Coronary artery stenoses: assessment with contrast-enhanced electron-beam CT and axial reconstructions.

PURPOSE: To evaluate the usefulness of electron-beam computed tomography (CT) for identification of coronary artery stenoses. MATERIALS AND METHODS: Coronary angiography and contrast material-enhanced, electrocardiographically triggered electron-beam CT of the heart were performed in 23 patients. With axial CT images and axial maximum intensity projection reconstructions, the coronary arteries were assessed by two observers blinded to the results of angiography. RESULTS: Cardiac motion artifact (unsharpness) precluded evaluation of the right coronary artery (RCA) in six subjects and the left circumflex coronary artery (LCX) in one patient. With the vessels degraded by motion artifact eliminated from analysis, overall sensitivity of electron-beam CT for hemodynamically significant stenoses was 88%, and specificity was 79%. In the left anterior descending coronary artery (LAD), sensitivity was 93% and specificity was 63%; in the LCX, sensitivity was 100% and specificity was 67%; and in the RCA, sensitivity was 67% and specificity was 77%. The presence of coronary artery calcification did not have an effect on sensitivity for stenoses, but it did decrease specificity. CONCLUSION: Electron-beam CT angiography can depict hemodynamically significant stenoses in the LAD and LCX with a sensitivity of more than 90%. The presence of coronary artery calcification resulted in decreased specificity but no appreciable change in sensitivity.