Turf questions have always surrounded the provision and interpretation of coronary CT angiography (CCTA) studies. Who should read these studies? Cardiologists and radiologists are unlikely to exclude each other from interpreting these studies, but the application of standards may help both specialties ensure an emphasis on appropriate training and experience as indicators of probable interpretation quality.
Professional standards are becoming increasingly important as part of the reimbursement process as well. For example, Medicare carriers may require compliance with the specified levels of competence for the professional and technical components of CCTA, as defined by the two guidelines issued by the ACR¹ and the American College of Cardiology Foundation/American Heart Association (ACCF/AHA).2 For political reasons, two competing guidelines exist for cardiac CT; at this time, neither set of guidelines is universally accepted or endorsed.
Cardiology and Radiology Standards
The ACCF/AHA guidelines for qualifying to perform and interpret CCTA, issued in 2005, were based on the contributions of the ACCF, the AHA, the American Society of Echocardiography, the American Society of Nuclear Cardiology, and the Society of Atherosclerosis Imaging, and they were endorsed by the Society of Cardiovascular Computed Tomography (SCCT). They specify three levels of competence; in order to interpret CCTA unsupervised, the physician must reach level² (contrast cardiac CT).
This level requires eight weeks of training, the performance of 50 mentored exams, and the interpretation of 150 mentored exams (with the use of textbook and teaching-file reviews permitted). In addition, the candidate must have completed 20 hours of lecture instruction in general CT or cardiac CT. Continuing experience of 50 contrast cardiac CT exams conducted and interpreted per year is also required.
The ACR guidelines have separate criteria for physicians with and without prior qualification in CT interpretation. Physicians who have prior qualification in CT interpretation should meet one of two requirements. The first calls for the completion of at least 30 hours of CME training in cardiac anatomy, physiology, and pathology and in cardiac CT imaging. The second calls for interpretation, reporting, and/or supervised review of at least 50 cardiac CT examinations in the preceding 36 months; coronary-artery calcium scoring does not qualify for inclusion in meeting these requirements.
For physicians without prior qualification in CT interpretation, the ACR guidelines require completion, within the specialty practiced by the physician, of a training program approved by the Accreditation Council for Graduate Medical Education, plus 200 category-1 CME credits in the performance/interpretation of CT exams. In addition, the physician must have completed, under supervision, during the preceding 36 months, the supervision, interpretation, and reporting of 500 cases, at least 100 of which must be thoracic CT or thoracic CTA (with coronary-artery calcium scoring being exempt).
The candidate must also complete 30 hours of category-1 CME in cardiac imaging and interpretation, as well as the reporting and/or supervised review of at least 50 cardiac CT exams in the previous 36 months. Again, coronary-artery calcium scoring is not counted toward this total. The ACR has an additional practice guideline for CCTA that advocates interpreting physicians having a knowledge of the entire chest, as well as a knowledge of the administration of contrast media.
Outside the Heart
Radiologists cannot assume that CCTA technology will be their sole domain. Cardiologists, like radiologists, are already involved. They conduct and attend CME courses on CCTA that are geared for cardiologists.
They are also instrumental in the SCCT; founded in 2005, it already has more than 3,900 members, many of whom are cardiologists (as are 12 of its 16 board members). As its advocacy mission, the SCCT is dedicated to ensuring that competent, skilled physicians—regardless of specialty—can perform (and be reimbursed for) cardiovascular CT procedures.
The turf questions involved in performing and interpreting CCTA are complicated by the fact that extracardiac findings are common in patients who undergo CCTA. For example, of 258 consecutive CCTA patients in a 2007 study,³ 56.2% had significant noncardiac abnormalities seen on CCTA. These included lung and pericardial abnormalities, liver disease, adrenal