[Digital subtraction angiography of the coronary artery: evaluation of morphological aspects].

The usefulness of digital subtraction angiography (DSA) in coronary angiography was evaluated in terms of its ability to delineate the coronary artery and aortocoronary (A-C) bypass grafts. First, 59 intra-arterial injections of contrast media were made for 23 patients with ischemic heart disease. With aortic root injection, the proximal coronary artery was moderately well visualized, but visualization of the peripheral arteries was inadequate. By selective coronary injection, good images of the coronary arteries were obtained using small quantity of contrast media; however, detailed evaluations of the degrees of stenosis and collateral circulation were difficult, because of limitations in spatial resolution and misregistration artifacts due to cardiac pulsations. In addition, the patencies of 12 A-C bypass grafts were evaluated using intravenous (IV-) DSA for three cases and intraaortic (IA-) DSA for five cases. Ten grafts were shown to be patent. With IV-DSA, the graft was imaged as superimposed on the ascending aorta. In IA-DSA, a small (4F) catheter was introduced via the right brachial artery and advanced to the ascending aorta where an aortic root injection was performed. With aortic root injection, not only the anastomotic portion but also the distal native coronary artery were visualized. Lateral and severe left anterior oblique projections were best to visualize the grafts. IA-DSA using 4F catheter could be performed for outpatients without complications. The patency of a graft can be evaluated with the time density curve between two points in the graft, and the coronary blood flow can be calculated using the time density curve measurements and the diameter of the artery.(ABSTRACT TRUNCATED AT 250 WORDS)