Electron Beam Ct In Coronary Artery Disease, Clinical Applied Research

Objectives: we investigated the applicability of three dimensional medial axis reformation (MAR) for evaluation of contrast-enhanced electron beam CT (EBCT) scans of the coronary arteries. And sought to idendify and localize significant stenoses on a segmental base , to determine the accuracy of diagnosing stenoses of coronary artery and intracoronary stents by EBCT and intravenous administration of a constrast agent and assess its clinical value. Methods: EBCT scan was performed within one month inteval of selective coronary angiography and stent implanted in consecutive 25 patients with coronary artery disease ( 24 men and 1 woman, mean [ ± SD] age 55.8±10.6 years old). Thirty-five intracoronary stents were implanted in thirty-one diseased segments of two hundred and twenty-five segmental coronary artery. Continuous axial cross sections of the heart were acquired, triggered to the electrocardiography before and after injection of IV contrast medium. MAR were obtained separately for each coronary artery. Both the reconstructions and cross-sectional images were independently evaluated by investigators for the presence of significant stenoses ( ≥50% luminal diameter ). The results were then compared with coronary angiography results, of which investigators had been unaware. Results: Nine distal segments of two hundred and twenty-five segmental coronary arteries were not evaluable due to decreased imaged quality. EBCT coronary angiography visualized all thirty-one segmental coronary arterial lesions with stents implanted. In the remaining one hundred and eighty-five segmental vessels, 10 of 13 ( 76.9%) significant stenoses were correctly detected ( 76.9% sensitivity). Absence of significant stenoses was correctly depicted in 163 of 172 segmental vessels (94.8% specificity). The negative and positive predictive values were 98.2% and 52.6%, respectively. For the detection of significant stenosis of intracoronary stents, the sensitivity, specificity, the negative and positive predictive value in EBCT coronary angiography and three dimensional MAR were 71.4%, 92.9%, 92.9% and 71.4%, respectively. Overall, the sensitivity, specifity and accuracy for detecting coronary and intracoronary stents stenosis in EBCT coronary angiography and MAR were 75%, 94.5% and 92.7%. Conclusions: Noninvasive EBCT coronary angiography and three dimensional MAR is very accuracy in detecting significant coronary artery lesions, and identifing the intracoronary stents locations. EBCT scans may be of value for evaluating therapy effect and follow-up monitoring after percutaneous coronary interventions, especially in stented patients. MAR are an extremely useful postprocessing tool in the evaluation of EBCT data sets of coronary artery.