超声激励微泡的空化效应对兔肾皮质血流灌注的实验研究

目的探讨超声激励微泡的空化效应对实验兔肾皮质血流灌注的改变。 方法选择20只新西兰大白兔,经实验兔耳缘静脉团注微泡造影剂SonoVue（0.1 ml/kg）30 s。将20只实验兔随机分为4组,每组各5只,造影模式下调节机械指数（MI）分别为0.6、0.75、1.1、1.3,辐照各组实验兔肾均60 s,辐照后15 min再次进行常规超声造影,得出时间-强度曲线（TIC）,并获得肾皮质血流灌注参数包括上升支斜率（A）、下降支斜率（α）、曲线下面积（AUC）、达峰时间（TTP）、达峰强度绝对值（DPI）。采用单因素方差分析比较MI0.6组、MI0.75组、MI1.1组、MI1.3组实验兔A、α、AUC、DPI、TTP差异,进一步组间两两比较采用LSD-t检验。 结果MI1.1组、MI1.3组实验兔A、α均小于MI0.6组实验兔,AUC、DPI、TTP均大于MI0.6组实验兔,且差异均有统计学意义（MI1.1组vs MI0.6组：t值分别为3.13、5.31、4.25、4.53、5.72,P均<0.05;MI1.3组 vs MI0.6组：t值分别为3.67、6.23、4.47、5.48、6.86,P均<0.05）。MI1.1组、MI1.3组实验兔α均小于MI0.75组实验兔,AUC、DPI、TTP均大于MI0.75组实验兔,且差异均有统计学意义（MI1.1组vs MI0.75组：t值分别为6.02、4.36、4.85、5.83,P均<0.05;MI1.3组vs MI0.75组：t值分别为6.19、4.51、5.73、6.97,P均<0.05）;MI1.1组、MI1.3组实验兔A均小于MI0.75组实验兔,但差异均无统计学意义。MI1.1组与MI1.3组实验兔、MI0.6组与MI0.75组实验兔A、α、AUC、DPI、TTP差异均无统计学意义。 结论兔肾皮质血流在超声联合微泡造影剂的空化效应下可发生血流动力学改变,MI的增高引起肾皮质血流的淤滞和血流灌注的减慢,导致肾脏的损伤,应用TIC可定量分析肾功能改变。

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

ObjectiveTo explore the change of renal cortical perfusion in rabbits by microbubbles-enhanced ultrasound cavitation. MethodsTotally 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. ResultsCompared 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. ConclusionsTo 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.