Characterization of atherosclerotic plaque components by high resolution quantitative MR and US imaging

High resolution MRI at 3 T and US imaging at 50 MHz were used for atheroscl erotic plaque characterization. For 14 excised segments of human arteries, conventional MR and US images, quantitative MR T2 maps, US integrated atten uation (IA) maps, and histologic sections were produced and compared. The M R T2 and US attenuation mean values estimated in selected regions of intere st were related with tissue type as identified on histologic sections. Sign ificant distinction between media or collagen and lipid or collagen lipidic plaque was achieved with both techniques (MR: P < .001; US: P < .01). Sign ificant distinction was obtained between media and collagen (P < .0001) and between iliac and aortic media (P < .05) with MR T2 but not with IA. MR an d US native and parametric images, with different sensitivities to tissue t ype, provide complementary information useful for quantitative plaque chara cterization.