PURPOSE: To evaluate the anatomic and functional change in acutely obstructed kidneys, and the probability of functional recovery after resolving the obstruciton. MATERIALS AND METHODS: There were 5 animal groups(6 rabbits in each group)-normal control group, 4 acute ureteral obstruction group. Each of the latter group was imaged with Gd-DTPA enhanced dynamic MR 2, 6, 24, and 48 hours after ligation of the left proximal urter, respectively. We compared the findings of dynamic MR imaging and histopathological findings. RESULTS: We could observe centripetal movement of dark band pattern which could be defined as 3 phasesrenal cortex, outer medulla, and inner medulla in normal rabbits. The appearance of the dark band pattern was delayed or absent in ureteral obstruction group with a linear relationship to the duration of the obstruction. CONCLUSION: Gd-DTPA enhanced MR can be used to differentiate acute obstructive nephropathy from other causes of nephropathy and foretell the prognosis of the obstruction.