Objective Our aim is to investigate the feasibility of detecting vulnerable plaque and thrombosis by use of MRI.

Methods 24 male New Zealand White rabbits were divided into two groups: the atherosclerosis group (As group, n=20) and the normal control group (C group, n=4). After induction of atherosclerosis, MRI exams were conducted separately before and after the induction, triggering the plagues' disruption. The rabbits were then massacred to obtain data of pathology. The animals in the normal control group were fed a standard diet, and we performed MRI exam separately before and after, triggering the plagues' disruption too. After MRI exams, rabbits were massacred to obtain data of pathology. The in vivo imaging results of MRI were compared with the histological structure of the specimens, and the concordance of κ was calculated. Furthermore, the effect of plaque's component on the rupture was evaluated with logistic models.

Results 63% (7 of 11) in rabbits in as group had thrombosis after plagues' disruption was triggered. In contrast, vessels in C group were smooth without plaque or thrombus. Sensitivity of MRI for detecting thrombosis' numbers was 71.4%, and specificity was 100%. The correlation of thrombosis' position (r=0.91, p<0.001) and length (r=0.88, p=0.001) were detected by MRI and by histopathology were statistically significant. The correlation of area of lipid core (r=0.9, p<0.001) and area of plaque (r=0.85, p<0.001) detected by MRI and by histopathology were both statistically significant. The comparison of components with t test showed that thickness of fibrous cap (p=0.005), area of lipid core (p=0.001) and area of lipid core/area of plaque (p<0.001) were significantly different between rupture group and non-rupture group. In addition, for unvaried ordinal regression analysis, the percentage of lipid core area in plaque area was independently associated with the rupture of plaques (OR: 1.277, 95% CI 1.025 to 1.591; p=0.03).

Conclusion MRI can be used to detect atherosclerotic thrombosis, and may be become a useful tool to identify vulnerable plaques.