目的 探讨DW-MRI在肾乏脂肪 血管平滑肌脂肪瘤(lipid poor renal angiomyolipoma, LPRAML)与肾透明细胞 癌(renal clear cell carcinoma, RCCC) 的鉴别诊断价值，提高LPRAML的诊断准确 率。方法 对经病理证实为LPRAML的21例 和RCCC 20例术前磁共振图像进行分析， 分别测量病灶的ADC值并计算出平均值， 用独立样本t检验比较两组病例的平均 ADC值的差异。结果 LPRAML的病灶的ADC 值为(1.21±0.21)×10﹣3 mm2 /s；RCCC的 平均ADC值为(0.89±0.08)×10﹣3 mm2 /s， LPRAML的ADC值高于RCCC，且差异具有统 计学意义(t=8.32,P<0.01)。结论 LPRAML 和RCCC具有不同的扩散特征，ADC值对两 者的鉴别诊断具有重要价值。

Objective To explore the value of Diffusion-weighted imaging (DWI-MRI) in differentiation of lipid poor renal angiomyolipoma (LPRAML) from renal clear cell carcinoma (RCCC), and to improve the accuracy in diagnosing LPRAML. Methods The MR images of pathologically confirmed LPRAML (21 cases) and RCCC (20 cases) were analyzed and the mean ADC values were calculated, then the means ADC values of the two groups were compared with the student's test. Results The mean ADC values of LPRAML and RCCC were (1.21±0.21)×10-3mm2 /s and (0.89±0.08)×10-3mm2 / s respectively, and the mean ADC value of LPRAML was significantly higher than that of RCCC (t=8.32, P<0.01). Conclusion LPRAML and RCCC have different characteristics, ADC value can be applied as an important tool in differentiate LPRAML from RCCC.