original and transmitted images. It is notable that they still

had 12 patients in whom disease was not correctly identified even though the

original films were digitized with 12-bit grey scale. Slovis et al. (Slovis &

Guzzardo-Dobson 1991) also had an agreement of 98% in their work with 4,200

conventional paediatric images. Goldberg et al. (Goldberg et al. 1993) had

discrepant interpretations in 18 (2.6%) of 685 cases while using a 12-bit scanner.

When standard computer programs are adapted for clinical work, some

limitations are encountered. The programs may not have been specifically

designed for medical work and require many adjustments. In the first two phases

of this study, the participants had to perform all the preparatory steps and make

the changes from the viewing program to the transmission program. This was the

reason why they let a computer operator send the images from the health care

centre. This caused some quality problems because the computer operator was not

accustomed to making decisions on the technical quality of scanned images.

The easier graphical interface, the “shell” used in phase three, resulted in

more convenient image transmission. It eliminated complicated steps and required

less training. It made it possible for x-ray technicians to transmit the images as

part of their normal daily routine without being too much concerned with the

technology. This is important, because x-ray technicians cannot spend too much

time on teleradiology efforts. The x-ray technicians were also able to maintain a

constant image quality. This is important for the cost-effectiveness of the system.

If a teleradiology system is based on standard low-end personal computers,

one has to be aware of the limitations. Depending on the scanner, the grey scale

dynamics and scanning density might not be sufficient for the most detailed

images, such as mammograms. In addition, the smaller display unit necessitates

the use of image zooming. If these problems could be resolved, the same central

unit could be used for office automation, Medline literature searches and

scientific image processing. Radiologists who are familiar with computers do not

need to learn a new user interface, but can utilize the skills they already have.

Images are also transferable into teaching programs and archives, for example.

Our investigation suggested that good image quality can be restored in the

transmission of images with the standard personal computers tested and a

commonly available commercial software configuration. This could make it

possible to build low-end technology teleradiology links for special purposes at a

lower cost compared to the commercial high-end systems. However, this study

was not specifically focused on making a detailed cost analysis of teleradiology.

One should bear in mind that the fixed costs related to equipment are a function

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of the equipment existing on the market at that time and all the economic

conclusions are therefore related to the specific equipment and specific

teleradiology setting.

According to the experience in this study, the scanner is the most critical unit

and its 8-bit grey scale should be extended. In this system, the total sending

procedure still took a relatively long time, and the manoeuvrability of the system

was thus another important limitation. Concerning clinical application areas, the

system investigated here was not suitable for mammographic image transmission.

6.2 Work practise analysis

New technologies necessarily provoke changes that go beyond the technical

system itself. The work practice-oriented study of everyday clinical teleradiology

work clearly illustrates that this is also the case with teleradiological systems, and

it should be taken into account in designing and implementing them in practice.

The study reveals important aspects that have previously gone unnoticed or been

invisible (Plowman et al. 1995). For example, the articulation work done to

ensure the smooth flow of the teleradiology service made up a major part of the

work process both in terms of the amount of activities and importance for the

whole process. Several aspects of cooperative work between the two

geographically separate radiology communities were also identified. Moreover,

articulation work and issues dealing with cooperation were neglected or

underestimated in the system design and organization of teleradiology work

practice.

From radiologists’ point of view, it is important that the system does not

interfere with the accustomed script of interpretation and reporting by causing

disruptions and breakdowns. On the other hand, it has to be kept in mind that

established work practices have been historically formed in close relation with

associated technologies. Therefore, former working habits cannot always be kept

in place as a standard way of working but should be critically evaluated. The

work practice-oriented approach also proved to be useful in detecting those areas

of work that are essential for the primary goal, i.e. accurate interpretation of

images. The system should support the essential parts and typical tasks of work.

Image comparison is an elementary component in radiologists’ work.

Computer screen-based image interpretation technologies cannot supply as much

display space as the radiologists are used to having with traditional light screens.

However, the need for the system to allow for easy juxtaposition of images

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remains. The lack of display space has to be compensated in another ways by the

digitized images and computing power. Comparison could be made easier e.g. by

always displaying chest studies on the screen in the same order. New display

techniques, like stack or cine mode, could be used more often while reading a

series of CT images. There is evidence in literature, that his will enhance the

reading speed (Mathie & Strickland 1997, Kim et al. 2005b). Another aspect

contributing to the ease of comparison of images is the image articulation work

that is done as much as possible prior to the actual sessions. It remains to be seen

to what extent this can be supported automatically by the system, as there seems

to be a great deal of tacit knowledge involved in the articulation work carried out

by the assistants. Unnecessary image arrangement tasks during the interpretation

session should be avoided because they are time-consuming and can weaken the

radiologist’s concentration on the image reading process itself. The initial image

display should give an overview of the kind of images there are to be interpreted.

A structured way of showing the time order of images is also useful. The interface

should be simple, with only relevant buttons and menus, so as not to hinder the

interpretation process.

In the system studied here, the most often used image processing tools were

adjustment of brightness and contrast as well as image zooming. Even though

these features need training and take some time, they offer advantages by

revealing diagnostic information that is otherwise not as easily noticeable. The

investigated system had brightness/contrast control in the mouse, and some

radiologists used it in an interactive way even while examining various parts

within one image. More complicated image processing features seem not be

needed in the busy routine praxis.

Improvements to system usability were identified during the study. Some

specific design guidelines for the development of the system were provided.

However, this remains an area where more empirical work is needed, as the

introduction of new technologies is always a process of learning and adaptation as

well as innovation.

The workshops helped a new work community emerge around the new

system, as the simplest method is to let people from both ends meet each other in

person! The personnel were able to discuss and compare their local procedures,

and see for themselves how the work was carried out at the other end. This helped

in building a shared understanding of the cooperative work process and in

agreeing on common procedures – which is often a complicated issue with

distributed systems. It is important to involve not only final end-users of the

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system but also representatives of all of the tasks that will be changed by the

system in the design process. This kind of approach is thus recommended when

implementing new telemedical services.

New technologies may introduce tasks that are altogether new; in this case

such tasks included the scanning and sending of images in Kuusamo Primary

Health Care Centre. It is important to adapt the new or modified tasks to local

conditions and other practices that will exist in parallel when the system is used.

Furthermore, it is important to identify what kinds of skills and knowledge are

needed in the new tasks: not only training in skills for the new application

programs or one’s own tasks is needed, but also knowledge of the tasks of others

and one’s own role in the system as a whole to help in adjusting to team work.

In the system studied, texts (requests and reports) and images were linked

together. This approach is different from many teleradiology systems, where only

images are transferred electronically while texts are sent via telefax (Goldberg et al. 1993, Davis 1997, Poca et al. 2004). The approach used in the studied system

makes it easier to combine patient information and refer back to earlier cases.

However – from the point of view of clinical praxis – an even more extended

connection to patient records is preferred. Image comparison would be easier if

earlier images could be acquired from a digital archive whenever needed. A

hospital should maintain a common regional archive together with primary health

care centres connected to it. This would increase the quality of care by making the

diagnoses more accurate and also decrease unnecessary retakes as the patient

moves from one institute to another. In addition, the report texts need to be

integrated to the EPR. During the study, the primary health care centre printed out

the reports in paper form. The goal is that physicians can automatically receive

reports directly into their terminals. At that point, teleradiology would finally

support medical work flow as part of vital patient information.

6.3 Internet teleradiology

The value of this early study was that it showed the potential of the Internet,

because only a few cases of international teleradiology had been reported earlier.

This work also highlighted the common issues that are constantly relevant in

connection with this type of distant communication.

The technical quality of digitized and transmitted images was found to be

adequate for diagnosis. A common image file format and common transmission

protocols available for Internet connections made it possible to establish links

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between different institutions in different countries. Standard data format

developed for medical images (DICOM) will make this even easier in the future.

The value of the Internet is its wide availability – connections are made using

existing networks. This can help in sharing medical expertise in various part of

the world in a way not experienced before and open new possibilities especially

to the developing countries (Wootton et al. 2005). The openness of the Internet

can on the other hand cause problems with data safety. Encryption of patient

identification data is therefore needed in clinical use. For certain purposes even

anonymized data can be used, where all patient ID information has been removed.

The Swinfen Charitable Trust has successfully used the anonymization principle

in their charity low-level telemedicine e-mail consultations for the third world

since 1999 (Vassallo et al. 2001). In any case, hospital networks must also be

protected by firewall systems against intruders from outside.

Because of different transfer speeds between links, sending times can vary a

lot. The speed of the fastest connection in the work discussed here was 2 Mbits/s

and that of the slowest 9.6 kbit/s. To increase the throughput within such a slow

channel, efficient data compression is necessary. Even though data transmission

speeds have steadily increased within the Internet as well, and in 2010 Funet

member organizations connect to the new routers with either 1 Gbit/s or 10 Gbit/s

connections (CSC 2010), no QoS can be guaranteed. This is however not a major

concern in the “store and forward” type of practice used in teleradiology.

Commercial dedicated wide area networks have promised to fulfil the

requirements of speed and data safety. Their problem is, however, that

international connections are either not widely available or that they are still

expensive. There are only few examples of dedicated health care networks that

cross national borders, one of them being the Scandinavian health network

(Duedal Pedersen 2004), which connects Medicom in Denmark, Carelink in

Sweden and the Norwegian Healthnet.

Therefore, secure connections over the Internet and compliance with the

DICOM standard in file format and transmission have been used for offshore

teleradiology services, e.g. examinations made in the US are read in reading

centres in Australia and Switzerland (Bradley 2004, Bradley 2008).

The effectiveness of a remote consultation system is not only a matter of time

and technical image quality; informal additional information also needs to be

negotiated during the consultation sessions. Special consultation software with

multimodality capability (video, speech, cursor synchronization) is an advantage

(Ligier et al. 1993).

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In this study with a few real consultation cases a secondary sub-specialist

opinion between university hospitals was considered useful, because the way

medicine is performed was similar between those participated institutions. For

small scale secondary opinion consultations between experts the language issue

was not a problem, as medical English was used here. In the case of larger-scale

consultations between the clinical physicians and radiologists the language issue

becomes more relevant. E.g. in the European Baltic eHealth project the language

issue was recognized as the biggest barrier to overcome in cross-border

teleradiology (Ross et al. 2010). Therefore, they created a structured reporting

tool to overcome this barrier and used that in consultations between the Baltic

states and Denmark. Also multilingual transcriptionists were used. They also

verified the medical quality of the reports before entering to production phase.

Today, the success of cross-border teleradiology seems to be more dependent

of organizational and quality issues than on pure technology. Also legal issues

need more clarification (Stanberry 2006, Pattynama 2010).

6.4 Mobile PC teleradiology

The benefits of teleradiology have been especially apparent in neurological

emergencies (Lee et al. 1990, Spencer et al. 1991, Gray et al. 1997, Hazebroucq

& Fery-Lemonnier 2004, Ashkenazi et al. 2007, Kreutzer et al. 2008,). Fixed

connections like computer networks or telephone lines have mostly been used

(Batnitzky et al. 1990, Dwyer et al. 1991, Stewart et al. 1992). This limits the

mobility of a consulting senior to a certain place. Yamamoto published the idea of

using wireless communication and portable computers for radiological

consultation (Yamamoto 1995). However, analogue wireless communication

involved transmission errors and the effective speed was slow. The digital GSM

technology used in this study gives reliable connections and tolerable

transmission speed with compressed images. In digital form the data remain

unchanged.

The relatively slow speed of the GSM network requires special techniques to

keep total connection time on an acceptable level. To reduce the required

bandwidth, we used JPEG compression for the images. In various studies it has

been shown that a slight compression with a compression ratio from 1:10 to 1:15

does not affect diagnostic quality of radiological images (Lo & Huang 1986,

Ishigaki et al. 1990, MacMahon et al. 1991). The system in this study was

constructed using existing networking and image processing standards. Image

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compression is also available for the DICOM format. Mobile telephone networks

are becoming faster and thus more suitable for image consultations.

The resolution and contrast of the active matrix display system of the portable

computer used in the present study was sufficient for CT work. In particular, the

relatively high luminance compared to older passive matrix screens was found to

be suitable for CT reading. The active matrix display itself was capable of

showing 256 colours with adjustable brightness. The screen in this investigation

was better than in an earlier study, where a 16 grey-shade display was not found

good enough to display X-ray images adequately (Yamamoto 1995). Modern

laptop computers seem to be appropriate for clinical work. In this investigation,

CT-images were interpreted with high reliability.

One of the limitations in the system studied was display size. In one case the

neuroradiologist would have liked to review the images side by side. An

alternative is to use cine mode or a zoom tool of the image viewing software.

Bigger flat screens have become available for portable computers, too.

One of the reasons why experts considered some images only adequate for

preliminary diagnosis was their inability to change the grey scale window and

level. This is not related to the display technology, but to the file format used. In

image file conversion, the original pixel depth is compressed from 16 to 8 bits.

This means that in the studied system the images had to be windowed by the

sender in order to optimize their visualization. This causes problems, if, for

example, bone structure has to be interpreted and only soft tissue images have

been sent. If DICOM format images would have been used, the receiver could

have adjusted the images.

In other cases the neuroradiologist was only able to give a preliminary

diagnosis, because previous images would have been needed for comparison.

With electronic archiving, these will be readily available on-line. This suggests

that any teleradiology system should have a link with hospital PACS.

In the study series, the two slight misdiagnoses caused no change in treatment.

The first one appeared in the very first case in the study series and was due to

uncertainty about the capabilities of the computer. This emphasizes the

importance of individual experience with any new computer tool. The

neuroradiologist was familiar with PC teleradiology, but had used a tabletop

computer with an ordinary cathode ray tube (CRT) display. More aggressive use

of brightness and contrast adjustment would have helped in making a correct

diagnosis. The second case was difficult to decide even from the original image.

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When widely-available network tools are used, data security is an important

issue. The system studied here used a private dial-in server with user

authentication requiring a password. No public computer networks, such as the

Internet, were used. In the GSM network itself, the data are transmitted in

encrypted digital form, and no additional encryption is thus needed.

The usefulness of communication technology enables more efficient use of

expert consultation. Patient care is more efficient and economical when a final

diagnosis can be made at an early stage. This is very important in neurosurgical

emergencies (Richter & Braun 1993). Consultants can react more promptly if they

do not have to travel to a hospital to give their opinion. When hospital-wide

image networks are built, remote links should also be considered. With mobile

communication, experts can be reached if required, wherever they are – even in

another country. This type of sub-specialist expertise could be useful in

circumstances where the health care delivery system is similar, e.g. in the sparsely

populated northern areas in the Nordic countries

With modern technology, it is now possible for a radiologist to carry a

toolbox for CT scan interpretation in a briefcase. The main limitation in wireless

communication is the data transfer speed, but the situation is steadily improving.

The presented initial study confirmed the feasibility of mobile PC teleradiology.

6.5 Smartphone teleradiology

6.5.1 Feasibility study

Clinical results

No studies were found in the literature on pocket-sized teleradiology terminals

using intelligent phones or PDA-devices with combined digital phone capabilities

in one device (a smartphone) before this investigation was accomplished.

Wireless transfer of radiology images to a portable computer has been reported

with analogue and digital technique (Yamamoto 1995). He also published at the

same time a small series of 5 transmitted images to a pocket computer with a

separate wireless modem connection (Yamamoto 2000).

Image reading on a smartphone-type PDA-device was capable of serving as a

preliminary reading station: no significant findings went unnoticed and a senior

opinion could be given. A possibility to window and level the images might have

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helped in detecting missed secondary findings. Actual reports showed a good

agreement with reference film reading; only 3 cases had minor differences,

although the neuroradiologist originally scored 20 cases in the category

“preliminary report”. On the other hand, smaller findings can also go unnoticed in

the case of film reading, as happened during this study for a small pons infarction,

which was at first attempt only detected on the PDA terminal by the

neuroradiologist. Using a PDA terminal was found suitable for reading the most

common emergency CT findings like haemorrhages and brain infarctions, and it

gives added value by enabling clinical consultations (by a neurosurgeon or

neurologist) based on images.

Technical limitations and expectations

Although the PDA devices are small enough to be carried in the pocket, their

networking and display technology must improve before they are more widely

accepted as teleradiology terminals. Unlike many other telemedicine solutions,

the cost is not a major barrier. Because off-the-shelf technology can be used, the

cost of the terminal devices remains low. With the data call costs at the time of the

study in Finland (0.20 Euros/min) the connection costs of a 30-minute session are

also acceptable (6 Euros). Currently, there are several different vendors providing

PDA devices on the market. Until recently, communication with these devices

was complicated. The Nokia Communicator 9000 was the first device to

successfully combine a PDA with a GSM-phone and make connectivity easy to

use for everyone.

The limited grey-shade resolution of the investigated PDA device was

probably the limitation behind the difficulties to notice very small changes.

Another limitation was the small screen pixel amount (even less than VGA). Both

of these limitations can be partly solved by display software by providing tools

for windowing and levelling the image as well as functions to zoom and scroll the

image. Flat panel display technology itself is also evolving fast. Third-generation

mobile terminals and phones will be capable of showing more grey-shades and

pixels and even sharp colour images on a small display. If the power consumption

of these new displays can be set to a reasonable level, image quality in a portable

terminal will no longer be an issue. It is also possible to design the telemedicine

service so that several optional devices can access the system. Some of the

portable devices can also be connected to larger external display devices.

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One might also ask how small displays could suffice in portable devices

when at the same time a great deal of attention is given to the requirements and

quality control of image reading displays in the radiology department and clinical

wards. The answer may partially be related to the main purpose of these devices.

For clinical decision-making, when there is no other option to get access to

images, these devices provide a helping hand. In addition, many findings

especially on cross-sectional CT and MRI images that are relevant to the clinical

question at hand can be visualized with lower resolution requirements, if the tools

are carefully used.

One of the biggest restrictions of communicative PDA-technology in this

study was the available bandwidth. The standard GSM data speed is 9.6 kbit/s,

which restricts considerably the amount of data that can be transferred. The

situation where multiple images in a CT scan series can be sent on average in 21

minutes is just within acceptable limits. However, one uncompressed chest X-ray

image is 10MB in size, for example, and it would take several hours to transfer it

over the GSM-network. In the work of Yamamoto and Williams (2000) viewing

times from turning on the pocket computer to viewing the entire image ranged

from 4 to 6 minutes, but only single images were sent, not series. Reliability in

obtaining a wireless Internet connection was good, but not perfect. In the studied

case with a dedicated device, reliability in connections was not considered a

problem.

Faster GSM network enables speeds up to 14.4 and 57.6 kbit/s. The first 14.4

kbit/s commercial service started in 1999. These higher speeds are achieved by

high-speed circuit-switched data (HSCSD) technology by using multiple time

slots for the data connection. Other approaches to speed up mobile data

transmission in wide area networks are GPRS and EDGE. Finally, 3G (UMTS)

technology with wireless data rates of up to 2 Mbit/s became commercially

available in the mid-2000s, its latest high-speed downlink packet access (HSDPA)

developments giving in 2010 a theoretical mobile data speed up to 14.4 Mbit/s

depending on the capabilities of the network and terminal devices.

There are also other global possibilities for wireless communication, such as

mobile satellite services (Lamminen 1999). Their restriction compared to cellular

networks is higher price and unavailability of integrated PDA devices. In

summary, the spectrum of wireless communication for medical purposed covers

radio pagers, radios, cellular telephones, satellite communication and personal

communication services (Yoho 1994).

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Rapid development in network technology means that mobile systems will

come close to LANs in performance and that in the years to come, transmission

times will no longer be a barrier, at least not in the vicinity of urban settlements.

The latest development in mobile network family, fourth-generation mobile

networks (4G) like LTE (long time evolution) wireless networks can theoretically

provide downward links to the terminal with speeds of 100 Mbits/s, which is in

the magnitude of fixed wired networks. The world premier for these networks

took place in December 2009 in Stockholm and Oslo (Wikipedia 2010).

For medical purposes, network security is an issue. The digital GSM system

is inherently more secure than analogue systems due to its use of speech coding,

digital modulation and TDMA (time division multiple access) channel access. The

additional security mechanisms (such as authentication, encryption and temporary

identification numbers) specified in the GSM standard make it one of the most

secure telecommunications systems that are publicly available. Eavesdropping a

GSM transmission is currently considered only a minor risk.

Usage areas

In emergency cases the ability to obtain advice for interpreting radiographs from a

non-resident senior doctor seems to be very beneficial. It may be especially

important in cases where decision on treatment options must be made in just a

few hours.

At present, PDA technology may not always be good enough for detailed

diagnosis but it may be of great help in many clinical consultations where the

radiological diagnosis is evident and the question concerns treatment actions. The

majority of users may thus eventually be non-radiologists.

The method was found suitable for clinical diagnosis of brain attacks.

Intelligent phones, which can be carried in the pocket, make it possible to reach

radiology consultants regardless of place. In the future, clinical consultations of

e.g. neurosurgeons and neurologists will become easier, thus facilitating earlier

treatment in the case of serious diseases like intracranial haemorrhages. Timely

clinical specialist consultation has become more important not only in

neurosurgical emergencies but also in the treatment of brain infarctions, where,

according to the general guidelines, thrombolytic treatment should be started

within three hours after the onset of symptoms (Käypä hoito 2006). It has been

estimated that the main cause of delay in starting stroke treatment with

thrombolytic drugs is the time required to perform the CT-scan. Part of the delay

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may come from the delay of interpreting the examination. In future, the PDA

terminal may speed up this process by providing direct access to the right expert.

6.5.2 Clinical study

Network issues

In the latter PROMODAS part of the clinical study, the faster download times

between 5 to 10 minutes were achieved for a full series of CT or MRI scans using

GPRS network technology. Even though mobile teleradiology in this manner is

already feasible for special purposes and can be used clinically, standard mobile

telecom networks still provide rather slow data transfer speeds. As mentioned

earlier, the 3G networks (UMTS) and its 4G (LTE) successors are breaking this

barrier by bringing real broadband to mobile devices. Another interesting wireless

broadband technology is WLAN (Pagani et al. 2003), but its previously discussed

geographical limitation of being available only in so-called service points, “hot

spots”, means that it is usable only as an alternative or supplementary

communication network for health professionals.

Terminal device and software development

Handheld devices are becoming more and more powerful tools. The

computational capabilities are reaching the levels needed for many medical

imaging requirements. The devices used in the PROMODAS project were already

acceptable in terms of computational power. The image manipulation functions as

well as rapid change of images were considered good enough for consultation

purposes. However, as we are still in a phase of rapid development in mobile

technology, the lifetime of mobile devices is rather limited. In practice, more than

3-year-old devices can be considered outdated.

Because of the advances in network technology, but more importantly,

because of the rapid progress of terminal devices and their operation systems, the

development costs of consultation systems described in this study may rise

compared to the expected lifetime of the applications. A new generation of

devices every two to four years means challenges to both the technology provider

and the user site. This problem can be alleviated by careful system design. For

example, the DICOM standard can be considered a rather stable technology and it

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should be used where possible. Similarly, general Internet-technology may be one

solution: platform-independent applications may release us from platform

dependence. The standardization of information transfer, contents and formats is

needed for data exchange.

At the time of this study, the MDD was not yet implemented to telemedicine

software. In the future, the directive will have an effect on the development cycle

of software for mobile devices. The evaluation of their safety and clinical

feasibility has to be conducted in a regulated manner. However, in this study

clinical evaluation was performed when diagnostic accuracy was compared to the

original data on full-size image reading terminals.

Most recently, PDAs have continued to advance with faster processors and

faster wireless network connections, increased storage capabilities and improved

screen resolutions. The Apple iPhone (Cupertino, CA, USA) released in 2007 has

a screen resolution of 480 × 320 pixels in colour with high luminance LED

backlight; its newest version, iPhone4 released in 2010, has a screen resolution of

960 × 640 pixels with a contrast ratio of 800:1 and a 500 cd/m2 brightness. A

tablet size variant called iPAD already has a 1024 × 768 pixel resolution. In a

recent study the luminance and contrast response of iPhone/iPodTouch displays

was in the level of high-end commercial laptop displays and even medical display

quality control phantom performance was adequate (Kondoh & Okuda 2010).

High-resolution displays have also become standard in the Android and Symbian

family of mobile phones. A new phenomenon in these operation systems is an

easier way of making small applications (apps) to the new smartphones, so that

there are already thousands of medical apps available. In addition, almost all

PDAs now offer the ability to connect to standard WLAN networks, in addition to

standard cellular networks. These portable devices will only continue to improve.

Clinical experiences

Also other research groups have shown the clinical usefulness of PDA devices in

remote image consultation. Raman et al. (2004) have developed a PDA-based,

DICOM-compatible teleradiology system that is capable of vendor-independent

seamless integration with a PACS. Their system incorporates a Web interface and

custom viewers for Palm OS and the Windows CE operating system, making it

compatible with most PDA models available at that time. Their custom PDA

image viewer software provides basic patient information and image management

and viewing functions. The system supports compression and encryption and is

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compatible with most wired and wireless communication methods. Although

some hardware and software limitations still remain with respect to the

development and implementation of the system, many of these limitations will be

overcome in the near future thanks to ongoing development. Their experience

showed that PDAs are capable of serving as a powerful platform for mobile

image review and management. They expected that in the future, as high-speed

wireless networks become ubiquitous, personal handheld devices will become an

important platform for image review and reporting in the radiology department

work flow and will enhance communication with referring clinicians.

In their study, Yaghmai et al. (2004) found that PDAs are an effective way of

transmitting 256 × 256 pixel resolution images through a PDA using the CDMA

(code division multiple access) wireless network. These images were sent using

standard e-mail clients, and the terminal used was a standard commercially

available Treo-270 communicator PDA (palmOne, Milpitas, CA, USA).

Instant transmission of radiological images may be important for making

rapid clinical decisions about emergency patients. Kim et al. (2005a) examined an

instant image transfer system based on a personal digital assistant (PDA) phone

with a built-in camera. Images displayed on a picture archiving and

communication systems (PACS) monitor can be captured directly by the camera

in the PDA phone. Images can then be transmitted from an emergency centre to a

remote physician via a wireless high-bandwidth network (CDMA 1 × EVDO,

evolution data optimized). They reviewed radiological lesions in 10 normal and

10 abnormal cases produced by modalities such as CT, MR and DSA. The images

were of 24-bit depth and 1144 × 880, 1120 × 840, 1024 × 768, 800 × 600, 640 ×

480 and 320 × 240 pixels. Three neurosurgeons found that for satisfactory remote

consultation a minimum size of 640 × 480 pixels was required for CT and MR

images and 1024 × 768 pixels for angiography images. Although higher

resolution produced higher clinical satisfaction, it also required more transmission

time. At the limited bandwidth employed, higher resolutions could not be justified.

The strength of this study was that it demonstrated that the mobility and

portability resulting from the use of a personal digital assistant (PDA) in an

emergency setting was beneficial, as it did not require the consultant to be

available in a fixed location. However, the patient material was small compared to

our clinical series.

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Integration to medical record systems

Teleradiology services can be utilized to their full potential only if they are

integrated with EPR systems. Therefore the development of an initial mobile

physician terminal was continued to clinical phase within the EU fourth-

framework projects MOMEDA and PROMODAS, both working with technology

and process. One of the key elements in this project was to make technology more

user-friendly, so that e.g. image transmission can take place in the background,

without user interference. Thus it helped overcome the time delay spent on file

managing found in the present study. The wireless terminal for a physician

enables receiving of images, text and other components of multimedia patient

record regardless of time and place. It is connected both to the radiology image

network and to the comprehensive EPR system of Oulu University Hospital. The

EPR is a multimedia record using WWW approach (Reponen et al. 2004), so

additional information can be fetched with the common HTTP (hypertext transfer

protocol) protocol. This means that the presented smartphone terminals gave full

access to the medical record and not only to the radiological part of that. In this

aspect the studied MOMEDA and PROMODAS terminals had an advantage

compared to other studied terminals in literature.

New models of work

This development of personal wireless terminals may mean that some of the duty

services can be centralized and that fewer physicians are needed during duty-

hours. In the future, hospitals can directly consult e.g. neurosurgeons,

neurologists or orthopaedic surgeons by sending images and referral letters to

their portable devices. Ideally this will lead to re-engineering of current health

care processes, freeing resources. Wireless workstations will also revolutionize

the development of EPR in hospital. One of the biggest barriers of EPR

development has been the cost caused by the distribution of enough workstations

in the hospital to allow access to EPR from different work spots. Wireless

workstations will give health care professionals liberty to move around and yet

have fast access to the EPR using various wireless LAN-technologies and even

switch between mobile data networks (3G) and WLAN with the same device.

While the various barriers are lowering, the future telemedicine will be

integrated tightly into the normal care processes and the technology that is needed

will be in the routine toolbox of health care professionals. The patient is the final

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winner when medical professionals can access information in the most practical

way.

6.6 Integration of teleradiology as a part of eHealth services

The present study is part of a continuing survey, which follows the

implementation of the Finnish national eHealth roadmap. The ideas are based on

the European eHealth action plan (2002), e.g. citizen-centred and patient-centred

services, full continuum of care and the well-informed patient. This series of

studies reveals data for administration and planning and even for international

benchmarking.

Teleradiology has been one of the first applications of telemedicine in Finland.

According to a Finnish study, all the five Finnish university hospitals already had

teleradiology services in 1994 (Reponen 1996). Regular service first started in the

sparsely populated northern areas, but has since spread to all parts of the country.

In the primary health care centres, the current trend is not to have a PACS of

their own, but to combine efforts with a local regional hospital or with a larger

hospital district. There are many innovative solutions available. For example in

the most northern hospital district in Finland, all primary health care centres that

produce x-rays are fully digitized and store their images at the central hospital.

Those images can be accessed directly from the physician’s desktop through an

EPR interface. In some areas small regional hospitals have a combined image

archive and distribution system together with the primary health care centres.

The boarder line between teleradiology and image distribution through a

regional archive is gradually vanishing with certain services. In the current survey,

all the methods used for a regional image transfer service were investigated. For a

regional service, the basic assumption was that a hospital should have a local

PACS installed. Then, the technical infrastructure behind the implementation of

regional image distribution could differ. In some areas, images are viewed

through a regional reference database. In other areas there is a dedicated common

regional radiological database (“regional PACS”). A third solution is to view

images through regional access to an EPR archive, which also contains images.

The EPR is the most important tool for health professionals in acquiring and

documenting information about patient care. During the year 2005 study in

Finland, 95.6% of the primary health care centres and 95% of the hospital

districts used EPR as their primary tool for patient data. Compared to the year

2003, there is very strong progress in secondary care both in terms of coverage in

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various medical specialities and in the intensity of use. Because of the complexity

of secondary care (hospital) medical records, the coverage aspect is an important

indicator of EPR penetration there. Among primary health care centres, the

proportion of health centres using EPR was already 93.6% in 2003. The most

recent survey update in this series shows that 100% of Finnish hospital districts

and practically 100% of health centres now have EPR in use (Hämäläinen et al. 2009). Knowing all this, one can say that the penetration of EPR is no longer a

measure of ICT usage in Finland and that new indicators need to be sought.

International comparison of eHealth status

When comparing the Finnish health care ICT situation internationally, Finland

belongs to the global leaders together with Denmark and Sweden, according to a

recent report of the Information Technology and Innovation Foundation (Castro

2009). According to the report, all of these there countries are definitely ahead of

the United States and most other countries in moving forward with their health

information technology systems. This is because these three countries have nearly

universal usage of electronic health records among primary care providers, high

rates of adoption of electronic health records in hospitals, widespread use of

health information technology applications, advanced telehealth programs and

portals that provide access to online information.

Similar high uptake of health ICT applications as in our study was also found

in a study of ICT usage among general practitioners in Europe made by the

research institute Empirica by assignment of the European Commission (Empirica

2008). They identified five eHealth frontrunner countries with the eHealth use

indicator scoreboard: Denmark, the Netherlands, Finland, Sweden and the UK. Of

these, Finland was the only country where all the primary care physicians used

computers (and thus EPR) during their patient consultations.

New indicators and challenges of eHealth implementation

One new indicator is the exchange of information between health care institutions,

mostly between primary and specialized health care. In Finland, regional

exchange of information has been possible because of the high usage of EPR

systems within institutions. Regional exchange of radiological and laboratory data

has been one of the first applications, but today eReferrals and eDischarge letters

directly from EPR to EPR are on the increase. All these contribute to the seamless

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service systems of the patient. The popularity of regional data exchange has

resulted in four different widely used data exchange systems. With the patient’s

consent, the physician has instant access to previous patient data from other

institutions through a secure connection.

The exchange of electronic patient information between providers of health

services necessitates the use of networks with high data security, which can be

actualized through different kinds of intranet solutions or secure Internet

connections. This data exchange is increasing rapidly in Finland. This is because

digital data depositories in individual health care institutions are in active clinical

use, and protected data connections enable the communication of electronic

patient information.

Electronic prescription has been mentioned as an important indicator of

health care ICT maturity. In Finland, a national e-Prescribing pilot-project was

launched in 2002. The pilot-project ran from 2004 to 2006. The system was tested

in two hospital districts and a few health care centres. In 2007 a new law was

issued (L 61/2007) where Finland opted for a system based on a national

prescription database. In the pilot-project system, a doctor creates a prescription

with a legacy system, signs it with a strong electronic signature, and sends the

secured message to the national prescriptions database. The patient goes to a

pharmacy where the pharmacist accesses the database with the pharmacy’s system.

The pharmacist makes the required changes and marks the dispensing information

on the electronic prescription, signs the markings with a personal smart card, and

saves the markings to the prescription in the database and then delivers the

medication to the patient. The clinical use of electronic prescription in Finland

started in May 2010 in the city of Turku (STM 2010b).

Once the backbone for electronic management of patient data in Finland is

ready, the next major challenge is the construction and implementation of the

National EPR Archive. The task is not a minor one. The stage is already set by the

law on electronic management of patient information in social and health care (L

159/2007), which defines one secure national archive for permanent archiving of

standardized medical data. Finland has taken a bold initiative and is now building

a centralized, truly national solution. There are changes that need to be made, not

only in technology but also in ways of conducting daily tasks in health care.

According to the present law, the local systems should be connected to the archive

by April 2011, but in practice a transition period of several years is needed. The

greatest challenges may occur in communication between local and regional

systems and the national archive. This might require major changes in the current

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software being used in hospital districts and health care centres. The goal is

increased access to electronic personal of health records, both by the physician

and the patient.

Update on national health care information architecture

It has been a great challenge to implement the previously mentioned current

legislation of electronic management of patient information (L 159/2007). That is

why the Finnish government issued in autumn 2010 a new proposal for a

modified act that would enable the national medical record archive to serve

patient care better and make it easier for health care personal to have access to the

required health information. It is also proposed that the implementation timetable

should be adjusted. (HE 176/2010, STM 2010a.)

According to the proposal, the medical record archive (eArchive) will be

constructed stepwise in several phases. The contents will be further regulated by a

decree of the Ministry of Social Welfare and Health. According to the current

document, the first phase includes the so-called principal data, which contain

medical narrative texts, nursing summary information, risk information,

pharmaceuticals, laboratory results, radiological requests and reports as well as

electronic referral and discharge letter contents. (STM 2009, KanTa 2010, STM

2010a.)

Concerning medical imaging, it is important to note that initially only textual

information (requests and reports) contained in the main patient record system

will be archived. If the information is residing only in external systems (RIS), it is

not obligatory to store it in the national archive.

Medical images are not included in the first phase of archived material, but

their turn will come in the next phase. As of autumn 2010 the enterprise

architecture will be investigated and a proper solution will be suggested according

to an expert consultation. The task will probably include discussion of whether

images should also be stored at a single storage site, or whether regional storages

should also have a role and what the relationships will be between them. At the

same time, the processes concerned and therefore functional data architecture will

be investigated. The extra time will give an opportunity to learn more about

international experiences in this field.

At the same time, the method of obtaining patient’s consent for delivery of

electronic material from the national archive is made easier and more flexible.

Patients can in the future provide access to their information to all professionals

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involved in their care, even in different institutions. The authorization is valid

until further notice, but patients can always cancel it. Of course, patients can

prevent the delivery of information that is too sensitive (opt-out principle). While

patients can use secure web access to view their most important health data

(eView) they can in the future use the same tool to manage their consent

(eConsent). (HE 176/2010.)

The timetable will be adjusted according to current reality. According to the

government proposal, all public health care organisations should have the first

phase finished by 9/2014, and the private sector should follow by 9/2015. This

means that there will be an extension of three to four and a half years compared to

present regulations. (HE 176/2010.)

Finally, more resources will be devoted to accomplishing the task. The

changes include shifting operational steering of national health information

system development and implementation from the Ministry to the National

Institute for Health and Welfare. (HE 176/2010.)

6.7 General discussion – from teleradiology to eHealth and beyond

During this study, technical platforms for teleradiology services were designed

and built for a regional service setting, for international communication settings

and for various mobile usage settings. Of these, no mobile smartphone combined

teleradiology and EPR terminal was found in the medical literature before this

study, and the international teleradiology connection using the Internet was also

one of the early experiments in this area. Their evaluation consisted of the

assessment of technical feasibility and diagnostic accuracy. Work practice issues

with teleradiology were also studied in the early stage of this discipline, and

finally, the distribution of teleradiology in the Finnish telemedicine and eHealth

context was investigated in a nationwide comprehensive survey targeting health

care institutions.

One of the strengths of the study was that the concepts developed in this

study were taken into clinical usage, or resulted in better system developments.

The joint lessons learned from the regional low-end teleradiology study and the

work practice study influenced the development of teleradiology scanners and

workstation software. Finally, mobile smartphone teleradiology consultation has

now been in clinical use at Oulu University hospital for 10 years.

From a technical point of view, this study showed that common consumer

technology in personal computers and communication networks is good enough

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for medical purposes if performance aspects are discussed. Rosset et al. (2005)

and Ratib et al. (2009) have made observations on the same topic. Of course,

regulations and reliability requirements mean that medical device certification is

needed for those implementations that are finally taken into permanent patient

care. However, this general development has decreased the price of medical

technology; especially powerful computers for medical image processing are now

available at affordable prices.

The value of standardization cannot be overestimated. During the time course

of this study the DICOM standard was gradually becoming implemented in all

areas of teleradiology, making data compatibility an easier task. However, in

practical workflow issues more specific definitions are needed, and hopefully IHE

profiles will be used more for teleradiology, too. In the Western Health Region in

Norway, they have been able to connect numerous RIS/PACS solutions from

different public and private institutions using IHE radiological cross enterprise

document sharing definitions (Stoerkson & Aslaksen 2010). Another set of de

facto standards that have simplified data communication have been the Internet

protocols, which have made it easier to design data transfer tasks. In Swedish

Västra Götaland region (VGR) they have been able to develop a joint

teleworkspace which is integrated to the various RIS and PACS systems with

networked tools and graphical user interfaces (Lundberg et al. 2010). According

to the authors, the need for teleradiology as a service provided "by somebody" has

disappeared in VGR; today it is a shared service embedded in the innovative

radiology information infrastructure.

In this investigation, data compression was used a lot after its usefulness was

initially assured. Data compression is still necessary for teleradiology because of

the narrow bandwidths used especially in mobile or home connections. Actually,

successful use of data compression has been an enabling factor for new frontiers.

Large datasets in cross-sectional imaging can also be one reason to use data

compression. Fortunately, in literature it has been shown that diagnostic quality of

the images is not compromised by moderate compression levels, not even lossy

compression in the magnitude of 1:10 to 1:25. This naturally depends of image

type and size and in Germany they have published recommendation to use a

modest lossy compression in the magnitude of 1:5 to 1:15 depending on the target

modality (Loose et al. 2009).

The Internet provided a pathway and model for international teleradiology

consultations. This investigation covered the most typical user case, i.e. the need

of expert consultation for rare cases. It is worthwhile to notice that these

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international consultations can be arranged in an easy and affordable manner.

Because data security is an issue, it is important to note that today there are ways

of setting up secure private connections over public networks. International

teleconsultations, however, have certain aspects that go beyond the technical ones.

The discussion of medical competence required and moreover, the discussion of

whether radiological image interpretation is merely “image reading” or high-

quality medical specialist consultation is an ongoing debate.

Recent advances in medical ICT usage have taken electronic patient records

to the level where more tight integration between imaging systems and HIS can

be predicted. Finland is one of the countries where EPRs have reached in practice

100% coverage and where picture archiving and communications systems are

used comprehensively in health care. This study has revealed important new

indicators, such as interorganizational data exchange, that can be used for

benchmarking health care ICT services. It this setting regional image distribution

and teleradiology have an increasing role as one of the eHealth services.

Most of the technical challenges of teleradiology are solved little by little as

the general digitalization of the imaging process and patient records progresses.

Solutions are also gradually being found for a common digital working

environment and eHealth-related workpractice issues in the most common

teleradiology settings. However, work practices should be carefully adjusted in

every new type of service setting. In its essence, teleradiology is a matter of

conducting computer-assisted and remote co-operative work, either within the

teleradiology work chain itself or in the longer medical work-up between patients,

practicing physicians and teleradiology consultants. With increasing possibilities

of implementing workload off-shoring and even international teleradiology,

medical quality of the services and issues related to legal aspects, such as liability

issues and patient’s consent will became more important. For international

teleradiology, the issue of different languages and medical tradition remains a

future challenge. The major development steps and driving forces for

teleradiology have been discussed in table 8.

100

Table 8. The major development steps in teleradiology related to enabling factors in

general ICT, medical ICT and the interests of various stakeholders.

Decade Achievements Enabling factors Acting forces

1900 First ideas Telephone, telegram, radio Individuals

1920 First experiments Telegraphs, image facsimiles Individuals

1950 Clinical videoteleradiology Television, video cable

networks

Individuals, hospitals

1980 Commercial camera-on-stick

devices, early computer-based

systems

Affordable video cameras,

modems, first digital imaging

modalities, computer

workstations

Individuals, hospitals,

research institutions,

commercial enterprises

1990 Commercial high-end systems,

advent of PC-based teleradiology,

clinical operation, point-to-point-

services, international experiments

PC revolution, PACS and digital

imaging, standardization

(DICOM), digital data networks,

the Internet

Reseach institutions,

hospitals, commercial

enterprises

2000 Teleradiology-PACS integration,

teleradiology service providers,

mobile systems development,

international pilots

Acceptance of DICOM

standard, large scale PACS,

fast data networks, mobile

networking and computing,

affordable data security

Commercial enterprises,

health care providers,

research institutions

2010

and

beyond

Practice of remote image reading

and distribution (“virtual hospital”),

workload off-shoring, to-the-point

mobile distribution, service quality

management

Integration of PACS-RIS-HIS

with IHE profiles, eHealth

promotion, ubiquitous

computing, government interest

Governments and other

public stakeholders,

health care providers,

commercial enterprises

Teleradiology as a concept has already moved on from its technical background.

It can be used to denote a service within public health care, e.g. between primary

care and secondary care hospitals, or it can be seen as an external service, where

part of the work has been outsourced to external (private) providers. There are

already services like mammography screening which mostly rely on teleradiology

in image interpretation.

One could say that teleradiology has become a fully-fledged tool in eHealth

service delivery. Medical imaging results can be distributed, and so can image

interpretation tasks. Ubiquitous imaging is already here.

101

7 Summary and Conclusions

1. This investigation suggested that a good image quality can be restored in the

transmission of images with the low-end personal computer and a commonly

available commercial software configuration tested. This could make it

possible to build teleradiology links for special purposes at a lower cost

compared to the commercial high-end systems. There were limitations in

technical quality and manoeuvrability, however.

2. Teleradiology between two institutions changed the image interpretation

work processes and revealed hidden aspects of work practice that are not

normally noticed. Especially articulation work that supports the key tasks is

now mostly conducted at the receiving site. The receiving site is also heavily

dependent on the decisions made at the sending site. The radiologists have to

rely on less information than in the case of on-site image reading.

Communication of relevant information is essential in both directions.

3. This study showed that with careful planning the Internet can provide a

feasible transmission channel for international teleradiology consultations

between hospital networks. Even though the Internet is readily available,

there are shortcomings in its speed and safety. Therefore, further investigation

and development is needed, especially in the field of data safety.

4. According to this study, a radiologist can carry his workstation for CT

interpretation as a laptop computer in his briefcase. The main limitation was

the speed of data transfer, but this situation will improve steadily with

technological developments. Ubiquitous communication technology enables

a more efficient use of expertise. However, the new tools require training in

order to be utilized to full extent.

5. Smartphones offer a new tool to gain access to patient information outside the

hospital. Despite the small screen, the image quality in the terminals is

sufficient for clinical decision-making, and even with low bandwidth the data

transfer speed is tolerable. With the progress in technology, these devices

seem to become more useful.

6. Teleradiology has become an integrated part of eHealth and its distribution

together with PACS distribution has steadily increased in Finland during the

2000s. From primary health care users’ point of view it seems to be irrelevant

whether the image transfer services are called teleradiology or regional

imaging study results delivery.

102

103

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Original publications

This thesis is based on the following original articles, which are referred to in the

text by their Roman numerals.

I Reponen J, Lähde S, Tervonen O, Ilkko E, Rissanen T & Suramo I (1995) Low-cost Digital Teleradiology. Eur J Radiol 19: 226–231.

II Karasti H, Reponen J, Tervonen O & Kuutti K (1998) The teleradiology system and changes in work practices. Comput Methods Programs Biomed 57(1–2): 69–78.

III Reponen J, Palsson T, Kjartansson O, Ilkko E, Störmer J, Päivänsalo M, Pyhtinen J, Laitinen J, Eiriksson A & Brekkan A (1995) Nordic Telemedicine Consultation Network Using Internet. Proceedings of CAR ´95 Computer Assisted Radiology and Surgery. Berlin, Springer Verlag: 723–728.

IV Reponen J, Ilkko E, Jyrkinen L, Karhula V, Tervonen O, Laitinen J, Leisti E-L, Koivula A & Suramo I (1998) Wireless radiological consultation with portable computers. J Telemed Telecare 4: 201–205.

V Reponen J, Ilkko E, Jyrkinen L, Tervonen O, Niinimaki J, Karhula V & Koivula A (2000) Initial experience with a wireless personal digital assistant as a teleradiology terminal for reporting emergency computerized tomography scans. J Telemed Telecare 6(1): 45–9.

VI Reponen J, Niinimäki J, Kumpulainen T, Ilkko E, Karttunen A & Jartti P (2005) Mobile teleradiology with smartphone terminals as a part of a multimedia electronic patient record. Int Congr Ser 1281: 916–921.

VII Reponen J, Winblad I & Hämäläinen P (2008) Current status of national eHealth and telemedicine development in Finland. Stud Health Technol Inform 134: 199–208.

Reprinted with permission from Elsevier (I, II, VI), Springer (III), Royal Society

of Medicine (RSM) press (IV, V) and IOS press (VII).

Original publications are not included in the electronic version of the thesis.

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S E R I E S D M E D I C A

1063. Gäddnäs, Fiia (2010) Insights into healing response in severe sepsis from aconnective tissue perspective : a longitudinal case-control study on woundhealing, collagen synthesis and degradation, and matrix metalloproteinases inpatients with severe sepsis

1064. Alaräisänen, Antti (2010) Risk factors and pathways leading to suicide with specialfocus in schizophrenia : the Northern Finland 1966 Birth Cohort Study

1065. Oja, Paula (2010) Significance of customer feedback : an analysis of customerfeedback data in a university hospital laboratory

1066. Mustonen, Erja (2010) The expression of novel, load-induced extracellular matrixmodulating factors in cardiac remodeling

1067. Mäkinen, Johanna (2010) Systematic search and evaluation of published scientificresearch : implications for schizophrenia research

1068. Jartti, Pekka (2010) Computed tomography in subarachnoid haemorrhage :studies on aneurysm localization, hydrocephalus and early rebleeding

1069. Rantala, Aino (2010) Susceptibility to respiratory tract infections in young men:the role of inflammation, mannose-binding lectin, interleukin-6 and their geneticpolymorphisms

1070. Tanskanen, Päivikki (2010) Brain MRI in subjects with schizophrenia and in adultsborn prematurely : the Northern Finland 1966 Birth Cohort Study

1071. Abass, Khaled M. (2010) Metabolism and interactions of pesticides in human andanimal in vitro hepatic models

1072. Luukkonen, Anu-Helmi (2010) Bullying behaviour in relation to psychiatricdisorders, suicidality and criminal offences : a study of under-age adolescentinpatients in Northern Finland

1073. Ahola, Riikka (2010) Measurement of bone exercise : osteogenic features ofloading

1074. Krüger, Johanna (2010) Molecular genetics of early-onset Alzheimer's disease andfrontotemporal lobar degeneration

1075. Kinnunen, Urpo (2010) Blood culture findings during neutropenia in adultpatients with acute myeloid leukaemia : the influence of the phase of the disease,chemotherapy and the blood culture systems

1076. Saarela, Ville (2010) Stereometric parameters of the Heidelberg RetinaTomograph in the follow-up of glaucoma

ABCDEFG

UNIVERS ITY OF OULU P.O.B . 7500 F I -90014 UNIVERS ITY OF OULU F INLAND

A C T A U N I V E R S I T A T I S O U L U E N S I S

S E R I E S E D I T O R S

SCIENTIAE RERUM NATURALIUM

HUMANIORA

TECHNICA

MEDICA

SCIENTIAE RERUM SOCIALIUM

SCRIPTA ACADEMICA

OECONOMICA

EDITOR IN CHIEF

PUBLICATIONS EDITOR

Professor Mikko Siponen

University Lecturer Elise Kärkkäinen

Professor Hannu Heusala

Professor Olli Vuolteenaho

Senior Researcher Eila Estola

Information officer Tiina Pistokoski

University Lecturer Seppo Eriksson

Professor Olli Vuolteenaho

Publications Editor Kirsti Nurkkala

ISBN 978-951-42-6371-2 (Paperback)ISBN 978-951-42-6372-9 (PDF)ISSN 0355-3221 (Print)ISSN 1796-2234 (Online)

U N I V E R S I TAT I S O U L U E N S I S

MEDICA

ACTAD

D 1077

ACTA

Jarmo R

eponen

OULU 2010

D 1077

Jarmo Reponen

TELERADIOLOGY—CHANGING RADIOLOGICAL SERVICE PROCESSES FROM LOCAL TO REGIONAL, INTERNATIONAL AND MOBILE ENVIRONMENT

UNIVERSITY OF OULU,FACULTY OF MEDICINE,INSTITUTE OF DIAGNOSTICS,DEPARTMENT OF DIAGNOSTIC RADIOLOGY;UNIVERSITY OF OULU,FACULTY OF MEDICINE,INSTITUTE OF BIOMEDICINE,DEPARTMENT OF MEDICAL TECHNOLOGY