3.0T MR扩散加权成像诊断肾脏恶性肿瘤

3.0T MR diffusion weighted imaging in diagnosis of malignant renal tumors

目的评估3.0T MR扩散加权成像(DWI)及ADC值鉴别肾脏恶性肿瘤不同病理类型及组织学分级的价值。方法回顾性分析66例经我院手术病理证实的肾脏恶性肿瘤患者的术前DWI图像,测量肿瘤及对侧相应部位正常肾实质的ADC值,并进行统计学分析。结果肾脏恶性肿瘤及正常肾实质的ADC值分别为(1.653±0.598)×10-3mm2/s、(2.305±0.218)×10-3mm2/s,差异有统计学意义(P<0.001);以ADC值<2.0×10-3mm2/s为阈值,诊断肾脏恶性肿瘤的特异度为93.94%、敏感度为71.21%、准确率为82.58%。肾透明细胞癌与非透明细胞癌ADC值差异有统计学意义(P=0.001)。肾透明细胞癌Ⅰ级与Ⅲ级、Ⅱ级与Ⅲ级间ADC值比较差异有统计学意义(P=0.002、0.004),Ⅰ级与Ⅱ级间差异无统计学意义(P=1.000)。结论3.0T MR DWI可用于肾脏恶性肿瘤的诊断,定量分析ADC值可能有助于鉴别肾脏恶性肿瘤的不同病理类型及组织学分级。

Objective To evaluate 3.0T MR diffusion weighted imaging（DWI） and ADC value in diagnosis of different pathological types and grades of malignant renal tumors.Methods DWI images of 66 patients of malignant renal tumors proved pathologically were retrospectively reviewed.ADC values of tumors and the corresponding areas of lateral normal renal parenchyma were measured and analyzed statistically.Results There was significant difference between the mean ADC value of malignant renal carcinomas（[1.653±0.598]×10-3 mm2/s） and that of normal renal parenchyma（[2.305±0.218]×10-3 mm2/s,P 0.001）.ROC curve showed that taking ADC value of lower than 2.0×10-3 mm2/s as a threshold for diagnosing renal malignant tumor,the specificity,sensitivity and accuracy was 93.94%,71.21% and 82.58%,respectively.Statistical differences were found between clear cell carcinoma and non-clear cell carcinoma（P= 0.001）,as well as clear cell carcinoma grade Ⅰ and Ⅲ（P= 0.002）,grade Ⅱ and Ⅲ（P= 0.004） respectively.However,no statistical difference was observed between grade Ⅰ and Ⅱ（P= 1.000）.Conclusion 3.0T MR DWI can be used in diagnosis of malignant renal tumors,and ADC value may help to differentiate the pathological type and grade.