Abstract
Background Although multidetector computed tomography (MDCT) allows non-invasive assessment of coronary artery stenosis, the presence of calcified lesions often lead to an overestimation of the stenosis. The present study was an evaluation of whether enhancement of first-pass myocardial data can improve the diagnostic accuracy of 64-MDCT. Methods and Results Data from 70 patients with single-vessel disease who underwent 64-MDCT followed by catheter-based coronary angiography (CAG) were analyzed. Myocardial enhancement was quantified by exaimining the signal densities at diastole. Among a total of 83 plaque segments, 35 calcified plaque segments were detected and 46 segments were found to have more than 50% coronary stenosis on catheter-based CAG. The average diameter stenosis was 75.2±12.8%. Diagnosis by 64-MDCT of significant stenosis (segment-based analysis) had a sensitivity, specificity and accuracy for segments without calcified lesions of 92%, 100% and 99.7%, respectively, and 95.2%, 50%, and 77.1%, respectively, for calcified lesions. Taking into account the myocardial enhancement by calculating the decrease of the standardized signal densities in percent, these parameters could be improved to 95.2%, 85.7% and 91.4%, respectively, for segments with calcified lesions. Conclusions The diagnostic accuracy of 64-MDCT for stenosis with calcified lesions in particular can be improved by taking into account the myocardial enhancement data. (Circ J 2009; 73: 116 - 124)
