obsp digital mammography qc technologist_rev3.2_final

Ontario Breast Screening Program

Digital Mammography Quality Control for the Mammographic

Technologist

Authors: G.E. Mawdsley, A.K. Bloomquist, M.J. Yaffe

November 2012

Revision 3.2

Mammographic Physics Consulting Group Ontario Breast Screening Program

Main: Room S6-32 Sunnybrook Health Sciences Centre

2075 Bayview Avenue Toronto, ON M4N 3M5

QC Support: Sunnybrook Imaging Research

[email protected]

Telephone: 416.480.5705

Fax: 416.480.6719

The latest version of this manual can be downloaded from:

http://www.sunnybrook.utoronto.ca/~yaffegrp/OBSP/

Or from: https://share.cancercare.on.ca/

2 Digital Mammography Quality Control Technologist - Rev. 3.2

Blank page

1 OBSP Mammographic Physics Consulting Group

TABLE OF CONTENTS

I. INTRODUCTION 3

Equipment Downtime and Technical Problem Report ......................................................................................................... 17

X-Ray Safety Policy and Procedures ................................................................................................................................... 19 X-Ray Safety Policy & Procedures Signature Sheet ............................................................................................................ 22

II. IMPORTANT POINTS 25 1. Time for Quality Assurance Procedures ........................................................................... 25

2. Information Storage and Mammography Unit Identification .............................. 27

3. Establishing Operating Levels and Control Limits ..................................................... 30

4. Test Frequencies ............................................................................................................................ 30

5. Control Charts .................................................................................................................................. 31

6. Mammography QC Checklists ................................................................................................. 32

7. Technique Charts ........................................................................................................................... 38

8. Image Viewing Conditions ....................................................................................................... 39

9. Third Party Printing ...................................................................................................................... 39

III. DIGITAL MAMMOGRAPHY QUALITY CONTROL TESTS 41

1. Daily Quality Control Test Procedures .............................................................................. 41 Test #1: Monitor Inspection, Cleaning and Viewing Conditions......................................................................................... 42 Test #2: Daily Checklist ...................................................................................................................................................... 44 Test #3: Laser Printer Sensitometry .................................................................................................................................... 46 Test #4: Daily Flatfield Image ............................................................................................................................................. 53 Test #5: Visual Inspection for artefacts (CR systems only) ................................................................................................. 56 Test #6: Image Plate Erasure (CR systems only) ................................................................................................................ 58

2. Weekly Quality Control Test Procedures ......................................................................... 59 Test #7: Phantom Image Quality ......................................................................................................................................... 60 Test #8: Display Monitor QC .............................................................................................................................................. 69 Test #9: Viewbox Cleanliness ............................................................................................................................................. 79

3. Monthly Quality Control Test Procedures........................................................................ 81 Test #10: Full Field Artefacts Test ...................................................................................................................................... 82 Test #11: Monthly Checklist of Exam Room ...................................................................................................................... 87 Test #12: Laser Printer Artefact Test .................................................................................................................................. 91 Test #13: CAR Mammography Accreditation Phantom Image ........................................................................................... 94

4. Quarterly Quality Control Test Procedures ......................................................................................... 98 Test #14: Retake Analysis ................................................................................................................................................... 99 Test #15: Resolution / MTF .............................................................................................................................................. 105 Test #16: Printed Image Quality Test ................................................................................................................................ 109 Test #17: Analysis of Fixer Retention ............................................................................................................................... 113

5. Semi-annual Quality Control Test Procedures ........................................................... 115 Test #18: Compression Force ............................................................................................................................................ 115

QC Test Images Suggested Names and Client ID: ........................................................................................................... 8 Changes to the Mammographic Imaging System ................................................................................................................ 9 Mammography QC Test Image and Record Retention ...................................................................................................... 13 End-of-Month QC Reports for Digital Mammography Systems ....................................................................................... 15

Yearly QC Submission: X-Ray Safety Policy & Procedures ............................................................................................. 18

Phantoms, Test Tools and Test Images for Digital QC ...................................................................................................... 23 ACR/CAR Mammographic Accreditation Phantom .......................................................................................................... 24


IV. REVISION CHANGES FROM 3.1 118

V. REFERENCES 119

VI. APPENDIX SAMPLE CHARTS 120


I. INTRODUCTION

This document lists the quality control (QC) procedures, their frequencies, and action limits that should be used for clinical Digital Mammography (DM)

systems used in the Ontario Breast Screening Program. DM includes systems previously identified as: Full-Field Digital Mammography (FFDM), computed

radiography (CR), and digital radiography (DR). All QC procedures listed here must be performed at the required intervals or more frequently if the individual

situation dictates. The tests in this manual are those required by the OBSP, and form a set of comprehensive tests performed in a standardized manner that

can be compared across machines and facilities.

These tests must be done by all OBSP sites to maintain accreditation. Some

manufacturers have QC tests in their manuals which are similar to tests in this manual; since those tests provide essentially the same information, those

manufacturers QC tests do not need to be performed by the site to maintain CAR accreditation. There are also some manufacturer specific tests which a site

could perform in addition to the OBSP required tests, and additional tests that

must be done in order to use the equipment, but those are not required by OBSP. The site should continue to perform any additional manufacturer tests

that are required for their unit to ensure it stays correctly calibrated and does not void the manufacturers warranty. If you are confused about which tests are necessary, please consult with your physicist and applications training or service person.

This QC Manual for the mammographic technologist has procedures with frequencies ranging from daily to semi-annually. There is also a Medical

Physicists Manual which has tests that are to be performed upon installation, semi-annually or when significant changes or repairs have been made to the

unit. The site is responsible for notifying OBSP when changes or repairs are made to the unit.

The data charts used to record test results are provided in this manual in paper form. In addition, each chart is downloadable in Excel format from the OBSP

Physics website:

http://www.sunnybrook.utoronto.ca/~yaffegrp/OBSP/,

And from the OBSP Collaborative Webspace: https://share.cancercare.on.ca/

(Documents section).

The use of the Excel spreadsheets will simplify procedures significantly, since

many plots and calculations are done automatically.

The tests described in this manual are designed to verify the correct operation

of the entire imaging chain by evaluating the three components of digital mammography systems: image acquisition (x-ray generation and detection,


flat-field correction), image processing (dynamic range adjustment,

sharpening, peripheral equalization), and image display (gray-scale calibration and display resolution for both monitors/softcopy and printed/hardcopy

images). When problems are detected, further tests may be required to diagnose and isolate the cause of the problems so that they can be corrected.

Depending on the resources available at the facility and the nature of the problems, such diagnostic testing may be performed by the quality control

technologist, the facilitys medical physicist, equipment service personnel, or other suitably trained and qualified personnel.

The mammographic technologist must understand that the CAR accreditation requirements require the medical physicist to either perform a mammography

equipment evaluation whenever a new unit or processor is installed, a unit or processor is disassembled and reassembled at the same or a new location, or

major components of a mammography unit or processor equipment are changed or repaired, or to review the results of the testing performed by another qualified individual. This includes the replacement of detectors, as well

as moving the machine from one room to another. For new mammography units, this equipment evaluation is essentially an acceptance test and involves more complete testing and evaluation than that required for the annual survey. All tests must pass before the equipment may be used for

the mammography of clients and in order to comply with HARP Regulations, the report must be sent by the facility within 60 days of the test to:

Ministry of Health and Long-Term Care X-ray Inspection Service

Performance Improvement and Compliance Branch 1075 Bay St., 11th Floor,

Toronto ON M5S 2B1

In addition, the facility can minimize costly mistakes by involving the medical physicist in the purchase decision, the siting, the viewing room design and

specifying the computer requirements, well in advance of installation.

The importance of involving the medical physicist in the purchase decision and the value of his or her equipment evaluation prior to equipment use is even

more critical for digital mammography than it was for screen film, as facilities rapidly depart from a single-vendor environment where appropriate

communication among system components was assured by design. It is not uncommon for a facility to install several different acquisition systems,

interface them with review workstations from different vendors, and share the images over an existing picture archiving and communications system (PACS).

When this occurs the medical physicist must perform an equipment evaluation on the review workstations and it must pass the softcopy tests described in the

medical physicists manual, using test images that imitate those produced by


each acquisition system. If the workstation properly displays test images that

imitate those from a given acquisition device, that workstation passes the equipment evaluation. However, this does not confirm that hanging protocols

will be properly followed, or that a given manufacturers image processing will be properly applied.

As in screen-film mammography, DM QC is only effective if the procedures are performed correctly, results are charted and compared to previous results and

to test limits as data are collected, and appropriate corrective actions are taken when needed. QC is ineffective if procedures are not performed

regularly, if tests are performed but results are not charted, or if the charted results are not reviewed carefully to determine if corrective actions are needed.

To aid in recognizing when corrective actions should be taken, specific test or action limits are given for all QC test results.

Because these action limits have been developed based on the performance of only a few units of each design and from the earlier DM systems, some of the

action limits may need to be revised as systems improve over time. These will

be periodically reviewed by OBSP Physics and updates will be provided by your OBSP Regional Centre. Updates will also be available on the OBSP Collaborative

Webspace.

Some tests specify that corrective action must be taken immediately; this

means that the device must not be used for clients until the problem is corrected. For example, if corrective action must be taken immediately on a

review workstation, the interpreting physicians (radiologists) may not use it for interpretation until the problem is satisfactorily repaired. However, the facility

is not required to immediately cease mammography; they may continue to acquire client images for a reasonable length of time. In this example, a

reasonable length of time would be 3 working days since acceptable medical practice involves notifying health care providers of positive examinations as

soon as possible (as guidance, within 3 business days).

Images are generally provided to PACS systems in a For Presentation or processed form. Some of the tests in this quality control program require images in the For Processing or raw format. In order to properly evaluate signal levels and noise in the system using phantoms, edge enhancement and

dynamic range compression (thickness equalization) must not be applied to the images. It may also be important to ensure that the auto-push DICOM server is set to the appropriate state at the completion of the testing.

The mammographic technologists Procedures for DM for all units are shown in Table 1 and Table 2 below. Most evaluations can be recorded directly on the checklists (Daily and Weekly Tests and Monthly, Quarterly and Semi-Annual

Tests). Note: the tests and frequencies may vary with the type of processing used (wet vs. dry) with the laser printer.


Table 1: DM Radiologic Technologists QC Procedures and Minimum Frequencies without Laser Printer

Test

# Test DM Systems

Minimum

Frequency

Corrective Action

Timeframe Charts

1.

Monitor inspection,

cleaning and

viewing conditions

All Daily Immediately Chart A

2. Daily checklist All Daily

Immediately, before

checked component

is used for clients

Chart A,

Chart 1

4. Daily flatfield image All Daily Immediately Chart A,

Chart 4

5. Visual inspection

for artefacts CR Daily Immediately Chart 1

6. Image plate

erasure CR Daily NA Chart 1

7. Phantom Image

quality All Weekly Immediately Chart 5

8. Display Monitor QC All Weekly

Immediately:

workstation-before

client images

interpreted;

acquisition station

monitor-before

clients imaged

Chart A,

Chart 6,

Chart 7

9. Viewbox

Cleanliness

All where

prior films

are

hardcopy

Weekly

Immediately, before

client images

interpreted or

comparison films

reviewed

Chart A

10. Full field artefacts All systems Monthly Immediately Chart B,

Chart 8

11. Monthly Checklist All Monthly

Immediately or

within 30 days,

depending on check

Chart B,

Chart 9

13

CAR Mammography

Accreditation

Phantom Image

All Monthly Immediately Chart 11

14. Repeat Analysis All

Quarterly

(pref.

Monthly)

Within 30 days of

the test date

Chart B,

Chart 12,

Chart 13

15.

Resolution/

Modulation Transfer

Function (MTF)

All with

scanned

image

acquisition

Quarterly Immediately Chart B

18. Compression Force All Semi-Annually Immediately Chart B


Table 2: DM Radiologic Technologists QC Procedures and Minimum Frequencies including Laser Printer

Test

# Test DM Systems

Minimum

Frequency

Corrective Action

Timeframe Charts

1.

Monitor inspection,

cleaning and

viewing conditions

All Daily Immediately Chart A

2.

Digital

mammography

equipment daily

checklist

All Daily

Immediately, before

checked component

is used for clients

Chart A,

Chart 1

3. Laser printer

sensitometry All hardcopy

Daily (wet)

Monthly (Dry)

Immediately, before

client images

printed

Chart 2,

Chart 3

4. Daily flatfield image All Daily Immediately Chart A,

Chart 4

5. Visual inspection

for artefacts CR Daily Immediately Chart A

6. Image plate

erasure CR Daily NA Chart A

7. Phantom image

quality All Weekly Immediately

Chart A,

Chart 5

8. Display monitor QC All Weekly

Immediately:

workstation-before

client images

interpreted;

acquisition station

monitor-before

clients imaged

Chart A,

Chart 6,

Chart 7

9. Viewbox cleanliness All hardcopy Weekly

Immediately, before

client images

interpreted or

comparison films

reviewed

Chart A

10. Full field artefacts All Monthly Immediately Chart B,

Chart 8

11. Monthly Checklist All Monthly

Immediately or

within 30 days,

depending on check

Chart B,

Chart 9

12. Laser printer

artefacts All hardcopy Monthly

Immediately, before

client images

printed

Chart B,

Chart 10

13.

CAR Mammography

Accreditation

Phantom Image

All Monthly Immediately Chart 11

14. Repeat analysis All

Quarterly

(pref.

Monthly)

Within 30 days of

the test date

Chart B,

Chart 12,

Chart 13

15. Resolution/ MTF

All with

scanned

image

acquisition

Quarterly Immediately Chart B


16. Printed image

quality All hardcopy Quarterly

Immediately, before

client images

printed

Chart B,

Chart 14

17. Analysis of fixer

retention

All hardcopy

with wet

processors

Quarterly Within 30 days of

the test date Chart B

18. Compression force All Semi-Annually Immediately Chart B

QC TEST IMAGES SUGGESTED NAMES AND CLIENT ID:

Client ID numbers assigned to the test images should be chosen so they fall outside the range used for imaging real clients. This is done to avoid

difficulties with any PACS, radiology information system (RIS) or health information system (HIS) in use. The numbers assigned should also be unique

to each test. Below we suggest possible ID numbers for the technologists QC test images, which can be used provided they meet the above criteria. Table 3

lists the images generated by the technologists QC tests along with a suggested client naming convention. Suggested Client IDs are given, in the

following format: 990XUYYMMDD where X is the test number, U is the

mammography unit or room number and YYMMDD is the date the images are acquired.

Table 3: Mammographic Technologists QC Test Images and Suggested Names and Client ID

Test

# Test Client Name

Images

Required

Suggested Client

ID

# of Images

Expected

1. Monitor

cleaning NA No NA NA

2. Daily checklist NA No NA NA

3. Laser printer sensitometry

NA Yes NA 1 film/day (wet) or 1 film/month (dry)

4. Daily flatfield

image

QCDAILY,

DMUP Yes 9904UYYMMDD 1/day

5.

Visual

inspection for artefacts

NA No NA NA

6. Image plate erasure

NA No NA NA

7. Phantom image quality

QCWEEKLY, DSB

Yes 9907UYYYMMDD

1/week

8. Display monitor QC

NA No NA NA

9. Viewbox cleanliness

NA No NA NA

10. Full field artefacts

QCMONTHLY, DMUP

Yes 9910UYYMMDD 2 or more

11. Monthly NA No NA NA


checklist

12. Laser printer artefacts

NA Yes NA 1 film/month

13. CAR MAP Image

QCMONTHLY,MAP

Yes 9913UYYMMDD 1/month

14. Repeat analysis NA No NA NA

15. Resolution/ MTF

QCQUARTER

LY, Resolution

Yes 9915UYYMMDD 1/quarter

16. Printed image quality

NA Yes NA 1 film/quarter

17. Analysis of fixer retention

NA Yes NA 1 film/quarter (wet)

18. Compression force

NA No NA NA

CHANGES TO THE MAMMOGRAPHIC IMAGING SYSTEM

To comply with CAR Accreditation requirements, all changes to the imaging

system that might affect image quality must be done in consultation with the OBSP Regional Administration and the medical physicist for your site, and must

be reported to the CAR office when completed.

Specifically, if new equipment is installed, the mammography machine is

moved, the X-ray tube is replaced, the detector is replaced or the image processing (software) is changed, these items must be discussed, and may

require additional tests to be performed. If site personnel change (radiologists and technologists) this must also be reported to the CAR office (this is a CAR

requirement, not the OBSPs).

Following this section, Table 4 details some specific changes and the

associated requirements.

In general, for any proposed change(s):

Contact the OBSP Regional Administration and the OBSP Physics Consulting Group to notify them of the proposed change(s) before they are implemented.

Additional testing and/or submission of phantom images, flat-field images and

processor sensitometry may be required. For major changes, or new installations, a physics visit must be scheduled. Note that while rush visits are

possible to arrange, frequently visits to other facilities have been scheduled, and rush visits may not be possible. There will be a delay before the facility

can image patients.

Contact the CAR and notify them of the change(s). The CAR will inform the

centre as to what is required in order to maintain CAR accreditation. In most


cases, an accredited facility will be required to submit their most recent QC

chart and a phantom image (both from the same month), to ensure that the same high level of quality that was originally demonstrated at the time of

accreditation has been maintained following the change.

Note:

Clinical as well as phantom images must be submitted when the unit is changed.

Clinical images are not necessarily required for changes in grid, equipment location, or a tube replacement.

Physicists reports submitted to the CAR must be signed by a physicist accredited in Mammographic Physics by the Canadian

College of Physicists in Medicine.

Table 4: Required Action for Specific Changes to the Imaging System

Changes to the Imaging System

Proposed

Change

Step 1 Step 2 CAR Fee*

Notify OBSP Physics of the

proposed change(s) prior

to implementation.

Notify the CAR of

the change

With a

physicists report

Without a

physicists report

Replacement X-ray Tube

the service personnel installing the tube will complete HARP testing;

However, the physicist must be consulted prior to installation and may either:

o Visit the centre to perform tests of their own, OR

o Request a copy of the service report along with phantom images to evaluate and dose information.

Phantom image & QC data (with a physicists report)

Phantom image, Dose & QC data (without a physicists report)

$210.00 $210.00

* The fees charged by CAR were current at the time of printing. Always check with CAR for

current fees.



Proposed Change




to implementation.

Notify the CAR of

the change

With a

physicists report

Without a

physicists report

Replacement Grid or Replacement Detector

Or

Replacement Imaging Plates for CR

Physics may request:

o Phantom and flat-field images after the installation and dose information. If so, a follow-up report will be issued to the site after the images have been evaluated, OR

o Regular 6 month testing may be arranged to coincide with the replacement. The new grid can be evaluated at that time.

Phantom image & QC data (with a physicists report)

Phantom image, Dose & QC data (without a physicists report)

$210.00 $210.00

Replacement Image Processing Software or Algorithm


o Processed phantom image(s) after the installation. If so, a follow-up report will be issued to the site after the image(s) have been evaluated

OR

o Regular 6 month testing may be arranged to coincide with the replacement. The new software can be evaluated at that time.

N/A N/A N/A

Replacement Monitor(s) for Radiologists Review Workstation or Technologists Acquisition Workstation


o Installation Report and Monitor QC after the installation demonstrating that the monitors are calibrated to meet OBSP requirements (DICOM GSDF)

OR

o Regular 6 month testing may be arranged to coincide with the replacement. The new monitor(s) can be evaluated at that time.

N/A N/A N/A



Proposed Change




to implementation.

Notify the CAR of

the change

With a

physicists report

Without a

physicists report

New Printer Physics may request:

o AAPM-TG18 test image and uniform test image, as well as printer sensitometry after the installation. A follow-up report will be issued after these materials are reviewed; OR

o Regular 6 month testing may be arranged to coincide with the installation. These changes can be evaluated during the visit.

Phantom image & Printer QC data

$210 $210

Moving an

Existing Unit

o Acceptance Testing by physicist (refer to Page 4) is required when a new unit is acquired by a centre, or an existing unit is relocated. This is required by HARP, CAR and OBSP, and is covered by OBSP Physics. Physics will issue a report to the centre including the results of the acceptance testing.

o The results of the Acceptance Testing must be submitted to the HARP Commission within 60 days of the installation (and/or set-up after a move) of the new unit(s).

o The report, including entrance exposure for the average client, must be kept on site in the quality control log.

For relocating an

existing unit, the CAR requires an application be made to register the unit

(Full clinical image submission is not required).

$210 $210

New Unit

For a new unit, the CAR requires an application be made to register the unit, including full phantom and clinical image submission.

N/A $2100

A New or

Recalibrated

Densitometer

(for sites

printing

images)

There is no specific requirement for testing;

However, this will affect the film laser printer QC program that was initially established.

It will be necessary to re-establish the baseline operating levels for the film laser printer (refer to Section III.2.3.B.)

N/A



Proposed Change




to implementation.

Notify the CAR of

the change

With a

physicists report

Without a

physicists report

New

Dosimeter Contact CAR if a site images the dosimeter incorrectly or damages it in some way and it cannot be imaged and used, but it must be replaced.

$157.50

Lost

Dosimeter Contact CAR if a site loses the dosimeter and need to replace it for imaging.

$78.75

Changes to

Personnel:

New

Radiologist

One New

Technologist

All

Technologists

*This is a CAR

requirement, not the

OBSPs; however, the Regional OBSP

Administrator should be

notified.

----->

----------------------------

----->

----------------------------

----->

Changes to

personnel must be

reported to the CAR

and require the

following:

Change Form

& Curriculum Vitae

(40 hours) & C-MAP

Copy of license &

CME

Clinical Images,

Copies of licenses &

CME

N/A

N/A

N/A

N/A

N/A

N/A

MAMMOGRAPHY QC TEST IMAGE AND RECORD RETENTION

As with screen-film mammography QC, the medical physicist will review the facilitys DM QC data, including test results and images during their annual inspection. Table 5 summarizes the length of time these records must be maintained at the facility.

HARP regulations require that QC records be maintained for at least six years from the time of their making in the facility in which the x-ray machine to

which the records referred is operated. These records must include type and result of test, frequency of testing and actions taken to correct each deficiency

identified, but do not include the actual images.

Table 5: OBSP Requirements for Mammography QC Test Image

Retention

QC Images / Records Retention

Daily QC Images previous 60 days


Weekly QC Previous 12 weeks

Monthly QC Until the next semi-annual inspection has been completed and it has been determined that the facility

is in compliance with the quality assurance requirements.

Quarterly QC Until the next semi-annual inspection has been completed and it has been determined that the facility is in compliance with the quality assurance

requirements.

Semi-annual QC tests Until the next semi-annual inspection has been

completed and it has been determined that the facility is in compliance with the quality assurance

requirements or until the test has been performed two additional times at the required frequency, whichever is longer.

Mammography Equipment Evaluations

Images documenting test failures be provided to the facility to assist them in making corrective actions.

These should be kept for 12 months.


END-OF-MONTH QC REPORTS FOR DIGITAL MAMMOGRAPHY SYSTEMS

At the end of each month a CQ report is to be submitted to OBSP. This report can be sent by email to: [email protected], or through the Regional

Centre.

All charts are available in Excel format from the physics group, Or from the

OBSP Collaborative Webspace: http://www.obsp.webexone.com (Documents section). The Excel versions of the charts perform calculations and plot data

automatically.

Please include the Monthly QC Report Cover Sheet with the submission (see example on following page).

Information to be submitted includes:

Monthly QC Report Cover Sheet requires an email address and phone number for the QC contact at the site as essential information.

Chart 2 Laser printer sensitometry (only if hardcopy reading is performed)

Chart 4 Daily flatfield image Chart 5 Phantom measurements

o signal level in region of interest (ROI) - this gives a measure of

sensitivity o noise level (standard deviation) in same ROI

o signal-difference (SD) - provides a measure of contrast o signal-difference to noise ratio - an index of image quality

o mAs ties the results to dose

Chart 6 and Chart 7 Display monitor QC summary (replaces processor QC)

Chart 13 Retake analysis for digital images

The monthly QC submission must also include clear notes documenting

problems (i.e.: when values on chart 5 were out of range) and any corrective action(s) that were taken (including copies of service reports). The form,

Equipment Downtime and Technical Problem Report, is provided here (following the cover page) and should be completed for each occurrence where

regular mammography activity has to be stopped for service/repairs to equipment (this includes the mammography unit(s), viewing stations and CR

readers). This form must be kept in the QC files on site, and a copy should also be included with the monthly QC submission.

If you are submitting QC electronically, emailing the Excel spreadsheet, do not delete any charts; instead, email us the entire file. Deleting charts from the

spreadsheet can result in broken links.


OBSP Physics Consulting Group

[email protected]

Monthly QC for

Equipment Downtime/Service Report

Other

If images are not read on site (no Review Work Station), please list locations where OBSP

images are read below:

ext.

Version 3.2

Message:

Please contact the HEAD QC TECHNOLOGIST as soon as possible if you do not receive all pages.

Name:

Phone:

Department:

Re:

Monthly QC Report Cover Sheet

Facility Name:

Address:

Phone:

Email address:

Excel File Submission

Prepared by:

Date:

Attention:

Email Address:

Number of Files:

Confidientiality Statement: The documents accompanying this transmission contain confidential information intended for a specific individual and purpose.

The information is private and protected by law. If you are not the intended recipient, you are hereby notified that any dis closure of the contents of this information is strictyl prohibited. Ifyou have received this information in error, plse notify us im mediately by

telephone and return the original to us by regular mail at our expense. THANKYOU.


Equipment Downtime and Technical Problem Report

This includes mammography units, viewing stations and processing facilities. Send in one copy to OBSP Physics (FAX 416-480-6719) and keep one in your QC binder.

Facility: _______________________________________________________________

Date of Occurrence:_______________ Date of Report: ________________

Equipment/Product Affected: ________________________________________________________

Nature of Problem (and diagnosis by technologist): Include description of symptoms and degree of inconvenience / urgency.

Service Company (name): _________________________________________

Time service company contacted:_ ___________Individual: _______________

Promised arrival time: __________ Actual arrival time: ___________________

Technician / Engineer name: ________________________________________

Diagnosis of Problem (as reported by service rep):

Service action taken:

Length of time to complete service: ______Charge for service: __________

Number of Clients re-booked: _______ Machine downtime: ____________

Was problem completely solved? ___________

Follow up action required:

Comments:

Other Centres Affected? (Y/N) _______

Other Centres Notified (or Head Office) _______

Physics Group Informed? _____ if so, date sent to Physics Group: _______________

Other Action:


YEARLY QC SUBMISSION: X-RAY SAFETY POLICY & PROCEDURES

In January of each year, all of the Mammography Technologists (including part-time) should read the current X-ray Safety Policy & Procedures pages of this

QC manual and sign the X-ray Policy and Procedures Signature Sheet. The CMRTO registration number for each MRT must also be recorded on this sheet

in the column provided. The relevant pages and the signature sheet immediately follow this section.

A copy of the completed signature page should be sent by FAX to the OBSP

Physics Consulting Group (416-480-6719) by the middle of January each year, as well as being posted in the technologists work area with the X-ray Policy and Procedures sheets.

In addition to the above mentioned yearly submission, the X-ray Policy and

Procedures Signature Sheet should also be completed and submitted by FAX to the OBSP Physics Consulting Group in the following circumstances:

a) When a New Revision of the OBSP QC Manual has been Published

All of the Mammography Technologists (including part-time) and every

radiologist at the facility must review the new manual in its entirety, and familiarize themselves with the changes and updates that have occurred

since the last revision.

The X-ray Policy & Procedures Signature Sheet should then be completed

and submitted to the OBSP Physics Consulting Group by FAX (416-480-6719).

b) When a Mammography Technologist/Radiologist is Newly Hired

During the Year

The new Mammography Technologist and/or Radiologist must review the

current OBSP QC Manual in its entirety, including the X-ray Safety Policy & Procedures pages, and sign the X-ray Policy and Procedure Signature

Sheet.

A copy of the completed signature sheet should then be sent by FAX to the

OBSP Physics Consulting Group (416-480-6719).

NOTE: Changes to personnel must be reported to the CAR (refer to Changes to the Mammographic Imaging System, and Table 4).


X-Ray Safety Policy and Procedures

This policy will be periodically reviewed and updated. Latest revision: October, 2011.

The Mammography Technologist must be registered with the CMRTO.

All technologists must read and sign these X-ray Policy and Procedures pages

and record their CMRTO registration number annually.

The entire QC manual must be reviewed, and the X-ray Policy and Procedures

pages read and signed by each technologist and radiologist when:

they are newly hired

a new revision of the OBSP QC Manual is published and distributed

A Radiation Protection officer must be designated for the facility. This person must be a radiologist and is normally the radiologist for the centre.

A technique chart must be posted. Most centres will use Automatic Exposure control and Automatic kVp for nearly all patients. If manual kVp is used, 28 or

29 kVp is recommended for use with the average patient, increasing to 32 kVp for very dense or thick breasts. The radiographic technique as well as

compression thickness must be recorded either in the image header, or on the clients mammography record sheet.

Views: For screening, bilateral Craniocaudal and bilateral mediolateral oblique views will be taken unless otherwise indicated. The nipple is to be in profile in

at least one view for each breast if possible. Nipple markers may be used, but are not required.

Consent: A signed consent for the procedure is not required by the program.

X-ray shielding devices are not required for patient protection; however they can be used to allay fear of radiation exposure. The aprons and thyroid collar

are not to be kept on display in the mammography room, and should be kept in a drawer or in another room.

The table acts as a complete beamstop and does not permit any primary radiation to hit the client behind it. Scatter from the surface of the breast is

minimal (less than 1/1000) of the entrance exposure and radiation at 30 kVp has much less penetration than that normally used for general radiography.

The exposure to the thyroid is extremely small (less than .03 mGy for a 4 view study). The average glandular dose to the breast for a 4 view study is about 3

mGy for the average client.


An overexposure is defined as: An examination in which the entire breast

tissue is over-penetrated and the mAs have exceeded 600 at 28 kVp. Double exposures due to equipment failure may cause this.

When overexposure occurs:

Inform Radiation Protection Officer, who is to contact the Director of X-Ray Safety, Ontario Ministry of Health at (416) 963-1030 as well as the Physics Support Group at (416) 480-5724.

Before imaging another client, determine cause of problem and if it requires repair, rebook all clients until problem is corrected.

The door of the mammography room must be closed during exposure.

The door must have a warning sign stating "Unauthorized Entry Prohibited" and

have an automatic door closer as required in HARP regulations.

A copy of the OBSP Quality control manual(s) must be kept in the

technologists work area, and all tests must be carried out when required and recorded in the manual. A record of the acceptance tests and 6-month checks

is to be kept in the same location.

A copy of the HARP Act and Regulations should be on site (available at http://www.e-laws.gov.on.ca/html/regs/english/elaws_regs_900543_e.htm).

Dosimeters: Mammography Technologists are not required to wear dosimeters if they only perform mammography. If they are performing other radiography,

their employers for that site will provide dosimetry if required. In that case, the technologist should wear the same badge at both locations.

Pregnant technologists will be treated no differently than other technologists, since a negligible exposure is received when the equipment is operated from

the control area.

CR cassettes will be stored in a shielded area within the mammography room,

preferably on a shelf beside the mammography unit, and behind the operator shield.

Equipment problems are to be repaired as soon as possible and the appropriate service organization must be contacted directly by the local centre. The

technologist should attempt to provide the service personnel with an idea of

the nature of the problem, if possible, by telephone. Below is a short list of the most likely problems, and how to approach them.

AEC malfunction: Determine the nature of the failure using the DSB phantom. If the problem cannot be reproduced, continue imaging


clients, monitoring the mAs used. If the problem is consistent, call

service and rebook all clients for the next day. Manual timing using a technique chart may be acceptable, but not recommended.

Burnt-out collimator lamp: call for "non-urgent" service; position clients carefully.

QC action limits exceeded: determine cause of problem following troubleshooting chart. Call equipment Service Company. Do not

radiograph clients until the system is within limits.

Cracked or ripped compression paddle: order a new one, "rush". You may use the other size compressor plate if required. It may be advisable to keep a spare compression plate on site.

Acquisition Display Monitor QC test failure: The monitors should be cleaned and re-calibrated to meet the DICOM Grayscale Standard

Display Function (GSDF) when displaying mammography (MG) images.

MTF test failure: Service should be contacted to recalibrate/repair the CR plate reader.

A Record of Repairs and Problems must be kept in the Quality Control Manual

for the equipment, including the time the service company was called, and the total downtime for the problem.


X-Ray Safety Policy & Procedures Signature Sheet

Facility: __________________________________________________________

Submission for:

Annual review* of the latest X-Ray Safety Policy and Procedures pages for Mammography Technologists in the Ontario Breast Screening Program.

Newly hired Mammography Technologist(s) and/or Radiologist(s). Current OBSP QC Manual, including the latest X-ray Policy and Procedures pages, has been reviewed.

New revision of the OBSP QC Manual received. All Mammography Technologists and Radiologists at the facility have reviewed it and are familiar with the major updates.

Name Signature CMRTO Reg No.

Date signed

The Radiation Safety officer is:______________________________________

Phone:_________________________________________________________

* This sheet should be filled out by each of the mammography technologists including part-

time staff. A copy is to be Faxed to the Physics Group (Fax: 416-480-6719) by the middle of

January each year. CAR must be notified of all personnel changes (refer to Table 4).


PHANTOMS, TEST TOOLS AND TEST IMAGES FOR DIGITAL QC

The only phantoms required to perform OBSP and CAR QC at the site are the Digital Mammography Uniform Phantom (DMUP) and the Digital Standard

Breast (DSB) Phantom. Both are provided by the OBSP Physics Group.

The DMUP is a 4 cm thick slab of PMMA (poly methyl methacrylate, a clear

plastic) which covers the entire image receptor (see Figure 1). This phantom is also used to evaluate the uniformity of the image, and the presence of

artefacts. If the DMUP phantom is damaged through misuse or lost, the cost of

replacement is $750 (less than a CAR phantom).

Figure 1: OBSP Digital Mammography Uniform Phantom (DMUP) with 1

mm thick contrast disc on top.

The DSB phantom is a new phantom. It consists of two semi-circular slabs of

PMMA which total 4.5 cm in thickness. It comes with a 1 mm thick contrast disc which is placed on the top of the phantom and used to measure the

system speed and contrast (see Figure 2). Until the DSB phantom is provided, use the DMUP Phantom in its place. If the DSB phantom is damaged

through misuse or lost, the cost of replacement is $550 (less than a CAR phantom). The disc has a $10 replacement fee.


Figure 2: OBSP Digital Standard Breast (DSB) phantom with 1 mm disc on top

Facilities which have CR systems will need to have the phantom specified by the manufacturer to perform the quarterly MTF (resolution) test or a suitable

resolution test pattern such as Fluke Biomedical models 07-521, 07-515 or 07-

523-2000, available from www.maquet-dynamed.com .

Monitor test patterns (AAPM TG-18) should be loaded on your acquisition

workstation and onto your review workstations by your physicist or service person, and should not be removed. The images will also be available on

DICOM compliant CD from OBSP Physics.

ACR/CAR MAMMOGRAPHIC ACCREDITATION PHANTOM

This phantom was a cornerstone of accreditation programs in the U.S. and

Canada for screen-film mammography, and while not designed for QC, has been used for that purpose for screen-film mammography. It has been

demonstrated, however, that this phantom is of little value for QC in digital mammography and is therefore not recommended for that purpose in the

OBSP. Nevertheless, since these phantoms are available in most sites as a holdover from screen-film mammography, some facilities may choose to image

them periodically.

Imaging of the CAR phantom weekly is at the discretion of the facility, but is

not required to meet OBSP QC requirements.

As well, at the time of writing, the submission of an image of this phantom is

still part of the CAR Mammography Accreditation Program. Therefore facilities should be prepared to submit such images at the time of renewal of

accreditation.


II. IMPORTANT POINTS

1. TIME FOR QUALITY ASSURANCE PROCEDURES

Each of the elements of a facilitys quality assurance program must be assigned to individuals who are qualified for their assignments and the facility must

allow these individuals adequate time to perform these duties. The approximate times to implement, analyze, and document the DM QC tests

described in this manual are listed in Table 6. Additional time must be allocated for retesting, corrective action, and retesting again if the initial

results do not meet performance criteria.

Table 6: Responsibilities of the QC Technologist and Typical Amount of

Time Required

Nature of Procedure / Task and

Minimum Performance Frequency Time Required*

Daily

Daily checklist

Monitor Cleaning

Daily flatfield image

Visual inspection for artefacts (CR)

Image plate erasure (CR)

Total Time Daily

2 min

2 min

5 min

0 min (ongoing)

20 min

9 min (29 CR)

Weekly

Phantom Image Quality Test (SDNR and Flat-Field)

Display Monitor

Viewbox Cleanliness

Total Time Weekly

6 min

6 min

5 min

17 min

Monthly

Laser printer sensitometry

Full Field Artefact Evaluation

Monthly Checklist

Laser Printer Artefacts

Repeat Analysis

MAP Phantom Image

Total Time Monthly

3 min

15 min (45 min CR)

2 min

4 min

20 min 20 min

10 min

47 min (77 min CR)

Quarterly

MTF

Printed Image Quality

Meetings with Radiologist

Total Time Quarterly

4 min

8 min

45 min

49 min

Semiannually

Compression Force Test

Total Time Semiannually

5 min

5 min

Total Time for QC per Year (5-day week)

78.1 hours Hard Copy

64.5 hours Soft Copy

153.8 hours CR

*Estimated times include setup, testing, and recording of results for a facility with two mammography units, one dry laser printer and one processor.


All of the routine QC must be performed by the quality control technologist or

by other personnel qualified to perform the tasks. When other personnel perform these tasks, the quality control technologist must ensure the tasks are

completed properly.

The laser printer sensitometry test must be conducted daily for systems with

wet processing of printed images, and monthly for systems with dry processing. Daily darkroom cleaning need not be performed by the

mammographic QC technologist if it is being performed adequately by other qualified facility personnel; however, darkroom and monitor cleanliness must

be checked on a daily basis.


2. INFORMATION STORAGE AND MAMMOGRAPHY UNIT

IDENTIFICATION

In addition to quality requirements already in place for digital mammography,

we point out that it is important to ensure certain key information is automatically transferred from the digital mammography image acquisition

system to the stored DICOM image.

This information is required for several purposes: 1) QC, 2) to enable review of

images by other facilities, 3) the estimation of client dose, 4) tracking of imaging parameters, and, 5) for use in retrospective studies.

Specifically, systems MUST provide all information fields listed in Table 7, ideally without additional manual entry by the operator. In addition, it is

DESIRABLE that systems also provide the information listed in Table 8.

The Institution Address must include at least the city, province and postal code

of the institution. The Station Name would preferably be the CAR Unit number.

Table 7: Required DICOM Header Tags

Tag Number Tag Description

0008,0080 Institution Name

0008,0022 Acquisition Date

0008,0032 Acquisition Time

0008,0081 Institution Address

0008,1010 Station Name

0008,1070 Operator

0010,0010 Patient Name

0010,0020 Patient ID

0018,0060 kV

0018,1152 Exposure or the two tags below

0018,1150 0018,1151

Exposure Time and X-ray Tube Current

0018,1191 Anode Target Material

0018,5101 View Position

0018,7050 Filter Material

0020,0020 Patient Orientation

0020,0062 Image Laterality

To fully document the imaging technique used, either tag 0018, 1152 (Exposure) or both tags 0018, 1150 and 0018, 1151 (Exposure time and x-ray

tube current) must be included.


Table 8: Desirable DICOM Header Tags

Tag Number Tag Description

0018,1114 Radiographic Magnification factor or the two tags listed below

0018,1111 Distance Source to Patient

0018,1110 Distance Source to Detector

0018,1400 Image Processing

0018,1401 Acquisition Device Processing Code

To know the magnification factor used (i.e., when imaging on a magnification

stand), either tag 0018, 1114 (Estimated Radiographic Magnification Factor) or both tag 0018, 1111 (Distance Source to Patient) and tag 0018, 1110

(Distance Source to Detector) should be included.

The Integrating the Healthcare Enterprise (IHE) (www.ihe.org) mammography handbook is useful for those who prepare Request For Proposal (RFP) documents for digital mammography. By specifying how systems interact, the standard ensures that images from different brands of mammography

machines will be displayed in a consistent manner on all brands of review workstations. One of the requirements for compliance with IHE is the inclusion

and correct population of the DICOM tags listed in Table 9.

Table 9: Additional Desirable DICOM Header Tags for compliance with

IHE

Tag Number Tag Description Comments

0008,0070 Manufacturer

0008,1090 Manufacturers model name

0010,0030 Patients birth date

0010,1010 Patients age

0018,1000 Device serial number

0018,1004 Plate ID Required for CR

0018,1008 Gantry ID Required for CR

0018,1020 Software versions

0018,11A0 Body part thickness

0018,11A2 Compression force

0018,1405 Relative X-ray exposure

0018,1510 Positioner primary angle

0018,2112 Source image sequence Needed for CAD

0018,700A Detector ID DR only


0018,700C Date of last detector calibration

Required if detector undergoes periodic calibration

(e.g., may not be applicable for CR).

0028,0120 Pixel padding value Required if background air suppression has been performed by replacing the

pixels with a value not used within the breast tissue, so

that pixels with this value can be excluded from contrast transformations.

0028,0121 Pixel padding range limit Required if Pixel Padding Value (0028,0120) is present

and the padding values are a range rather than a single value.

0028,0301 Burned in annotation Shall have the value NO unless the image was

obtained by film digitization. 0028,1055 Window center and width

explanation

Required if more than one

Window Centre/Width pair or at least one window center/width and VOI LUT

sequence 0028,1056 Values of Interest Look-up

table (VOI LUT) function

Required if window center

and width are not intended to be interpreted as parameters of a linear function

0028,1300 Implant present

0028,3010 VOI LUT sequence Required if window center

and width not present >0028,3003 >LUT explanation Required if more than one

sequence item or at least one

sequence item and window center/width

0040,0316 Organ dose

0040,8302 Entrance dose in mGy

To the best of our knowledge, all current DM systems are capable of providing

this information; however, it has come to our attention that for some CR systems, additional hardware or software might be required to achieve this

functionality. It would be IDEAL to have this information transferred automatically, but manual entry is acceptable by the OBSP until automatic

transfer is available.


CAR and OBSP both require that if there is more than one mammography unit

in a facility, the Unit Number must be clearly identified on the image. Properly operating and configured software will provide all of the required information in

the DICOM header. For computed radiography (CR) systems, radio-opaque markers may be needed to identify the unit and view.

In addition, systems should have the capability of exporting DICOM images to a portable external medium such as: DVD or USB flash disk.

As we become more familiar with digital mammography and as more new systems are introduced, additional requirements may become evident.

3. ESTABLISHING OPERATING LEVELS AND CONTROL

LIMITS

Control limits are established by the medical physicist at equipment evaluation, when the equipment is known to be operating correctly.

When a quality control program is started or when equipment is newly installed, it is necessary to establish operating levels and control limits. The

operating level is the level that is normally expected. For example, the

background pixel value or optical density measured on a phantom image would be expected to be at, or close to, a particular value that is the standard

operating level. The control limits are performance criteria established based on operating levels which, if reached or exceeded by subsequent

measurements, require additional action. If wet processing of hardcopy film is performed in the testing procedure, operating levels should be established

using seasoned chemistry in the processor.

If repairs or changes are made to the equipment such that new baselines need

to be established, the medical physicist will either visit the site to determine the new operating levels as part of an acceptance test of the repaired/modified

equipment or work with the site by telephone/email to guide the establishment of the new baselines. If a site changes from using screen-film to CR cassettes

and a CR plate reader for mammography, a physics visit for equipment evaluation is needed, and operating levels will be established at that time.

The only baselines that may be established by the site without consulting OBSP

Physics are for the laser printer, where new baselines may need to be set when the film emulsion changes.

4. TEST FREQUENCIES

The frequency of tests specified in this manual (Table 1 and Table 2) is the minimum frequency. The actual frequency that the QC tests should be


conducted may vary with factors such as the age and stability of the imaging

equipment and the number of problems being encountered.

After the operating levels have been determined, the tests should be run more

frequently than specified in this document for a few test periods. For example, if the recommended frequency is weekly, then the test should be performed

daily for a few weeks. This provides a large amount of data quickly to determine whether rapid changes are occurring and allows for operating levels

to be established accurately, where appropriate. It also allows the individual performing the tests to gain more experience in a shorter period of time.

The frequency of the tests may be modified in consultation with the consulting medical physicist. It may be prudent to increase the frequency of the tests if

problems are frequently detected.

NOTE: If problems are seldom detected, DO NOT discontinue testing or

reduce the frequencies below the OBSP/CAR minimums for any of the tests in the quality control program! The lack of problems indicates

that the process is in control at the present time but does not predict the stability of the process in the future.

The control limits should not be widened to accommodate varying performance. If the equipment produces results which are consistently outside

of the control limits specified in this manual, then it will be necessary to have the appropriate repairs made or the equipment replaced.

5. CONTROL CHARTS

The QC technologist will be monitoring quantitative performance of DM systems in a number of QC tests (e.g., laser printer sensitometry, phantom

image quality, etc.). Plotting the results on a quality control chart will enable

the technologist to quickly and visually determine if the system is performing as it should (i.e., within control), if trends are occurring which may eventually lead to an out-of-control system, and if performance variations are related to other events (e.g., service, calibration, etc). The QC technologist must

immediately plot the data on the control chart (either by hand or by computer) for reliable monitoring of the measurements in the QC program. For example,

the film density, region of interest (ROI) mean value, SDNR and exposure time or mAs should be plotted on a control chart. The date should be indicated,

along with the initials of the individual performing the test. Notes regarding changes in operating conditions (e.g., recent service, new flat-field maps or

replacement of detector) should also be recorded.

Normally, if the control limits are reached or exceeded, the test procedure

should be reviewed to determine if human error was a factor and the test should be immediately repeated to confirm the problem. If a repeat of the test


gives a similar out-of-limits result, then corrective action is required. In this

case, the out-of-control data point should be circled or annotated, the cause of the problem noted (when known), the corrective action documented and the

in-control data point plotted. Corrective action may include contacting the medical physicist to investigate the problem and recommend corrective

actions, or contacting a service engineer to correct a confirmed problem.

If the performance criteria or control limits from this manual are consistently

exceeded, then it will be necessary to determine the cause of the problem. The cause may be the measurement technique. For example, if a CR plate is

processed immediately after exposure one time, and after a delay the next, such variations in technique may be responsible for results that vary beyond

control limits. All of these variables should be eliminated and data collected for another period of time before making a decision. If the control limits are still

consistently exceeded, then the measurement equipment (e.g., the densitometer) should be evaluated.

If the measurement equipment is found to be functioning properly and all other

variables have been eliminated, then equipment repair, or in extreme situations, replacement should take place. All of the problem data should be

reviewed by the medical physicist, who may be able to make recommendations regarding correction of the problem.

NOTE: If the action limits are consistently exceeded, then it is necessary to improve the quality control procedures, or repair or replace the appropriate equipment. DO NOT widen the action limits

since the data are indicating that the process is out of control and corrective action is essential.

Control charts also allow the detection of trends regarding an unstable process

or drifting equipment calibration. A trend is an upward or downward change in the measured data when three data points move in the same direction. The

cause of a trend should be investigated before the control limits are reached or exceeded.

Finally, there may be situations when operating levels and action limits need to

be re-established. Typical examples are when the detector is recalibrated or changed or when new x-ray equipment is installed. This should be done in

consultation with the medical physicist.

6. MAMMOGRAPHY QC CHECKLISTS

Two DM quality control checklists are provided to help ensure that all QC tests

are completed (Chart A and Chart B). These checklists provide a quick reminder of when quality control tasks are due and also provide a record

indicating that the appropriate tasks have been completed in a timely manner.


All dates should be filled in prior to use of the checklist. Each time a task is

completed, the individual carrying out the task should initial the appropriate area on the checklist. Although Chart A and Chart B do not need to be

submitted monthly in the QC report, they should be completed for review by the site radiologist and physicist.

Record all daily and weekly DM QC procedure results on Chart A. Record the performance of all monthly, quarterly and semi-annual DM QC tests on Chart

B. Monthly, quarterly and semi-annual DM QC tests should be conducted on the same day each week. It is suggested that approximately one-half hour be

set aside to conduct these procedures. The system should be allowed to stabilize before acquiring phantom images. It may be helpful to conduct these

weekly procedures for the first time with your medical physicist present to answer any questions that arise.

Each CAR Accredited facility has a lead interpreting physician who has the general responsibility of ensuring that the quality assurance program meets all

CAR requirements. The CAR recommends that the lead interpreting physician

reviews the QC technologists test results at least once every 3 months. In addition, the medical physicist must review the results of the technologists QC at least semi-annually. Spaces are provided in the monthly, quarterly and semi-annual DM QC checklist (Chart B) for the lead interpreting physician and

medical physicist to initial their reviews.

34

Chart A: Digital Mammography Quality Control Checklist (Daily & Weekly Tests) Room: Month/Year:

MAP ID Number: MAP Unit Number:

Checkmark () = Pass/Adequate; = Fail; initial when complete C =Facility closed O = Facility open HD = Facility open for half a day

Test

Date 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

Hours of

operation

Initials

1 Monitor

Cleaning

2 Daily Checklist

(Chart 1)

4 Full Field

Artefact

(daily)

8 Review

Monitor QC

weekly)

8 Acquisition

Monitor QC

(weekly)

7 QC Test Image

Evaluation

(SDNR)

(weekly)

Printer Quality Control (If Applicable)

3 Laser Printer

Sensitometry-

wet (daily)

9 Viewbox

Cleanliness

(weekly)

This form has been approved by the CAR MAP, as of November 2012. No alterations to this form are permitted, by the OBSP or

its affiliates, without the CAR MAPs formal written consent. Unauthorized alterations of this form can result in suspension or revocation of accreditation.

35

Date: Test: Comments:

36

Chart B: Digital Mammography Quality Control Checklist (Monthly,

Quarterly & Semi-annual Tests)

Room: Year: Minimum Resolution: Checkmark () = Pass/Adequate; = Fail; initial when complete

C = Facility closed O = Facility Open HD = Facility Open for Half a Day

Test

Month JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Hours of operation

Initials

13 MAP Phantom Image

(CAR monthly)

11 Mechanical Inspection

(Chart 9 - monthly)

14 Repeat Analysis

(monthly or quarterly)

10 Full-Field Artefacts

(monthly)

18 Compression Force

25-45 lb (semi-annually)

Physicists Survey (semi-annually)

Radiologists QC Review (monthly)

Medical Physicist QC Review

(semi-annually)

Additional CR Quality Control (if applicable)

10 CR Plate Artefacts

(monthly)

15

Resolution / MTF

Horizontal Bars (scanning-

quarterly)

Resolution / MTF Vertical

Bars (scanning-quarterly)

Overall Pass/Fail

CR Plate sensitivity matching

(semi-annually, done by

physicist)

Additional Printer Quality Control (if applicable)

16 Printed Image Quality

(quarterly)

17 Analysis of Fixer Retention

(quarterly)

12 Laser Printer Artefacts

(monthly)

3 Laser Printer Sensitometry

dry monthly

Film Digitizer (quarterly)

This form has been approved by the CAR MAP, as of November 2012. No alterations to this

form are permitted, by the OBSP or its affiliates, without the CAR MAPs formal written consent. Unauthorized alterations of this form can result in suspension or revocation of accreditation.

37

Date: Test: Comments:

38 Digital Mammography Quality Control Technologist- Rev. 3.2

7. TECHNIQUE CHARTS

Ideally, digital mammography units should expose all breasts optimally.

However there are cases where the breast shapes or compositions do not fit within the expectations of the equipment designer. This problem may be

reduced by using a Digital Mammography Technique Chart (Chart C) that should be developed by the mammographic technologist in consultation with

the medical physicist.

Some mammography units offer the selection of an anode target material and x-ray beam filter. In cases where the choices of target and filter are prescribed

by the mammographic technologist, those choices should be included on the technique chart.

It may be necessary to use manual techniques to obtain appropriate exposures on images of breasts containing implants. The appropriate information can also

be recorded on the technique chart.

Once the technique chart has been filled out, it should be posted on the DM

unit adjacent to the control panel and followed by every technologist using the equipment when indicated. The manufacturers recommendations should be followed, but the medical physicist, applications specialist and radiologist should be involved in optimizing this chart, and in setting appropriate aim

values.

Chart C: Digital Mammography Technique Chart

No Implants

Compressed Breast

Thickness (cm)

Mammography

Density

AEC

Setting

Target Filter kVp mAs Aim Value (S#, EI or ADU)

Implants Compressed Breast

Thickness (cm)

Mammography

Density

AEC

Setting

Target Filter kVp mAs Aim Value (S#, EI or ADU)

OBSP Mammographic Physics Consulting Group

39

8. IMAGE VIEWING CONDITIONS

Viewing conditions are extremely critical in mammography. The information for

the procedures entitled, Display Monitor QC (Test #6) and, Viewbox Cleanliness (Test #8) should be read and followed with great care. The higher optical density mammograms needed to maximize lesion detection require high luminance viewboxes, proper masking of each film, and low ambient room

light. All mammograms and mammography test images must be completely masked when being viewed, i.e., no light should come directly from the

viewbox surface or monitor to the eye of the observer. These viewing conditions apply to the technologist QC area as well as the area where the

radiologist interprets images. If printed digital mammograms are viewed on the viewbox, it should be understood that the printer is calibrated for use with

a viewbox with a given intensity, and that the diagnostic quality of the image may not be as expected.

The correct calibration of monitors used to view digital mammograms takes

into account the effect of ambient room light on the final appearance of the image. Thus, appropriate room lighting should be determined during initial

setup of the monitors in consultation with the radiologist(s) and site physicist. These viewing conditions should be maintained for all future use and testing of

the monitors. If the ambient illumination changes, it will be necessary to have the monitor calibration adjusted.

Current research publications suggest that the ambient light level in reading rooms can be higher than previously thought (20-40 lux). This level of light

(enough to read black text printed on a white page) may reduce eye-strain.

Whenever mammograms or phantom images are viewed, they should be

viewed under identical conditions. For example, phantom images should be viewed on the same viewbox or monitor, with the same lighting conditions, and

using the same magnifier as used for viewing clinical mammographic images and at the same time of day, for example, first thing in the morning. In

addition, the same viewbox masking should be used for both clinical and

phantom images.

Whenever it is necessary to make subjective judgments about phantom

images, e.g., determining resolution in test images, the perception of low contrast changes or the detection of artefacts, the evaluation should be carried

out by the same person using conditions identical to those used for previous evaluations.

9. THIRD PARTY PRINTING

If your site uses a third party (a different mammography facility or separate entity) to print digital mammograms onto films, it is the responsibility of your


site to verify that appropriate quality control of the printer(s) used is being

carried out, and that the printed image quality is acceptable. Your facilitys QC technologist is responsible for overseeing the laser printer QC. This may be

done by obtaining the monthly QC records from the printing service and evidence that problems are corrected when detected. Please forward the third

partys monthly QC records to the OBSP Mammographic Physics Consulting Group along with your monthly QC package. In addition, printed films of a

uniform image should be provided monthly and films of an appropriate test pattern should be provided quarterly so that test procedures 11 and 14 (Laser

Printer Artefacts Test and Printed Image Quality Test) can be performed. Periodically, clinical cases should also be reviewed.


41

III. DIGITAL MAMMOGRAPHY QUALITY CONTROL TESTS

The QC test procedures required by the mammographic technologist are listed in this section. Each test is numbered in order to coordinate with Table 1,

Table 2, Table 3, Chart A and Chart B.

1. DAILY QUALITY CONTROL TEST PROCEDURES

Performance of daily monitor cleaning and the daily checklist (Chart 1) should

be recorded on Chart A. Daily laser printer sensitometry should be recorded on Chart 2. Baselines can be established using Chart 3. Performance and

results of the daily flatfield image test should be recorded on Chart 4.


Test #1: Monitor Inspection, Cleaning and Viewing

Conditions

Objective

To keep monitor screens free of dust, fingerprints and other marks that might

interfere with image interpretation. To confirm that image viewing conditions are acceptable.

Frequency

Daily

Required Test Equipment

Dry, soft, lint-free cloth or lens tissue

Water or approved monitor face cleaner

Test Procedure Steps

1. Clean all monitor screens gently with the cloth lightly dampened with water if required.

2. Record the monitor cleaning on the daily and weekly checklist (Chart A).

3. Ensure that appropriate cleaning solutions are in the examination room.

4. Record viewing condition status in the daily and weekly checklist (Chart

A).

Precautions and Caveats

Abrasive materials or alcohols should not be used on monitor faces, since the anti-glare surface on the display might be destroyed.

Performance Criteria and Corrective Action

Monitor screens must be free of dust, fingerprints and other marks that might

interfere with image interpretation. There should be no shiny patches or obvious non-uniformities on the surface.

The lighting conditions and room configuration must match what is described on the medical physicists worksheet. Sources of bright light must not be present in the room and must not be reflected from the viewbox and/or monitor surfaces. Any required corrective action must be undertaken before

images are interpreted.


43

Timeframe for Corrective Action

Before client images are interpreted.


Test #2: Daily Checklist

Objective

To confirm that the digital mammography unit is functioning adequately.

Frequency

Daily


Daily checklist (Chart 1)


1. Visually inspect the unit for loose parts, cracks in the compression paddles, compressor and Bucky cleanliness and overall integrity.

2. Check that all hoses and cables are free from breaks, crimps, or knots. Hoses and cables should not be under other heavy equipment.

3. Ensure that the current technique chart is posted.

4. Ensure that the cleaning solution for the breast support plate and

compressor is available.

5. Perform any additional daily tests or procedures required by the

manufacturers QC programme.

6. Record status on the dailyweekly checklist (Chart A).


If the criteria for the manufacturers recommended daily checks are not met, service support should be called.

Timeframe for Corrective Action

Immediately, before any patients are imaged.

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Chart 1: Daily Checklist

Facility: MAP ID number: MAP unit number:

Room: Month/Year

Checkmark () = Pass/Adequate; = Fail; initial when complete

C = Facility closed O = Facility open HD = Facility open for half a day

Date 1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

Hours of operation

Initials

No Loose Parts

Overall Integrity

Cleanliness

No Cracks in Paddles

Housing and Cabling

Unobstructed

Additional CR Quality Control (if applicable)

CR Reader

Cleanliness

Imaging Plate Erasure

CR-Visual inspection

for artefacts

Additional Manufacturers calibration procedures (if applicable)

Date: Comments:

This form has been approved by the CAR MAP, as of November 2012. No alterations to this form are permitted, by the

OBSP or its affiliates, without the CAR MAPs formal written consent. Unauthorized alterations of this form can result in suspension or revocation of accreditation.


Test #3: Laser Printer Sensitometry

The printer should be set up by the manufacturer and tested before use by the

medical physicist to establish baseline performance. These baseline values are called reference operating levels (ROL). Alternatively, the radiographer can establish the ROL values for sensitometry as described later in this section.

Objective

To confirm and verify that the laser film processing system used to print client

images is working in a manner consistent with baseline performance as established by the physicist so that printed image quality is consistently high.

Printing should be conducted from each workstation that is normally used to submit client films for printing. Testing of all images sources is performed

during the quarterly Printed Image Quality test.

Frequency

Daily Systems with wet processing: daily or on each day before clinical images are

to be printed; and when changes in sensitometry are suspected.

Monthly

Systems with dry processing: monthly, and when changes in sensitometry are suspected.


Densitometer

TG18-QC pattern (use one specific to one of your DM units Figure 3) or, Printer-produced sensitometry strip (gray-scale step wedge) Chart 2 and Chart 3

A. Laser Printer Sensitometry


1. Expose and process a single TG18-QC film or a gray-scale step wedge. Always use the same window width and level settings.

2. If using the TG18-QC pattern, note the box numbers run from darkest (#1) to brightest (#18) (see Figure 3). Read and record the densities on

the pattern as follows:

a) Maximum density area (Dmax) Box #1

Digital Mammography Quality Control Technologist- Rev. 3.2 47

b) Density difference (DD) Box #16 (DD1) minus Box #5 (DD2)

c) Mid-density (MD) Box #11

d) Base+fog (B+F) Box #18

3. If using a gray-scale step wedge, choose step numbers as follows:

a) Dmax darkest step

b) DD step closest to 2.20 (DD1) minus step closest to but not less than 0.45 (DD2)

c) MD step closest to but not below an optical density (OD) of 1.20 or your working OD

d) B+F lightest step

4. Record and plot these four values (Dmax, DD, MD and B+F) on Chart 2.

5. Record completion of the sensitometry procedure on the daily and weekly checklist (Chart A).


Table 10: Tolerances for film sensitometry

Parameter Acceptable tolerance Achievable tolerance

Dmaxa ROL 0.15 or 3.50

whichever is least ROL 0.10 or 3.50 whichever is least

DD ROL 0.15 ROL 0.10 MD ROL 0.15 ROL 0.10

B+F ROL + 0.03 - a Note, that there is no upper control limit.

If the Dmax falls below the control limit of -0.15 of its respective operating level or is < 3.50, the source of the problem must be determined

and corrected before digital mammograms are printed. (Note: there is no upper control limit; darker Dmax values are desirable).

If the Dmax falls below -0.10 of its respective operating level but is still above -0.15, the test should be repeated immediately. If the same result

is obtained, it is acceptable to print films, but the printer or processor should be monitored closely.

If the DD or MD exceeds the control limit of 0.15 from its operating

level, the source of the problem must be determined and corrected before digital mammograms are printed.


If the DD or MD falls outside of the 0.10 control limit but are within a

range of 0.15, the test should be repeated immediately. If the same result is obtained, it is acceptable to print films, but the printer or processor should

be monitored closely.

If the B+F exceeds the control limit of

obsp digital mammography qc technologist_rev3.2_final

Documents

control charts

control limits

test frequencies

quality assurance procedures

mammography qc checklists

daily flatfield image

daily checklist

image viewing conditions