MSCT灌注成像评价兔积水肾肾功能的可复性

MSCT perfusion imaging in evaluation of restorability of rabbits renal function of hydronephrotic kidney

目的探讨MSCT灌注成像对积水肾肾功能可复性的预测价值。方法48只雄性新西兰大白兔随机分为1周组、3周组、5周组和7周组(每组n=12),每组再随机分为假手术组(Sham,n=6)和梗阻组(Ob,n=6)。梗阻组通过手术制成输尿管完全梗阻及积水肾模型,假手术组施行同样手术,但不结扎输尿管。分别于术前及各自的梗阻时间点接受MSCT灌注扫描和SPECT检查,测定左肾皮质的血流量(BF)、血容量(BV)、达峰时间(TTP)和肾小球率过滤(GRF)。解除梗阻2个月后再次复查。各阶段分别处死1只动物行病理学观察。结果①MSCT灌注扫描:不同时间段,假手术组术前、术后BF、BV、TTP值比较差异无统计学意义(P>0.05)。梗阻后,随梗阻时间延长,BF、BV值逐渐降低,4组间梗阻解除前BF、BV值比较,差异均有统计学意义(P<0.05)。梗阻解除后,梗阻1周组BF、BV值恢复到接近术前水平(P>0.05);梗阻3周组BF、BV值与术前比较差异有统计学意义(P<0.05),与解除前比较差异无统计学意义(P>0.05);梗阻5周组及梗阻7周组BF、BV值持续降低,与梗阻解除前、术前比较,差异均有统计学意义(P<0.05)。梗阻后,梗阻1、3、5周组TTP值随梗阻时间延长而逐渐延长(P<0.05),梗阻5周组与7周组间比较及各自与解除后比较均无变化(P均>0.05)。②SPECT肾动态显像:不同时间段,假手术组术前、术后GRF值比较差异无统计学意义(P>0.05)。假手术组及梗阻组术前、梗阻解除前及梗阻解除后各组GRF值比较,差异无统计学意义(P>0.05)。梗阻解除前1、3、5及7周组间GRF值比较,差异均有统计学意义(P<0.05)。③病理学结果:随梗阻时间延长,肾小管扩张越明显,肾纤维化程度逐渐渐加重。结论单侧输尿管完全梗阻后,积水肾皮质BF、BV值分别下降志(312.21±26.35)ml/(100g.min)、(10.76±5.37)ml/(100g)时,肾功能难以恢复到正常水平。MSCT灌注成像能为术前肾功能恢复潜力评价提供有价值信息。

Objective To assess the value of MSCT perfusion in the restorability of renal function of hydronephrotic kidney due to completed unbilateral uterus obstruction. Methods Forty eight healthy adult male rabbits were randomly divided into 4 groups as 1 week group, 3 weeks group, 5 weeks group and 7 weeks group （1 w, 3 w, 5 w, 7 w, each n=10）. Then rab- bits in every group were randomly divided into sham-operated subgroup and obstruction subgroup. Rabbits in obstruction subgroups were operated as complete ureteral obstruction and renal water model, and in sham operated subgroups were operated as same as obstruction subgroups except ureter being not ligated. MSCT perfusion imaging and SPECT examination were performed before operation and at each obstruction time to detect the left renal cortical blood flow （BF）, blood volume （BV）, time to peak （TTP） and glomerular filtration rate （GRF）. Then obstruction was lifted, and MSCT perfusion imaging and SPECT examination were performed again after 2 months. One rabbit was sacrificed in every stage for pathological examination. Results （1）There was no significant difference （P〉0.05） of BF, BV, TTP （P〉0.05） before and after surgery of sham operated subgroups at different time periods. After obstruction, BF, BV value reduced gradually with time pro- longed. There was no statistical difference of the BF, BV value among the 4 groups before the obstruction being relieved （P 〈0.05）. After lifting obstruction, the BF, BV value of 1 w restored to near preoperative levels （P〉0.05）, but not recovered in 3 w（P〈0.05）, while no statistical difference was found in 3 w （P〉0.05）. BF, BV value of 5 w and 7 w continued to decrease, and the differences were statistically significant （P〈0.05） compared with obstruction being relieved and before operation. After obstruction, TTP value of 1, 3 and 5 w gradually extended （P〈0.05） with the period being prolonged, no statistical difference was found between 5 w and 7 w, as well as between each group and after lifting the obstruction （all P〉 0.05）. （2）There was no significant difference for GRF value between pre- and post-operation for sham-operated subgroups （P〉0.05）, none between sham operated subgroups and obstruction subgroups for preoperation, before and after lifting the obstruction （P〉0.05）. Statistical difference was also found between 1 w, 3 w, 5 w and 7 w groups for GRF value before the obstruction being relieved. （3）With obstruction time prolonged, tubular expansion increasingly clear and the degree of renal fibrosis increased gradually. Conclusion After complete unilateral ureteral obstruction, when the BF, BV value of hydronephrotic kidney cortical decreased to （312.21±26.35）ml/（100 g ·min）, （10.76±5.37）ml/（100 g）, the renal function is difficult to restore to normal levels. MSCT perfusion imaging can provide valuable information for evaluating the capability of renal function recovery before operation.