Atherosclerotic plaque components in human aortas contrasted by ex vivo imaging using fast spin-echo magnetic resonance imaging and spiral computed tomography

RATIONALE AND OBJECTIVES. Imaging techniques that distinguish atherosclerotic plaque components may be useful in identifying the nature of the atherosclerotic lesion and determining the best method of treatment for obstructive vascular disease. This study compares fast spin-echo (FSE) magnetic resonance (MR) and spiral computed tomography (CT) images of excised human atherosclerotic aortas to determine which imaging technique provides the best contrast between plaque components ex vivo. METHODS. Aortas were imaged using four FSE sequences in MR with and without frequency-selective fat saturation, and using spiral CT without contrast. The average signal intensity of a region of calcification, thrombosis, fatty plaque, and normal vessel wall was measured on all images and compared. RESULTS. The use of fat saturation pulses in MR did not significantly alter the signal from atherosclerotic plaque for the sequences used. Proton density-weighted FSE sequences that collected early echoes were better than other FSE sequences and CT at differentiating calcification from all soft tissues. T2-weighted FSE sequences that collected later echoes were best at soft-tissue discrimination. CONCLUSION. The FSE techniques used were superior to nonenhanced spiral CT in discriminating plaque components ex vivo, including calcification.