Evaluating Atherosclerosis of the Abdominal Aorta in Rabbits Using 2-D Strain Imaging

Abstract

After establishment of an animal model of atherosclerosis, speckle tracking imaging was performed to analyze the correlation between ultrasound characteristics and pathological manifestations. Rabbits were divided into the normal control (NC) and atherosclerosis (AS) groups. Rabbits in the AS group were subjected to ultrasound-guided balloon injury of the abdominal aorta and fed a high-fat diet for 16 wk. Rabbits in the NC group were fed a normal diet for the same period. After 16 wk, all animals underwent serological tests, ultrasound and speckle tracking circumferential strain analysis. In the AS group, 28 hypo-echoic plaques had formed. The circumferential strain of six segments at the short axis of plaques in the AS group was lower than that in the NC group (p < 0.001), and global circumferential strain (GCS) in the AS group was significantly reduced compared with the NC group (p < 0.001). In the AS group, the area ratio of type I to type III collagen fibers was smaller than that in the NC group. The GCS of atherosclerotic plaques was positively correlated with the area ratio of type I to type III collagen fibers in plaques (r = 0.7181, p < 0.001). In conclusion, there is a significant positive correlation between the decreased circumferential strain and the decreased area ratio of type I to type III collagen fibers in hypo-echoic plaques.

Keywords: Atherosclerosis; Circumferential strain; Collagen fiber; Ultrasound.