In this issue of Academic Radiology , Dr. Minocha et al present the results of a survey to evaluate the current state of training in cardiac imaging among radiology residency programs . Responses from 52 programs demonstrate that most do have some form of a cardiac imaging rotation, but that the rotations vary in length and that most programs have fewer than 5 hours of cardiac conference time for the residents per year. Only 17% of residents feel that their training in cardiac imaging is adequate. The overall message of the manuscript is clear: “Where is the curriculum for cardiac imaging in radiology residency? How can radiologists deliver high-quality imaging for cardiac patients when our residents get minimal training in cardiac imaging? How can organized radiology expect others medical specialties to respect our training in cardiac imaging if there is no standard curriculum?”
Cardiac imaging consists of plain films, nuclear perfusion studies, echocardiography, computed tomography (CT) angiography, cardiac magnetic resonance (MR), and conventional cardiac angiography. Our discussion will focus on the four “high-tech” forms of cardiac imaging. Echocardiography and nuclear scintigraphy have been integral components of the imaging of cardiac disease over the past few decades, and CT/MR have more recently become valuable components of the cardiac evaluation. Many radiology training programs now offer elective rotations in advanced cardiac imaging . Most academic radiologists would agree that radiology residents have an inadequate number of rotations and lectures in cardiac imaging. However, the training problem is not simply in the quantity of rotations and lectures, but is also qualitative in nature.
Training in ultrasound (US)/CT/MR of the heart is frequently left to an imaging section whose members themselves have not been trained in cross-sectional imaging of diseases of the heart. Although most radiology programs have shifted from an emphasis on modality based sections (US, CT, and MRI) to body system–based sections (neurology, thoracic, abdominal, and musculoskeletal), there is no clear home for cardiovascular imaging in many radiology departments. Recent advances in myocardial perfusion imaging with CT/MR have increased the overlap of information that may be obtained from CT/MR versus nuclear perfusion imaging. Nonetheless, nuclear imaging is almost always separated from cardiac CT/MRI, and echocardiography is rarely practiced within the radiology department. Is there any individual who understands how these four modalities are used in clinical practice for the prevention, diagnosis, and management of cardiovascular disease? Who is the most knowledgeable person in the radiology department with respect to cardiac disease and cardiac imaging—could it be the referring cardiologist?
The cardiovascular system differs from other body systems in the paramount importance of real-time functional information. Cardiac disease is manifest as a loss of the normal pumping function of the heart. The liver has functional importance, but hepatic imaging with US, CT, and MR continues to focus predominantly on static anatomic details (this too, may change). However, isolated anatomic assessment of the heart without a functional evaluation is a diagnostic exercise of limited clinical value. The cardiac imager must understand the value of systolic contractility and myocardial perfusion, the implications of segmental versus global systolic dysfunction, systolic versus diastolic dysfunction, and subendocardial versus transmural perfusion abnormalities. The presence of an anatomic stenosis in a coronary artery is often of unclear clinical significance; however, when a stenosis is associated with a segmental wall motion abnormality or perfusion defect, the combination of anatomic and functional information may be complementary to provide a clear clinical diagnosis . Myocardial perfusion must be interpreted in light of various factors that may alter myocardial oxygen requirements. Assessment of cardiac valves requires an evaluation of the dynamic motion pattern of the valves. The distinction between a bicuspid and trileaflet aortic valve cannot be based on a static diastolic phase image, because a bicuspid valve with a pseudoraphae may mimic a trileaflet valve. A measured gradient across the aortic valve must be interpreted in light of left ventricular contractility and flow velocity in the left ventricular outflow tract. The optimal imaging planes for cardiac assessment are also different from those used in imaging of other organs, and are designed to provide important functional information. Imaging of the heart is most appropriately performed in short-axis and long-axis (four chamber, three chamber, and two chamber) views rather than the horizontal axis and vertical axis. Aortic leaflets should be assessed in the short axis of the aortic valve. The appropriate imaging plane for diagnosis of mitral valve prolapse is the three chamber long axis view through the left ventricle . Many radiologists are not comfortable with functional assessment and imaging in anatomic short- and long-axis planes.
A cardiac curriculum for radiology residents must teach about cardiac disease with both an anatomic and functional approach. It is not sufficient for our residents to learn the names of the cardiac chambers and coronary arteries and to assess each vessel for percent stenosis. Radiology residents must learn about cardiac disease with an integrated approach that includes the various disease states and imaging modalities. When a neurosurgeon enters the neuroradiology section of an academic department, the neuroradiologist is treated as a valuable colleague because our training in neuroradiology provides a comprehensive understanding of neurological disease as well as brain anatomy. The cardiac curriculum must train radiology residents to that same level of expertise in cardiac disease, so that they can provide the same added value as cardiac imaging consultants.
The American College of Cardiology Foundation training statement on cardiovascular imaging provides three levels of training expertise in cardiac imaging . Level I is basic training such that the trainee is conversant with all the imaging modalities and their clinical application. Such training includes 3 months of echocardiography, 2 months of nuclear cardiology, and 1 month each of cardiac CT and MRI. Thus, the official cardiology standards require 6 months of basic training in cardiac imaging for all cardiology fellows. Level II training, which enables the physician to interpret studies independently, requires an additional 3 months in echocardiography, 2–4 months in nuclear cardiology, 2–5 months in cardiac MR, and 1 month in cardiac CT. Thus, level II training in cardiac imaging would require a minimum of 15 months of training. One might argue that radiology residents already receive much of the basic training in imaging physics in other rotations. However, in-depth knowledge of cardiac disease requires time on rotation with a dedicated, integrated cardiac curriculum.
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References
1. Minocha J., Yaghmai V., Hamond N., et. al.: Cardiac imaging training in radiology residency programs: a survey of radiology chief residents. Acad Radiol 2010; 17: pp. 795-798.
2. Zaheer A., Raptopoulos V.: Establishing a cardiac imaging rotation in radiology residency. Acad Radiol 2006; 13: pp. 871-873.
3. Halpern EJ, Fischman D, Savage M, et al. Decision analytic model for evaluation of suspected coronary disease with stress testing and coronary CT angiography. Acad Radiol 17:577–586.
4. Levine R.A., Triulzi M.O., Harrigan P., et. al.: The relationship of mitral annular shape to the diagnosis of mitral valve prolapse. Circulation 1987; 75: pp. 756-767.
5. Thomas J.D., Zoghbi W.A., Beller G.A., et. al., American College of Cardiology Foundation (ACCF); American Heart Association (AHA); American College of Physicians (ACP) Task Force on Clinical Competence and Training: ACCF 2008 Training Statement on Multimodality Noninvasive Cardiovascular Imaging A Report of the American College of Cardiology Foundation/American Heart Association/American College of Physicians Task Force on Clinical Competence and Training developed in collaboration with the American Society of Echocardiography, the American Society of Nuclear Cardiology, the Society of Cardiovascular Computed Tomography, the Society for Cardiovascular Magnetic Resonance, and the Society for Vascular Medicine. J Am Coll Cardiol 2009; 53: pp. 125-146.