Remarkable advances in multidetector CT angiography (CTA) not only have produced great excitement among both radiology and cardiology specialty groups but also have raised issues of responsibility for interpretation of the resulting images. Cardiologists offer extensive knowledge of cardiovascular pathophysiology as well as clinical expertise obtained from traditional cardiac catheterization, coronary angiography, peripheral vascular intervention, and other techniques. Meanwhile, radiologists bring specialized training in CT and fluency in imaging protocols and 3D renderings produced using specialized workstations.
Incidental findings abound in cardiac CT imaging, with some 37 percent of studies having incidental findings. Problems can stem from chest pain that turns out to be rib fractures or stomach issues, or stomach problems that reveal bowel disease or lung cancer. No matter the case, radiologists and cardiologists must be diligent and cautious in fully reading each study — that ideally is acquired with thinner, faster slices. Also important are excellent technologists, selecting appropriate patients, standardizing image review, fine-tuning imaging protocols, and acquiring the best 64-slice scanners and workstations in the first place.
Mark J. Miller, MD, president and CEO of Advanced Medical Diagnostics in Wisconsin, a firm focused on assisting small and mid-sized hospitals to strengthen, improve, and expand the level of service within their radiology departments. In his role, Miller has consulted with more than 100 hospitals concerning CT equipment and in developing imaging programs centered on advanced technology.
“A commonly addressed issue involves professional interpretation of CTAs; particularly in light of the fact that lung tissues, bones, and other non-cardiac structures are included in the scans,” says Miller. “In this situation, the hospital has three options.”
The first is to allow radiologists to read the scans, with the advantage of having a single reading group perform the service. He asserts that CTA is a natural outgrowth of peripheral CTA that radiologists have performed for many years. The disadvantage of this approach from a business perspective is that since radiologists do not order exams, the volumes generated by a CTA service will develop more slowly.
The second option is for the hospital to involve cardiologists in reading the scans. The advantage is that cardiologists will order a large number of exams, thereby enhancing the CTA business for the hospital. While cardiologists usually have a strong clinical background in cardiac anatomy, they may lack formal training in CT scanning, unless they have sought additional education. Therefore, there may be a need for an over-read by a radiologist of the non-cardiac soft-tissue images. Additionally, some have argued this approach may lead to overuse of the modality given the lack of checks and balances by employing this structure.
The third option — and the one most commonly employed across the country — involves shared responsibility where professionals read the exams jointly from both groups. This scenario permits incorporation of clinical knowledge about a patient’s cardiac history with a strong understanding of diagnostic imaging. The cardiologists promote the business of CTA, but there are checks and balances through radiology to prevent overuse.
“I believe that an arrangement of joint reading of CTA exams, with each study being double-read in a collaborative fashion, will lead to the highest-quality patient care,” Miller concludes. Cardiovascular Institute of the South (CIS) in Houma and Lafayette, La., offers a comprehensive heart and vascular program. Craig Walker, MD, its founder and medical director, describes how they started with a Toshiba Aquilion 16-slice scanner and since have increased their capabilities to three Aquilion 64-slice scanners to perform cardiac CTA. “In our situation, our cardiologists actually read the angiographic section of the CT,” Walker says. “Several of us have level two and level three interpreters training for CT.” While they review all aspects of the study, their primary emphasis is on making sure they have acquired a quality vascular study. In addition, a radiologist reads some scans.
At CIS, images are read by a cardiologist and a radiologist, and two reports are generated, according to Ritchie Dupre, the diagnostic services manager, and Joey Fontenot, COO. When a vascular CT exam is performed,