血氧水平依赖MRI纵向监测亲体肾移植术后保留肾与移植肾血氧水平改变

Blood Oxygen Level-dependent MRI Longitudinal Monitor of Changes in Blood Oxygen Levels in Remaining and Donated Kidney After Receiving Parental Kidney Transplantation

目的探讨采用血氧水平依赖(BOLD)MRI纵向评估供体保留肾及对应受体的移植肾术后肾脏血氧水平改变的价值。资料与方法前瞻性收集2015年7月-2017年2月天津市第一中心医院行亲体肾移植术的60例患者,包括30例健康肾移植供体以及与之相对应的30例受体。供体于单侧肾切除术前3 d和术后2周接受肾脏BOLD检查,受体于肾移植术后2周接受肾脏BOLD检查,其中15对亲体肾移植患者于术后半年再次接受肾脏BOLD检查。测量并记录手术前后不同时间肾脏皮质、髓质的表观弛豫率(R2~*)。比较手术前30例供体双肾皮质、髓质R2~*值的差异,比较手术前及术后2周30组受试者保留肾及移植肾皮质髓质R2~*值的差异,比较15组随访的受试者手术前后不同时间保留肾及移植肾皮质髓质R2~*值的差异。结果 60例受试者均成功完成MRI扫描。30例受试者手术前供体双肾间皮质及髓质R2~*值差异无统计学意义(P>0.05)。髓质R2~*值高于皮质,差异有统计学意义(P<0.01)。30组受试者单侧肾切除术后2周保留肾皮质及髓质R2~*值较术前均减低,移植肾皮质和髓质R2~*较术前均减低,差异均有统计学意义(P<0.01)。15组随访半年的受试者术后2周保留肾和移植肾皮质及髓质R2~*值较术前均明显降低,术后半年R2~*值较术后2周水平升高,但仍低于术前水平,差异均有统计学意义(P<0.05)。结论 BOLD MRI可以用于纵向监测亲体肾移植术后保留肾及移植肾血氧水平改变情况。

Purpose To discuss the value of longitudinal assessment of the remaining kidney of the donor and kidney blood oxygen level changes after receiving kidney transplantation by applying blood oxygen level-dependent（BOLD） MRI. Materials and Methods Sixty patients underwent parental kidney transplantation from Jul. 2015 to Feb. 2017 in Tianjin First Center Hospital were prospectively collected, including 30 healthy kidney transplant donors and 30 recipients corresponding to them. The donors received renal BOLD examination 3 days before and 2 weeks after unilateral nephrectomy. Recipients received renal BOLD examination 2 weeks after kidney transplantation, of which, 15 pairs of patients underwent parental kidney transplantation received renal BOLD examination again six months after surgery. The apparent transverse relaxation rate（R2^＊） values of the cortex and medulla at different times before and after transplantation were measured and recorded. The differences of R2^＊ values between 30 donors＇ cortex and medulla in both kidneys before surgery were compared; the differences of R2^＊ values between 30 pairs of subjects＇ cortex and medulla in remaining and donated kidney within 2 weeks before and after surgery were compared; variance gained through single factor repeated measurement was applied to analyze and compared the difference of R2^＊ values between 15 pairs of follow-up subjects＇ cortex and medulla in remaining and donated kidney at different time points before and after surgery. Results All 60 subjects received MRI scan, and there was no statistical difference in R2^＊ values between 30 subjects＇ cortex and medulla in both kidney before surgery（P〈0.05）. The difference between the cortex and medulla was statistically significant, with R2^＊ value of medulla higher than that of cortex（P〈0.01）. R2^＊ values of cortex and medulla of the remaining kidney in 30 subjects two weeks after receiving unilateral nephrectomy were lower than those before surgery. R2^＊ value of cortex and medulla of donated kidney were both lowered before surgery, the difference of which was statistically significant（P〈0.01）. R2^＊ values of cortex and medulla in remaining and donated kidney of 15 pairs of subjects who have received half a year＇s follow up were both evidently reduced two weeks after surgery, and R2^＊ values six months after surgery were raised compared with two weeks after surgery, but were still lower than that before surgery, the difference of which were both statistically significant（P〈0.05）. Conclusion BOLD MRI can be used for longitudinal monitor of changes in blood oxygen levels in remaining and donated kidney after receiving parental kidney transplantation.