CORONARY-ARTERY STENOSES - ASSESSMENT WITH CONTRAST-ENHANCED ELECTRON-BEAM CT AND AXIAL RECONSTRUCTIONS

PURPOSE: to evaluate the usefulness of electron-beam computed tomograp hy (CT) for identification of coronary artery stenoses. MATERIALS AND METHODS: Coronary angiography and contrast material-enhanced, electroc ardiographically triggered electron-beam CT of the heart were performe d in 23 patients. With axial CT images and axial maximum intensity pro jection reconstructions, the coronary arteries were assessed by two ob servers blinded to the results of angiography. RESULTS: Cardiac motion artifact (unsharpness) precluded evaluation of the right coronary art ery (RCA) in six subjects and the left circumflex coronary artery (LCX ) in one patient. With the vessels degraded by motion artifact elimina ted from analysis, overall sensitivity of electron-beam CT for hemodyn amically significant stenoses was 88%, and specificity was 79%. in the left anterior descending coronary artery (LAD), sensitivity was 93% a nd specificity was 63%; in the LCX, sensitivity was 100% and specifici ty was 67%; and in the RCA, sensitivity was 67% and specificity was 77 %. The presence of coronary artery calcification did not have an effec t on sensitivity for stenoses, but it did decrease specificity. CONCLU SION: Electron-beam CT angiography can depict hemodynamically signific ant stenoses in the LAD and LCX with a sensitivity of more than 90%. T he presence of coronary artery of coronary artery calcification result ed in decreased specificity but no appreciable change in sensitivity.