Background-We investigated the ability of multidetector spiral computed tomography (MDCT) to detect atherosclerotic plaque in nonstenotic coronary arteries. Methods and Results-In 22 patients without significant coronary stenoses, contrast-enhanced MDCT (0.75-mm collimation, 420-ms rotation) and intravascular ultrasound (IVUS) of one coronary artery were performed. A total of 83 coronary segments were imaged by IVUS (left main, 19; left anterior descending, 51; left circumflex, 4; right coronary, 9). MDCT data sets were evaluated for the presence and volume of plaque in the coronary artery segments. Results were compared with IVUS in a blinded fashion. For the detection of segments with any plaque, MDCT had a sensitivity of 82% (41 of 50) and specificity of 88% (29 of 33). For calcified plaque, sensitivity was 94% (33 of 36) and specificity 94% (45 of 47). Coronary segments containing noncalcified plaque were detected with a sensitivity of 78% (35 of 45) and specificity of 87% (33 of 38), but presence of exclusively noncalcified plaque was detected with only 53% sensitivity (8 of 15). If analysis was limited to the 41 proximal segments (segments 1, 5, 6, and 11 according to American Heart Association classification), sensitivity and specificity were 92% and 88% for any plaque, 95% and 91% for calcified plaque, and 91% and 89% for noncalcified plaque. MDCT substantially underestimated plaque volume per segment as compared with IVUS (24Ϯ35 mm 3 versus 43Ϯ60 mm 3 , PϽ0.001). Conclusions-The results indicate the potential of MDCT to detect coronary atherosclerotic plaque in patients without significant coronary stenoses. However, further improvements in image quality will be necessary to achieve reliable assessment, especially of noncalcified plaque throughout the coronary tree. Key Words: tomography Ⅲ atherosclerosis Ⅲ coronary disease D irect, noninvasive imaging of coronary atherosclerotic plaque might potentially improve risk stratification for the occurrence of coronary events in selected asymptomatic individuals. 1,2 Initial reports of the ability of contrastenhanced multidetector spiral computed tomography (MDCT) to visualize noncalcified coronary atherosclerotic plaque have thus received widespread attention. [3][4][5][6][7][8] However, the ability of MDCT to detect and quantify coronary atherosclerotic plaque in vivo has never been systematically validated. We therefore evaluated the ability of MDCT with submillimeter slice collimation to detect and quantify coronary atherosclerotic plaque in patients without significant coronary artery stenoses in comparison with intravascular ultrasound (IVUS).
Methods
PatientsIn 22 patients (14 male, 8 female; mean age, 58 years), MDCT was performed as part of research protocols that enrolled consecutive subjects who were scheduled for invasive coronary angiography for clinical reasons. In all patients, coronary artery stenoses (Ն50% diameter reduction) had been ruled out by coronary angiography, and an IVUS study of the largest coronary vessel was performed. Patients wi...
