DWI在持续非卧床腹膜透析患者残余肾功能评估中的作用

Application of Diffusion-Weighted MRI in Assessing Residual Renal Function in Continuous Ambulatory Peritoneal Dialysis Patients

目的研究扩散加权成像(DWI)的表观扩散系数(ADC)值与持续非卧床腹膜透析(CAPD)患者残余肾功能(RRF)的关系。方法前瞻性纳入40例腹膜透析患者及40名健康志愿者进行肾脏常规和DWI扫描,CAPD组中有10例患者分别于透析前和透析时进行扫描,b值为0,300,600 s/mm2,记录每例患者的临床资料,包括残余肾功能、肌酐、胱抑素C、尿素氮、尿量等数据。测量每位受试者的肾脏实质厚度和ADC值,然后进行组间比较;10例进行两次扫描患者前后ADC值采用配对检验比较组间差异;患者的ADC与临床数据的相关性采用线性相关分析。结果与对照组对比,CAPD组的肾脏实质厚度明显较小(t=13.28,P<0.001),ADC值明显降低(t=16.92,P<0.001)。10例CAPD患者腹膜透析时ADC值(1.74±0.10)mm2/s较腹膜透析前(1.62±0.10)mm2/s稍高(t=1.62,P<0.05)。另外,CAPD患者的ADC值与残余肾功能呈正相关(r=0.447,P=0.004),与胱抑素C呈负相关(r=-0.352,P=0.026),与尿量呈正相关(r=0.354,P=0.025)。结论 CAPD患者的肾脏弥散功能明显受损,DWI可用于评估CAPD患者的RRF。

Objective To prospectively evaluate the residual renal function（ RRF） using diffusion-weighted（ DW）magnetic resonance（ MR） imaging,and to investigate the relationship between ADC value and RRF in continuous ambulatory peritoneal dialysis（ CAPD） patients. Methods Forty CAPD patients（ study group） and forty healthy volunteers（ control group） were recruited for this study,and conventional and DW-MR imaging with three different b values（ 0,300 and 600 sec / mm2 respectively） were performed in all subjects. Ten patients of the study group received MR scanning before and during peritoneal dialysis. The clinical data including RRF,serum creatinine,cystatin C,urea nitrogen and urine output were recorded. The renal parenchymal thickness and apparent diffusion coefficient（ ADC） values were measured,and the results were compared between the two groups. The two-tailed paired Student＇s t-test was used to analyze the difference between the two groups. The relationship between ADC values and the clinical data was evaluated by linear correlation analysis. Results Compared to the control group,in the study group the renal parenchymal thickness was significantly reduced（ t = 13. 28,P 0. 001） and ADC value was significantly decreased（ t = 16. 92,P 0. 001）. The ADC value in 10 patients during peritoneal dialysis was（ 1. 74 ± 0. 10） mm2/ s,which was significantly higher than the pre-dialysis value of（ 1. 62 ± 0. 10） mm2/ s（ t = 1. 62,P 0. 05）. In addition,in the study group a parallel correlation existed between ADC values and RRF（ r = 0. 447,P = 0. 004） as well as between ADC values and urine output（ r = 0. 354,P = 0. 025）,and a negative correlation existed between ADC values and cystatin C level（ r =- 0. 352,P = 0. 026）. Conclusion In patients receiving continuous ambulatory peritoneal dialysis,the renal diffusion function is seriously impaired,which can be assessed by DW-MRI.