MRI评价肾纤维化形态学变化的实验研究

Evaluation of Morphological Changes in Renal Fibrosis Using MRI: An Experimental Study

目的:建立肾纤维化兔模型,结合病理改变研究T2WI评价单侧输尿管梗阻(unilateral ureteral obstruction,UUO)肾纤维化兔模型的形态学变化。方法:40只新西兰大白兔随机分为手术组(n=32)和假手术组(n=8),手术组行左侧输尿管结扎。分别于建模前及建模后的2、4、6、8周行冠状位及轴位T2WI扫描,完成扫描后处死取左肾行病理学检查。选取轴位T2WI肾门最大层面测量肾皮质面积A1(cm2)、肾实质面积A2(cm2)。采用单因素方差分析比较建模前后各时间点的A1值及A2值。结果:随着梗阻时间的延长,A1值于建模后2周明显升高,于4~8周逐渐减小(P<0.05),A2值于建模后2~8周逐渐减小(P<0.05)。病理显示随着梗阻时间延长手术组兔肾小管于建模后2周明显扩张,伴上皮细胞肿胀变性,4~8周肾小管逐渐萎缩、消失;肾间质于建模后增宽、炎症细胞浸润,纤维化逐渐形成。肾皮质于建模后2周明显增厚,第4~8周逐渐变薄。结论:单侧输尿管梗阻可成功建立肾纤维化兔模型,MRI T2WI能准确地反映肾纤维化的形态学变化,为临床观察和诊断提供一种有效的影像学检查方法。

Purpose： A Rabbit model of renal fibrosis was established and utilized to evaluate the morphologic changes of unilateral ureteral obstruction （Unilateral ureteral obstruction, UUO） based on pathological study and T2W[ MR[ exam. Methods： Forty New Zealand white rabbits were randomly assigned into operation group （n=32） and sham group （n=8）, and the operation group was with unilateral ureteral ligation. All the rabbits underwent coronal and axial T2WI scanning before and 2, 4, 6, 8 weeks after the establishment of models. The rabbits were sacrificed and the left kidney tissues were collected for pathological examination after the scanning was finished. The maximum level of the renal hilum from axial T2WI was selected to measure the renal cortex area A~ （cm2） and renal parenchyma area A2 （cm2）. Single factor analysis of variance was used to compare the A~ and A2 values before and after the model was established. Results： With the extension of the obstruction time, the value of A~ was significantly increased in 2 weeks after the model was established, but decreased gradually in 4-8 weeks （P〈0.05）, while the value of A2 was decreased gradually （P〈0.05）. Pathology results showed that with the obstruction time prolonged, the renal tubules of the rabbits were significantly expanded, and the renal tubular epithelial cells were swollen and degenerated in 2 weeks after the model was established but gradually withered to disappearance in 4-8 weeks, during which renal interstitial fibrosis with inflammatory cell infiltration were observed. Thickening of the renal cortex was observed obviously in 2 weeks after the model was established, and then gradually thinning in 4-8 weeks. Conclusion： Rabbit model of kidney fibrosis obstruction. The morphological changes of the rabbit model T2WI. can be successfully established by unilateral ureteral of kidney fibrosis can be accurately displayed on MRI