title: Evaluation of multicontrast MRI including fat suppression and inversion recovery spin echo for identification of intra-plaque hemorrhage and lipid core in human carotid plaque using the mahalanobis distance measure.
abstract: Intra-plaque hemorrhage (IPH) and lipid core, characteristics of rupture prone carotid plaques, are often visualized in vivo with MRI using T1 weighted gradient and spin echo, respectively. Increasing magnetic field strength may help to identify IPH and lipid core better. As a proof of concept, automatic segmentation of plaque components was performed with the Mahalanobis distance (MD) measure derived from image contrast from multicontrast MR images including inversion recovery spin echo and T1 weighted gradient echo with fat suppression. After MRI of nine formaldehyde-fixated autopsy specimens, the MDs and Euclidean Distances between plaque component intensities were calculated for each MR weighting. The distances from the carotid bifurcation and the size and shape of calcification spots were used as landmarks for coregistration of MRI and histology. MD between collagen/cell-rich area and IPH was largest with inversion recovery spin echo (4.2/9.3, respectively), between collagen/cell-rich area/foam cells and lipid core with T1 weighted gradient echo with fat suppression (26.9/38.2/4.6, respectively). The accuracy of detection of IPH, cell-rich area, and collagen increased when the MD classifier was used compared with the Euclidean Distance classifier. The enhanced conspicuity of lipid core and IPH in human carotid artery plaque, using ex vivo T1 weighted gradient echo with fat suppression and inversion recovery spin echo MRI and MD classifiers, demands further in vivo evaluation in patients.
authors: Department of Cardiology, University Medical Center Utrecht, Utrecht, Netherlands. b.t.boekhorst@tue.nl
authors: Bernard C
authors: BC
authors: te Boekhorst
authors: Ronald
authors: R
authors: van 't Klooster
authors: Sandra M
authors: SM
authors: Bovens
authors: Kees W
authors: KW
authors: van de Kolk
authors: Maarten J
authors: MJ
authors: Cramer
authors: Matthijs F
authors: MF
authors: van Oosterhout
authors: Pieter A
authors: PA
authors: Doevendans
authors: Rob J
authors: RJ
authors: van der Geest
authors: Gerard
authors: G
authors: Pasterkamp
authors: Cees J
authors: CJ
authors: van Echteld
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000465:Algorithms; D016893:Carotid Stenosis / Q000150:complications / Q000378:metabolism* / Q000473:pathology*; D006470:Hemorrhage / Q000150:complications / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D050356:Lipid Metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels