Noninvasive Vascular Diagnosis

Second Edition

Ali F. AbuRahma and John J. Bergan, Eds.

Noninvasive VascularDiagnosisA Practical Guide to Therapy

Second Edition

Ali F. AbuRahma, MD, FACS, FRCS, RVT, RPVI John J. Bergan, MD, FACS, Hon FRCSProfessor UCSD School of MedicineChief, Vascular/Endovascular Surgery La Jolla, CADepartment of Surgery USARobert C. Byrd Health Sciences CenterWest Virginia UniversityandMedical Director, Vascular LaboratoryCo-Director, Vascular Center of ExcellenceCharleston Area Medical CenterCharleston, WV, USA

British Library Cataloguing in Publication DataNoninvasive vascular diagnosis : a practical guide to therapy. 2nd ed.

1. Blood-vessels Diseases Diagnosis 2. Diagnosis, NoninvasiveI. AbuRahma, Ali F. II. Bergan, John J., 1927616.130754

ISBN-13: 9781846284465ISBN-10: 1846284465

Library of Congress Control Number: 2006924879

ISBN-10: 1-84628-446-5 2nd edition e-ISBN 1-84628-450-3 2nd edition Printed on acid-free paperISBN-13: 978-1-84628-446-5 2nd editionISBN 1-85233-128-3 1st edition

Springer-Verlag London Limited 2007

First published 2000Second edition 2007

Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be repro-duced, stored or transmitted, in any form or by any means, with the prior permission in writing of thepublishers, or in the case of reprographic reproduction in accordance with the terms of licences issuedby the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should besent to the publishers.The use of registered names, trademarks, etc. in this publication does not imply, even in the absence ofa specic statement, that such names are exempt from the relevant laws and regulations and thereforefree for general use.Product liability: The publisher can give no guarantee for information about drug dosage and applica-tion thereof contained in this book. In every individual case the respective user must check its accuracyby consulting other pharmaceutical literature.

9 8 7 6 5 4 3 2 1

Springer Science+Business Mediaspringer.com

To my loving children,Zachary, Chelsea, and Joseph,for their patience and support

during the preparation of this book.Ali F. AbuRahma

I join in that dedication because of my admiration forAli and his splendid family.

John Bergan

Foreword to the Second Edition

Rapid development of sophisticated technology, as well as efforts by vascular surgeons to improve vascular care, has resulted in the widespread proliferation ofvascular laboratories throughout the United States in the last three decades.Prior to that, only a handful of vascular laboratories were available, and all servedas space for an academic surgeon to study peripheral circulation in humans. Earlyinstrumentation included the use of various types of cumbersome plethysmographs.The introduction of ultrasound technology in the 1970s ushered in a new era in non-invasive diagnosis. At present, noninvasive vascular diagnostic techniques havemuch wider applications, and there is a need for a book on noninvasive vasculardiagnosis to guide therapy. After all, effective treatment follows precise diagnosis.Noninvasive Vascular Diagnosis: A Practical Guide to Therapy, edited by Ali AbuRahma and John Bergan, is a welcome addition to the eld of noninvasive diagnosis.

The continued renement of duplex ultrasound technology has led to the gradualreplacement of indirect tests using plethysmography in the diagnosis of deep vein thrombosis or carotid artery disease. Duplex scan is now the dominant technology in vascular laboratories, and its use has extended to the diagnosis of chronic venous insufciency, mesenteric ischemia, and disease of the renal artery. In addition to diagnostic use, duplex ultrasound has also found use in surveillance of patency of bypass or hemodialysis grafts and following carotidendarterectomy or stent placement. It also is helpful to map saphenous veins priorto infrainguinal bypass. In addition, use of duplex scan has evolved to therapeuticapplications, such as sclerotherapy for varicose veins, newer minimally invasive abla-tion procedures, injection of thrombin into pseudoaneurysms of the femoral arteryafter catheterization, and bedside placement of vena cava lter. Meanwhile, anklesystolic pressure recorded by a handheld Doppler probe, rst introduced in 1969,has stood the test of time as a simple diagnostic test for arterial occlusive diseaseof extremities. Doppler ankle pressure is now widely used to grade degree ofischemia objectively and as a screening test for peripheral arterial disease and epidemiology study. Newer ultrasound technologies, such as transcranial Doppler,intravascular ultrasound, and 3-D ultrasound, have found new application in noninvasive vascular diagnosis.

The last three decades also have seen a rapid development of imaging technique,ushering in an era in which diagnosis and early detection of arterial and venousdisease can be readily made by a host of noninvasive diagnostic techniques.High-resolution ultrasound, magnetic resonance, and CT technology have completely changed the face of imaging techniques. At present, we have manychoices in imaging techniques that can be used alone or in combination to obtainthe needed diagnostic information. Arteriography by CT or MR has providedimages similar to those obtained by the traditional invasive contrast arteriography,thus signicantly decreasing the clinical use of venography or invasive contrast arteriography.

There is no question that advancement of vascular care depends on technology.Noninvasive technology is now an important component in training of future generations of vascular surgeons. However, the widespread use of vascular labora-tories calls for quality control and certication of the laboratories as well as

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the technologists and physicians. Technology, when used wisely, benets the patient;when used indiscriminately, it results in waste of time, energy, and resources.The reader is advised to follow the excellent guidelines and advice put forth in thisvolume by the editors and the group of distinguished contributors that they haveassembled.

James S.T. Yao, MD, PhDEmeritus Professor of Surgery

Division of Vascular SurgeryDepartment of Surgery

Northwestern University, Feinberg School of MedicineChicago, Illinois

Foreword to the First Edition

This book is remarkable when compared with books concerning the vascular diag-nostic laboratory of a few years ago, one of which Dr AbuRahma co-authored. Atthe present time, noninvasive diagnosis is dominated by duplex scanning and otherimaging modalities. Physiologic studies are being down-played. This is due to theincreasing dominance of the eld by radiology-based laboratories. Therefore it is apleasure to see this book which covers both imaging and physiologic studies well,and does so in a problem-oriented format.

This volume does more than that. It addresses the full gamut of vascular laboratory operations including accreditation of laboratories and their personnel;it covers the basic physics of ultrasound instrumentation; and it treats thoroughly each of the four important components of vascular laboratory accreditation:cerebrovascular, peripheral arterial, venous and abdominal studies. The book also deals with a number of special areas which are peripheral to most vascular diagnostic laboratories but are included in their operations by some three-dimensional imaging, intravascular ultrasound, magnetic resonanceangiography and Doppler ow wire to name just a few. This breadth of coverage has not been seen since the mammoth volumes of a decade ago that the late Gene Bernstein published as proceedings of his San Diego meetings.But this book differs from those volumes in that it is not a compendium of focused presentations for a meeting. It is instead a carefully organized comprehen-sive coverage of everything one would need to know and could expect to encounter in the most complete vascular laboratory operation conceivable.For example, the section on cerebrovascular diagnosis not only includes overviewsof clinical considerations and the various techniques, it provides individual chapters on carotid duplex examination, evaluation of the proximal aortic arch vessels, examination of the vertebral arteries and even descibes use of the transcranial Doppler. This then ends up with a clinical correlation chapter that critiques these competitive techniques and discusses their relative value in specic clinical settings. The intraoperative assessment of technical adequacy of carotid endarterectomy or angioplasty is described, for example;then the survey of a patient developing neurological decits after operation is addressed; the postoperative surveillance after endarterectomy or angioplasty is detailed; the laboratory evaluation of the trauma victim is included; and examination of the patient presenting with vertebrobasilar symptoms is explained. Each major section has a nal chapter such as this which brings all the preceding information together in a practical and meaningful summary forthe clinician.

As organized, this book is ideal for any physician of any specialty background,whether in training or in practice, who wants current and in-depth coverage of non-invasive vascular diagnosis from operations and administration, to credentialing, tofundamental techniques and their instrumentation or specic clinical applicationsin every conceivable setting.

The authors are to be commended for putting together such a compre-hensive text at this time of need to hold all the components of noninvasive diagnosis together as a traditional vascular diagnostic laboratory. The reader will

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benet from their vision and from efforts of their well-selected contributing authors.

Robert B. Rutherford, MDEmeritus Professor of Surgery

University of Colorado

Preface

The purpose of this revision of what has become a very popular textbook is to high-light recent advances in the investigation of vascular disorders. The additions to thisvolume describe new methods of investigation and how they can be used to the bestadvantage of the patient by the physician. This volume is designed to instruct physi-cians on how to make a greater number of correct decisions regarding care and howto save some patients from unnecessary and expensive procedures.

Although it is nearly 200 years since John Hunter transformed vascular surgeryfrom a terrifying craft to a positive scientic success, there have been long stagnantperiods during which little progress could be seen. That is not true of the past 10years. During this time, the noninvasive vascular laboratory has become an essen-tial part of every general hospital. It is now a place where objective measurementscan be obtained on which prognosis and treatment can be based. There is a growingsophistication of methods and new terms have emerged that are at rst sight unfa-miliar. This volume is designed to help guide the reader through these problems.

The rapid expansion of this eld in the past several years, in terms of new modal-ities and new applications, justies this second edition. A few examples of these arethe role of duplex technology in carotid stenting, the diagnosis of temporal arteri-tis, surveillance after percutaneous transluminal angioplasty/stenting of peripheralarteries, abdominal stent grafts for abdominal aortic aneurysms, and the use ofduplex ultrasound for bedside insertion of inferior vena cava lters. Interestingly,noninvasive vascular technology has spread from a very few early pioneers, mostlyvascular surgeons inuenced by the late Gene Strandness, to a much broader groupof physicians, including neurologists, radiologists, cardiologists, and internists. Anentire corps of vascular technologists has evolved. There are now vascular sonog-raphers, a number of whom participate in the development of new and importantapplications of ever changing diagnostic equipment.With this in mind, this textbookis designed to be comprehensive enough to address the needs of all who are involvedin vascular diagnostic technology.

A new level of maturity and technological advancement in the eld of noninvasivetesting has been reached and, as a result, 14 chapters of the current edition are newand 24 chapters have been radically revised.The section on cerebrovascular diagno-sis includes several new chapters: Carotid Plaque Echolucency Measured byGrayscale Median (GSM) Identies Patients at Increased Risk of Stroke duringCarotid Stenting: The ICAROS Study, Duplex Ultrasound in the Diagnosis of Temporal Arteritis, Duplex Ultrasound Velocity Criteria for Carotid StentingPatients, Use of Transcranial Doppler in Monitoring Patients during Carotid ArteryStenting, and the Use of an Angle-Independent Doppler System for IntraoperativeCarotid Endarterectomy Surveillance. The section on peripheral arterial diseaseincludes the following new chapters: Rationale and Benets of Surveillance afterProsthetic Infrainguinal Bypass Grafts, Rationale and Benets of Surveillance afterPercutaneous Transluminal Angioplasty and Stenting of Iliac and Femoral Arteries,Duplex Ultrasound in the Diagnosis and Treatment of Femoral Pseudoaneurysms,Lower Extremity Arterial Mapping: Duplex Ultrasound as an Alternative to Arteriography Prior to Femoral and Popliteal Reconstruction, Noninvasive Diagno-sis of Upper Extremity Vascular Disease, and Protocol and Technique for DialysisUltrasound Surveillance. The section on venous disorders includes new chapters on

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Duplex Ultrasound Use for Bedside Insertion of Inferior Vena Cava Filters andVenous Stenting Using Intravascular Ultrasound (IVUS). In the section on deepabdominal Doppler, a new chapter was added on The Role of Color Duplex Ultra-sound in Patients with Abdominal Aortic Aneurysms and Stent Grafts.These reectthe development of better methods and display the changing indications for use ofthe new technology. The earlier techniques must be placed in a proper perspective.

Several modalities are now described in this edition by new authors who wereselected because of their comparative knowledge of alternative and supplementaryapproaches. These new contributors and their increasingly diverse backgroundshave added immeasurably to the breadth of this volume. To these contributors, theprevious authors, and all of their staffs, the editors wish to express their full andmost sincere appreciation. We hope that the reader will enjoy dipping into thisvolume as much as we have enjoyed updating it.

Ali F. AbuRahmaJohn J. Bergan

Acknowledgments

This book owes much to our colleagues, who have contributed a great deal to thetext. Their particular interests and expertise add substance to this book. Withoutexception, they managed to submit intelligent and up-to-date contributions.

This volume survived thanks to the support of our technical staff, particularlyMona Lett in Charleston for transcribing and revising the various versions of thechapters and for maintaining contact with contributing authors regarding guidelinesand deadlines.

Our profound appreciation goes to Maynard Chapman for producing the major-ity of the illustrations used in this book. We appreciate the efforts of Kimberly S.Jarrett, Chief Vascular Technologist, Vascular Laboratory, Charleston Area MedicalCenter, Charleston, West Virginia for her assistance in providing some of the illus-trations for this book.

The Springer-Verlag publishing team and Grant Weston recognized the worth ofthis project. Hannah Wilson provided much invaluable support and guidance.Without the support of those named here, and many others, this edition could nothave seen the light of day.

Ali F. AbuRahmaJohn J. Bergan

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Contents

Foreword to the Second by James S.T. Yao . . . . . . . . . . . . . . . . . . . . . . . . . viiForeword to the First Edition by Robert B. Rutherford . . . . . . . . . . . . . . . . ixPreface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiAcknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiiiContributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix

SECTION I VASCULAR LABORATORY OPERATIONS

1 Improving Quality in Noninvasive Testing by Certication and Accreditation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1J. Dennis Baker and Anne M. Jones

2 Qualications of the Physician in the Vascular Diagnostic Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Michael A. Ricci and Robert B. Rutherford

SECTION II BASIC PHYSICS

3 Principles and Instruments of Diagnostic Ultrasound and Doppler Ultrasound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Kirk W. Beach, Marla Paun, and Jean F. Primozich

SECTION III CEREBROVASCULAR DIAGNOSIS

4 Overview of Cerebrovascular Disease . . . . . . . . . . . . . . . . . . . . . . . . . . 33Ali F. AbuRahma

5 Overview of Various Noninvasive Cerebrovascular Techniques . . . . . 50Ali F. AbuRahma

6 Duplex Scanning of the Carotid Arteries . . . . . . . . . . . . . . . . . . . . . . . 60Ali F. AbuRahma and Kimberly S. Jarrett

7 The Role of Color Duplex Scanning in Diagnosing Diseases of the Aortic Arch Branches and Carotid Arteries . . . . . . . . . . . . . . . 89Clifford T. Araki, Bruce L. Mintz, and Robert W. Hobson II

8 Vertebral Artery Ultrasonography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97Marc Ribo and Andrei V. Alexandrov

9 Transcranial Doppler Sonography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103Marc Ribo and Andrei V. Alexandrov

10 Ultrasonic Characterization of Carotid Plaques . . . . . . . . . . . . . . . . . 127Andrew N. Nicolaides, Maura Grifn, Stavros K. Kakkos,George Geroulakos, Efthyvoulos Kyriacou, and Niki Georgiou

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xvi Contents

11 Carotid Plaque Echolucency Measured by Grayscale Median Identies Patients at Increased Risk of Stroke during Carotid Stenting. The Imaging in Carotid Angioplasty and Risk of Stroke Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149A. Froio, G. Deleo, C. Piazzoni, V. Camesasca, A. Liloia,M. Lavitrano, and G.M. Biasi

12 Duplex Ultrasound in the Diagnosis of Temporal Arteritis . . . . . . . . . 155George H. Meier and Courtney Nelms

13 Duplex Ultrasound Velocity Criteria for Carotid Stenting Patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161Brajesh K. Lal and Robert W. Hobson II

14 Use of Transcranial Doppler in Monitoring Patients during Carotid Artery Stenting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167Mark C. Bates

15 Use of an Angle-Independent Doppler System for Intraoperative Carotid Endarterectomy Surveillance . . . . . . . . . . . . . . . . . . . . . . . . . . 176Manju Kalra, Todd E. Rasmussen, and Peter Gloviczki

16 Clinical Implications of the Vascular Laboratory in the Diagnosis of Cerebrovascular Insufciency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183Ali F. AbuRahma

SECTION IV NONINVASIVE DIAGNOSIS OF PERIPHERAL ARTERIAL DISEASE OF THE EXTREMITIES

17 Overview of Peripheral Arterial Disease of the Lower Extremity . . . 207Ali F. AbuRahma

18 Overview of Noninvasive Vascular Techniques in Peripheral Arterial Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221Ali F. AbuRahma

19 Segmental Doppler Pressures and Doppler Waveform Analysisin Peripheral Vascular Disease of the Lower Extremities . . . . . . . . . 231

Ali F. AbuRahma and Kimberly S. Jarrett

20 Pulse Volume Recording in the Diagnosis of Peripheral Vascular Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245Jeffrey K. Raines and Jose I. Almeida

21 Duplex Scanning for Lower Extremity Arterial Disease . . . . . . . . . . . 253Paul A. Armstrong and Dennis F. Bandyk

22 Duplex Surveillance of Infrainguinal Bypass Grafts . . . . . . . . . . . . . . 262Patrick A. Stone and Dennis F. Bandyk

23 Rationale and Benets of Surveillance After Prosthetic Infrainguinal Bypass Grafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273Stephen Kolakowski, Jr., Keith D. Calligaro, Sandy McAffe-Benett,Kevin J. Doerr, Kathy Mueller, and Matthew J. Dougherty

24 Rationale and Benets of Surveillance after Percutaneous Transluminal Angioplasty and Stenting of Iliac and Femoral Arteries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279Evan C. Lipsitz and George L. Berdejo

25 Duplex Ultrasound in the Diagnosis and Treatment of Femoral Pseudoaneurysms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287Patrick A. Stone

Contents xvii

26 Lower Extremity Arterial Mapping: Duplex Ultrasound as an Alternative to Arteriography Prior to Femoral and Popliteal Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293Enrico Ascher, Sergio X. Salles-Cunha, Natalie Marks,and Anil Hingorani

27 Preoperative Saphenous Vein Mapping . . . . . . . . . . . . . . . . . . . . . . . . 303Benjamin B. Chang, Ann Marie Kupinski, R. Clement Darling III,Philip S.K. Paty, Paul B. Kreienberg, Sean P. Roddy,Kathleen J. Ozsvath, Manish Mehta, and Dhiraj M. Shah

28 Noninvasive Diagnosis of Upper Extremity Vascular Disease . . . . . . . 312Jocelyn A. Segall and Gregory L. Moneta

29 Ultrasound Imaging of Upper Extremity Arteries: Clinical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325Sergio X. Salles-Cunha

30 Protocol and Technique of Dialysis Ultrasound Surveillance . . . . . . . 334Niten Singh, Cameron M. Akbari, and Anton N. Sidawy

31 Noninvasive Evaluation for Congenital Arteriovenous Fistulas and Malformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341Robert B. Rutherford

32 Clinical Implications of the Vascular Laboratory in the Diagnosis of Peripheral Arterial Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349Ali F. AbuRahma

SECTION V NONINVASIVE DIANOSIS OF VENOUS DISORDERS OF THE EXTREMITIES

33 Overview of Venous Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369John J. Bergan

34 Overview: Plethysmographic Techniques in the Diagnosis of Venous Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375M. Ashraf Mansour and David S. Sumner

35 Venous Duplex Ultrasound of the Lower Extremity in the Diagnosis of Deep Venous Thrombosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385Bruce L. Mintz, Clifford T. Araki, Athena Kritharis, and Robert W. Hobson II

36 Venous Imaging for Reux Using Duplex Ultrasonography . . . . . . . . 394Jeffrey L. Ballard, John J. Bergan, and Lisa Mekenas

37 Duplex Ultrasound Use for Bedside Insertion of Inferior Vena Cava Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400JimBob Faulk and Thomas C. Naslund

38 Venous Stenting Using Intravascular Ultrasound . . . . . . . . . . . . . . . . 406Peter Negln

39 Ultrasound Guidance for Venous Therapy: VNUS, Endovenous LaserTreatments, and Foam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414John J. Bergan and Luigi Pascarella

40 Clinical Implications of the Vascular Laboratory in the Diagnosis of Venous Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422John J. Bergan

xviii Contents

SECTION VI DEEP ABDOMINAL DOPPLER

41 Deep Doppler in the Liver Vasculature . . . . . . . . . . . . . . . . . . . . . . . . 431Peter N. Burns, Heidi Patriquin, and Michel Lafortune

42 Duplex Evaluation of the Renal Arteries . . . . . . . . . . . . . . . . . . . . . . 450Marsha M. Neumyer and John Blebea

43 Duplex Ultrasonography of the Mesenteric Circulation . . . . . . . . . . . 466David G. Neschis and William R. Flinn

44 The Role of Color Duplex Ultrasound in Patients with Abdominal Aortic Aneurysms and Stent Grafts . . . . . . . . . . . . . . . . . . . . . . . . . . . 476George H. Meier and Kathleen A. Carter

SECTION VII MISCELLANEOUS

45 Transcutaneous Oxygen Tension: Principles and Applications . . . . . . . 491Jeffrey L. Ballard

46 Role of Magnetic Resonance Angiography in Peripheral Vascular Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497Sandra Carr, William Turnipseed, and Thomas Grist

47 Intravascular Ultrasound Applications . . . . . . . . . . . . . . . . . . . . . . . . . 506Donald B. Reid, Khalid Irshad, and Edward B. Diethrich

48 Three-Dimensional Vascular Imaging and Three-Dimensional Color Power Angiography Imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517Ali F. AbuRahma and Phillip J. Bendick

49 Contrast-Enhanced Ultrasound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529Lyssa N. Ochoa, Esteban Henao, Alan Lumsden, and Ruth L. Bush

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547

Ali F. AbuRahma, MD, FACS, FRCS, RVT, RPVIProfessorChief, Vascular/Endovascular SurgeryDepartment of SurgeryRobert C. Byrd Health Sciences CenterWest Virginia UniversityandMedical Director, Vascular LaboratoryCo-Director, Vascular Center of ExcellenceCharleston Area Medical CenterCharleston, WV, USA

Cameron M. Akbari, MD, MBA, RVTSenior Attending in Vascular SurgeryDirector, Vascular Diagnostic LaboratoryDepartment of Vascular SurgeryWashington Hospital CenterWashington, DC, USA

Andrei V. Alexandrov, MD, RVTDirectorStroke Research and Neurosonology ProgramBarrow Neurological InstitutePhoenix, AZ, USA

Jose I. Almeida, MD, FACSMedical DirectorMiami Vein CenterandVoluntary Assistant Professor of SurgeryUniversity of Miami Miller School of MedicineMiami, FL, USA

Clifford T. Araki, PhD, RVTAssociate ProfessorDepartment of Medical Imaging SciencesUniversity of Medicine and Dentistry of New JerseySchool of Health Related ProfessionsNewark, NJ, USA

Paul A. Armstrong, DOAssistant ProfessorDivision of Vascular and Endovascular SurgeryUniversity of South Florida College of MedicineTampa, FL, USA

Enrico Ascher, MDVascular Institute of New YorkMaimonides Medical CenterBrooklyn, NY, USA

J. Dennis Baker, MDChief, Vascular Surgery SectionWest Los Angeles VA Medical CenterandProfessor of SurgeryDavid Geffen School of MedicineUCLALos Angeles, CA, USA

Jeffrey L. Ballard, MD, FACSClinical Professor of SurgeryUniversity of California,Irvine School of MedicineandStaff SurgeonDepartment of Vascular SurgerySt. Joseph HospitalOrange, CA, USA

Dennis F. Bandyk, MDDivision of Vascular and Endovascular SurgeryUniversity of South Florida College of MedicineTampa, FL, USA

Mark C. Bates, MDSenior ScientistCardiovascular Research CAMC Health Education and

Research InstituteClinical Professor of Medicine and SurgeryRobert C. Byrd Health Sciences Center of West Virginia

UniversityCharleston, WV, USA

Kirk W. Beach, PhD, MDResearch ProfessorDepartment of SurgeryUniversity of WashingtonSeattle, Washington, USA

Contributors

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xx Contributors

Phillip J. Bendick, PhDDirector of Surgical ResearchDirector, Peripheral Vascular Diagnostic CenterDepartment of SurgeryWilliam Beaumont HospitalRoyal Oak, MI, USA

George L. Berdejo, BA, RVT, FSVUDirector, Vascular Diagnostic LaboratoriesMonteore Medical Center and Jack D. Weiler HospitalsVascular LaboratoryBronx, NY, USA

John J. Bergan, MD, FACS, Hon FRCSProfessor of SurgeryUCSD School of MedicineLa Jolla, CA, USA

G.M. Biasi, MD, FACS, FRCSDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

John Blebea, MD, FACSProfessorChief, Section of Vascular SurgeryTemple University Health Sciences CenterPhiladelphia, PA, USA

Peter N. BurnsDepartment of Medical Biophysics and RadiologyImaging ResearchSunnybrook Health CentreUniversity of TorontoToronto, Ontario, Canada

Ruth L. Bush, MDAssistant ProfessorDivision of Vascular SurgeryandEndovascular TherapyMichael E. DeBakey Department of SurgeryBaylor College of MedicineHouston, TX, USA

Keith D. Calligaro, MDChief, Section of Vascular SurgeryPennsylvania HospitalPhiladelphia, PA, USA

V. Camesasca, MDDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

Sandra C. Carr, MDDepartment of SurgeryUniversity of WisconsinMadison, WI, USA

Kathleen A. Carter, BSN, RN, RVT, FSVUTechnical DirectorVascular LaboratoryVascular and Transplant Specilists Virginia Beach, VA, USA

Benjamin B. Chang, MDAssociate ProfessorThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical College, Albany Medical Center

HospitalAlbany, NY, USA

R. Clement Darling III, MDProfessorChief, The Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

G. Deleo, MDDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

Edward B. Diethrich, MDMedical DirectorArizona Heart Hospital and FoundationPhoenix, AZ, USA

Kevin J. Doerr, RVTSection of Vascular SurgeryPennsylvania HospitalPhiladelphia, PA, USA

Matthew J. Dougherty, MDSection of Vascular SurgeryPennsylvania HospitalPhiladelphia, PA, USA

Contributors xxi

JimBob Faulk, MDVascular Surgery FellowDepartment of Vascular SurgeryVanderbilt University Medical CenterNashville, TN, USA

William R. Flinn, MDDepartment of SurgeryDivision of Vascular SurgeryUniversity of Maryland School of MedicineBaltimore, Maryland, USA

A. Froio, MDDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

Niki Georgiou, RNVascular Ultrasonographer/NurseVascular Screening and Diagnostic CentreAyios Dhometios, Nicosia, Cyprus

George GeroulakosDepartment of SurgeryCharing Cross HospitalLondon, UK

Peter Gloviczki, MDDivision of Vascular SurgeryMayo Clinic College of MedicineRochester, MN, USA

Maura Grifn, MSc (Hons), PhDChief Clinical ScientistVascular ClinicVascular Noninvasive ScreeningandDiagnostic CentreLondon, UK

Thomas Grist, MDDepartment of RadiologyUniversity of WisconsinMadison, WI, USA

Esteban Henao, MDVascular FellowDivision of Vascular Surgery and Endovascular TherapyMichael E. DeBakey Department of SurgeryBaylor College of MedicineHouston, TX, USA

Anil Hingorani, MDVascular Institute of New YorkMaimonides Medical CenterBrooklyn, NY, USA

Robert W. Hobson II, MDProfessorDepartment of Surgery and PhysiologyUMDNJ-New Jersey Medical SchoolNewark, NJ, USA

Khalid Irshad, FRCSConsultant Vascular and Endovascular SurgeonKing Edward Medical CollegeLahore, Pakistan

Kimberly S. Jarrett, RVTTechnical Director, Vascular LaboratoryDepartment of SurgeryCharleston Area Medical CenterRobert C. Byrd Health Sciences Center of West Virginia

UniversityCharleston, WV, USA

Anne M. Jones, RN, BSN, RVT, RDMSInstructor in NeurologyTranscranial Doppler Consultant to Clinical TrialsDepartment of NeurologyMedical College of Georgia-AugustaAugusta, GA, USA

Stavros K. Kakkos, MD, MSc, PhDDepartment of Vascular SurgeryImperial CollegeLondon, UK

Manju Kalra, MBBSAssistant Professor Department of SurgeryDivision of Vascular SurgeryMayo Clinic College of MedicineRochester, MN, USA

Stephen Kolakowski, Jr.Section of Vascular SurgeryPennsylvania HospitalPhiladelphia, PA, USA

Paul B. Kreienberg, MDAssociate Professor Department of SurgeryThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

xxii Contributors

Athena Kritharis, BAMedical StudentNew York University School of MedicineNew York, NY, USA

Ann Marie Kupinski, PhD, RVTDirector, Karmody Vascular LaboratoryThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

Efthyvoulos Kyriacou, PhDVisiting LecturerDepartment of Computer ScienceUniversity of CyprusNicosia, Cyprus

Michel Lafortune, MDUniversity of MontrealHpital Saint-LucMontreal, Quebec, Canada

Brajesh K. Lal, MDAssistant ProfessorDivision of Vascular SurgeryUMDNJ-New Jersey Medical SchoolNewark, NJ, USAandAssistant ProfessorDepartment of Biomedical EngineeringStevens Institute of TechnologyHoboken, NJ, USA

M. Lavitrano, PhDDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

A. Liloia, MDDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

Evan C. Lipsitz, MDAssociate Professor Department of SurgeryMedical Director, Vascular Diagnostic LaboratoryMonteore Medical CenterandThe Albert Einstein College of MedicineVascular LaboratoryBronx, NY, USA

Alan Lumsden, MB ChB, RVT, FACSProfessor and Chief Baylor College of MedicineDivision of Vascular Surgery

and Endovascular TherapyMichael E. DeBakey Department of SurgeryBaylor College of MedicineHouston, TX, USA

M. Ashraf Mansour, MDDepartment of SurgeryDivision of Vascular SurgerySpectrum Health Butterworth HospitalGrand Rapids, MI, USAandSouthern Illinois University School of MedicineSpringeld, IL, USA

Natalie Marks, MD, RVTVascular Institute of New YorkMaimonides Medical CenterBrooklyn, NY, USA

Sandy McAffe-Benett, RVTSection of Vascular SurgeryPennsylvania HospitalPhiladelphia, PA, USA

Manish Mehta, MD, MPHAssistant Professor Department of SurgeryThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

George H. Meier, MD, RVT, FACSChief of Vascular SurgeryProgram DirectorFellowshipDepartment of Vascular SurgeryEastern Virginia Medical SchoolandVascular and Transplant SpecialistsNorfolk, VA, USA

Lisa Mekenas, RVTVein Institute of La JollaLa Jolla, CA, USA

Bruce L. Mintz, DOClinical Assistant Professor of MedicineUniversity of Medicine and Dentistry of New Jersey

(UNDNJ)New Jersey Medical School (NJMS)andDirector, Venous Discase Clinic UMDNJ-NJMS University Hospital Nework, NJ, USA

Contributors xxiii

Gregory L. Moneta, MDProfessor and ChiefDivision of Vascular SurgeryOregon Health Science UniversityPortland, OR, USA

Kathy Mueller, RVTSection of Vascular SurgeryPennsylvania HospitalPhiladelphia, PA, USA

Thomas C. Naslund, MDAssociate Professor Chief, Vascular SurgeryDepartment of Vascular SurgeryVanderbilt University Medical CenterNashville, TN, USA

Peter Negln, MD, PhDVascular SurgeonRiver Oaks HospitalFlowood, MS, USA

Courtney Nelms, BS, RVT, RDMSSenior Vascular TechnologistVascular and Transplant SpecialistsVirginia Beach, VA, USA

David G. Neschis, MDDepartment of SurgeryDivision of Vascular SurgeryUniversity of Maryland School of MedicineBaltimore, MD, USA

Marsha M. Neumyer, BS, RVT, FSVU, FAIUMInternational DirectorVascular Diagnostic Educational ServicesVascular Resource AssociatesHarrisburg, PA, USA

Andrew N. Nicolaides, MS, FRCS, FRCSEEmeritus Professor of Vascular SurgeryImperial CollegeLondon, UKandSpecial ScientistDepartment of Biological SciencesUniversity of CyprusNicosia, CyprusandDirectorVascular Screening and Diagnostic CentreNicosia, Cyprus

Lyssa N. Ochoa, MDSurgery ResidentMichael E. DeBakey Department of SurgeryBaylor College of MedicineHouston, TX, USA

Kathleen J. Ozsvath, MDAssistant Professor Department of SurgeryThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

Luigi Pascarella, MDDepartment of BioengineeringUCSD School of MedicineLa Jolla, CA, USA

Heidi Patriquin, MDDepartment of RadiologyUniversity of MontrealHpital Sainte-JustineMontreal, Quebec, Canada

Philip S.K. Paty, MDAssociate Professor Department of SurgeryThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

Marla Paun, BS, RDMS, RVTResearch Trauma SonographerDepartment of SurgeryUniversity of WashingtonSeattle, WA, USA

C. Piazzoni, MDDepartment of Surgical Sciences and Intensive CareUniversity of Milano-BicoccaVascular Surgery UnitSan Gerardo HospitalMonza (MI), Italy

Jean F. Primozich, BS, RVTResearch Vascular TechnologistDepartment of SurgeryUniversity of WashingtonSeattle, WA, USA

Deceased

xxiv Contributors

Jeffrey K. Raines, PhDDirectorVascular Laboratory and ResearchMiami Vein CenterandProfessor Emeritus of SurgeryUniversity of Miami Miller School of MedicineMiami, FL, USA

Todd E. Rasmussen, MDWilford Hall USAF Medical CenterLackland Air Force BaseTX, USA

Donald B. Reid, MD, FRCSConsultant Vascular and Endovascular SurgeonWishaw HospitalScotland, UK

Marc Ribo, MD, PhDUnitat Neurovascular Vall dHebronBarcelona, Spain

Michael A. Ricci, MD, RVTProfessor of SurgeryDivision of Vascular SurgeryUniversity of Vermont College of MedicineBurlington, VT, USA

Sean P. Roddy, MDAssociate Professor Department of SurgeryThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

Robert B. Rutherford, MDEmeritus Professor of SurgeryFormerly at University of Colorado Health Science

CenterColorado, USA

Sergio X. Salles-Cunha, PhD, RVT, FSVUClinical Research DirectorJobst Vascular CenterToledo, OH, USA

Jocelyn A. Segall, MDVascular FellowDivision of Vascular SurgeryOregon Health and Science UniversityPortland, OR, USA

Dhiraj M. Shah, MDProfessorDepartment of SurgeryDirectorThe Vascular Group, PLLCThe Institute for Vascular Health and DiseaseAlbany Medical CollegeAlbany Medical Center HospitalAlbany, NY, USA

Anton N. Sidawy, MD, MPH, FACSChief, Surgical ServicesVA Medical CenterandProfessorDepartment of SurgeryGeorge Washington and Georgetown UniversitiesWashington, DC, USA

Niten Singh, MD, MSVascular FellowDepartment of Vascular SurgeryWashington Hospital Center/Georgetown UniversityWashington, DC, USA

Patrick A. Stone, MDAssistant ProfessorVascular and Endovascular SurgeryRobert C. Byrd Health Sciences CenterCharleston, WV, USA

David S. Sumner, MDDepartment of SurgeryDivision of Vascular SurgerySpectrum Health Butterworth HospitalGrand Rapids, MI, USAandSouthern Illinois University School of MedicineSpringeld, IL, USA

William D. Turnipseed, MDDepartment of SurgeryUniversity of WisconsinMadison, WI, USA

Section IVascular Laboratory Operations

Noninvasive testing had its roots in early research labo-ratories more than half a century ago. The rst facility in this country was established at the MassachusettsGeneral Hospital in 1946 and others appeared over thefollowing years. The work focused on research effortswith little thought about providing routine clinicaltesting. By the 1960s arterial reconstructive proceduresbecame increasingly frequent and there was a surge ininterest in the clinical investigation of blood ow. Theability of the early measurement methods to provideobjective noninvasive determination of vascular parame-ters attracted the interest of vascular surgeons and by the1970s there was regular clinical use of a number of tests.What had been quiet (and often esoteric) research labo-ratories expanded, providing an increasing volume ofroutine examinations directed toward patient manage-ment. By the late 1970s the majority of hospital-basedfacilities were dedicated to routine clinical service ratherthan to research. At the same time, physicians took thetesting modalities into the ofce, thus increasing theavailability of the tests.

Education and Training

Physician

The testing in the early laboratories was done and super-vised by the physicians who worked on developing andvalidating the techniques. These researchers were com-mitted to critical evaluation of the tests being developedand careful work preceded widespread clinical applica-tion. Once the value of vascular testing was promulgated,increasing numbers of physicians became interested inthe eld. The majority of physicians who established clin-ical laboratories in the late 1970s and early 1980s lackedthe research background and the experience of the orig-inal investigators.The newcomers relied on learning whatthey could from the few published articles and visits to

observe the work done in established laboratories. Overtime there has been an increase in the quality and avail-ability of courses and teaching materials available. Somespecialties require training in vascular testing in the corecurriculum. Many programs include didactic presenta-tions, direct participation in examinations, and experiencein test interpretation. As the result of these programsmany doctors come out of training much better preparedfor vascular testing.

Technologist

With the expansion of vascular testing into the clinicalarena and the increasing demand for services came aneed for additional personnel and the training of thesepeople. The most important change was adding person-nel whose job was to perform the different testing pro-tocols. People from a variety of technical backgroundswere recruited, including nurses, radiology technicians,and catheter laboratory specialists. With time this hybridgroup evolved into vascular technologists. Adequatetraining and supervision became an obvious problem.These people were initially taught the basics by the super-vising physician, who might or might not have an ade-quate background. With time there was a growth inmeetings and courses dedicated to teach the principlesand practice of the different testing methods. In general,most technologists learned by a hit-or-miss approach of on-the-job training. Where a knowledgeable physi-cian supervised the experience, a reasonable level ofexpertise could result, but often trainees were on theirown, learning by rote without understanding what was being done. In the past two decades, noninvasivetesting has become more complex both in terms of equip-ment and procedures. Understanding vascular diseaseand the instrumentation used has become increasinglyimportant. In many settings physicians rely on the tech-nologists to assess patients with vascular disease andensure appropriate utilization of noninvasive testing,

1Improving Quality in Noninvasive Testing byCertication and AccreditationJ. Dennis Baker and Anne M. Jones

1

2 J.D. Baker and A.M. Jones

thus the increased need for better and more advancededucation.

Dedicated vascular technology educational programshave continued to evolve over the past decade. Theirmeasured development can be attributed partly to inad-equate funding and partly to the classication of vas-cular technology within the allied health specialty of cardiovascular technology (CVT). The CVT specialtywas formally recognized by the Committee on AlliedHealth Education and Accreditation of the AmericanMedical Association in 1981. Essentials and Guidelinesof an Accredited Educational Program for Cardiovas-cular Technology were completed in 1983, and adopted by 12 allied health organizations [including the Society of Vascular Ultrasound (SVU)]. While recognition gavecredibility to the cardiovascular technology profession,and established Standards and Guidelines, it failed to rec-ognize the practical specialty of vascular technology. Intheory, CVT includes invasive and noninvasive cardio-vascular technology as well as peripheral vascular testing.As a result, educational programs in CVT routinelyincluded very limited didactic or clinical exposure toperipheral vascular testing.

Increased utilization of noninvasive vascular testingcombined with local carrier directives requiring certiedvascular technologists to perform noninvasive vasculartesting has created a high demand for vascular technol-ogy programs. Three baccalaureate programs in vasculartechnology are currently available (Oregon Institute ofTechnology, Rush University, and Nova SoutheasternUniversity). In addition, vascular programs are offered by10 CVT-CAAHEP accredited associate degree programsand 2 baccalaureate programs. Several accredited Diag-nostic Medical Sonography programs also offer vascu-lar tracks. This educational information can be accessedthrough the SVU and CAHEP websites.

The emergence of distance or internet educationalprograms is also impacting the educational choices of vascular technologists. Currently, registered vasculartechnologists desiring a bachelors degree in vasculartechnology can do so through the Oregon Institute ofTechnology (OIT). The school began the rst vasculartechnology bachelor degree program in the nation, andcurrently enrolls 30 to 40 students on-campus and up to100 students in the off-campus annually. The DegreeCompletion Program integrates basic medical science andvascular diagnostic courses with a general college educa-tion, allowing students to complete a Bachelor of ScienceDegree in Vascular Technology.The distance program wasdeveloped for vascular technologists desiring a degreewithout leaving their present employment. The programis available to technologists who lack a bachelors degree,and credits are awarded for achieving certication as aRegistered Vascular Technologist (RVT). Details of theprogram are available at the schools website.

Certication

From the early days of vascular testing there was concernabout the level of knowledge, experience, and compe-tence of the individual technologist. In 1979, the nationalassociation of vascular technologists, the Society of Non-invasive Vascular Technologists (SNIVT, which laterbecame the SVU) recognized that validation of the specialty required documentation of competencethrough certication. The American Registry of Diag-nostic Medical Sonographers (ARDMS) was selected toprovide the vascular technology certication examina-tion. For 30 years, the ARDMS has developed and admin-istered practice-based examinations in six ultrasoundspecialty areas. Certied by the National Commission of Health Certifying Agencies (NCHCA), ARDMS has consistently maintained category A classicationwith the National Commission for Certifying Agencies(NCCA). ARDMS has certied more than 45,000 indi-viduals and has become a recognized standard for diag-nostic medical ultrasound credentialing by many facilityaccreditation programs. The ARDMS has well-denededucational and clinical prerequisites for candidatespreparing to sit for ultrasound certication examinations.These prerequisites are available on the website. Oncethe prerequisites are met, applicants are required to passtwo comprehensive examinations to earn a credential: (1)a physical principles and instrumentation examination,and (2) a specialty examination. After acquiring a cre-dential, continuing competency must be documented bysubmitting evidence of continuing medical education tothe ARDMS. The rst vascular technology examinationwas administered by ARDMS in 1983; since that time,over 14,000 RVT credentials have been awarded. Nearly600 RVTs are also MDs. An important component ofmaintaining information on registrants is the ongoingdocumentation of the profession of vascular technologythrough periodic task analysis surveys. These surveys,completed by active RVTs, reect changes occurringwithin the practice of vascular technology and assist withexamination validation by documenting the tasks rou-tinely performed by vascular technologists in the clinicalsetting.As new ultrasound technology emerges, and oldermethods are discarded, the task survey documents thechanging clinical practice. The information is used toupdate examination content so that candidates areassured that the examination reects technologicaladvances within the profession. The surveys are alsorequired to maintain accreditation by the NCCA. TheNCCA establishes accreditation standards; ARDMS isthe only certifying body for sonography accredited byNCCA.

Survey results are also used to provide historical dataabout trends within the specialty. For instance, in 1982,over 75% of practicing vascular technologists were

1. Improving Quality in Noninvasive Testing by Certication and Accreditation 3

nurses; this number decreased to only 18% by 1994.Similarly, in early surveys, most vascular technologistsacquired their training in vascular technology on the job;by 1995, 40% of the respondents had graduated from atechnical program in vascular technology, while 37% hada bachelors or masters degree. In 1988, most RVTsworked in the department of vascular surgery (70%) indedicated vascular laboratories. By 1994, this number haddecreased to 51%, with an increasing number of vasculartechnologists in radiology (18%) and ultrasound depart-ments (17%). Increasingly, the individual seeking theRVT credential may be cross-trained in other areas ofultrasound. Data collected between 2000 and 2004 showthat 55% of vascular technologists are RVT-only, 34%are RVT/RDMS (general sonographers), and 11% areRVT/RDCS (cardiac sonographers).

A second pathway to certication is through Cardio-vascular Credentialing International (CCI). Establishedin 1988, CCI is a not-for-prot corporation founded forthe purpose of administering credentialing examinations.The CCI Corporation of today is the result of corporatemergers of the testing components of the NationalAlliance of Cardiovascular Technologists (NACT), theAmerican Cardiology Technologists Association(ACTA), and the National Board of CardiovascularTesting (NBCVT). CCI registry examinations are offeredin three specialty areas: invasive/cardiac catheterization,noninvasive echocardiography, and vascular technol-ogy/ultrasound. The Registered Vascular Specialist(RVS) credential is awarded to candidates who success-fully complete the two-part examination in vascular technology. Similar to the ARDMS process, the onlymechanism for obtaining the CCI credential is throughexamination. Candidates for the RVS credential mayqualify for exemption for the Cardiovascular Sciencecomponent of the examination if they hold an activeCCI registry or meet two additional criteria, as noted onthe website. There are currently 950 active CCI regis-trants with the RVS credential; nearly 40% also hold theCCI Registered Cardiac Sonographer (RCS) credential.Recent data indicate that fewer than 5% of the RVSs alsohold the RVT (1%) or RDMS (4%) credentials awardedby ARDMS. Only 13 MDs (less than 1%) have acquiredthe RVS credential. Not surprisingly, Registered VascularSonographers are frequently employed by cardiologists,although a growing number are being hired in radiologydepartments. Ongoing documentation of continuingmedical education is required to maintain active status.

In an effort to demonstrate competence in vasculartechnology, many vascular surgeons have acquired theRVT credential. The majority of MD/RVTs are vascularsurgeons. There has been concern expressed that theRVT credential, designed to evaluate the knowledge andcompetence of the vascular technologist, is not the appro-priate vehicle for a physician. To address these concerns,

in 2003, the Society for Vascular Surgery submitted aformal request to the ARDMS to explore the interest ina voluntary credential for physicians in vascular ultra-sound interpretation. A market analysis was conducted,and based on the favorable response, a physician inter-pretation examination was developed. This examinationis designed to target physicians in many medical special-ties who practice vascular ultrasound. The Physician Vascular Interpretation (PVI) examination is currentlyunder development by a six-member examination devel-opment task force. The group is chaired by R. EugeneZierler, MD and represents all major medical specialtiespracticing vascular technology, and one registered vascu-lar technologist. A detailed survey of the tasks andexpertise relevant to the practice of vascular interpreta-tion was developed and randomly distributed to 6000physicians in February 2005.The results of the survey willbe used to develop a blueprint of the practice, and thefoundation of the PVI examination. Prerequisite guide-lines and examination format have also been developed.The PVI examination will combine physics and non-physics questions into a single, 45 hour examination,with one single passing score. A pilot examination wasdelivered in the last quarter of 2005, so that the content,scoring, reliability, and validity of the examination couldbe determined prior to delivering a qualied PVI exam-ination in 2006. Examination prerequisites and applica-tions are available on the ARDMS website.

Accreditation

An important concern in the late 1980s was the lack ofany standards or guidelines for establishing and runninga vascular laboratory. For the neophyte there were nobenchmarks to be met regarding entry level educationand experience for physicians and technologists, whatconstituted a complete examination, extent of ongoingsupervision, quality of equipment, reporting practices, orvalidation studies. The great escalation in vascular testingthat came in the early 1980s was accompanied by a widerange of quality of the work being done. The problemwith the accuracy of the diagnostic examinations came inpart as the result of the common practice of simplybuying equipment and following protocols described inarticles or recommended by manufacturers. Likewise,diagnostic criteria were accepted as described, presumingthat the accuracies of tests by the newly established lab-oratory would be similar to those reported by the experts.Internal validation of the work of an individual labora-tory was rarely obtained. It became clear that high accu-racy of testing is dependent on both (1) technicalconsiderations of protocols and procedures and (2) theknowledge and clinical experience of the technologistperforming the examinations. In addition, there was a

4 J.D. Baker and A.M. Jones

growing concern among the leaders in noninvasivetesting about the calls from the medical insurance com-panies for regulation of all testing and for elimination ofpayment for vascular tests. Isolated cases of fraudulentoperations were well publicized and caught the attentionof many payers. Leaders in the eld voiced the need forbetter self-policing but had no way to bring this about.There was also concern that some state or specialtyorganization might take the initiative to create standardsfor vascular laboratories. Often when regulation comesfrom government or from a single specialty group, thereis limited or unbalanced input from the other profes-sionals to be regulated. In some cases the regulation isskewed in favor of one or more special interest groups.

Intersocietal Commission for theAccreditation of Vascular Laboratories

Finally in 1989, an informal meeting of leaders in the eldof noninvasive testing proposed the possibility of estab-lishing a voluntary accreditation process. This initialgroup included vascular surgeons, radiologists, and vas-cular technologists. They concluded that there was nosuitable existing accreditation option and that theyneeded to study the feasibility of creating an accreditingorganization. Support and nancial sponsorship weresought from a variety of professional societies whosemembers were involved in noninvasive vascular testing.The initial goals were (1) to have a broad base of supportacross different specialty lines and (2) to have an inde-pendent entity that was not specically allied with anyone specialty or society. From the very beginning theemphasis was on an intersocietal approach. The Ameri-can Academy of Neurology, American College of Radi-ology, American Institute of Ultrasound in Medicine,International Society for Cardiovascular Surgery (NorthAmerican Chapter), Society for Vascular Surgery, Societyfor Vascular Medicine & Biology, Society of DiagnosticMedical Sonographers, and Society of Vascular Technol-ogy committed to sponsor the initial efforts and an initialwork group was formed with two representatives fromeach society.

The initial meetings were dedicated to dening thescope of vascular laboratory accreditation and theminimum guidelines necessary for the assurance ofquality. The overall objective was To ensure high qualitypatient care by providing a mechanism that recognizeslaboratories providing quality vascular diagnostic tech-niques through a process of voluntary Accreditation.This goal was to be achieved by establishing an accredi-tation process, issuing certicates of accreditation, andmaintaining a registry of accredited laboratories. Animportant principle that was established early was thatthe accreditation should be as inclusive as possible, some-thing that could be achieved by even the smallest labo-

ratory that was doing quality work. Another importantprinciple adopted was that accreditation would notrequire a specic medical specialty training but wouldevaluate the particular education and experience of thedoctors and the technologists in each laboratory. Stan-dards for the overall laboratory organization addressedthe qualications of the medical and technical personnel,the layout of the laboratory, the support personnel,reports, record keeping, patient safety, and equipmentmaintenance. Additional standards were developed forspecic testing areas (cerebrovascular, peripheral arte-rial, peripheral venous, and abdominal vascular). Atten-tion was also given to indications, testing protocols,diagnostic criteria, and quality assurance. Not all compo-nents of the standards carried equal weight; some aspectswere mandatory or required while others were recom-mended. It was decided that the accreditation would belimited to 3 years, requiring an application for renewalafter that time. In March 1990 the group adopted theConstitution and Bylaws for the Intersocietal Commis-sion for the Accreditation of Vascular Laboratories(ICAVL) and in November 1990 it was incorporated as anonprot corporation in Maryland. The members of thead hoc work group became the original Board of Direc-tors and Brian Thiele, MD, who had chaired the workgroup, was elected the rst President. In January 1991Sandra Katanick, RN, RVT, was selected as the Execu-tive Director and charged with creating the administra-tive structure for the Commission.

The accreditation process starts with submission of adetailed application form, which includes documentationof all aspects of the facility. The sample cases and theirreports are the most important part of the application, forthe greatest weight in the evaluation process is on thequality of the testing provided. The nal part of eachtesting section is the laboratorys documentation of vali-dation or quality assurance. The Board of Directorsreviews applications quarterly and decides on grantingaccreditation. Some applications have noted decienciesand in these cases the decision is delayed. Commonly alaboratory is accredited in some areas while having apostponed decision in others. Once the additional mate-rial is received completing the application or document-ing the correction of a problem, the nal decision is made.If a laboratory is not considered to be in substantial com-pliance with the Essentials and Standards, a site visit isrequired to permit more extensive evaluation of theproblem areas. While the visit may conrm the problemsdetected in the application, experience through the yearshas been that more often than not the problem was notwith the laboratory itself but with a poorly preparedapplication. Also noted is that some laboratories withclearly documented problems have identied these andefforts toward correction are being made by the time ofthe site visit.

1. Improving Quality in Noninvasive Testing by Certication and Accreditation 5

Accreditation is granted for 3 years. Reaccreditationrequires an abbreviated application. New personnel com-plete an information and background section but forprior staff only an updated listing of CME is required. Aswith the original accreditation, the most important aspectof the application is the quality of the studies performed.A new set of case studies is required along with copies ofthe current protocols and diagnostic criteria. The othercritical part of the reaccreditation is the adequate docu-mentation of correction of the deciencies or weaknessesidentied in the previous accreditation. The reviewprocess is the same as described above except that specialattention is given to evaluating improvement in problemareas.

From its inception the Commission operated on theprinciple that vascular testing is an advancing eld andthat the Essentials and Standards needed regular reviewand consideration for revision. The revisions to the Stan-dards give examples of the Commissions response tochanges in vascular testing. In 1994 the Venous TestingStandard was changed to make duplex scanning the onlyprimary modality, so that laboratories performing onlyphysiologic tests would no longer qualify for accredita-tion in venous testing. Later, additional testing areas werecreated for Intracranial Cerebrovascular and VisceralVascular testing. A more recent policy change concernedthe minimum volume required for a laboratory to applyfor accreditation. The initial philosophy was that someminimum number was required to maintain competenceand prociency in the procedures. The requirement wasset at 100 tests per year for each primary test. Ultimatelythe Board of Directors went back to its primary philoso-phy: the most important factor in granting accreditationshould be the quality of the work being done. In the expe-rience of the members of the Board, low volume labora-tories often have trouble producing good quality studies,therefore the solution adopted was to increase the levelof scrutiny for these applications. In 1997 the policy wasrevised so that laboratories with less than 100 studies peryear could apply but would be required to submit ahigher number of sample cases, some randomly selectedby the ICAVL.

Through the years the ICAVL Board has been con-cerned about the validity of the review process. Site visitswere used only when the review identied serious con-cerns about the data in the application. For several yearsconsideration was given to instituting a process forrandom site visits to validate applications the quality ofwhich did not trigger additional scrutiny. In 1998 a policywas established for random site visits to be carried outeach quarter. The ndings and recommendations of thesite visit team will be compared with the recommenda-tions resulting from the regular review of the applications.

The Commission was created as an independent, self-funded organization, so it was critical to generate suf-

cient interest in accreditation to be able to cover theentire cost of the operation. At rst there were lownumbers of applicants, but there has been a continuingsteady growth in the number of accredited laboratories,currently totaling 1150. It was encouraging that most lab-oratories chose to reapply for accreditation after the rst3 years. An increasing number of laboratories have com-pleted ve cycles. One of the leading goals set by ICAVLwas to help improve the quality of testing through theeducation resulting from completing the applicationprocess. Probably the most important evidence of impactof accreditation is the fact that most laboratories apply-ing for reaccreditation show improvement over what wasfound the rst time around. Another indicator of successwas the fact that ICAVL was used as the basis for the cre-ation of the Intersocietal Commission for the Accredita-tion of Echocardiography Laboratories (ICAEL) in 1996and of the Intersocietal Commission for the Accredita-tion of Nuclear Medicine Laboratories (ICANL) in 1997.

American College of Radiology

Even though the American College of Radiology (ACR)was one of the original sponsors of ICAVL, its leadershipdecided to create its own ultrasound accreditation.A majorreason put forth for this change was the interest by radiol-ogists in having a single accreditation for all the areas ofdiagnostic ultrasound. This move certainly came inresponse to the success of ICAVL. In 1997 the new accred-itation was offered to radiology-based laboratories. Thevascular component directly paralleled that of ICAVL,butthe requirements were less stringent and the applicationtherefore easier to complete.A number of radiology labo-ratories have stopped renewing their ICAVL accreditationin favor of that offered by ACR. Approximately 900 facil-ities have this vascular accreditation.

Accomplishments and Impact

Over the years since the introduction of certication, andlater accreditation, there has been growth in both theseareas. The number of RVT certicates issued was low inthe early years but has shown a later growth. In general,laboratory directors have found that people who haveobtained the RVT are better prepared and ultimatelyshow better potential for improvement of skills. Manyinstitution-based laboratories use the RVT as a lever toplace the technologist at a higher pay level than theaverage hospital technicians. ICAVL has always recom-mended that all technical personnel be credentialed, butlast year a mandate was introduced requiring that alltechnical directors hold an approved credential. Thegrowing appreciation of technologist credentialing wasreected by the creation by CCI of a parallel process.

6 J.D. Baker and A.M. Jones

quality issue, with 27 companies requiring either accred-itation or that credentialed technologists perform thetests. An additional 11 recommend (do not require) thatthese standards be met. It is encouraging to see thatgroups outside the Medicare carriers are beginning tolook at similar mandates. The Coalition for Quality inUltrasound (CQU), a group of professional organizationsparticipating in diagnostic ultrasound studies, is conduct-ing an active campaign to increase the mandates for cer-tication and accreditation across the country. The idealwould be to achieve these regulations on a national basis.This will fulll the goal of wide reaching improvement inthe quality of vascular testing and hopefully the elimina-tion of poor operations, which have been the bane of thespecialty throughout the years.

Appendix

Educationwww.oit.edu/zimmermg/mithome/vtdcom/vasgate.html

(Oregon Institute of Technology)www.CAAHEP.org (education info)www.svunet.org

Credentialingwww.ARDMS.orgwww.CCI-online.org

Accreditationwww.icavl.orgwww.acr.org

When ICAVL was incorporated in 1991 there were nostandards or guidelines for the evaluation of noninvasivelaboratories. One of the original expectations of thefounding members of the Board of Directors was that theaccreditation would gain recognition and come to beused as an index of quality of vascular testing. Once theCommission succeeded in becoming established and sur-viving as an independent organization, there was growinginterest in this type of accreditation. The Standards stoodthe test of time and became the basis for similar effortsby other national groups. In 1996 the American Instituteof Ultrasound in Medicine established an accreditationfor the areas of general and obstetrical ultrasound andfollowed the next year by the creation of the ACR ultra-sound accreditation. The ICAVL staff participated in thecreation of standards for accreditation in echocardiogra-phy and nuclear medicine laboratories.

In the early years of noninvasive testing the insurancecompanies paying for the work had little to no interest in the quality of testing provided to patients. As onecompany ofcer stated, We assume that anyone billingus for a test is providing a quality examination. This atti-tude is changing and in recent years different insuranceprograms including Medicare have developed an interestin the quality of work done in vascular laboratories.Therehas been a growing recognition of technologist certica-tion and laboratory accreditation as predictors of higherquality. An important step occurred in March 1998 whenthe Medicare carrier for Virginia implemented a regula-tion requiring ICAVL accreditation as a prerequisite forreimbursement. Additional carriers have addressed the

The vascular diagnostic laboratory (VDL) is of increas-ing importance in the care of patients with vasculardisease13 while coming under greater governmentalscrutiny and economic pressures.4 In view of these chal-lenges, the qualications and credentials of physicianswho interpret noninvasive diagnostic studies have takenon additional importance. The InterSocietal Commissionfor the Accreditation of Vascular Laboratories (ICAVL)has established overall standards for vascular laborato-ries, including credentials for interpreting physicians.Several professional societies510 have published guide-lines for credentials for physicians interpreting noninva-sive vascular studies but, as yet, there is no universallyaccepted standard. Physicians from different specialtybackgrounds and with different training and clinical diag-nostic experience may all read and direct vascular labo-ratories.7,11,12 Can these diverse backgrounds and trainingbe accommodated in a single set of standards that quali-es physicians for working in the VDL in these capaci-ties? This chapter will examinationine the desiredattributes in regard to formal education and necessaryskills, as well as special qualications required for physi-cians interpreting noninvasive vascular diagnosticstudies.

Educational Background

Although the rst vascular laboratories were developedby vascular surgeons,13 today a variety of other physicianspecialties are involved in the interpretation of noninva-sive vascular studies. These include radiology, cardiology,neurology, and neurosurgery, as well as vascular medicinespecialists.7 However, each of these specialties has, stereo-typically, certain deciencies in their usual training expe-riences when it comes to understanding and interpretingvascular diagnostic laboratory tests. Neurologists andneurosurgeons have clinical knowledge regarding cere-bral vascular disease, particularly stroke, but are less fre-

quently provided the opportunity to acquire signicantexperience in the VDL evaluation of patients with thoseconditions. In addition, cerebrovascular diagnosis is onlya limited segment of the broad scope of todays VDL.Radiologists often are well-grounded in the principles ofultrasound and have experience interpreting and per-forming duplex ultrasound examinations, but generallylack knowledge of the principles that govern physiologicvascular testing and the clinical aspects of vasculardisease. Training in cardiology includes a focus on thepathogenesis of arterial disease, particularly atheroscle-rosis, and the clinical aspects of some other peripheralvascular diseases, such as venous thromboembolism, butit infrequently includes adequate exposure to noninva-sive vascular diagnosis or nonarterial vascular disease,such as chronic venous insufciency. Vascular surgeonsand vascular internists have broad educational exposureto the hemodynamic principles, the pathogenesis, andclinical aspects of a broad spectrum of vascular diseaseand how they apply to diagnosis. However, they are lessoften exposed to the principles and instrumentation ofultrasound and often are not given the opportunity toactually perform duplex ultrasound examinations.

While training requirements in each of these elds has evolved considerably in the past several years, no one specialty characteristically provides adequate expo-sure to all the educational components of vascular diag-nosis that have been recommended7,12,14 to qualifyphysicians to interpret noninvasive vascular tests. Theseeducational components, listed in Table 21, require amultispecialty approach to the education of residents orfellows in the vascular diagnostic laboratory. The tablelists all the areas in which knowledge and skills should beacquired. These components provide a framework fornoninvasive vascular diagnosis training within standardspecialty training so that individuals can work effectivelyin the VDL.

Although residency and fellowship training may varybetween specialties, and between different programs

2Qualications of the Physician in the VascularDiagnostic LaboratoryMichael A. Ricci and Robert B. Rutherford

7

8 M.A. Ricci and R.B. Rutherford

within those specialties, individuals interpreting vascularlaboratory studies should have acquired a certain set ofbasic skills (Table 22). A thorough understanding of dis-eases that affect the vascular system is an absoluterequirement.This should include an understanding of theepidemiology and pathophysiology of vascular disordersas well as their clinical signs and symptoms, prognosis,and treatment options. This fundamental knowledge isnecessary because noninvasive VDL tests are based uponboth normal and abnormal vascular physiology. By thesame token, since noninvasive testing is an adjunct tocaring for patients with vascular disease, physicians interpreting noninvasive vascular tests should have athorough understanding of appropriate indications forthe performance of these tests. It is incumbent upon the

interpreting physician to understand these indications toensure appropriate clinical conclusions are reached andwasteful or excess testing is avoided. This, of course,includes an understanding of the false-positive and false-negative rates of VDL studies.

It should also be understood that not every laboratorywill be able to produce an equivalent experience forevery individual in each listed area, nor is it absolutelynecessary (i.e., there is little need for residents in neurol-ogy to learn venous testing). Areas of expertise andemphasis can and should be designated by each specialty,although individuals who hope to direct a VDL shouldseek an educational experience that covers all the com-ponents listed in Tables 21 and 22. Additionally, it isdesirable that individuals learn how to utilize instrumentsby actually performing clinical studies, although this maybe more difcult to achieve in some specialty areas. As aminimum, in our opinion, a basic knowledge of the instru-mentation and testing is desirableif not essential. Expe-rience actually performing the various examinations isnecessary in order to adequately assist technologists withdifcult examinations and, for the surgeon, to performintraoperative duplex scanning.1

Qualications

The qualications for physicians interpreting vascularnoninvasive studies have been outlined previously.12 Theyconsist of the following: (1) understand instrumentation(and be able to troubleshoot technical problems); (2) beable to perform and instruct others in performing nonin-vasive tests; (3) have a thorough knowledge of vasculardiseases studied in the VDL; (4) understand the meaning,accuracy, and limitations of test results in light of othertests and the clinical setting; (5) either be completely sup-ported by the VDL or have other activities that do notinterfere with the ability to be accessible for the VDL;and (6) have no conicts of interest between acting asboth diagnostician and clinician. The individual shouldhave a valid medical license and be in good standing inthe medical community. Some professional organizationshave suggested minimum numbers of examinations toqualify interpreting physicians in the VDL, but no con-sensus exists.5,710,15 In many situations, no single individ-ual will meet those criteria and more than one individual(physician, engineer, or technologist) may need to sharethese qualications.

Credentialing

ICAVL encourages all technologists to seek certicationas Registered Vascular Technologists (RVT) and consid-ers such certication by physicians suitable evidence

Table 21. Educational components of training in vascular laboratories.7,12,14

Ultrasound and doppler physics Plethysmographic principles Hemodynamic principles Instrumentation Extremity arterial disease

Continuous wave Doppler Segmental limb pressures and plethysmography Duplex ultrasound scanning Provocative testing (reactive hyperemia, exercise)

Cerebrovascular disease Duplex ultrasound scanning Transcranial Doppler (TCD)

Visceral disease Renal arterial duplex ultrasound Mesenteric artery duplex ultrasound Organ transplant duplex ultrasound Portal venous duplex ultrasound

Venous disease (acute and chronic) Duplex ultrasound scanning Photoplethysmography Air plethysmography

Testing for erectile dysfunction Ophthalmic ultrasound

Table 22. Prerequisite skills for physicians interpreting noninvasive vascular studies.5

Thorough understanding of vascular disease Understanding of principles of vascular testing

Hemodynamics Physiology Ultrasound and Doppler physics

Understanding of the appropriate tests and indications for testing Familiarity with instrumentation Ability to perform vascular noninvasive tests Understanding of the clinical utility of noninvasive vascular tests

Reliability Accuracy False-positive and false-negative rates Technical limitations

2. Qualications of the Physician in the Vascular Diagnostic Laboratory 9

of appropriate experience and training. However, itshould be noted that a credential specically for physicians has only recently been introduced by theAmerican Registry of Diagnostic Medical Sonographers(ARDMS). Until there is widespread adoption of thiscredential it remains up to individual departments andhospitals to set credentialing criteria in a responsiblerather than self-serving manner. For examinationple, atthe University of Vermont, a Department of Surgeryultrasound credentialing committee reviews and sets criteria for physicians using diagnostic ultrasound.14 Thecriteria and subsequent credentialing recommendationsare then sent to the hospitals credentials committee.However, this oversight obviously falls short for free-standing VDLs, pointing out the need for a national,multispecialty credentialing system. Such an approach to credentialing should be inclusive, not exclusive, toallow for the variety of specialists who have a stake in vascular noninvasive diagnosis. It may be difcult for certain specialists to obtain the adequate hands-onexperience that is necessary, particularly after completingformal training. We would suggest spending an extendedperiod of time in the VDL, e.g., 12 hours per week for 612 months, depending upon the tests to be inter-preted, which could serve as a means to gain adequateexperience.

The vascular surgical societies have developed hospi-tal privileging guidelines for vascular surgery, includ-ing noninvasive vascular diagnosis.5 Besides a medicallicense, these suggested requirements basically includethe skill sets listed in Tables 21 and 22, as well asminimum numbers of cases and experience necessary forphysicians in established practices, newly trained physi-cians, and those without formal training in the VDLduring residency.5

Initial credentialing must be followed by periodicrecertication. Such a process should include, as aminimum, evidence of continued effective clinical activ-ity in the VDL and attendance at continuing medical education courses related to the VDL and vascular diagnosis.5,12,14 Educational activities should include specic ultrasound and vascular diagnostic training butalso continuing education in the vascular diseases beingreferred to the VDL.

Registered Vascular Technologists Examination

Can the RVT examination, administered by the Regis-tered Physician in Vascular Interpretation (RPVI) examination serve as a suitable substitute for credential-ing of physicians interpreting noninvasive studies? First, it should be pointed out that no examination

guarantees competence. Thus, as noted above, it falls to hospital and/or departmental credentialing commit-tees to assess initial and continued competence in the awarding of credentials.5,12,14 However, many of the criteria noted above may be fullled in meeting the eligibility for and passing the ARDMS examina-tions.16 The RVT examination requires documentation of signicant hands-on clinical experience before one can sit for the examination. The RPVI examination does not require hands-on experience, however. The 3-hour RVT examination uses a two-part format to test the candidate on (1) the principles of physics,hemodynamics, and noninvasive testing, and (2) the clinical aspects of vascular disease.The RVT examinationis criterion-referenced; the minimum level for passing is set in advance, and will not be adversely affected by highly trained physicians who might skew the exami-nation results.16 Although it should not be an absoluterequirement, it seems desirable for physicians inter-preting noninvasive vascular tests to be qualied as RVTs or RPVIs.

The RPVI credential provides an alternate, andperhaps more appropriate credential for physicians inter-preting vascular noninvasive studies.

Requirements for Physicians DirectingVascular Laboratories

In addition to the training, skills, and qualications outlined above, physician-directors of VDLs must have additional capabilities. Minimum training shouldcover all the aspects discussed above for physician-readers in the VDL. It has also been suggested that a mandatory requirement should be for the director to have obtained the RVT credential,17 though in thefuture this may be the RPVI credential. The broadestclinical experience and skills are desirable for someoneto serve as a VDL director. Clinical experience will be necessary for credibility when the director is asked to resolve issues or complaints regarding appropriateselection of diagnostic tests or assistance in under-standing test results in light of a clinical situation. In addition to diagnostic skills, the director must also haveadministrative and budgeting skills, particularly in difcult nancial times.11,17 Directors must be responsiblefor developing and instituting scanning protocols,interpretation criteria, accreditation applications, person-nel decisions, and day-to-day operational management.Additionally, good interpersonal skills are impor-tant, for the person in this position must lead as well as direct, but these are judgment attributes.Finally, while an academic career is not essential, a good

10 M.A. Ricci and R.B. Rutherford

VDL director should not only be interested in the per-formance of the laboratory and its staff, but ideallyshould be interested in examining and, where appropri-ate, reporting clinically signicant correlations with labo-ratory tests or their diagnostic criteria. Clearly, directorshave much greater responsibility and the selection ofthose individuals should reect these needs.

References

1. Ricci MA. The changing role of duplex scan in the man-agement of carotid bifurcation disease and endarterectomy.Sem Vasc Surg 1998;11:311.

2. Kasper GC, Lohr JM, Welling RE. Clinical benet ofcarotid endarterectomy based on duplex ultrasonography.Vasc Endovasc Surg 2003;37:3237.

3. Jaff MR. Diagnosis of peripheral vascular disease: Utility ofthe vascular laboratory. Clin Cornerstone 2002;4:1625.

4. Zwolak RM. Coding and billing issues in the vascular lab-oratory. Semin Vasc Surg 2001;14:1608.

5. Moore WS, Clagett GP, Veith FJ, et al. Guidelines for hos-pital privileges in vascular surgery: An update by an ad hoccommittee of the American Association for VascularSurgery and the Society for Vascular Surgery. J Vasc Surg2002;36:127680.

6. Spittell JA, Jr, Creager MA, Dorros G, et al. Recommenda-tions for training in vascular medicine. J Am Coll Cardiol1993;22:6268.

7. Creager MA, Goldstone J, Hirshfeld JW Jr, et al.ACC/ACP/SCAI/SVMB/SVS: Clinical competence state-ment on vascular medicine and catheter-based peripheralvascular interventions. J Am Coll Cardiol 2004;44:94157.

8. Gomez C, Kinkel P, Masdeu J, et al. American Academy ofNeurology Guidelines for Credentialing in Neuroimaging;Report from the task force on updating guidelines for credentialing in neuroimaging.

9. Grant EG, Barr LL, Borgestede J, et al. ACR standard for performing and interpreting diagnostic ultrasoundexaminations. 1992; revised 2000, http://www.acr.org/s_acr/bin.asp?TrackID=&SID=1&DID=12267&CID=539&VID=2&DOC=File.PDF, accessed July 27, 2006 Neurology1997;49:17341737.

10. Johnson B, Moneta G, Oliver M. Suggested minimum qualications for physicians interpreting noninvasive vascular diagnostic studies. http://www.svunet.org/about/positions/standard.physicianquals.htm, accessed July 27,2006.

11. Rutherford RB. Qualications of the physician in charge of the vascular diagnostic laboratory. J Vasc Surg 1988;8:73235.

12. Rutherford RB. Physicians in the vascular diagnostic labo-ratory: Educational background, prerequisite skills, creden-tialing, and continuing medical education. Sem Vasc Surg1994;7:21722.

13. Kempczinski RF. Challenging times for the vascular labo-ratory. Sem Vasc Surg 1994;7:21216.

14. Shackford SR, Ricci MA, Hebert JC. Education and cre-dentialing. Prob Gen Surg 1997;14:12632.

15. Ricci MA. Qualications and competence of vascular labo-ratory personnel. In: Mansour A, Labropoulos N (eds). Vas-cular Diagnosis. Philadelphia, PA: WB Saunders Co, 2004.

16. Jones AM. Training and certication of the vascular tech-nologist. Sem Vasc Surg 1994;7:22833.

17. Kempczinski RF. Challenging times for the vascular labo-ratory. Sem Vasc Surg 1994;7:21216.

Section IIBasic Physics

This chapter is an April 2005 revision of a chapter writtenin April 1998. During that period, the basics of ultrasoundexamination have been surprisingly stable. Electronicshave shrunk so that now full function ultrasound duplexscanners can t in your pocket. The speed of personalcomputers has advanced so that the new scanners are justsoftware residing in personal computers equipped withan ultrasound receiver on the front end and a printer orDICOM adaptor on the back end.

In spite of shrinking electronics, all of the moderntriplex-Doppler, color ow, (three-dimensional real-time)four-dimensional scanners have converged on a singlestandard package. Most instruments are still 20 inches (50cm) wide, 30 inches (75cm) long, and 50 inches (125cm) tall, with a power cord that requires 120V (240V in Europe), 60Hz (50Hz in Europe), delivering amaximum of 15 A (7.5 A in Europe) or 1800W (volts multiplied by amps) with a printer included.This standardwas developed because doorways are 30 inches (760mm)wide and the eyes of ultrasound examiners are located 60 inches (150cm) off the ground, and power outlets are ubiquitous. This way, an examiner can roll the ultrasound instrument through a door while the exam-iners view over the top of the instrument is unobstructedand connect the instrument to power at the patientsbedside. Thus the systems are portable, something thatwill always be out of reach of the computed tomography(CT) and magnetic resonance imaging (MRI) alternativetechnologies. It is truly surprising that the manufacturers,over the period from 1979 (when commercial duplexscanners became popular) to 2005, while electronics haveshrunk to (1/2)18 or 1/250,000 size, have elected to keepthe instrument package unchanged until this year with theintroduction of notebook size systems. What has changedis that the complexity of the systems has exploded. Nowultrasound scanners are over 4000 times as complex as in 1979. But, that era has come to an end. The rst companies to introduce palm size scanners have revertedto mounting them on standard size carts, not because

small size is impossib