BACKGROUND: Little is known about the comparative results of coronary plaque assessment by multidetector computed tomography (MDCT) against the novel intravascular ultrasound virtual histology (IVUS-VH). METHOD: Threevessel IVUS-VH and MDCT were prospectively obtained from 21 patients. Each vessel was divided into 4-mm subsegments, which were used as the basic unit for analysis. The 4-mm subsegments were matched by their axial location. Lumen and outer vessel boundaries for IVUS-VH and for MDCT were traced by specific automatic softwares. The percent contribution of each IVUS-VH plaque tissue type and the ratio of necrotic tissue to calcium were quantified. The MDCT plaque was evaluated through its average density in Hounsfield units (HU). RESULTS: A total of 641 matched subsegments were computed from 70 vessels. Overall, the average IVUS-VH tissue composition was: fibrous = 64%; fibrofatty = 20%; necrotic tissue = 11%; dense calcium = 5%; and calcium/necrosis ratio = 5.1. MDCT average plaque attenuation ranged from 44 to 440 HU and was divided into three groups of similar size (1st tertile: 44-128 HU; 2nd tertile: 129-178 HU; 3rd tertile: 178-440 HU). There was an inverse correlation between IVUS-VH necrotic/ dense calcium ratio and MDCT plaque density (1st tertile: 4.1, 2nd tertile: 2.9, 3rd tertile: 2.3; P < 0.01) and a direct relationship between percent IVUS-VH dense calcium and MDCT plaque density (1st tertile: 1.5%, 2nd tertile: 2.5%, 3rd tertile: 3.8%; P < 0.01). CONCLUSION: Atherosclerotic plaque density evaluated by 64-MDCT significantly associates with plaque composition assessed by IVUS-VH.
Tomography, spiral computed; Ultrasonography, interventional; Coronary artery disease
