Abstract 206: Feasibility and Three Dimensional Color-coded Maps of Tissue Characterization of Coronary Plaques Using 320-detector Row Computed Tomography - A Comparison With an Integrated Backscatter Intravascular Ultrasound
Background: Recently, a new generation of multi-detector row computed tomography (MDCT) with 320-detector rows (DR) has become available in clinical settings. However, tissue characterization of coronary plaques using 320-DRCT has not been established well.
Methods: Seventy-seven coronary atherosclerotic lesions in 77 patients with angina were visualized by both 320-DRCT (Aquilion One, Toshiba) and integrated backscatter intravascular ultrasound (IB-IVUS, YD co., Ltd.) at the same lesion. To determine the thresholds for discrimination of plaque components, we compared CT values with IB values as a gold standard. Optimal thresholds were determined from the analysis of receiver operating characteristic curves. Then, we constructed three dimensional (3D) color-coded maps of 320-DRCT based on the thresholds.
Results: CT values of lipid pool (n=115), fibrosis (n=93), vessel lumen and calcification (CL: n=73) were 28±19 HU (range: −18 to 69 HU), 98±31 HU (44 to 195), 357±65 HU (227 to 534) and 998±236 HU (366 to 1489), respectively. The thresholds of 50 HU, 210 HU and 450 HU were the most reliable predictor of lipid pools, fibrosis, vessel lumen and calcification. Lipid volume measured by 320-DRCT was correlated with that measured by IB-IVUS (r=0.63, p<0.05), whereas fibrous volume measured by 320-DRCT was not.
Conclusion: Quantitative analysis of lipid volume by 320-DRCT was feasible, whereas that of fibrosis was not feasible because manual exclusion of the outside of vessel hindered rigorous discrimination between fibrosis and extra-vessel components. Three dimensional color-coded maps of 320-DRCT were promising non-invasive methods for lipid pool of coronary plaques.