Computed tomographic coronary angiography: experience at Baylor University Medical Center/Baylor Jack and Jane Hamilton Heart and Vascular Hospital

Abstract

Noninvasive cardiac computed tomographic imaging using multislice or electron beam technology has been shown to be highly specific and sensitive in diagnosing coronary heart disease. It is about a fifth of the cost of coronary angiography and is particularly well suited for evaluating patients with a low or low to moderate probability of having obstructive coronary atherosclerosis. In addition, it offers more information than calcium scoring: because of the intravenous contrast used, it temporarily increases the density of the lumen and allows differentiation of soft plaque from calcified plaque. The Baylor Hamilton Heart and Vascular Hospital now uses this modality to define coronary atherosclerosis in patients who would otherwise have needed invasive coronary angiography; several research protocols with the technique are also under way. Baylor has recently upgraded to the 64-slice scanner. It is expected that computed tomographic coronary angiography will replace a significant percentage of invasive cardiac catheterizations.

Figure 1

Noncontrast computed tomography (i.e., calcium score) of the left main artery (LMA) and left anterior descending artery (LAD). Areas of dense calcium (HU > 130) are highlighted. The amount of calcium demonstrated would place this patient in the 90th percentile compared with age- and sex-matched controls. Ao indicates aorta.

Figure 2

Plaque in the proximal left anterior descending artery: both calcified (white arrowhead) and soft (black arrow).

Figure 3

Multiple reconstructions of the same data set to visualize the coronary arteries. Three-dimensional reconstruction of the (a) coronary tree and (b) larger cardiac structures demonstrates the spatial relationships of the arteries as well as their relationship to the larger cardiac structures. Multiplanar reformat views of the (c) left anterior descending artery and (d) right coronary artery allow for more detailed evaluation of the coronary lumen. A small amount of calcific plaque (arrow) is seen, as well as a mild amount of soft plaque (arrowhead).

Figure 4

This patient presented with minimal symptoms of angina approximately 10 years after four-vessel coronary bypass. Three-dimensional reconstruction of the heart clearly demonstrates patent left internal mammary artery graft to left anterior descending coronary artery (white arrow), patent saphenous vein graft to circumflex system (black arrow), and occluded saphenous vein graft to diagonal artery (black arrowhead). The saphenous vein graft to the right coronary artery is also occluded (white arrowhead).

Figure 5

Three-dimensional reconstruction of the left atrium and pulmonary veins. There are four normal pulmonary veins, two superior and two inferior veins, with normal branch distribution and separate ostiae. RSPV indicates right superior pulmonary vein; LIPV, left inferior pulmonary vein.