Comparison of MRI manifestations and histopathologic findings of the elderly carotid arteries in ex vivo

Abstract

Objective To evaluate the ability of high resolution magnetic resonance (MR) imaging at 3.0 tesla to depict the characterization of human carotid arterial vessel wall and detect atherosclerotic lesions ex vivo in comparison to histopathologic results. Methods Eighteen carotid arteries obtained from 9 elderly donors underwent fat-suppressed T1 - and T2-weighted MR imaging at 3.0 tesla MR system with a mouse coil. Corresponding histological sections were obtained for the comparison. Correlation between MR images and histopathologic slices was obtained by Pearson or Spearman correlation coefficient. Cohen K was computed to quantify the agreement between MRI and histopathologic findings. Results Lumen area,intima and media area measured on fat-suppressed T2-weighted images showed stronger correlation with the corresponding histopathologic slices [ MRI vs. histopathology: ( 27. 53 ± 6. 77 ) mm2 vs. ( 25.83 ±6. 69 ) mm2, r2 ＝ 0. 91,P2 ＝ 0. 024, ( 12.31 ± 3. 31 ) mm2 vs. ( 12. 28 ± 3.71 ) mm2, r2 ＝ 0. 70, P2 ＝ 0. 020,Median 12. 29 mm2(Min 1.12 mm2, Max 33.18 mm2) vs. Median 11.62 mm2(Min 0.89 mm2, Max 32. 84 mm2 ), r2 ＝ 0. 74, P2 ＝ 0. 016, respectively]. The Cohen K score between the MR imaging and American Heart Association classifications was 0. 74, which corresponds to a good agreement. Conclusions 3.0 T high-resolution multi-sequence MRI can clearly show the structure of ex vivo carotid artery wall and allow quantitative assessment. Fat-suppressed T2W imaging has a greater advantage in presenting atherosclerotic lesions. Key words: Carotid artery diseases ; Atherosclerosis; Magnetic resonance imaging