BOLD MRI Of Rat Kidney Changes During Acute Unilateral Ureteral Obstruction In 3.0T

Objective: To evaluate the renal oxygenation changes during acute unilateral ureteral obstruction in rats using blood oxygen level-dependent MR imaging(BOLD MRI) in 3.0 T MR.Methods: 16 healthy SD rats, 3 rats died because of anesthesia, 13 rats were performed kidney T2WI and coronal BOLD imaging respectively before UUO(obstruction former group), 1hour afer UUO(obstruction group) and 1 hour after release of UUO (lift group). Observed the signal and anatomical structure changes among the different groups of renal cortex and medulla, compared the SNR of renal parenchyma among three groups. BOLD images were reconstructed on 4.4 workstation, R₂^* values were determined in the cortex and medulla of the obstructed and the contrlateral nonobstructed kidneys, then comparative analysis of R₂^*values of renal cortex and medulla among different groups. According to the different affected side renal pelvis expansion rates, divided into mild obstruction and severe obstruction, then compared with the rate of R₂^* values changes; according to the different renal pelvis recovery rate, divided into relief group and no relief group, then analyze the relationship with obstructions and R₂^* changes.Results: The SNR between left and right renal were the same, and renal anatomy were showed clearly before UUO . After UUO the SNR of 13 rats affected side renal was significantly higher than before, the boundaries of cortex and medulla show blurry, and the pelviectasis in varying degrees. After release of UUO, the SNR higher than the obstruction former group, lower than the obstruction group, the boundaries got clearly, and the renal pelvis recovery in varying degrees. Before UUO, the R₂^* values of medulla was significantly higher than that of renal cortex, but during the UUO was associated with a decreased R₂^*in medulla, and after release of obstruction the medulla Objective: To evaluate the renal oxygenation changes during acute unilateral ureteral obstruction in rats using blood oxygen level-dependent MR imaging(BOLD MRI) in 3.0 T MR.Methods: 16 healthy SD rats, 3 rats died because of anesthesia, 13 rats were performed kidney T2WI and coronal BOLD imaging respectively before UUO(obstruction former group), 1hour afer UUO(obstruction group) and 1 hour after release of UUO (lift group). Observed the signal and anatomical structure changes among the different groups of renal cortex and medulla, compared the SNR of renal parenchyma among three groups. BOLD images were reconstructed on 4.4 workstation, R₂^* values were determined in the cortex and medulla of the obstructed and the contrlateral nonobstructed kidneys, then comparative analysis of R₂^*values of renal cortex and medulla among different groups. According to the different affected side renal pelvis expansion rates, divided into mild obstruction and severe obstruction, then compared with the rate of R₂^* values changes; according to the different renal pelvis recovery rate, divided into relief group and no relief group, then analyze the relationship with obstructions and R₂^* changes.Results: The SNR between left and right renal were the same, and renal anatomy were showed clearly before UUO . After UUO the SNR of 13 rats affected side renal was significantly higher than before, the boundaries of cortex and medulla show blurry, and the pelviectasis in varying degrees. After release of UUO, the SNR higher than the obstruction former group, lower than the obstruction group, the boundaries got clearly, and the renal pelvis recovery in varying degrees. Before UUO, the R₂^* values of medulla was significantly higher than that of renal cortex, but during the UUO was associated with a decreased R₂^*in medulla, and after release of obstruction the medulla...