Authors: Wisnumurti Kristanto Peter M A van Ooijen Marcel J W Greuter Jaap M Groen Rozemarijn Vliegenthart Matthijs Oudkerk
Publish Date: 2013/01/17
Volume: 29, Issue: 5, Pages: 1137-1148
Abstract
Computed tomography CT may characterize lipidrich and presumably ruptureprone noncalcified coronary atherosclerotic plaque based on its HounsfieldUnit HU but still inconclusively This study aimed to evaluate factors influencing the HUvalue of noncalcified plaque using software simulation Several realistic virtual plaqueburdened coronary phantoms were constructed at 5 μm resolution CT scanning was simulated with settings resembling a 64row multidetector CT 64MDCT and reconstructed at 64MDCT 04 mm and MicroCT 48 μm resolutions Influences of lumen contrastenhancement stenosisgrades and plaque compositions on plaque visualization were analyzed Lumen contrastenhancement and mean plaque HUvalue were positively correlated R2 092 with approximately the same slopes for all plaque compositions Percentage lipidcontent and mean plaque HUvalue were negatively correlated R2 098 Stenosisgrade and noise had minimal influence on the correlations Influence of lumen contrastenhancement on plaque HUvalue was following a specific exponentially declining pattern y = Ae−λx + c from the lumen border until 2pixel radius Outside 2pixel radius plaque HUvalues deviated maximally 5 HU from noncontrastenhanced reference Thus to avoid lumen contrastenhancement influence plaques should be measured outside 2pixel radius from the lumen border Based on the patterns found a lumen influence correction algorithm may be developed HUbased plaque percentage lipidcontent determination might serve as an alternative plaque characterization method However its applicability is still hindered by many inherent limitations
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