Analysis of the Usefulness of Optical Coherence Tomography and Intravascular Ultrasonography for the Examination of Rabbit Atherosclerotic Plaques

In the present study, we aimed to establish a rabbit atherosclerosis model and examine atherosclerotic plaques by using optical coherence tomography (OCT) and intravascular ultrasonography (IVUS) to evaluate the clinical usefulness of these diagnostic tools in the detection of atherosclerotic plaques. Twenty healthy New Zealand rabbits were fed on a high-fat diet for 4 weeks and then subjected to abdominal aortic intimal injury. The OCT and IVUS were performed after 8 weeks. The distal and proximal plaque images were marked to observe the plaque thickness and features of the lesions at the tunica intima and tunica media. Moreover, a pathological examination was performed to evaluate the efficacies of OCT and IVUS. The mean (SD) plaque thickness on OCT and IVUS images was 386.5 (125.3) m and 412.7 (165.8) m, respectively. Pathological examinations indicated a mean (SD) plaque thickness of 360.2 (98.l) m (P > 0.05). No significant differences were noted between the 2 methods. The intimal and medial thickness measured with OCT showed greater correlation with pathologically measured thickness (r = 0.95, P < 0.001 for OCT; r = 0.88, P < 0.001 for IVUS); in particular, the intimal thickness measurements on OCT showed a higher correlation (r = 0.98, P < 0.001). However, the measurements obtained using IVUS were not accurate. Thus, compared with IVUS, OCT was more accurate in determining the nature and thickness of vascular plaques.