noninvasive vascular diagnosis a practical guide to therapy

1. Noninvasive Vascular Diagnosis Second Edition

2. Ali F. AbuRahma and John J. Bergan, Eds. Noninvasive Vascular Diagnosis A Practical Guide to Therapy Second Edition

3. Ali F. AbuRahma, MD, FACS, FRCS, RVT, RPVI John J. Bergan, MD, FACS, Hon FRCS Professor UCSD School of Medicine Chief, Vascular/Endovascular Surgery La Jolla, CA Department of Surgery USA Robert C. Byrd Health Sciences Center West Virginia University and Medical Director, Vascular Laboratory Co-Director, Vascular Center of Excellence Charleston Area Medical Center Charleston, WV, USA British Library Cataloguing in Publication Data Noninvasive vascular diagnosis : a practical guide to therapy. 2nd ed. 1. Blood-vessels Diseases Diagnosis 2. Diagnosis, Noninvasive I. AbuRahma, Ali F. II. Bergan, John J., 1927616.130754 ISBN-13: 9781846284465 ISBN-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 paper ISBN-13: 978-1-84628-446-5 2nd edition ISBN 1-85233-128-3 1st edition Springer-Verlag London Limited 2007 First published 2000 Second 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 the publishers, or in the case of reprographic reproduction in accordance with the terms of licences issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside those terms should be sent to the publishers. The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specic statement, that such names are exempt from the relevant laws and regulations and therefore free for general use. Product liability: The publisher can give no guarantee for information about drug dosage and application thereof contained in this book. In every individual case the respective user must check its accuracy by consulting other pharmaceutical literature. 9 8 7 6 5 4 3 2 1 Springer Science+Business Media springer.com

4. 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 for Ali and his splendid family. John Bergan

5. 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 of vascular laboratories throughout the United States in the last three decades. Prior to that, only a handful of vascular laboratories were available, and all served as space for an academic surgeon to study peripheral circulation in humans. Early instrumentation included the use of various types of cumbersome plethysmographs. The introduction of ultrasound technology in the 1970s ushered in a new era in noninvasive diagnosis. At present, noninvasive vascular diagnostic techniques have much wider applications, and there is a need for a book on noninvasive vascular diagnosis 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 gradual replacement 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 carotid endarterectomy or stent placement. It also is helpful to map saphenous veins prior to infrainguinal bypass. In addition, use of duplex scan has evolved to therapeutic applications,such as sclerotherapy for varicose veins,newer minimally invasive abla- tion procedures, injection of thrombin into pseudoaneurysms of the femoral artery after catheterization, and bedside placement of vena cava lter. Meanwhile, ankle systolic 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 disease of extremities. Doppler ankle pressure is now widely used to grade degree of ischemia 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 venous disease 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 many choices in imaging techniques that can be used alone or in combination to obtain the needed diagnostic information. Arteriography by CT or MR has provided images 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 laboratories calls for quality control and certication of the laboratories as well as vii

6. viii Foreword to the Second Edition 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 this volume by the editors and the group of distinguished contributors that they have assembled. James S.T. Yao, MD, PhD Emeritus Professor of Surgery Division of Vascular Surgery Department of Surgery Northwestern University, Feinberg School of Medicine Chicago, Illinois

7. Foreword to the First Edition This book is remarkable when compared with books concerning the vascular diagnostic laboratory of a few years ago, one of which Dr AbuRahma co-authored. At the present time, noninvasive diagnosis is dominated by duplex scanning and other imaging modalities. Physiologic studies are being down-played. This is due to the increasing dominance of the eld by radiology-based laboratories. Therefore it is a pleasure 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 resonance angiography 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 comprehensive 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 overviews of 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 for the 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 noninvasive vascular diagnosis from operations and administration, to credentialing, to fundamental techniques and their instrumentation or specic clinical applications in every conceivable setting. The authors are to be commended for putting together such a comprehensive text at this time of need to hold all the components of noninvasive diagnosis together as a traditional vascular diagnostic laboratory. The reader will ix

8. x Foreword to the First Edition benet from their vision and from efforts of their well-selected contributing authors. Robert B. Rutherford, MD Emeritus Professor of Surgery University of Colorado

9. 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 this volume describe new methods of investigation and how they can be used to the best advantage of the patient by the physician.This volume is designed to instruct physicians on how to make a greater number of correct decisions regarding care and how to save some patients from unnecessary and expensive procedures. Although it is nearly 200 years since John Hunter transformed vascular surgery from a terrifying craft to a positive scientic success, there have been long stagnant periods during which little progress could be seen. That is not true of the past 10 years. During this time, the noninvasive vascular laboratory has become an essential part of every general hospital. It is now a place where objective measurements can be obtained on which prognosis and treatment can be based.There is a growing sophistication 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 modalities and new applications, justies this second edition. A few examples of these are the role of duplex technology in carotid stenting, the diagnosis of temporal arteritis, surveillance after percutaneous transluminal angioplasty/stenting of peripheral arteries, abdominal stent grafts for abdominal aortic aneurysms, and the use of duplex ultrasound for bedside insertion of inferior vena cava lters. Interestingly, noninvasive vascular technology has spread from a very few early pioneers, mostly vascular surgeons inuenced by the late Gene Strandness, to a much broader group of physicians, including neurologists, radiologists, cardiologists, and internists. An entire corps of vascular technologists has evolved. There are now vascular sonographers, a number of whom participate in the development of new and important applications of ever changing diagnostic equipment.With this in mind, this textbook is designed to be comprehensive enough to address the needs of all who are involved in vascular diagnostic technology. A new level of maturity and technological advancement in the eld of noninvasive testing has been reached and, as a result, 14 chapters of the current edition are new and 24 chapters have been radically revised.The section on cerebrovascular diagnosis includes several new chapters: Carotid Plaque Echolucency Measured by Grayscale Median (GSM) Identies Patients at Increased Risk of Stroke during Carotid Stenting: The ICAROS Study, Duplex Ultrasound in the Diagnosis of Temporal Arteritis, Duplex Ultrasound Velocity Criteria for Carotid Stenting Patients, Use of Transcranial Doppler in Monitoring Patients during Carotid Artery Stenting, and the Use of an Angle-Independent Doppler System for Intraoperative Carotid Endarterectomy Surveillance. The section on peripheral arterial disease includes the following new chapters: Rationale and Benets of Surveillance after Prosthetic Infrainguinal Bypass Grafts, Rationale and Benets of Surveillance after Percutaneous 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 Dialysis Ultrasound Surveillance.The section on venous disorders includes new chapters on xi

10. xii Preface Duplex Ultrasound Use for Bedside Insertion of Inferior Vena Cava Filters and Venous Stenting Using Intravascular Ultrasound (IVUS). In the section on deep abdominal Doppler, a new chapter was added on The Role of Color Duplex Ultra- sound in Patients with Abdominal Aortic Aneurysms and Stent Grafts.These reect the development of better methods and display the changing indications for use of the new technology.The earlier techniques must be placed in a proper perspective. Several modalities are now described in this edition by new authors who were selected because of their comparative knowledge of alternative and supplementary approaches. These new contributors and their increasingly diverse backgrounds have added immeasurably to the breadth of this volume. To these contributors, the previous authors, and all of their staffs, the editors wish to express their full and most sincere appreciation. We hope that the reader will enjoy dipping into this volume as much as we have enjoyed updating it. Ali F. AbuRahma John J. Bergan

11. Acknowledgments This book owes much to our colleagues, who have contributed a great deal to the text. Their particular interests and expertise add substance to this book. Without exception, they managed to submit intelligent and up-to-date contributions. This volume survived thanks to the support of our technical staff, particularly Mona Lett in Charleston for transcribing and revising the various versions of the chapters and for maintaining contact with contributing authors regarding guidelines and deadlines. Our profound appreciation goes to Maynard Chapman for producing the majority of the illustrations used in this book. We appreciate the efforts of Kimberly S. Jarrett, Chief Vascular Technologist, Vascular Laboratory, Charleston Area Medical Center, Charleston, West Virginia for her assistance in providing some of the illustrations for this book. The Springer-Verlag publishing team and Grant Weston recognized the worth of this project. Hannah Wilson provided much invaluable support and guidance. Without the support of those named here, and many others, this edition could not have seen the light of day. Ali F. AbuRahma John J. Bergan xiii

12. Contents Foreword to the Second by James S.T. Yao . . . . . . . . . . . . . . . . . . . . . . . . . vii Foreword to the First Edition by Robert B. Rutherford . . . . . . . . . . . . . . . . ix Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix SECTION I VASCULAR LABORATORY OPERATIONS 1 Improving Quality in Noninvasive Testing by Certication and Accreditation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 J. Dennis Baker and Anne M. Jones 2 Qualications of the Physician in the Vascular Diagnostic Laboratory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Michael A. Ricci and Robert B. Rutherford SECTION II BASIC PHYSICS 3 Principles and Instruments of Diagnostic Ultrasound and Doppler Ultrasound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Kirk W. Beach, Marla Paun, and Jean F. Primozich SECTION III CEREBROVASCULAR DIAGNOSIS 4 Overview of Cerebrovascular Disease . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Ali F. AbuRahma 5 Overview of Various Noninvasive Cerebrovascular Techniques . . . . . 50 Ali F. AbuRahma 6 Duplex Scanning of the Carotid Arteries . . . . . . . . . . . . . . . . . . . . . . . 60 Ali F. AbuRahma and Kimberly S. Jarrett 7 The Role of Color Duplex Scanning in Diagnosing Diseases of the Aortic Arch Branches and Carotid Arteries . . . . . . . . . . . . . . . 89 Clifford T. Araki, Bruce L. Mintz, and Robert W. Hobson II 8 Vertebral Artery Ultrasonography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Marc Ribo and Andrei V. Alexandrov 9 Transcranial Doppler Sonography . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Marc Ribo and Andrei V. Alexandrov 10 Ultrasonic Characterization of Carotid Plaques . . . . . . . . . . . . . . . . . 127 Andrew N. Nicolaides, Maura Grifn, Stavros K. Kakkos, George Geroulakos, Efthyvoulos Kyriacou, and Niki Georgiou xv

13. 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 A. Froio, G. Deleo, C. Piazzoni, V. Camesasca, A. Liloia, M. Lavitrano, and G.M. Biasi 12 Duplex Ultrasound in the Diagnosis of Temporal Arteritis . . . . . . . . . 155 George H. Meier and Courtney Nelms 13 Duplex Ultrasound Velocity Criteria for Carotid Stenting Patients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Brajesh K. Lal and Robert W. Hobson II 14 Use of Transcranial Doppler in Monitoring Patients during Carotid Artery Stenting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Mark C. Bates 15 Use of an Angle-Independent Doppler System for Intraoperative Carotid Endarterectomy Surveillance . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Manju Kalra, Todd E. Rasmussen, and Peter Gloviczki 16 Clinical Implications of the Vascular Laboratory in the Diagnosis of Cerebrovascular Insufciency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Ali F. AbuRahma SECTION IV NONINVASIVE DIAGNOSIS OF PERIPHERAL ARTERIAL DISEASE OF THE EXTREMITIES 17 Overview of Peripheral Arterial Disease of the Lower Extremity . . . 207 Ali F. AbuRahma 18 Overview of Noninvasive Vascular Techniques in Peripheral Arterial Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 Ali F. AbuRahma 19 Segmental Doppler Pressures and Doppler Waveform Analysis in 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 Jeffrey K. Raines and Jose I. Almeida 21 Duplex Scanning for Lower Extremity Arterial Disease . . . . . . . . . . . 253 Paul A. Armstrong and Dennis F. Bandyk 22 Duplex Surveillance of Infrainguinal Bypass Grafts . . . . . . . . . . . . . . 262 Patrick A. Stone and Dennis F. Bandyk 23 Rationale and Benets of Surveillance After Prosthetic Infrainguinal Bypass Grafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Stephen 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 Evan C. Lipsitz and George L. Berdejo 25 Duplex Ultrasound in the Diagnosis and Treatment of Femoral Pseudoaneurysms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 Patrick A. Stone

14. Contents xvii 26 Lower Extremity Arterial Mapping: Duplex Ultrasound as an Alternative to Arteriography Prior to Femoral and Popliteal Reconstruction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 Enrico Ascher, Sergio X. Salles-Cunha, Natalie Marks, and Anil Hingorani 27 Preoperative Saphenous Vein Mapping . . . . . . . . . . . . . . . . . . . . . . . . 303 Benjamin 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 . . . . . . . 312 Jocelyn A. Segall and Gregory L. Moneta 29 Ultrasound Imaging of Upper Extremity Arteries: Clinical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 Sergio X. Salles-Cunha 30 Protocol and Technique of Dialysis Ultrasound Surveillance . . . . . . . 334 Niten Singh, Cameron M. Akbari, and Anton N. Sidawy 31 Noninvasive Evaluation for Congenital Arteriovenous Fistulas and Malformation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 Robert B. Rutherford 32 Clinical Implications of the Vascular Laboratory in the Diagnosis of Peripheral Arterial Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 Ali F. AbuRahma SECTION V NONINVASIVE DIANOSIS OF VENOUS DISORDERS OF THE EXTREMITIES 33 Overview of Venous Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 John J. Bergan 34 Overview: Plethysmographic Techniques in the Diagnosis of Venous Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 M. Ashraf Mansour and David S. Sumner 35 Venous Duplex Ultrasound of the Lower Extremity in the Diagnosis of Deep Venous Thrombosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 385 Bruce L. Mintz, Clifford T. Araki, Athena Kritharis, and Robert W. Hobson II 36 Venous Imaging for Reux Using Duplex Ultrasonography . . . . . . . . 394 Jeffrey L. Ballard, John J. Bergan, and Lisa Mekenas 37 Duplex Ultrasound Use for Bedside Insertion of Inferior Vena Cava Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 JimBob Faulk and Thomas C. Naslund 38 Venous Stenting Using Intravascular Ultrasound . . . . . . . . . . . . . . . . 406 Peter Negln 39 Ultrasound Guidance for Venous Therapy: VNUS, Endovenous Laser Treatments, and Foam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 John J. Bergan and Luigi Pascarella 40 Clinical Implications of the Vascular Laboratory in the Diagnosis of Venous Disorders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 John J. Bergan

15. xviii Contents SECTION VI DEEP ABDOMINAL DOPPLER 41 Deep Doppler in the Liver Vasculature . . . . . . . . . . . . . . . . . . . . . . . . 431 Peter N. Burns, Heidi Patriquin, and Michel Lafortune 42 Duplex Evaluation of the Renal Arteries . . . . . . . . . . . . . . . . . . . . . . 450 Marsha M. Neumyer and John Blebea 43 Duplex Ultrasonography of the Mesenteric Circulation . . . . . . . . . . . 466 David G. Neschis and William R. Flinn 44 The Role of Color Duplex Ultrasound in Patients with Abdominal Aortic Aneurysms and Stent Grafts . . . . . . . . . . . . . . . . . . . . . . . . . . . 476 George H. Meier and Kathleen A. Carter SECTION VII MISCELLANEOUS 45 Transcutaneous Oxygen Tension: Principles and Applications . . . . . . . 491 Jeffrey L. Ballard 46 Role of Magnetic Resonance Angiography in Peripheral Vascular Disease . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 Sandra Carr, William Turnipseed, and Thomas Grist 47 Intravascular Ultrasound Applications . . . . . . . . . . . . . . . . . . . . . . . . . 506 Donald B. Reid, Khalid Irshad, and Edward B. Diethrich 48 Three-Dimensional Vascular Imaging and Three-Dimensional Color Power Angiography Imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 Ali F. AbuRahma and Phillip J. Bendick 49 Contrast-Enhanced Ultrasound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 Lyssa N. Ochoa, Esteban Henao, Alan Lumsden, and Ruth L. Bush Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547

16. Ali F. AbuRahma, MD, FACS, FRCS, RVT, RPVI Professor Chief, Vascular/Endovascular Surgery Department of Surgery Robert C. Byrd Health Sciences Center West Virginia University and Medical Director, Vascular Laboratory Co-Director, Vascular Center of Excellence Charleston Area Medical Center Charleston, WV, USA Cameron M. Akbari, MD, MBA, RVT Senior Attending in Vascular Surgery Director, Vascular Diagnostic Laboratory Department of Vascular Surgery Washington Hospital Center Washington, DC, USA Andrei V. Alexandrov, MD, RVT Director Stroke Research and Neurosonology Program Barrow Neurological Institute Phoenix, AZ, USA Jose I. Almeida, MD, FACS Medical Director Miami Vein Center and Voluntary Assistant Professor of Surgery University of Miami Miller School of Medicine Miami, FL, USA Clifford T. Araki, PhD, RVT Associate Professor Department of Medical Imaging Sciences University of Medicine and Dentistry of New Jersey School of Health Related Professions Newark, NJ, USA Paul A. Armstrong, DO Assistant Professor Division of Vascular and Endovascular Surgery University of South Florida College of Medicine Tampa, FL, USA Enrico Ascher, MD Vascular Institute of New York Maimonides Medical Center Brooklyn, NY, USA J. Dennis Baker, MD Chief, Vascular Surgery Section West Los Angeles VA Medical Center and Professor of Surgery David Geffen School of MedicineUCLA Los Angeles, CA, USA Jeffrey L. Ballard, MD, FACS Clinical Professor of Surgery University of California, Irvine School of Medicine and Staff Surgeon Department of Vascular Surgery St. Joseph Hospital Orange, CA, USA Dennis F. Bandyk, MD Division of Vascular and Endovascular Surgery University of South Florida College of Medicine Tampa, FL, USA Mark C. Bates, MD Senior Scientist Cardiovascular Research CAMC Health Education and Research Institute Clinical Professor of Medicine and Surgery Robert C. Byrd Health Sciences Center of West Virginia University Charleston, WV, USA Kirk W. Beach, PhD, MD Research Professor Department of Surgery University of Washington Seattle, Washington, USA Contributors xix

17. xx Contributors Phillip J. Bendick, PhD Director of Surgical Research Director, Peripheral Vascular Diagnostic Center Department of Surgery William Beaumont Hospital Royal Oak, MI, USA George L. Berdejo, BA, RVT, FSVU Director, Vascular Diagnostic Laboratories Monteore Medical Center and Jack D. Weiler Hospitals Vascular Laboratory Bronx, NY, USA John J. Bergan, MD, FACS, Hon FRCS Professor of Surgery UCSD School of Medicine La Jolla, CA, USA G.M. Biasi, MD, FACS, FRCS Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy John Blebea, MD, FACS Professor Chief, Section of Vascular Surgery Temple University Health Sciences Center Philadelphia, PA, USA Peter N. Burns Department of Medical Biophysics and Radiology Imaging Research Sunnybrook Health Centre University of Toronto Toronto, Ontario, Canada Ruth L. Bush, MD Assistant Professor Division of Vascular Surgery and Endovascular Therapy Michael E. DeBakey Department of Surgery Baylor College of Medicine Houston, TX, USA Keith D. Calligaro, MD Chief, Section of Vascular Surgery Pennsylvania Hospital Philadelphia, PA, USA V. Camesasca, MD Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy Sandra C. Carr, MD Department of Surgery University of Wisconsin Madison, WI, USA Kathleen A. Carter, BSN, RN, RVT, FSVU Technical Director Vascular Laboratory Vascular and Transplant Specilists Virginia Beach, VA, USA Benjamin B. Chang, MD Associate Professor The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College, Albany Medical Center Hospital Albany, NY, USA R. Clement Darling III, MD Professor Chief, The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA G. Deleo, MD Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy Edward B. Diethrich, MD Medical Director Arizona Heart Hospital and Foundation Phoenix, AZ, USA Kevin J. Doerr, RVT Section of Vascular Surgery Pennsylvania Hospital Philadelphia, PA, USA Matthew J. Dougherty, MD Section of Vascular Surgery Pennsylvania Hospital Philadelphia, PA, USA

18. Contributors xxi JimBob Faulk, MD Vascular Surgery Fellow Department of Vascular Surgery Vanderbilt University Medical Center Nashville, TN, USA William R. Flinn, MD Department of Surgery Division of Vascular Surgery University of Maryland School of Medicine Baltimore, Maryland, USA A. Froio, MD Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy Niki Georgiou, RN Vascular Ultrasonographer/Nurse Vascular Screening and Diagnostic Centre Ayios Dhometios, Nicosia, Cyprus George Geroulakos Department of Surgery Charing Cross Hospital London, UK Peter Gloviczki, MD Division of Vascular Surgery Mayo Clinic College of Medicine Rochester, MN, USA Maura Grifn, MSc (Hons), PhD Chief Clinical Scientist Vascular Clinic Vascular Noninvasive Screening and Diagnostic Centre London, UK Thomas Grist, MD Department of Radiology University of Wisconsin Madison, WI, USA Esteban Henao, MD Vascular Fellow Division of Vascular Surgery and Endovascular Therapy Michael E. DeBakey Department of Surgery Baylor College of Medicine Houston, TX, USA Anil Hingorani, MD Vascular Institute of New York Maimonides Medical Center Brooklyn, NY, USA Robert W. Hobson II, MD Professor Department of Surgery and Physiology UMDNJ-New Jersey Medical School Newark, NJ, USA Khalid Irshad, FRCS Consultant Vascular and Endovascular Surgeon King Edward Medical College Lahore, Pakistan Kimberly S. Jarrett, RVT Technical Director, Vascular Laboratory Department of Surgery Charleston Area Medical Center Robert C. Byrd Health Sciences Center of West Virginia University Charleston, WV, USA Anne M. Jones, RN, BSN, RVT, RDMS Instructor in Neurology Transcranial Doppler Consultant to Clinical Trials Department of Neurology Medical College of Georgia-Augusta Augusta, GA, USA Stavros K. Kakkos, MD, MSc, PhD Department of Vascular Surgery Imperial College London, UK Manju Kalra, MBBS Assistant Professor Department of Surgery Division of Vascular Surgery Mayo Clinic College of Medicine Rochester, MN, USA Stephen Kolakowski, Jr. Section of Vascular Surgery Pennsylvania Hospital Philadelphia, PA, USA Paul B. Kreienberg, MD Associate Professor Department of Surgery The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA

19. xxii Contributors Athena Kritharis, BA Medical Student New York University School of Medicine New York, NY, USA Ann Marie Kupinski, PhD, RVT Director, Karmody Vascular Laboratory The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA Efthyvoulos Kyriacou, PhD Visiting Lecturer Department of Computer Science University of Cyprus Nicosia, Cyprus Michel Lafortune, MD University of Montreal Hpital Saint-Luc Montreal, Quebec, Canada Brajesh K. Lal, MD Assistant Professor Division of Vascular Surgery UMDNJ-New Jersey Medical School Newark, NJ, USA and Assistant Professor Department of Biomedical Engineering Stevens Institute of Technology Hoboken, NJ, USA M. Lavitrano, PhD Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy A. Liloia, MD Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy Evan C. Lipsitz, MD Associate Professor Department of Surgery Medical Director, Vascular Diagnostic Laboratory Monteore Medical Center and The Albert Einstein College of Medicine Vascular Laboratory Bronx, NY, USA Alan Lumsden, MB ChB, RVT, FACS Professor and Chief Baylor College of Medicine Division of Vascular Surgery and Endovascular Therapy Michael E. DeBakey Department of Surgery Baylor College of Medicine Houston, TX, USA M. Ashraf Mansour, MD Department of SurgeryDivision of Vascular Surgery Spectrum Health Butterworth Hospital Grand Rapids, MI, USA and Southern Illinois University School of Medicine Springeld, IL, USA Natalie Marks, MD, RVT Vascular Institute of New York Maimonides Medical Center Brooklyn, NY, USA Sandy McAffe-Benett, RVT Section of Vascular Surgery Pennsylvania Hospital Philadelphia, PA, USA Manish Mehta, MD, MPH Assistant Professor Department of Surgery The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA George H. Meier, MD, RVT, FACS Chief of Vascular Surgery Program DirectorFellowship Department of Vascular Surgery Eastern Virginia Medical School and Vascular and Transplant Specialists Norfolk, VA, USA Lisa Mekenas, RVT Vein Institute of La Jolla La Jolla, CA, USA Bruce L. Mintz, DO Clinical Assistant Professor of Medicine University of Medicine and Dentistry of New Jersey (UNDNJ) New Jersey Medical School (NJMS) and Director, Venous Discase Clinic UMDNJ-NJMS University Hospital Nework, NJ, USA

20. Contributors xxiii Gregory L. Moneta, MD Professor and Chief Division of Vascular Surgery Oregon Health Science University Portland, OR, USA Kathy Mueller, RVT Section of Vascular Surgery Pennsylvania Hospital Philadelphia, PA, USA Thomas C. Naslund, MD Associate Professor Chief, Vascular Surgery Department of Vascular Surgery Vanderbilt University Medical Center Nashville, TN, USA Peter Negln, MD, PhD Vascular Surgeon River Oaks Hospital Flowood, MS, USA Courtney Nelms, BS, RVT, RDMS Senior Vascular Technologist Vascular and Transplant Specialists Virginia Beach, VA, USA David G. Neschis, MD Department of Surgery Division of Vascular Surgery University of Maryland School of Medicine Baltimore, MD, USA Marsha M. Neumyer, BS, RVT, FSVU, FAIUM International Director Vascular Diagnostic Educational Services Vascular Resource Associates Harrisburg, PA, USA Andrew N. Nicolaides, MS, FRCS, FRCSE Emeritus Professor of Vascular Surgery Imperial College London, UK and Special Scientist Department of Biological Sciences University of Cyprus Nicosia, Cyprus and Director Vascular Screening and Diagnostic Centre Nicosia, Cyprus Lyssa N. Ochoa, MD Surgery Resident Michael E. DeBakey Department of Surgery Baylor College of Medicine Houston, TX, USA Kathleen J. Ozsvath, MD Assistant Professor Department of Surgery The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA Luigi Pascarella, MD Department of Bioengineering UCSD School of Medicine La Jolla, CA, USA Heidi Patriquin, MD Department of Radiology University of Montreal Hpital Sainte-Justine Montreal, Quebec, Canada Philip S.K. Paty, MD Associate Professor Department of Surgery The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA Marla Paun, BS, RDMS, RVT Research Trauma Sonographer Department of Surgery University of Washington Seattle, WA, USA C. Piazzoni, MD Department of Surgical Sciences and Intensive Care University of Milano-Bicocca Vascular Surgery Unit San Gerardo Hospital Monza (MI), Italy Jean F. Primozich, BS, RVT Research Vascular Technologist Department of Surgery University of Washington Seattle, WA, USA Deceased

21. xxiv Contributors Jeffrey K. Raines, PhD Director Vascular Laboratory and Research Miami Vein Center and Professor Emeritus of Surgery University of Miami Miller School of Medicine Miami, FL, USA Todd E. Rasmussen, MD Wilford Hall USAF Medical Center Lackland Air Force Base TX, USA Donald B. Reid, MD, FRCS Consultant Vascular and Endovascular Surgeon Wishaw Hospital Scotland, UK Marc Ribo, MD, PhD Unitat Neurovascular Vall dHebron Barcelona, Spain Michael A. Ricci, MD, RVT Professor of Surgery Division of Vascular Surgery University of Vermont College of Medicine Burlington, VT, USA Sean P. Roddy, MD Associate Professor Department of Surgery The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA Robert B. Rutherford, MD Emeritus Professor of Surgery Formerly at University of Colorado Health Science Center Colorado, USA Sergio X. Salles-Cunha, PhD, RVT, FSVU Clinical Research Director Jobst Vascular Center Toledo, OH, USA Jocelyn A. Segall, MD Vascular Fellow Division of Vascular Surgery Oregon Health and Science University Portland, OR, USA Dhiraj M. Shah, MD Professor Department of Surgery Director The Vascular Group, PLLC The Institute for Vascular Health and Disease Albany Medical College Albany Medical Center Hospital Albany, NY, USA Anton N. Sidawy, MD, MPH, FACS Chief, Surgical Services VA Medical Center and Professor Department of Surgery George Washington and Georgetown Universities Washington, DC, USA Niten Singh, MD, MS Vascular Fellow Department of Vascular Surgery Washington Hospital Center/Georgetown University Washington, DC, USA Patrick A. Stone, MD Assistant Professor Vascular and Endovascular Surgery Robert C. Byrd Health Sciences Center Charleston, WV, USA David S. Sumner, MD Department of SurgeryDivision of Vascular Surgery Spectrum Health Butterworth Hospital Grand Rapids, MI, USA and Southern Illinois University School of Medicine Springeld, IL, USA William D. Turnipseed, MD Department of Surgery University of Wisconsin Madison, WI, USA

22. Section I Vascular Laboratory Operations

23. Noninvasive testing had its roots in early research laboratories more than half a century ago. The rst facility in this country was established at the Massachusetts General Hospital in 1946 and others appeared over the following years. The work focused on research efforts with little thought about providing routine clinical testing. By the 1960s arterial reconstructive procedures became increasingly frequent and there was a surge in interest in the clinical investigation of blood ow. The ability of the early measurement methods to provide objective noninvasive determination of vascular parame- ters attracted the interest of vascular surgeons and by the 1970s there was regular clinical use of a number of tests. What had been quiet (and often esoteric) research laboratories expanded, providing an increasing volume of routine examinations directed toward patient management. By the late 1970s the majority of hospital-based facilities were dedicated to routine clinical service rather than to research. At the same time, physicians took the testing modalities into the ofce, thus increasing the availability of the tests. Education and Training Physician The testing in the early laboratories was done and supervised by the physicians who worked on developing and validating the techniques. These researchers were committed to critical evaluation of the tests being developed and careful work preceded widespread clinical application. Once the value of vascular testing was promulgated, increasing numbers of physicians became interested in the eld.The majority of physicians who established clinical laboratories in the late 1970s and early 1980s lacked the research background and the experience of the original investigators.The newcomers relied on learning what they could from the few published articles and visits to observe the work done in established laboratories. Over time there has been an increase in the quality and availability of courses and teaching materials available. Some specialties require training in vascular testing in the core curriculum. Many programs include didactic presentations,direct participation in examinations,and experience in test interpretation. As the result of these programs many doctors come out of training much better prepared for vascular testing. Technologist With the expansion of vascular testing into the clinical arena and the increasing demand for services came a need for additional personnel and the training of these people. The most important change was adding personnel whose job was to perform the different testing protocols. People from a variety of technical backgrounds were recruited, including nurses, radiology technicians, and catheter laboratory specialists. With time this hybrid group evolved into vascular technologists. Adequate training 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 adequate background. With time there was a growth in meetings and courses dedicated to teach the principles and 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 physician supervised the experience, a reasonable level of expertise could result, but often trainees were on their own, learning by rote without understanding what was being done. In the past two decades, noninvasive testing has become more complex both in terms of equipment and procedures. Understanding vascular disease and the instrumentation used has become increasingly important. In many settings physicians rely on the technologists to assess patients with vascular disease and ensure appropriate utilization of noninvasive testing, 1 Improving Quality in Noninvasive Testing by Certication and Accreditation J. Dennis Baker and Anne M. Jones 1

24. 2 J.D. Baker and A.M. Jones thus the increased need for better and more advanced education. Dedicated vascular technology educational programs have continued to evolve over the past decade. Their measured development can be attributed partly to inad- equate funding and partly to the classication of vascular technology within the allied health specialty of cardiovascular technology (CVT). The CVT specialty was formally recognized by the Committee on Allied Health Education and Accreditation of the American Medical Association in 1981. Essentials and Guidelines of 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 gave credibility to the cardiovascular technology profession, and established Standards and Guidelines, it failed to rec- ognize the practical specialty of vascular technology. In theory, CVT includes invasive and noninvasive cardiovascular technology as well as peripheral vascular testing. As a result, educational programs in CVT routinely included very limited didactic or clinical exposure to peripheral vascular testing. Increased utilization of noninvasive vascular testing combined with local carrier directives requiring certied vascular technologists to perform noninvasive vascular testing has created a high demand for vascular technology programs. Three baccalaureate programs in vascular technology are currently available (Oregon Institute of Technology, Rush University, and Nova Southeastern University).In addition,vascular programs are offered by 10 CVT-CAAHEP accredited associate degree programs and 2 baccalaureate programs. Several accredited Diag- nostic Medical Sonography programs also offer vascular tracks. This educational information can be accessed through the SVU and CAHEP websites. The emergence of distance or internet educational programs is also impacting the educational choices of vascular technologists. Currently, registered vascular technologists desiring a bachelors degree in vascular technology can do so through the Oregon Institute of Technology (OIT). The school began the rst vascular technology bachelor degree program in the nation, and currently enrolls 30 to 40 students on-campus and up to 100 students in the off-campus annually. The Degree Completion Program integrates basic medical science and vascular diagnostic courses with a general college education, allowing students to complete a Bachelor of Science Degree inVascularTechnology.The distance program was developed for vascular technologists desiring a degree without leaving their present employment. The program is available to technologists who lack a bachelors degree, and credits are awarded for achieving certication as a Registered Vascular Technologist (RVT). Details of the program are available at the schools website. Certication From the early days of vascular testing there was concern about the level of knowledge, experience, and competence of the individual technologist. In 1979, the national association of vascular technologists, the Society of Non- invasive Vascular Technologists (SNIVT, which later became the SVU) recognized that validation of the specialty required documentation of competence through certication. The American Registry of Diag- nostic Medical Sonographers (ARDMS) was selected to provide the vascular technology certication examination. For 30 years, the ARDMS has developed and administered practice-based examinations in six ultrasound specialty areas. Certied by the National Commission of Health Certifying Agencies (NCHCA), ARDMS has consistently maintained category A classication with the National Commission for Certifying Agencies (NCCA). ARDMS has certied more than 45,000 individuals and has become a recognized standard for diagnostic medical ultrasound credentialing by many facility accreditation programs. The ARDMS has well-dened educational and clinical prerequisites for candidates preparing to sit for ultrasound certication examinations. These prerequisites are available on the website. Once the prerequisites are met, applicants are required to pass two comprehensive examinations to earn a credential: (1) a physical principles and instrumentation examination, and (2) a specialty examination. After acquiring a credential, continuing competency must be documented by submitting evidence of continuing medical education to the ARDMS. The rst vascular technology examination was administered by ARDMS in 1983; since that time, over 14,000 RVT credentials have been awarded. Nearly 600 RVTs are also MDs. An important component of maintaining information on registrants is the ongoing documentation of the profession of vascular technology through periodic task analysis surveys. These surveys, completed by active RVTs, reect changes occurring within the practice of vascular technology and assist with examination validation by documenting the tasks routinely performed by vascular technologists in the clinical setting.As new ultrasound technology emerges, and older methods are discarded, the task survey documents the changing clinical practice. The information is used to update examination content so that candidates are assured that the examination reects technological advances within the profession. The surveys are also required to maintain accreditation by the NCCA. The NCCA establishes accreditation standards; ARDMS is the only certifying body for sonography accredited by NCCA. Survey results are also used to provide historical data about trends within the specialty. For instance, in 1982, over 75% of practicing vascular technologists were

25. 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 technologists acquired their training in vascular technology on the job; by 1995, 40% of the respondents had graduated from a technical program in vascular technology, while 37% had a bachelors or masters degree. In 1988, most RVTs worked in the department of vascular surgery (70%) in dedicated vascular laboratories. By 1994, this number had decreased to 51%, with an increasing number of vascular technologists in radiology (18%) and ultrasound departments (17%). Increasingly, the individual seeking the RVT credential may be cross-trained in other areas of ultrasound. Data collected between 2000 and 2004 show that 55% of vascular technologists are RVT-only, 34% are RVT/RDMS (general sonographers), and 11% are RVT/RDCS (cardiac sonographers). A second pathway to certication is through Cardio- vascular Credentialing International (CCI). Established in 1988, CCI is a not-for-prot corporation founded for the purpose of administering credentialing examinations. The CCI Corporation of today is the result of corporate mergers of the testing components of the National Alliance of Cardiovascular Technologists (NACT), the American Cardiology Technologists Association (ACTA), and the National Board of Cardiovascular Testing (NBCVT). CCI registry examinations are offered in three specialty areas: invasive/cardiac catheterization, noninvasive echocardiography, and vascular technology/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 only mechanism for obtaining the CCI credential is through examination. Candidates for the RVS credential may qualify for exemption for the Cardiovascular Science component of the examination if they hold an active CCI registry or meet two additional criteria, as noted on the website. There are currently 950 active CCI registrants with the RVS credential; nearly 40% also hold the CCI Registered Cardiac Sonographer (RCS) credential. Recent data indicate that fewer than 5% of the RVSs also hold the RVT (1%) or RDMS (4%) credentials awarded by ARDMS. Only 13 MDs (less than 1%) have acquired the RVS credential. Not surprisingly, Registered Vascular Sonographers are frequently employed by cardiologists, although a growing number are being hired in radiology departments. Ongoing documentation of continuing medical education is required to maintain active status. In an effort to demonstrate competence in vascular technology, many vascular surgeons have acquired the RVT credential. The majority of MD/RVTs are vascular surgeons. There has been concern expressed that the RVT credential, designed to evaluate the knowledge and competence of the vascular technologist, is not the appropriate vehicle for a physician. To address these concerns, in 2003, the Society for Vascular Surgery submitted a formal request to the ARDMS to explore the interest in a voluntary credential for physicians in vascular ultrasound interpretation. A market analysis was conducted, and based on the favorable response, a physician interpretation examination was developed. This examination is designed to target physicians in many medical specialties who practice vascular ultrasound. The Physician Vascular Interpretation (PVI) examination is currently under development by a six-member examination development task force. The group is chaired by R. Eugene Zierler, MD and represents all major medical specialties practicing vascular technology, and one registered vascular technologist. A detailed survey of the tasks and expertise relevant to the practice of vascular interpretation was developed and randomly distributed to 6000 physicians in February 2005.The results of the survey will be used to develop a blueprint of the practice, and the foundation of the PVI examination. Prerequisite guidelines 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 was delivered in the last quarter of 2005, so that the content, scoring, reliability, and validity of the examination could be determined prior to delivering a qualied PVI examination in 2006. Examination prerequisites and applications are available on the ARDMS website. Accreditation An important concern in the late 1980s was the lack of any standards or guidelines for establishing and running a vascular laboratory. For the neophyte there were no benchmarks to be met regarding entry level education and experience for physicians and technologists, what constituted a complete examination, extent of ongoing supervision, quality of equipment, reporting practices, or validation studies.The great escalation in vascular testing that came in the early 1980s was accompanied by a wide range of quality of the work being done. The problem with the accuracy of the diagnostic examinations came in part as the result of the common practice of simply buying equipment and following protocols described in articles or recommended by manufacturers. Likewise, diagnostic criteria were accepted as described, presuming that the accuracies of tests by the newly established laboratory would be similar to those reported by the experts. Internal validation of the work of an individual laboratory was rarely obtained. It became clear that high accuracy of testing is dependent on both (1) technical considerations of protocols and procedures and (2) the knowledge and clinical experience of the technologist performing the examinations. In addition, there was a

26. 4 J.D. Baker and A.M. Jones growing concern among the leaders in noninvasive testing about the calls from the medical insurance companies for regulation of all testing and for elimination of payment for vascular tests. Isolated cases of fraudulent operations were well publicized and caught the attention of many payers. Leaders in the eld voiced the need for better self-policing but had no way to bring this about. There was also concern that some state or specialty organization might take the initiative to create standards for vascular laboratories. Often when regulation comes from government or from a single specialty group, there is limited or unbalanced input from the other profes- sionals to be regulated. In some cases the regulation is skewed in favor of one or more special interest groups. Intersocietal Commission for the Accreditation of Vascular Laboratories Finally in 1989, an informal meeting of leaders in the eld of noninvasive testing proposed the possibility of establishing a voluntary accreditation process. This initial group included vascular surgeons, radiologists, and vascular technologists. They concluded that there was no suitable existing accreditation option and that they needed to study the feasibility of creating an accrediting organization. Support and nancial sponsorship were sought from a variety of professional societies whose members were involved in noninvasive vascular testing. The initial goals were (1) to have a broad base of support across different specialty lines and (2) to have an independent entity that was not specically allied with any one specialty or society. From the very beginning the emphasis 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 (North American Chapter), Society for Vascular Surgery, Society for Vascular Medicine & Biology, Society of Diagnostic Medical Sonographers, and Society of Vascular Technol- ogy committed to sponsor the initial efforts and an initial work group was formed with two representatives from each society. The initial meetings were dedicated to dening the scope of vascular laboratory accreditation and the minimum guidelines necessary for the assurance of quality.The overall objective was To ensure high quality patient care by providing a mechanism that recognizes laboratories providing quality vascular diagnostic techniques through a process of voluntary Accreditation. This goal was to be achieved by establishing an accreditation process, issuing certicates of accreditation, and maintaining a registry of accredited laboratories. An important principle that was established early was that the accreditation should be as inclusive as possible, something that could be achieved by even the smallest laboratory that was doing quality work. Another important principle adopted was that accreditation would not require a specic medical specialty training but would evaluate the particular education and experience of the doctors and the technologists in each laboratory. Stan- dards for the overall laboratory organization addressed the qualications of the medical and technical personnel, the layout of the laboratory, the support personnel, reports, record keeping, patient safety, and equipment maintenance. Additional standards were developed for specic testing areas (cerebrovascular, peripheral arterial, peripheral venous, and abdominal vascular). Atten- tion was also given to indications, testing protocols, diagnostic criteria, and quality assurance. Not all components of the standards carried equal weight; some aspects were mandatory or required while others were recommended. It was decided that the accreditation would be limited to 3 years, requiring an application for renewal after that time. In March 1990 the group adopted the Constitution and Bylaws for the Intersocietal Commis- sion for the Accreditation of Vascular Laboratories (ICAVL) and in November 1990 it was incorporated as a nonprot corporation in Maryland. The members of the ad hoc work group became the original Board of Direc- tors and Brian Thiele, MD, who had chaired the work group, was elected the rst President. In January 1991 Sandra Katanick, RN, RVT, was selected as the Execu- tive Director and charged with creating the administrative structure for the Commission. The accreditation process starts with submission of a detailed application form, which includes documentation of all aspects of the facility. The sample cases and their reports are the most important part of the application, for the greatest weight in the evaluation process is on the quality of the testing provided. The nal part of each testing section is the laboratorys documentation of validation or quality assurance. The Board of Directors reviews applications quarterly and decides on granting accreditation. Some applications have noted deciencies and in these cases the decision is delayed. Commonly a laboratory is accredited in some areas while having a postponed decision in others. Once the additional mate- rial is received completing the application or documenting 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 is required to permit more extensive evaluation of the problem areas. While the visit may conrm the problems detected in the application, experience through the years has been that more often than not the problem was not with the laboratory itself but with a poorly prepared application. Also noted is that some laboratories with clearly documented problems have identied these and efforts toward correction are being made by the time of the site visit.

27. 1. Improving Quality in Noninvasive Testing by Certication and Accreditation 5 Accreditation is granted for 3 years. Reaccreditation requires an abbreviated application. New personnel complete an information and background section but for prior staff only an updated listing of CME is required.As with the original accreditation, the most important aspect of the application is the quality of the studies performed. A new set of case studies is required along with copies of the current protocols and diagnostic criteria. The other critical part of the reaccreditation is the adequate documentation of correction of the deciencies or weaknesses identied in the previous accreditation. The review process is the same as described above except that special attention is given to evaluating improvement in problem areas. From its inception the Commission operated on the principle that vascular testing is an advancing eld and that the Essentials and Standards needed regular review and consideration for revision. The revisions to the Stan- dards give examples of the Commissions response to changes in vascular testing. In 1994 the Venous Testing Standard was changed to make duplex scanning the only primary modality, so that laboratories performing only physiologic tests would no longer qualify for accreditation in venous testing. Later, additional testing areas were created for Intracranial Cerebrovascular and Visceral Vascular testing. A more recent policy change concerned the minimum volume required for a laboratory to apply for accreditation. The initial philosophy was that some minimum number was required to maintain competence and prociency in the procedures. The requirement was set at 100 tests per year for each primary test. Ultimately the Board of Directors went back to its primary philosophy: the most important factor in granting accreditation should be the quality of the work being done. In the experience of the members of the Board, low volume laboratories often have trouble producing good quality studies, therefore the solution adopted was to increase the level of scrutiny for these applications. In 1997 the policy was revised so that laboratories with less than 100 studies per year could apply but would be required to submit a higher number of sample cases, some randomly selected by the ICAVL. Through the years the ICAVL Board has been concerned about the validity of the review process. Site visits were used only when the review identied serious concerns about the data in the application. For several years consideration was given to instituting a process for random site visits to validate applications the quality of which did not trigger additional scrutiny. In 1998 a policy was established for random site visits to be carried out each quarter. The ndings and recommendations of the site visit team will be compared with the recommendations 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 the entire cost of the operation. At rst there were low numbers of applicants, but there has been a continuing steady growth in the number of accredited laboratories, currently totaling 1150. It was encouraging that most laboratories chose to reapply for accreditation after the rst 3 years. An increasing number of laboratories have completed ve cycles. One of the leading goals set by ICAVL was to help improve the quality of testing through the education resulting from completing the application process. Probably the most important evidence of impact of accreditation is the fact that most laboratories apply- ing for reaccreditation show improvement over what was found the rst time around. Another indicator of success was the fact that ICAVL was used as the basis for the creation of the Intersocietal Commission for the Accredita- tion of Echocardiography Laboratories (ICAEL) in 1996 and 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 leadership decidedtocreateitsownultrasoundaccreditation.Amajor reason put forth for this change was the interest by radiologists in having a single accreditation for all the areas of diagnostic ultrasound. This move certainly came in response to the success of ICAVL.In 1997 the new accreditation was offered to radiology-based laboratories. The vascular component directly paralleled that of ICAVL,but the requirements were less stringent and the application therefore easier to complete.A number of radiology laboratories have stopped renewing their ICAVL accreditation in favor of that offered by ACR.Approximately 900 facilities have this vascular accreditation. Accomplishments and Impact Over the years since the introduction of certication, and later accreditation, there has been growth in both these areas. The number of RVT certicates issued was low in the early years but has shown a later growth. In general, laboratory directors have found that people who have obtained the RVT are better prepared and ultimately show better potential for improvement of skills. Many institution-based laboratories use the RVT as a lever to place the technologist at a higher pay level than the average hospital technicians. ICAVL has always recommended that all technical personnel be credentialed, but last year a mandate was introduced requiring that all technical directors hold an approved credential. The growing appreciation of technologist credentialing was reected by the creation by CCI of a parallel process.

28. 6 J.D. Baker and A.M. Jones quality issue, with 27 companies requiring either accreditation or that credentialed technologists perform the tests. An additional 11 recommend (do not require) that these standards be met. It is encouraging to see that groups outside the Medicare carriers are beginning to look at similar mandates. The Coalition for Quality in Ultrasound (CQU), a group of professional organizations participating in diagnostic ultrasound studies, is conduct- ing an active campaign to increase the mandates for certication and accreditation across the country. The ideal would be to achieve these regulations on a national basis. This will fulll the goal of wide reaching improvement in the quality of vascular testing and hopefully the elimination of poor operations, which have been the bane of the specialty throughout the years. Appendix Education www.oit.edu/zimmermg/mithome/vtdcom/vasgate.html (Oregon Institute of Technology) www.CAAHEP.org (education info) www.svunet.org Credentialing www.ARDMS.org www.CCI-online.org Accreditation www.icavl.org www.acr.org When ICAVL was incorporated in 1991 there were no standards or guidelines for the evaluation of noninvasive laboratories. One of the original expectations of the founding members of the Board of Directors was that the accreditation would gain recognition and come to be used as an index of quality of vascular testing. Once the Commission succeeded in becoming established and sur- viving as an independent organization, there was growing interest in this type of accreditation.The Standards stood the test of time and became the basis for similar efforts by other national groups. In 1996 the American Institute of Ultrasound in Medicine established an accreditation for the areas of general and obstetrical ultrasound and followed the next year by the creation of the ACR ultrasound accreditation. The ICAVL staff participated in the creation of standards for accreditation in echocardiography and nuclear medicine laboratories. In the early years of noninvasive testing the insurance companies paying for the work had little to no interest in the quality of testing provided to patients. As one company ofcer stated, We assume that anyone billing us for a test is providing a quality examination.This atti- tude is changing and in recent years different insurance programs including Medicare have developed an interest in the quality of work done in vascular laboratories.There has been a growing recognition of technologist certication and laboratory accreditation as predictors of higher quality. An important step occurred in March 1998 when the Medicare carrier for Virginia implemented a regulation requiring ICAVL accreditation as a prerequisite for reimbursement. Additional carriers have addressed the

29. The vascular diagnostic laboratory (VDL) is of increasing importance in the care of patients with vascular disease13 while coming under greater governmental scrutiny and economic pressures.4 In view of these chal- lenges, the qualications and credentials of physicians who interpret noninvasive diagnostic studies have taken on additional importance. The InterSocietal Commission for the Accreditation of Vascular Laboratories (ICAVL) has established overall standards for vascular laboratories, including credentials for interpreting physicians. Several professional societies510 have published guidelines for credentials for physicians interpreting noninvasive vascular studies but, as yet, there is no universally accepted standard. Physicians from different specialty backgrounds and with different training and clinical diagnostic experience may all read and direct vascular laboratories.7,11,12 Can these diverse backgrounds and training be 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 desired attributes in regard to formal education and necessary skills, as well as special qualications required for physicians interpreting noninvasive vascular diagnostic studies. Educational Background Although the rst vascular laboratories were developed by vascular surgeons,13 today a variety of other physician specialties are involved in the interpretation of noninvasive vascular studies. These include radiology, cardiology, neurology, and neurosurgery, as well as vascular medicine specialists.7 However,each of these specialties has,stereo- typically, certain deciencies in their usual training expe- riences when it comes to understanding and interpreting vascular diagnostic laboratory tests. Neurologists and neurosurgeons have clinical knowledge regarding cere- bral vascular disease, particularly stroke, but are less frequently provided the opportunity to acquire signicant experience in the VDL evaluation of patients with those conditions. In addition, cerebrovascular diagnosis is only a limited segment of the broad scope of todays VDL. Radiologists often are well-grounded in the principles of ultrasound and have experience interpreting and performing duplex ultrasound examinations, but generally lack knowledge of the principles that govern physiologic vascular testing and the clinical aspects of vascular disease. Training in cardiology includes a focus on the pathogenesis of arterial disease, particularly atheroscle- rosis, and the clinical aspects of some other peripheral vascular diseases, such as venous thromboembolism, but it infrequently includes adequate exposure to noninvasive vascular diagnosis or nonarterial vascular disease, such as chronic venous insufciency. Vascular surgeons and vascular internists have broad educational exposure to the hemodynamic principles, the pathogenesis, and clinical aspects of a broad spectrum of vascular disease and how they apply to diagnosis. However, they are less often exposed to the principles and instrumentation of ultrasound and often are not given the opportunity to actually 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 exposure to all the educational components of vascular diagnosis that have been recommended7,12,14 to qualify physicians to interpret noninvasive vascular tests. These educational components, listed in Table 21, require a multispecialty approach to the education of residents or fellows in the vascular diagnostic laboratory. The table lists all the areas in which knowledge and skills should be acquired. These components provide a framework for noninvasive vascular diagnosis training within standard specialty training so that individuals can work effectively in the VDL. Although residency and fellowship training may vary between specialties, and between different programs 2 Qualications of the Physician in the Vascular Diagnostic Laboratory Michael A. Ricci and Robert B. Rutherford 7

30. 8 M.A. Ricci and R.B. Rutherford within those specialties, individuals interpreting vascular laboratory studies should have acquired a certain set of basic skills (Table 22).A thorough understanding of diseases that affect the vascular system is an absolute requirement.This should include an understanding of the epidemiology and pathophysiology of vascular disorders as well as their clinical signs and symptoms, prognosis, and treatment options. This fundamental knowledge is necessary because noninvasive VDL tests are based upon both normal and abnormal vascular physiology. By the same token, since noninvasive testing is an adjunct to caring for patients with vascular disease, physicians interpreting noninvasive vascular tests should have a thorough understanding of appropriate indications for the performance of these tests. It is incumbent upon the interpreting physician to understand these indications to ensure appropriate clinical conclusions are reached and wasteful 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 laboratory will be able to produce an equivalent experience for every individual in each listed area, nor is it absolutely necessary (i.e., there is little need for residents in neurology to learn venous testing). Areas of expertise and emphasis can and should be designated by each specialty, although individuals who hope to direct a VDL should seek an educational experience that covers all the components listed in Tables 21 and 22. Additionally, it is desirable that individuals learn how to utilize instruments by actually performing clinical studies, although this may be more difcult to achieve in some specialty areas. As a minimum, in our opinion, a basic knowledge of the instrumentation and testing is desirableif not essential. Expe- rience actually performing the various examinations is necessary in order to adequately assist technologists with difcult examinations and, for the surgeon, to perform intraoperative duplex scanning.1 Qualications The qualications for physicians interpreting vascular noninvasive studies have been outlined previously.12 They consist of the following: (1) understand instrumentation (and be able to troubleshoot technical problems); (2) be able to perform and instruct others in performing noninvasive tests; (3) have a thorough knowledge of vascular diseases studied in the VDL; (4) understand the meaning, accuracy, and limitations of test results in light of other tests and the clinical setting; (5) either be completely sup- ported by the VDL or have other activities that do not interfere with the ability to be accessible for the VDL; and (6) have no conicts of interest between acting as both diagnostician and clinician. The individual should have a valid medical license and be in good standing in the medical community. Some professional organizations have suggested minimum numbers of examinations to qualify interpreting physicians in the VDL, but no con- sensus exists.5,710,15 In many situations, no single individual will meet those criteria and more than one individual (physician, engineer, or technologist) may need to share these qualications. Credentialing ICAVL encourages all technologists to seek certication as 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

31. 2. Qualications of the Physician in the Vascular Diagnostic Laboratory 9 of appropriate experience and training. However, it should be noted that a credential specically for physicians has only recently been introduced by the American Registry of Diagnostic Medical Sonographers (ARDMS). Until there is widespread adoption of this credential it remains up to individual departments and hospitals to set credentialing criteria in a responsible rather than self-serving manner. For examinationple, at the University of Vermont, a Department of Surgery ultrasound credentialing committee reviews and sets criteria for physicians using diagnostic ultrasound.14 The criteria and subsequent credentialing recommendations are 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, to allow 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-on experience that is necessary, particularly after completing formal training. We would suggest spending an extended period 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 adequate experience. The vascular surgical societies have developed hospital privileging guidelines for vascular surgery, including noninvasive vascular diagnosis.5 Besides a medical license, these suggested requirements basically include the skill sets listed in Tables 21 and 22, as well as minimum numbers of cases and experience necessary for physicians in established practices, newly trained physicians, and those without formal training in the VDL during residency.5 Initial credentialing must be followed by periodic recertication. Such a process should include, as a minimum, 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 but also continuing education in the vascular diseases being referred 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 credentialing 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 examinations.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 examination is 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 examination results.16 Although it should not be an absolute requirement, it seems desirable for physicians interpreting noninvasive vascular tests to be qualied as RVTs or RPVIs. The RPVI credential provides an alternate, and perhaps more appropriate credential for physicians interpreting vascular noninvasive studies. Requirements for Physicians Directing Vascular Laboratories In addition to the training, skills, and qualications outlined above, physician-directors of VDLs must have additional capabilities. Minimum training should cover 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 the future this may be the RPVI credential. The broadest clinical experience and skills are desirable for someone to serve as a VDL director. Clinical experience will be necessary for credibility when the director is asked to resolve issues or complaints regarding appropriate selection of diagnostic tests or assistance in understanding test results in light of a clinical situation. In addition to diagnostic skills, the director must also have administrative and budgeting skills, particularly in difcult nancial times.11,17 Directors must be responsible for developing and instituting scanning protocols, interpretation criteria, accreditation applications, personnel decisions, and day-to-day operational management. Additionally, good interpersonal skills are important, 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

32. 10 M.A. Ricci and R.B. Rutherford VDL director should not only be interested in the performance of the laboratory and its staff, but ideally should be interested in examining and, where appropriate, reporting clinically signicant correlations with laboratory tests or their diagnostic criteria. Clearly, directors have much greater responsibility and the selection of those individuals should reect these needs. References 1. Ricci MA. The changing role of duplex scan in the management of carotid bifurcation disease and endarterectomy. Sem Vasc Surg 1998;11:311. 2. Kasper GC, Lohr JM, Welling RE. Clinical benet of carotid endarterectomy based on duplex ultrasonography. Vasc Endovasc Surg 2003;37:3237. 3. Jaff MR. Diagnosis of peripheral vascular disease: Utility of the vascular laboratory. Clin Cornerstone 2002;4:1625. 4. Zwolak RM. Coding and billing issues in the vascular laboratory. Semin Vasc Surg 2001;14:1608. 5. Moore WS, Clagett GP, Veith FJ, et al. Guidelines for hospital privileges in vascular surgery:An update by an ad hoc committee of the American Association for Vascular Surgery and the Society for Vascular Surgery. J Vasc Surg 2002;36:127680. 6. Spittell JA, Jr, Creager MA, Dorros G, et al. Recommenda- tions for training in vascular medicine. J Am Coll Cardiol 1993;22:6268. 7. Creager MA, Goldstone J, Hirshfeld JW Jr, et al. ACC/ACP/SCAI/SVMB/SVS: Clinical competence statement on vascular medicine and catheter-based peripheral vascular interventions. J Am Coll Cardiol 2004;44:94157. 8. Gomez C, Kinkel P, Masdeu J, et al. American Academy of Neurology 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 ultrasound examinations. 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 Neurology 1997;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 laboratory: Educational background, prerequisite skills, credentialing, and continuing medical education. Sem Vasc Surg 1994;7:21722. 13. Kempczinski RF. Challenging times for the vascular laboratory. Sem Vasc Surg 1994;7:21216. 14. Shackford SR, Ricci MA, Hebert JC. Education and credentialing. Prob Gen Surg 1997;14:12632. 15. Ricci MA. Qualications and competence of vascular laboratory 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 technologist. Sem Vasc Surg 1994;7:22833. 17. Kempczinski RF. Challenging times for the vascular laboratory. Sem Vasc Surg 1994;7:21216.

33. Section II Basic Physics

34. This chapter is an April 2005 revision of a chapter written in April 1998. During that period, the basics of ultrasound examination have been surprisingly stable. Electronics have shrunk so that now full function ultrasound duplex scanners can t in your pocket. The speed of personal computers has advanced so that the new scanners are just software residing in personal computers equipped with an ultrasound receiver on the front end and a printer or DICOM adaptor on the back end. In spite of shrinking electronics, all of the modern triplex-Doppler,color ow,(three-dimensional real-time) four-dimensional scanners have converged on a single standard 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 a maximum of 15 A (7.5 A in Europe) or 1800W (volts multiplied by amps) with a printer included.This standard was 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 examiners view over the top of the instrument is unobstructed and connect the instrument to power at the patients bedside. Thus the systems are portable, something that will always be out of reach of the computed tomography (CT) and magnetic resonance imaging (MRI) alternative technologies. It is truly surprising that the manufacturers, over the period from 1979 (when commercial duplex scanners became popular) to 2005, while electronics have shrunk to (1/2)18 or 1/250,000 size, have elected to keep the instrument package unchanged until this year with the introduction of notebook size systems.What has changed is that the complexity of the systems has exploded. Now ultrasound 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 reverted to mounting them on standard size carts, not because small size is impossible,but because the customers appear to want ultrasound scanners that look large. Now, all the major manufacturers offer palm size ultrasound scanners as an alternative to the large systems. This chapter was written in the United States in a world where inches and feet, gallons and quarts are the rule, and room temperature is 72F (22C) and body temperature is 98.6F (37C). Science has advanced to use a decimal metric system. The decimal system, however, is misali

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