肾脏MR扩散加权成像的临床应用

目的：初步探讨肾脏MR扩散加权成像技术的临床应用。方法：肾功能正常者30例（无原发性和继发性肾病病史及相关危险因素），其中10例采用不同b值（50、500s／mm2）进行横断面和冠状面DWI成像；10倒进行了横断面或冠状面高b值DWI成像（500、800s／mm2），比较图像质量；10例在屏气和不屏气的情况下进行了两次肾脏冠状面DWI成像（b=500s／mm2）；10例进行两次肾脏冠状面DWI成像（b=500s／mm2），两次成像间隔时间为1～6个月。对不同b值肾脏ADC值、相同b值时肾脏横断面和冠状面ADC值及重复成像肾脏ADC值进行比较分析。分析屏气对成像结果的影响。结果：不同b值的肾脏ADC值间差异具有显著性意义；相同b值时肾脏横断面和冠状面ADC值间差异无显著性意义．b=800s／mm2时肾脏DWI图像质量低于b=500s／mm2；重复成像肾脏ADC值间差异无显著性意义；屏气与否不影响肾脏的ADC值。结论：肾脏冠状面DWI（b=500s／mm2）成像具有很好的可重复性，可用于屏气情况不同的患者，具有较好的临床应用前景。

Clinical Application of Diffusion-weighted MR Imaging in Normal Kidneys

Objective:To evaluate the clinical application of DWI in normal kidneys.Methods:30 healthy volunteers,without nephropathy,participated in this study.10 volunteers underwent transverse and coronal fat-saturated echo-planar DW MR imaging of the kidneys with b value 50 and 500s/mm2.Freehand regions of interest were delineated in the parenchyma of the kidneys.These ADC values were calculated for comparison and analysis.10 volunteers underwent transverse or coronal fat-saturated echo-planar DW MR imaging of the kidneys with b=500 and 800s/mm2.The image quality was classified into 3 grades and compared.10 volunteers underwent coronal fat-saturated echo-planar DW MR imaging of the kidneys with and without breath holding (b value 500s/mm2).And the ADCs with or without breath holding were compared.10 volunteers underwent coronal fat-saturated echo-planar DW MR imaging of the kidneys for twice (b value 500s/mm2),the interval being 1 to 6 months.Reproducibility was assessed.Results:In all volunteers,there was statistically significant difference between ADC low and ADC high.There was no difference in the ADC between coronal and transverse imaging.The image quality was better in DWI(b=500s/mm2).The ADCs were not affected by breath holding or not.No statistically significant changes were found in the repeated study of the volunteers.Conclusion:Coronal DW MR imaging is feasible and reproducible,having a good prospect in clinical application.