Animal experiment of the echo tracking technique in evaluating artery elasticity / 中华超声影像学杂志

ABSTRACT

Objective To assess the value of echo tracking(ET) technique on atherosclerosis in the rabbit models, and to probe the pathological foundation of its indexes changes and the usefulness in evaluating arterial elasticity. Methods Thirty New Zealand rabbits were divided into 3 groups randomly group A was the control group;group B,C were fed with high lipid feedstuffs for 8 weeks and 12 weeks, respectively. The ET examination of abdominal aorta was performed in group A and group B at the end of 8 weeks,it was performed in group A and group C at the end of 12 weeks. The parameters of elasticity were measured including pressure-strain elastic modulus (Ep), stiffness parameters(β), pulse wave velocity (PWVβ), augmentation index (AI), arterial compliance (AC), etc. Two dimensional ultrasound and pathological examination of abdominal aorta were performed at the same time. Results No obvious plaque and arterial wall thickness were seen in the abdominal aorta. Ep,β,PWVβ of group C were higher than that of group A and B, while AC of group C was lower than that of group A and B, and the difference had statistical significance (P<0.05). AI had no significant difference in all groups (P>0.05). Pathological examinations indicated that foam cell formation was seen in the abdominal aorta intima, the elastic fiber layer and smooth muscle layer were kept well in B group. Lots of cholesterol crystal formation was seen in the abdominal aorta intima and the two layer were obvious destroyed in group C. Conclusions ET can detect the atherosclerosis earlier than two-dimensional ultrasound. ET can detect the elasticity changes only when the elastic fiber layer and smooth muscle layer were destroyed . So it can be concluded that the destroy of elastic fiber layer and smooth muscle layer may be the pathological foundation of ET elasticity parameters changes.