[Coronary angiography with sixteen-slice spiral CT: an initial study]

To evaluate the scanning technique and primary clinical value of sixteen-slice spiral CT coronary angiography.

Plain and enhanced sixteen-slice spiral CT imaging was performed in 69 patients, including 64 cases of suspected coronary heart disease and 5 cases of coronary stent. Calcium scoring with plain scan images and MPR, MIP and VRT reconstruction with enhanced scan images were made in all cases, among which 10 underwent conventional coronary angiography. The demonstration and stenosis of coronary arteries were evaluated. The factors influencing the image quality were analyzed. Additional MPR and MIP reconstruction of slices perpendicular to the stent and virtual endoscopy of stent were made in 7 stents of the 5 cases of coronary stent. The patency of the stents was evaluated.

A four-step scanning procedure was devised. Coronary calcium score could be got by plain scanning with sixteen-slice spiral CT angiography. All of the primary, most of the secondary and tertiary, and part of the fourth level branches of coronary artery could be shown isotropically with MPR, MIP and VRT reconstruction images of enhanced scanning. MPR and MIP were better than VRT in demonstrating small branches. Evaluated by VRT image, the image quality of 79.7% of the patients were first class, 10.1% second class, and 10.1% third class. The image quality was correlated to the contrast concentration in the root of aorta, heart rate, existence or absence of arrythmia, and the patient's breath-holding ability. Stenosis of coronary arteries was evaluated by sixteen-slice spiral CT imaging in 10 cases, with a result comparable to that by conventional coronary angiography. The stents were well shown, six stents being evaluated as patent, while one not.

Sixteen-slice spiral CT coronary angiography is a noninvasive, simple and good method. Coronary calcium score and coronary artery stenosis can be evaluated with one study. The patency of stents can also be evaluated.