Application Of Intravoxel Incoherent Motion Imaging And Diffusion-tensor Imaging In Obstructive Nephropathy

Objective: To explore the application value of intravoxel incoherent motion anddiffusion-tensor imaging in obstructive nephropathy.Methods:40rats were randomly subdivided into UUO model group by ligatingthe left ureter(n=32) and sham-operated rats without ureteral ligation(n=8).The MRIscans were performed on10rats(UUO group:8, Sham-operated group:2) at pre-operation and4time points following the operation. After that they were executed tocheck renal pathologicl obseraton. Scan sequence:①Three planner orientation；②T2WI axial；③T2WI coronal；④IVIM coronal；④DTI coronal. The parametersof renal tissue between operated group and sham-operated group were calculated andmeasured in the workstation. And then they were compared statistically(One-WayANOVA and Pearson Correlation).At last, renal medulla tractography was reconstructed in the workstation.Result: Renal tractography showed the fiber of obstruction kidneys was sparseand disordered. According to statistic analysis, the Standard ADC, D, f, ADC andFA value in renal cortex, peripticon and opticon all decreased progressively with thetime after operation prolonged. And they all had a negative correlation (r＜0，P=0.000)with positive expression of α-SMA and the stage of tubulointerstitial lesions,respecttively.However, there was no difference of statistics in D*value among groups in themedulla. Only in the cortex D*was negatively correlated with positive expression ofα-SMA and the stage of tubulointerstitial lesions, respectively (r <0, P <0.05).Among renal cortex, peripticon and opticon,the result of Standard ADC, D, f, ADCvalue were cortex＞peripticon＞opticon,while the result of FA value was cortex＜peripticon＜opticon. There was no difference of statistics in D*value among three (P＞0.05).Conclusion: IVIM and DTI techology application in obstructive nephropathy not only can reflect the degree of renal interstitial fibrosis which closely correlates withdeterioration of renal function，but also can help to abtain the information about therenal blood perfusion, water metabolism and ultrastructure.