Fig. 2.

ROIs in histological and PCCT images. Representative plaque sections visualised with a Russel-Movat’s pentachrome stain (a) and von Kossa stain (b), with corresponding images of the same plaque locations (in the same plane) acquired during photon-counting CT (PCCT) scanning (c) are shown. Analysed plaque features—IPH, calcium, fibrous cap, fibrosis (elsewhere than in cap), lipid, necrosis and thrombus—are marked by circles and annotated. Black scale bars on the left represent 2 mm. IPH Intraplaque haemorrhage, PCCT Photon-counting computed tomography, ROI Region of interest