Fig. 1.1
American Registry for Diagnostic Medical Sonography (ARDMS) , incorporated 1975
Registered Vascular Technologists (RVTs) currently number 31,000, the majority of whom are registered in another specialty as well (general sonographers or cardiac sonographers). The RVT credential is now earned by successfully passing examinations in Sonography Principles and Instrumentation (SPI) and vascular technology (VT ). Prerequisites required to qualify for the examination include accredited allied health education programs, CAAHEP-approved ultrasound schools, medical school, or extensive clinical experience. All prerequisites include a minimum requirement of clinical experience in a vascular laboratory. Once the credential has been earned, continuing medical education (CME) is required, and the ARDMS will begin a recertification program in 2019.
The vascular technologist credential has been recognized by a broad range of professional organizations and societies. The SVS recognizes the credential as a basic starting point for building a successful vascular laboratory [2]. In a document describing the scope of practice for sonographers, credentialing has been formally endorsed by the American Society of Echocardiography (ASE), Joint Review Committee on Education in Diagnostic Medical Sonography (JRC-DMS), Society of Diagnostic Medical Sonography (SDMS), Society for Vascular Surgery (SVS), and Society for Vascular Ultrasound (SVU), along with support from a number of other organizations [3]. This broad recognition underlines the importance of documenting competency in the knowledge, training, and skills required to be a vascular technologist. Accreditation organizations , discussed later in this chapter, also recognize the importance of credentialing and will require that ALL vascular technologists hold such a credential by 2017.
Vascular specialists have long recognized the clinical importance of technologist credentialing and have sought out RVTs to organize and administer their laboratories. In most hospitals and office-based facilities, the technical director must hold a credential, and most, if not all, technologists must also obtain a credential. These requirements may be more stringent than nationally applied standards. In fact, medical directors of many vascular laboratories have obtained the RVT credential even though they might not physically perform the examinations. This is reflected in the ARDMS registry, where there were 1500 MD/RVTs in 2010 (Data provided by Dale Cyr, ARDMS).
Physician Credentialing
Further complicating the issue of credentialing of sonographers is the wide variability of utilization of sonographers worldwide. In Australia, there is a well-organized sonography community represented by the Australian Sonographers Association (ASA). In Canada, the Canadian Association of Registered Diagnostic Ultrasound Professionals (CARDUP) offers three credentials, one in vascular sonography. In the United Kingdom, the Consortium for Accreditation of Sonographic Education (CASE) oversees training of sonographers who also interpret examinations. In the United States CAAHEP/JRC-DMS recognizes 208 accredited programs, including Diploma, Associate, Bachelors, and Masters Degrees.
As extensive as this network seems, most of the rest of the world does not utilize sonographers. In Europe (except the United Kingdom), South America, Asia, India, and Africa, sonography is performed only by physicians specifically trained in the performance and interpretation of ultrasound examinations. Sonographers play only a very minor role in these countries.
In 2002, recognizing this discrepancy, the ARDMS surveyed medical directors and staff of ICAVL accredited vascular laboratories to define what physicians do in the vascular lab and to assess the level of support for a specific physician interpretation credential . Of 454 survey responses, 99% of responders reported that they interpreted examinations, but less than 33% actually performed hands-on scanning. Fifty-six percent of responders supported the idea of a physician vascular interpretation credential, support coming largely from vascular medicine, vascular surgery, and cardiology with radiologists less enthusiastic. This formed the impetus for the development of physician vascular laboratory interpretation credentialing in the United States (statistics provided by RE Zierler, University of Washington, ARDMS survey results, 2002).
ARDMS subsequently developed a new physician credential, the Registered Physician in Vascular Interpretation (RPVI) which would be granted after passing the Physician Vascular Interpretation (PVI) examination (Fig. 1.2). Prerequisites to qualify for the examination include an MD who already has attained the RVT credential or who works in an IAC-accredited laboratory. Physicians with formal and informal training including extensive experience in examination interpretation may also qualify for the examination. All prerequisites require a broad experience in the interpretation of vascular laboratory examinations in addition to academic training. The examination is delivered by computer in a secure Pearson Testing Center during a spring and fall testing schedule. Four hours are allowed to answer the 185 multiple choice questions. PACSim questions or items were recently introduced to simulate a realistic testing interpretation environment. The cost of the examination is $600.
Fig. 1.2
Registered Physician in Vascular Interpretatio n (RPVI), administered by ARDMS
The PVI examination is designed specifically to address the unique relationship between the physician and the laboratory. 8% of the questions address anatomy and physiology and 10% pathology. Physics and instrumentation represents 10% of test content, and 44% involves integration of data (Table 1.1). There are currently 3500 physicians holding the RPVI credential, made up of 45% cardiologists, 41% vascular surgeons, 3% vascular medicine physicians, and 2% radiologists.
Table 1.1
RPVI content outline
Anatomy and physiology (8%) • Abdominal/visceral • Cerebrovascular • Peripheral arterial • Venous | Pathology (10%) • Abdominal/visceral • Cerebrovascular • Peripheral arterial • Venous | Patient care (8%) • Abdominal/visceral • Cerebrovascular • Peripheral arterial • Venous • Communication • Risk assessment |
Integration of data (44%) • Abdominal/visceral • Cerebrovascular • Peripheral arterial • Venous | Protocols (16%) • Abdominal/visceral • Cerebrovascular • Peripheral arterial • Venous | Physics and instrumentation (10%) • Artifacts • Bioeffects • Hemodynamics • Imaging instruments • Quality assurance/statistics (sensitivity/specificity, pos/neg predictive value, accuracy) |
Other (4%) • New technologies • Traumatic injury • Physician’s role in procedure | ||
The Vascular Surgery Board of the American Board of Surgery have mandated that beginning in 2014, all applicants to the Vascular Surgery Qualifying Examination will be required to possess the RPVI credential offered by ARDMS. This has been the impetus for the Accreditation Council for Graduate Medical Education Association to require formal didactic sessions and vascular lab interpretation experience in the curriculum for all vascular residencies [4]. The Society for Vascular Ultrasound (SVU) and the SVS have partnered in offering RPVI review courses on a regular basis, including during the Vascular Annual Meeting (VAM) . These courses have helped resident applicants as well as practicing physicians prepare for the examination.
Beginning in 2016, ARDMS is undergoing a major restructuring to allow expansion and redefinition of its mission. Inteleos will be named as the umbrella and governance organization under which ARDMS) will continue as the sonographer credentialing arm. The Alliance for Physician Certification and Advancement (APCA) will become the physician-centric section, and the RPVI credential will move under its administration (Fig. 1.3). The APCA will allow expansion of physician credentialing and certification in the United States as well as globally, where physicians perform the majority of sonography examinations.
Fig. 1.3
2016 Logos for ARDMS (a) and APCA (b)
Accreditation
Background
The history of the noninvasive vascular flow lab dates back to the 1940s when the first blood flow studies were performed at the Massachusetts General Hospital, initially for research purposes. Similar laboratories developed in the 1950s and 1960s. J Raines and RC Darling opened the MGH clinical vascular laboratory in 1971 to showcase the application of their Pulse Volume Recorder (PVR) , still in use 45 years later. During the 1970s, the development and wide application of the continuous wave Doppler resulted in a proliferation of vascular laboratories [5]. Early vascular laboratories therefore generally measured blood flow indirectly, and applicability was somewhat limited as a result.
In 1974, the combination of greyscale imaging and pulsed Doppler spectral analysis (duplex scanning ) was first envisioned, and in 1978, David Phillips and Eugene Strandness at the University of Washington developed the first prototype duplex scanner, and the modern vascular lab era was begun (Fig. 1.4). The broad applicability and noninvasive nature of the studies resulted in an instant popularity and a proliferation of testing sites. Recommendations for the structure and function of vascular laboratories were soon to follow [6].
Fig. 1.4
1987 prototype first duplex scanner. (a) Scan head, (b) spectrum analyzer, (c) instrument rack (Photos courtesy of R. Eugene Zierler MD, the D.E. Strandness Jr. Vascular Laboratory, University of Washington)
These early and exciting developments in vascular laboratory structure and function were largely spearheaded by a visionary group of vascular surgeons who began to depend heavily on the results from their laboratories to help in making clinical decisions. Initial applications for measuring carotid stenosis rapidly expanded to studying deep venous thrombosis and peripheral arterial disease, and the broad applicability of these flow studies became apparent. Facilities now sprung up in every hospital and many physician offices, and this trend continues to this day. What was initially the purview of vascular surgery spreads rapidly to radiology departments, physician offices, and even mobile laboratories. More recently, cardiology departments and offices have added vascular testing to their cardiac ultrasound programs. Neurologists frequently administer laboratories that limit their studies to cerebrovascular and intracranial examinations. It is estimated that presently there are over 10,000 vascular laboratory sites in the United States, less than a quarter of which are accredited. This proliferation raised questions about the consistency and quality control of this critically important resource [7, 8].
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