正常成人肾脏磁共振扩散加权成像研究

目的 通过测量正常成人肾脏磁共振扩散加权成像(DWI)时的表观弥散系数(ADC)值,为肾脏病变患者在DWI成像时提供正常对照标准.资料与方法 20例健康志愿者均行MRI常规平扫及DWI成像,DWI成像时b值分别采用0s/mm2、200s/mm2、500s/mm2、800s/mm2、1000s/mm2.结果 不同b值下双侧肾脏皮髓质ADC值及双侧肾脏平均ADC值差异有统计学意义(F=57.863～240.324,P=0.000),双侧肾脏皮髓质ADC值及平均ADC值均高于肝、脾及胰腺ADC值.双侧肾脏皮质在不同b值下的ADC值均高于髓质,差异有统计学意义(t=8.436～20.281,P=0.000).左侧肾脏皮、髓质ADC值及平均ADC值在b=500s/mm2、b=800s/mm2及1000s/mm2时均高于右侧,差异有统计学意义(b=800s/mm2时t=2.023,P=0.048;其余P=0.000).b=200s/mm2时双侧肾脏皮、髓质ADC值及平均ADC值之间差异无统计学意义(t=1.739,P=0.098;t=0.704,P=0.490;t=-0.314,P=0.757).结论 正常成人肾脏ADC值在不同b值下有差异,双侧肾脏平均ADC值亦存在差异.

Diffusion Weighted MR Imaging in Normal Human Kidney

Purpose To measure the apparent diffusion coefficient(ADC) in kidneys of healthy volunteers.Materials and Methods Twenty healthy volunteers underwent transaxial fat-saturated echo-planar DWI MR imaging of the kidneys during normal breathing.Regions of interest were delineated manually in the cortex and medulla of the kidneys.ADC values of all b values(b = 0s/mm 2,200s/mm 2,500s/mm 2,800s/mm 2,1000s/mm 2) were calculated.Results In all volunteers,ADC values were significantly higher in the cortex than in the medulla(F low = 57.863,F high = 240.324,P = 0.000).When b values were 500s/mm 2,800s/mm 2 and 1000s/mm 2,AD,C values of left kidney were significantly higher than right kidney(t low = 8.436,t high = 20.281,P = 0.000).When b value was 200s/mm 2,there was no significant difference between left kidney and right kidney(t=1.739,P = 0.098;t = 0.704,P = 0.490;t =-0.314,P = 0.757).ADC values of kidney were higher than liver,spleen and pancreas.Conclusion ADC values in the kidneys of healthy volunteers are different at different b values,and the mean ADC values are different between left kidney and right kidney.