Identification and quantification of macrophage presence in coronary XXXX by optical coherence tomography.

@entity731 @entity32 @entity30 @entity5494
AIMS: Vulnerable plaques are characterized by a high macrophage content. We investigated the optical coherence tomography (OCT) capability of identifying coronary plaque macrophage presence using tissue property indexes. METHODS AND RESULTS: Fifteen epicardial coronary arteries were imaged by OCT and subsequently analysed by histology. Correlating OCT-histological sections were identified and @entity30 ( @entity30 ) were selected on both @entity731 and normal appearing vessel tracts. OCT-derived tissue property indexes named @entity5494 ( @entity5494 ), signal attenuation, and granulometry index were applied on @entity30 to identify inflamed @entity30 defined as a macrophage percentage >10 by histology. Forty-three paired samples (OCT frame and histology section) were considered suitable as @entity30 for analysis. Eleven out of 43 @entity30 were considered inflamed and the remaining 32 @entity30 were non-inflamed on the basis of histological count of macrophage percentage. All OCT-derived tissue property indexes were positively correlated with macrophage percentage (P = 0.0001 for all). Receiver operating characteristic curve analysis showed that @entity5494 , granulometry index, and signal attenuation had a significant area under the curve (area = 0.906, 0.804, and 0.793, respectively). A two-step algorithm requiring to first apply @entity5494 with a cut-off value of 0.0570 followed by granulometry index was able to identify an inflamed ROI with a sensitivity of 100% and a specificity of 96.8%. CONCLUSION: OCT was able to identify and quantify macrophage presence in coronary artery specimens using tissue property indexes. @entity5494 and granulometry index showed the highest accuracy in identifying a significant @entity32 , especially if used together in a two-step algorithm.
