细微血流成像对肾挫裂伤诊断价值的动物实验研究

目的通过细微血流成像（MV-Flow）模式观察实验动物经不同级别肾创伤后创伤灶的改变情况及肾微循环改变情况。 方法15只新西兰白兔采用自身对照的方式,按照创伤程度不同分为3组（每组对照肾10只,创伤肾10只）。实验动物开腹后,观察正常肾MV-Flow图像并测量正常皮质血管指数（VI）值作为对照。建模30 min后,通过常规二维超声、MV-Flow技术对肾进行检查,并测量肾创伤灶处的VI值。最后处死实验动物,取出肾,制备大体标本。采用Wilcoxon检验比较实验组与对照组肾VI值的差异,对各实验组不同创伤程度3组间VI值进行Kruskal-Wallis H检验。 结果在MV-Flow模式下,能清晰显示肾段血管、弓形血管及小叶间血管（充满皮质）;创伤后,创伤灶区域血流信号出现部分缺损,根据损伤等级不同可出现“虫噬样”或“裂隙样”缺损,提示该区域存在创伤。不同创伤程度对照组VI值高于实验组［96.3%（85.01%,96.1%）vs 2.21%（1.09%,3.16%）、91.71%（85.68%,93.94%）vs 1.81%（1.24%,5.60%）和92.45%（85.70%,95.25%）vs 1.95%（0.67%,5.43%）］,差异具有统计学意义（Z均=-2.803,P均=0.005）;实验组各不同损伤程度组间VI值比较,差异无统计学意义（H=0.025,P=0.987）。 结论MV-Flow成像显示,肾创伤灶处肾皮质血管可出现“虫噬样”或“裂隙样”缺损,VI值接近于1%。MV-Flow成像能精确通过肾微循环改变显示肾创伤灶,提示肾出现的不同级别创伤。

Microvascular flow imaging evaluation of renal trauma: an experimental animal study

ObjectiveTo observe the changes of traumatic lesions and renal microcirculatory system in experimental animals with different degrees of renal trauma by microvascular flow imaging (MV-Flow). MethodsFifteen New Zealand white rabbits were divided into three groups (10 control kidneys and 10 injured kidneys in each group) according to the degree of trauma. After a laparotomy was performed, the MV-Flow images of normal kidneys were observed, and the normal cortical vascular index (VI) was measured as a control. Thirty minutes after the model was established, the kidneys were examined by conventional two-dimensional ultrasound and MV-Flow imaging, and the VI of traumatic lesions was measured. Finally, the rabbits were killed, and their kidneys were removed to prepare gross specimens. The Wilcoxon test was used to compare the data between the experimental group and control group, and the Kruskal-Wallis H test was used for comparison among the experimental groups. ResultsMV-Flow imaging clearly displayed renal segmental blood vessels, arcuate blood vessels, and interlobular blood vessels (full of cortex). After trauma, there were partial defects in the blood flow signal in the area of the traumatic lesion, with "worm-like" or "slit-like" defects according to different trauma grades, indicating the presence of trauma in the area. The median VI values of the three groups (control group vs trauma group) were 96.3% (85.01%, 96.1%) vs 2.21% (1.09%, 3.16%), 91.71% (85.68%, 93.94%) vs 1.81% (1.24%, 5.60%) ,and 92.45% (85.70%, 95.25%) vs 1.95% (0.67%, 5.43%), respectively. The data of each group showed a non-normal distribution and the differences were statistically significant (Z=-2.803, P=0.005), suggesting that there was a significant difference between the VI values of normal cortex and traumatic lesion. There was no significant difference in VI among the three experimental groups, which indicated that there was no significant difference in VI values among different severity of traumatic lesions (H=0.025, P=0.987). ConclusionAfter renal trauma, MV-Flow imaging can show "worm-like" or "slit-like" defects in renal cortical vessels, and the VI value is close to 1%. MV-Flow imaging can accurately show renal traumatic lesions by monitoring the change of microcirculation of the kidneys, which indicates the presence of renal trauma.