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To evaluate the ability of 64-slice multidetector computed tomography (MDCT) –derived plaque parameters to detect and quantify coronary atherosclerosis, using intravascular ultrasound (IVUS) as the reference standard
METHOD AND MATERIALS
In 32 patients, IVUS and 64-MDCT was performed. The MDCT and IVUS datasets of 44 coronary arteries were co-registered using a newly developed fusion technique and quantitative parameters were derived from both imaging modalities. The threshold of >0.5mm of maximum wall thickness was used to establish plaque presence on MDCT and IVUS.
We analyzed 1364 coregistered 1-mm coronary cross-sections and 255 segments of 5-mm length. Compared with IVUS, 64-MDCT enabled correct detection in 957 of 1109 cross-sections containing plaque (sensitivity 86%). In 180 of 255 cross-sections atherosclerosis was correctly excluded (specificity 71%). On the segmental level, MDCT detected 213 of 220 segments with any atherosclerotic plaque (sensitivity 96%), whereas the presence of any plaque was correctly ruled out in 28 of 32 segments (specificity 88%). Interobserver agreement for the detection of atherosclerotic cross-sections was moderate (K=0.51), but excellent for the atherosclerotic segments (K=1.0). Detection rate was excellent for plaques >1 mm maximal intimal thickness (94%) and for plaques located within the proximal 40 mm from the ostium (>88%). Pearson’s correlation coefficient for vessel plaque volumes measured by MDCT and IVUS was r=0.91 (P<0.001). Bland-Altman analysis showed a slight non-significant underestimation of any plaque volume by MDCT (p=0.5), with a trend to underestimate noncalcified and overestimate mixed/calcified plaque volumes (p =0.22 and p=0.87 respectively).
MDCT is able to detect and quantify atherosclerotic plaque. Further improvement in CT resolution is required for more reliable assessment of very small and distal coronary plaques
MDCT angiography has the potential to become a non-invasive alternative to IVUS for plaque detection and quantification.
Radiological Society of North America 2011 Scientific Assembly and Annual Meeting; 11/2011