Diagnostic Accuracy of Quantitative and Qualitative Phase-Contrast Imaging for the ex Vivo Characterization of XXXX Coronary Atherosclerotic Plaques.

@entity1 @entity453 @entity730
UNASSIGNED: Purpose To investigate the accuracy of x-ray grating interferometry phase-contrast (PC) imaging for the characterization of @entity1 @entity453 . Materials and Methods PC and conventional absorption computed tomographic (CT) imaging was performed ex vivo in this institutional review board-approved study in 40 @entity1 coronary artery segments by using a synchrotron radiation source. Qualitative analyses and calculations of image quality (McNemar test), plaque components (McNemar test), and plaque classification (Cohen k test) according to the American Heart Association classification were performed in 38 plaques detected at histopathologic examination (reference standard). Quantitative measurements of plaque components (ie, collagen, lipids, smooth muscle, and @entity730 ) were compared among PC and absorption images by using analysis of variance for repeated measures with post hoc Bonferroni correction. Results Image quality was superior in PC (median image score, 1) in all cases (100%) compared with absorption imaging (median image score, 3) (P < .001). Plaque components were detected by means of PC without significant differences (seven of seven @entity730 , 22 of 22 plaques with collagen and smooth muscle cells, P > .99; 29 of 29 plaques with lipids, P = .10) with histopathologic findings, whereas absorption imaging was used to detect @entity730 (seven of seven, P > .99) without statistical differences only (nine of 29 plaques with lipids, 0 of 22 plaques with collagen and smooth muscle cells, P < .001). Accuracy for plaque stage assessment with PC (early vs advanced) was 100%, and characterization was correct in 33 of 38 plaques (87%), while conventional absorption imaging allowed correct characterization of seven plaques only (18%, P < .001). PC CT numbers were significantly different (P < .05) for all plaque components (mean for @entity730 , 1236 HU    69; collagen, 78 HU    24; lipids, -18 HU    23; and smooth muscle cells, 34 HU    12), whereas absorption images showed significant differences (P < .001) between @entity730 (1336 HU    241) and other plaque components, but not for collagen (22 HU    13), lipids (-15 HU    14), and smooth muscle (13 HU    9) (P > .99). Conclusion PC imaging allows accurate characterization of @entity1 coronary artery plaques and quantitative assessment of plaque components, thereby outperforming absorption imaging. (  ) RSNA, 2015 Online supplemental material is available for this article.
