体素内不相干运动预测肾小球滤过率的初步研究

A Preliminary Study of Intra-Voxel Incoherent Motion for Assessing Renal Glomerular Filtration Rate

目的探索多b值扩散加权成像(DWI)的体素内不相干运动(IVIM)模型预测肾脏肾小球滤过率(GFR)的价值。方法纳入56例因蛋白尿或持续微量蛋白尿就诊的患者,根据估计肾小球滤过率(e GFR)将56例患者分成明显肾功能损伤组(sRI,e GFR≤30 m L/min/1.73 m^2)和非明显肾功能损伤组(non-sRI)。56例患者均完成7个b值DWI序列扫描。多b值DWI图像选择右肾中心层面勾画肾实质区为感兴趣区(ROI),然后行IVIM模型分析,分别得到3个参数:慢、快扩散系数(D_(slow)、D_(fast))和快扩散系数的分数(F_(fast))。结果 sRI组的3个IVIM参数均小于non-sRI组(t≥3.793,P<0.05),3个参数均与e GFR呈线性相关(r>0.357,P<0.05)。当区分sRI和non-sRI组时,3个参数的受试者工作特征曲线(ROC)下面积没有明显差异(Z≤0.482,P>0.05)。结论基于IVIM模型分析的多b值DWI具有预测GFR的潜力。

Objective To determine the value of intra-voxel incoherent motion （IVIM） based diffusion weighted imaging in the assessment of renal glomerular filtration rate in vivo. Methods Fifty-six consecutive participants with albuminuria or persistent micro-albuminuria were recruited into this study. The estimated glomerular filtration rate （eGFR） was calculated to classify the participants as having severe renal injury （sRI, eGFR ≤ 30 mL/min/1.73 m^2） or not （nonsRI）. DWI with seven b-factors was performed. Image analysis was performed by a radiologist to generate diffusion coefficient （ Dslow and Dfast, ） and fraction of fast diffusion （ Ffast ） maps using IVIM model. The regions of interest were curved to cover the renal parenchyma for parameter measurements. Results The D jow, Draft and Ffast were less in sRI than non-sRI （t 〉13. 793. 547 ,P 〈 0.05 ）, and positively related with eGFR （ r 〉 0. 357, P 〈 0.05 ）. For differentiating sRI from nonsRI, receiver operating characteristic curve indicated no significant difference between the three parameters （Z ≤0. 482, P 〉 0. 05）. Conclusion The IV1M model based diffusion weighted imaging has the potential for assessing renal glomerular filtration rate in vivo.