Quantitative measurement of lipid rich plaque by coronary computed tomography angiography: A correlation of histology in sudden cardiac death

Abstract Background and aims Recent advancements in coronary computed tomography angiography (CCTA) have allowed for the quantitative measurement of high-risk lipid rich plaque. Determination of the optimal threshold for Hounsfield units (HU) by CCTA for identifying lipid rich plaque remains unknown. We aimed to validate reliable cut-points of HU for quantitative assessment of lipid rich plaque. Methods 8 post-mortem sudden coronary death hearts were evaluated with CCTA and histologic analysis. Quantitative plaque analysis was performed in histopathology images and lipid rich plaque area was defined as intra-plaque necrotic core area. CCTA images were analyzed for quantitative plaque measurement. Low attenuation plaque (LAP) was defined as any pixel  Results Among 105 cross-sections , 37 (35.2%) cross-sectional histology images contained lipid rich plaque. Although the highest specificity for identifying lipid rich plaque was shown with p  = 0.003) and no significant differences were observed between lipid rich plaque area and LAP area between histology and CT analysis (Histology: 0.34 ± 0.73 mm 2 , QCT: 0.37 ± 0.71 mm 2 , p  = 0.701). Conclusions LAP area by CCTA using a