Study of renal cortical perfusion in rabbits by microbubbles-enhanced ultrasound cavitation

Objective To explore the change of renal cortical perfusion in rabbits by microbubbles-enhanced ultrasound cavitation. Methods Totally 20 New Zealand rabbits were randomly divided into four groups, 5 rabbits in each group. SonoVue was injected via the ear vein at a dose of 0.1 ml/kg. The renal perfusion imaging 30 s modeling was made. Under the mode of contrast enhancement, the rabbit kidneys irradiated with different mechanical indexs (MI) were 0.6 (MI 0.6 group) , 0.75 (MI 0.75 group) , 1.1 (MI 1.1 group) and 1.3 (MI 1.3 group) for 60 s, 15 min respectively. After the irradiation and conventional ultrasound contrast was made again, the renal perfusion imaging was mad. The time-intensity curves (TIC) were analyzed obtained from the following parameters: the slope rate of ascending curve (A) , the slope rate of descending curve (α) , area under the curve (AUC) , time to peak (TTP) , and derived peak intensity (DPI) . One-way ANOVA and LSD-t were used to analyze all experimental data. Results Compared with the MI 0.6 group, the MI 1.1 group and the MI1.3 group, the A, α were less than MI 0.6 group, the AUC, DPI, TTP were greater than MI 0.6 group, and the differences were statistically significant (MI 1.1 group vs MI 0.6 group: t=3.13, 5.31, 4.25, 4.53, 5.72, all P<0.05; MI 1.3 group vs MI 0.6 group: t=3.67, 6.23, 4.47, 5.48, 6.86, all P<0.05). Compared with the MI 0.75 group, the MI 1.1 group and the MI 1.3 group, the α were less than MI 0.75 group, the AUC, DPI, TTP were greater than MI 0.75 group, and the differences were statistically significant (MI 1.1 group vs MI 0.75 group: t=6.02, 4.36, 4.85, 5.83, all P<0.05; MI 1.3 group vs MI 0.75 group: t=6.19, 4.51, 5.73, 6.97, all P<0.05); the MI 1.1 group and the MI 1.3 group, the A were less than MI 0.75 group, and the difference were not statistically significant. The MI 1.1 group and the MI 1.3 group, the MI 0.6 and the MI 0.75 group, and the difference were not statistically significant. Conclusions To the change of hemodynamic of the rabbits renal cortical perfusion in the microbubbles-enhanced ultrasound cavitation contrast agent can be observed. Along with the mechanical index increased renal cortical perfusion flow stasis and the perfusion on of slowed in rabbit, may cause renal damage, the TIC curve displayed further changes. Key words: Contrast media; Kidney cortex; Hemodynamic