Detection of thrombosis and plaque rupture in atherosclerotic rabbit model by using 3.0 T MR imaging

Objective: To explore the imaging of the thrombosis after pharmacological triggering of plaque rupture in atherosclerotic rabbit model by using 3.0 T high-resolution magnetic resonance imaging. Methods: Twenty male New Zealand white rabbits were divided into an experimental group (n=16) and a control group (n=4). The aortic wall injuries were induced by an intravascular balloon in experimental group rabbits after high cholesterol diet. The pharmacological triggering with Russell's viper venom and histamine was performed after 3 months of establishment of model. All of the animals underwent pre-trigger and post-trigger MR examinations including 3D time of fight (3D TOF), T1WI, T2WI and post contrast T1WI. Euthanasia was performed in all rabbits and gross anatomy and histological specimen of aorta were obtained. Comparing the location and length of the thrombus between MRI images and histopathology was used Pearson test. Comparing the calculated indexes of abdominal aorta between rabbits with and without thrombosis was used AVONA test and LSD-t test. Results: After triggering, 8 in 14 survived rabbits developed thrombosis in experimental group, meanwhile, no thrombus was found in control group. The accuracy of multi-sequences MRI for detecting of thrombus was 87.1% (27/31). MRI data correlated with the histopathology regarding thrombus length (r=0.85, P<0.01) and thrombus location (r=0.94, P<0.01). Compared with rabbits without thrombosis, the rabbits with thrombosis had narrower lumen of abdominal aorta in the pre-triggered MR images [(5.71±2.38) mm2 vs. (8.93±5.36) mm2, P<0.01]. Conclusion: MRI is useful tool to determine the thrombosis and plaque rupture in atherosclerotic rabbit model. (authors)