'Super' division strengthens radiology

As advances in CT and MR make it easier to noninvasively image the cardiovasculature, more cardiologists are moving from the heart into vascular interventions. Conversely, the same CT and MR advances are leading radiologists back to the heart. These two trends have some radiology departments revamping the structure of their divisions.

Dr. James H. Thrall, radiologist-in-chief at Massachusetts General Hospital, recently created the division of cardiovascular imaging and interventions. This "super" division, as Thrall describes it, combines vascular and cardiac radiology.

Thrall realized that cardiologists at MGH would have an advantage in the inevitable turf battle because they work in both the heart and the periphery. In contrast, radiologists were divided into two divisions: one specializing in peripheral vascular imaging and intervention and the other in cardiac imaging. Combining the two activities also made sense because the heart and peripheral vasculature are now easily studied using the same methods and often in the same exam.

For the most part, cardiologists and radiologists at MGH have a good relationship. The radiology department has an institutional agreement to work on cardiac CT and MR jointly with cardiology. This collaboration is modeled on the decades-old partnership radiology has enjoyed with nuclear cardiology. Additionally, Dr. Stephan Wicky, acting director of the new section of cardiovascular intervention, works in the cardiac catheterization laboratory in collaboration with cardiologists. Dr. Thomas J. Brady, who heads the new division, is also the institutional director for the cardiac MR and CT program, which comprises both radiologists and cardiologists. (Dr. Suhny Abbara rounds out the leadership of the super division as the chief of the cardiovascular imaging section.)

CT angiography and MR angiography, either alone or in combination, have nearly replaced conventional angiography in the periphery and the brain at many institutions. At MGH, CTA of the pulmonary arteries has eliminated both conventional pulmonary angiography and nuclear medicine ventilation/perfusion scanning.

"There has been a sea change. And we think we're poised on the brink of the sea change for coronary angiography. It is no longer necessary to take a patient to the cardiac cath lab to visualize the coronary arteries," Thrall said.

MGH, like other institutions, has cardiologists who rely on coronary CTA for patients with intermediate probabilities of coronary artery disease. CTA can clear the proximal coronary arteries and visualize a remarkable distance into the coronary circulation, he said. Patients with bypass grafts no longer go back to the cath lab to evaluate bypass graft patency; it's done with CTA.

Research is ongoing regarding patients who present to the emergency room with atypical chest pain syndrome. If they have an unequivocal myocardial infarction and are in clinical danger, they go to the cath lab to be evaluated for thrombolysis and stenting. If they have equivocal results, they are evaluated with CTA, which could prove to be a test with a very high negative predictive value.

"If you have a presumptive diagnosis of MI and can do a noninvasive test that reliably rules out MI, then you can change management," Thrall said. "We hope we can send a higher percentage of patients home with the correct diagnosis."

Cardiologists and vascular surgeons at MGH gained privileges to do peripheral vascular interventions within the last two years. Interventional radiologists compete for peripheral vascular interventions, but it's a friendly competition, Thrall said. They are working together on joint protocols for carotid stenting, and the institution has recently formed the MGH Vascular Center.

"I wouldn't say for a minute that all internal turf battles are resolved. But we are working through the issues institutionally, trying to determine how we can aim all that firepower externally and not at each other," he said.

The radiology department potentially stood to lose a great deal of vascular interventional work when competitors gained privileges, but it countered with a strong marketing effort. This resulted in:

- an increase in venous work;

- vascular access for patients undergoing dialysis;

- a very busy varicose vein treatment practice;

- a moderately busy uterine fibroid embolization practice; and

- an expanded chemoembolization cancer practice.

"When vascular surgeons and the cardiologists received privileges, we did see a very significant dip in number of arterial cases. But this also occurred when we were converting from diagnostic angiography to CTA and MRA. It's hard to narrow how much of the dip was due to cardiologists and vascular surgeons gaining privileges and how much was going to happen anyway because of advances in technology," Thrall said.