磁共振T2WI结合扩散加权成像对小肾癌亚型的诊断价值

目的 分析小肾癌(肿块直径≤3cm)亚型的磁共振扩散加权成像(DWI)、T2WI序列的影像特点,提高诊断准确率.资料与方法 回顾性分析72例经手术病理证实的小肾癌患者的MRI表现,并与手术病理结果进行对照.结果 72例小肾癌中,透明细胞癌61例(84.7％),乳头状肾细胞癌5例(6.9％),嫌色细胞癌4例(5.6％),囊性肾细胞癌2例(2.8％).61例透明细胞癌中56例(91.8％)T2WI表现为混杂高信号,54例(88.5％) DWI序列表现为高或稍高信号,5例(8.2％)表现为等信号,2例(3.3％) DWI及T2WI均表现为稍低信号；5例乳头状癌中4例T2WI表现为低信号,DWI表现为高或明显高信号；1例DWI与T2WI均表现为高信号；4例嫌色细胞癌中T2WI均呈低信号,DWI均呈高或明显高信号.结论 小肾癌亚型中肾透明细胞癌T2WI一般为混杂高信号,DWI为稍高信号或等信号；而非透明细胞癌则多为T2WI低信号,DWI为高或明显高信号,有助于提高小肾癌亚型的术前诊断率.

Value of MR T2WI Combined with Diffusion Weighted Imaging in the Diagnosis of Subtypes of Small Renal Cell Carcinoma

Purpose To explore the imaging features of MR T2WI and diffusion weighted imaging (DWI) for subtypes of small renal cell carcinoma (RCC) (diameter ≤ 3 cm),and to improve the diagnostic accuracy.Materials and Methods MR DWI and T2WI imaging findings of 72 patients with small RCC pathologically proved were retrospectively analyzed,and the results were compared with pathology.Results Out of 72 patients with RCC,61 cases (84.7%) were clear cell renal cell carcinoma,5 cases (6.9%) were papillary RCC,4 cases (5.6%) were chromophobic RCC,and 2 cases (2.8%) were cystic RCC.Among 61 cases of clear cell RCC,56 (91.8%) were heterogeneously hyperintensive on T2WI,54 (88.5%) were hyperintensive,or slightly hyperintensive,and 5 (8.2%) were isointensive on DWI,2 (3.3%) were slightly hypointensive on DWI and T2WI.Out of 5 cases of papillary RCC,4 were hypointensive on T2WI and hyperintensive on DWI,1 was hyperintensive on DWI and T2WI;4 cases of chromophobe RCC were hypointensive on T2WI,hyperintensive on DWI.Conclusion In the subtypes of small RCC,clear cell RCC generally is heterogeneously hyperintensive on T2WI and slightly hyperintensive on DWI;but non-clear cell RCC is hypointensive on T2WI and hyperintensive on DWI,which can help improve the preoperative diagnosis.