肾脏MR表观扩散系数与估算肾小球滤过率的关系

目的探讨肾脏扩散加权成像(diffusion weighted imaging,DWI)所测量表观扩散系数(apparent diffusion coefficient,ADC)值与估算肾小球滤过率(estimated glomerular filtration rate,eGFR)之间的关系。材料与方法 2013年1月至2015年5月,武汉大学人民医院627例受试者在3.0 T磁共振扫描仪上行肾脏扩散加权成像。根据eGFR的不同将受试者分为3组,即eGFR30 m L/min/1.73m~2组、30 mL/min/1.73m~2≤e GFR60 m L/min/1.73m~2组以及eGFR≥60 m L/min/1.73m~2组。测量肾门水平肾皮髓质交界区的ADC值。比较3组间ADC值的差异并分析ADC值与eGFR的相关性。结果 3组肾脏的平均ADC值分别为(1.72±0.10)×10~(-3) mm~2/s、(1.88±0.16)×10~(-3) mm~2/s、(1.90±0.16)×10~(-3) mm~2/s。3组肾脏ADC值间差异具有统计学意义(F=81.24,P0.001)。肾脏ADC值与eGFR之间有显著相关性(r=0.613,P0.05)。结论 ADC值的测量能在一定程度上反映患者肾脏滤过功能,DWI对肾功能的评价具有重要价值。

Correlation between estimated glomerular ifltration rate(eGFR) and apparent diffusion coefifcient (ADC) values of the kidneys

Objective:To determine the relationship between apparent diffusion coefifcient (ADC) values of the kidney measured by diffusion-weighted MR imaging and the estimated glomerular ifltration rate (eGFR).Materials and Methods:A total of 627 adult patients in Renmin Hospital of Wuhan University, apply for kidney DWI examination in our hospital between January 2013 and May 2015. Regions of interests (ROIs) were manually delineated in the parenchyma as large as possible at the level of the middle portion of the bilateral kidneys. The eGFR was calculated by an equation based on serum creatinine level. The patients were divided into 3 groups: eGFR<30 mL/min/1.73m2; 30 mL/min/1.73 m2≤eGFR<60 mL/min/1.73m2; and eGFR≥60 mL/min/1.73m2. Differences between the 3 groups respect to the mean renal ADCs and the correlation of the renal ADC value and eGFR were analyzed.Results:The mean ADC values of the 3 groups were (1.72±0.10)×10-3 mm2/s for the group with eGFR<30 mL/min/1.73 m2; (1.88±0.16)×10-3 mm2/s for those with 30 mL/min/1.73m2≤eGFR<60 mL/min/1.73m2; and (1.90±0.16)×10-3 mm2/s for those with eGFR≥60 mL/min/1.73m2. There was statistically significant difference in renal ADCs among the 3 groups (F=81.24,P<0.001). The ADC of kidney showed positive linear correlation with eGFR (r=0.613,P<0.05).Conclusion:ADC values can relfect kidney ifltration function to some extent. DWI may be useful to evaluate renal function.