Objective To explore the change of wall shear stress (WSS) parameter measured by vector flow imaging technology (V Flow) in evaluation of the early hemodynamic changes of aorta atherosclerosis (AS) in rabbit models.

Methods AS models were established by feeding high fat forage in healthy New Zealand rabbits (n=7). After 14 weeks of feeding, the formation of atherosclerotic plaque on the wall of rabbit abdominal aorta was observed by conventional gray-scale ultrasound, the blood flow volume (BFV) and peak systolic velocity (PSV) were measured by color Doppler flow imaging (CDFI), and V Flow was used to observe and measure the anterior and posterior wall WSS values of the rabbit aorta, then once a week. After 34 weeks of feeding, the pathological examination results were used as the gold standard to compare and analyze the dynamic changes of WSS in the formation and development of AS.

Results The pathological results showed that typical fatty streak changes of AS on the wall of rabbit aorta after 34 weeks of high-fat diet, and AS fibrous plaques appeared in the abdominal aorta of rabbits after 37 weeks. The dynamic changes of the anterior and posterior wall of the abdominal aorta with the progression of the AS course were as follows:from 14 weeks, it showed a decreasing trend, from 20/21 to 27 weeks, it showed an increasing trend, and after 27 weeks it gradually decreased. The inflection point values of the WSS maximum (WSS_max) and WSS average (WSS_mean) of the anterior and posterior walls of the abdominal aorta were significantly different from the baseline value at week 0 (P < 0.05). The inflection points of WSS_max and WSS_mean curves were earlier than the PSV and BFV values measured by conventional CDFI.

Conclusion Compared with traditional CDFI, V Flow can predict as plaque and evaluate hemodynamic changes in abdominal aorta, which has potential clinical application value.