正常成人肾脏磁共振扩散加权成像研究

摘要

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.%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/mm2, 200s/mm2, 500s/mm2, 800s/mm2, 1000s/mm2) were calculated. Results In all volunteers, ADC values were significantly higher in the cortex than in the medulla (Flow = 57.863, Fhigh = 240.324, P = 0.000). When b values were 500s/mm2, 800s/mm2 and 1000s/mm2, AD, C values of left kidney were significantly higher than right kidney (tlow = 8.436, fhigh = 20.281, P = 0.000). When b value was 200s/mm2, there was no significant difference between left kidney and right kidney (t= 1.739, P= 0.098; t = 0.704, P = 0.490; f = -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.