Evaluation Of Acute Renal Injury In Rabbits With Unilateral Ureteral Obstruction By IVIM-DWI

Objective: To investigate the value of IVIM-DWI in the evaluation of acute renal injury of unilateral ureteral obstruction of rabbit.Multiple B value IVIM-DWI,serum creatinine examination and pathological examination were performed in rabbits with unilateral ureteral acute obstruction model.The changes of imaging parameters,pathological examination and serum creatinine examination were observed and analyzed,and the correlation among them was analyzed.Methods: A total of 35 New Zealand special rabbits were selected,male and female,and randomly divided into experimental group(30 rabbits in 6h group,12h group,24h group,48h group,72h group,168h group)and control group(5 rabbits in control group).The left ureter of rabbits in experimental group were ligatured,the left ureter of rabbits in control group was only dissociated,not ligatured.Routine MR plain scan of both kidneys and IVIM-DWI scan with different B values(0、50、100、200、400、600、800、1000 s/mm~2)were performed in each group to determine the ADC,f,D and D* values.Venous blood from the left kidney was taken to measure the creatinine concentration;Histopathological examination of the left kidney was performed.one-way analysis of variance was conducted to compare left kidney IVIM-DWI parameters,serum creatinine and pathological scores between both groups.IVIM-DWI parameters of both kidneys at each time point in the experimental group were compared by means of Paired-Samples T test.The correlation between left kidney IVIM-DWI parameters,serum creatinine and pathological scores in each group was compared by means of Pearson correlation analysis.Results:(1)ADC:The renal cutaneous medulla in the experimental group was lower than that in the contralateral renal cutaneous medulla,except for the 12 h group(P<0.05).Except for the 48h group,the renal cutaneous medulla in the experimental group were lower than that in the control group.Within 12h,each group decreased gradually,and that in 48h group rose.The cortical cortex of 168h group was lower than that of 72h group,and the medulla of 48h-168h group gradually decreased(F=76.000,P<0.001),(F= 23.241,P<0.001).The difference between the 12h and 24 hrenal cortex groups,and between the 48h and 72h medulla groups were not statistically significant.f: The cutaneous medulla of the affected kidney is lower than that of the opposite kidney in experimental group(P<0.05).The renal cutaneous medulla in the experimental group was lower than that in the control group.Within12 h,there was a gradual decrease between groups.The medulla of 72h group was lower than that of 48h group,and the cortical cortex of 48h-168h group gradually decreased(F= 20.991,P<0.001),(F= 27.023,P<0.001);The differences between the 12 h and 48h groups,the72h to 168h medulla groups were not statistically significant.D: The renal cutaneous medulla in the experimental group was higher than that in the contralateral renal cutaneous medulla,except for the 24h and 72h groups.Except for renal cortex 12h group,medulla 12h,24h groups,the value of renal cutaneous medulla in the other groups was higher than that in the control group.Within 48 h,there was fluctuation between groups;The incidence of renal cortex decreased gradually from 48h to 168h group.The medulla of 72h and 168h groups was lower than that of 48h group(F= 37.934,P<0.001),(F=22.041,P<0.001).The difference in medulla between the groups for 72h and 168h was not statistically significant.D*:Except that renal medulla for 72h group was higher than that for 6h group,48h group was higher than that other group,the difference in the remaining renal cutaneous medulla between the groups was not statistically significant(F= 1.174,P=0.348),(F=2.593,P=0.023).(2)The difference of serum creatinine within 24h between these two groups was not statistically significant,the 24h-168h group increased gradually(P=0.001,P<0.001,P=0.038).The pathological score of affected kidney rose gradually with the passage of time of obstruction(P<0.001,P<0.001,P<0.001,P<0.001,P<0.001,P<0.001).(3)Value f of affected kidney was negatively correlated with pathological score(r=-0.846,P<0.001),and the value ADC was negatively correlated with pathological score(r=-0.392,P=0.020).Value f is negatively correlated with serum creatinine(r=-0.523,P=0.001).Serum creatinine was positively correlated with pathological score(r=0.809,P<0.001).Conclusion:(1)The value f and ADC can better indirectly reflect the pathological changes of renal injury in acute unilateral ureteral obstruction.And f showed the highest correlation with pathology score.(2)The value f can indirectly reflect the renal excretory function of acute unilateral ureteral obstruction in some extent.And f showed the highest correlation with serum creatinine.(3)IVIM-DWI can be a non-invasive method to evaluate renal injury in acute unilateral ureteral obstruction.The value f had the optimum assessing result.