MRI平扫在肾脏嗜酸细胞瘤与嫌色细胞癌鉴别诊断中的价值

目的:评估MRI平扫量化参数在肾脏嗜酸细胞瘤与嫌色细胞癌鉴别诊断中的价值。方法:本研究回顾性分析42例经病理证实患者的MRI平扫数据，其中嗜酸细胞瘤18例，嫌色细胞癌24例。由两名医生采用盲法测量肿瘤实性成分的T1WI及T2WI标准化信号值（SSI）、表观弥散系数（ADC）。应用组内相关系数（ICC）评估测量的可靠性，采用独立样本t检验分析各参数间差异的统计学意义，受试者工作特性（ROC）曲线分析来衡量各参数的诊断效能。结果:两名医师的测量具有极高的可靠性（ICC:0.805～0.911）。嫌色细胞癌的平均ADC值低于嗜酸细胞瘤（1.07±0.20）×10-3 mm2/s vs.（1.48±0.17）×10-3 mm2/s；P＜0.001]，T2WI-SSI高于嗜酸细胞瘤（1.72±0.22）vs.（1.32±0.26）；P＜0.001]，T1WI-SSI在两组间差异无显著意义（0.89±0.15）vs.（0.80±0.12）；P=0.35]。ROC分析显示ADC值的曲线下面积（AUC）高于T2WI-SSI（0.942 vs. 0.859）。结论:ADC值与T2WI标准化信号强度对于鉴别肾嗜酸细胞瘤和嫌色细胞癌均有帮助，但ADC值具有更高的诊断价值。

The value of MRI plain scan in the differential diagnosis of renal oncocytoma and chromophobe renal cell carcinoma

Objective: To evaluate the value of quantitative parameters of MRI plain scan sequence on distinguishing renal oncocytoma from chromophobe cell carcinoma. Methods: The MRI plain scan imaging of 42 patients were retrospectively evaluated. All cases were pathologically diagnosed after operation，including 18 renal oncocytoma and 24 chromophobe renal cell carcinoma. Two radiologists blindly measured the standardized signal intensity（SSI） of T1WI and T2WI，apparent diffusion coefficient（ADC） values of the solid components in the tumor. The intraclass correlation coefficient（ICC） was calculated to analyze the reliability of the measurements. The independent sample t-test was used to analyze the statistical significance of the differences between the parameters，and receiver operating characteristic （ROC） curve analysis was used to evaluate the diagnostic performance of each parameter. Results: The ICC value of the two radiologists ranged from 0.805 to 0.911，indicating highly reliable measurement. The mean ADC value of chromophobe cell carcinoma was lower than that of renal oncocytoma（1.07±0.20）×10-3 mm2/s vs.（1.48±0.17）×10-3 mm2/s；P<0.001]，and the mean T2WI-SSI was higher than that of renal oncocytoma（1.72±0.22） vs.（1.32±0.26），P<0.001]，while there was no significant difference in T1WI-SSI between renal oncocytoma and chromophobe renal cell carcinoma（0.89±0.15） vs. （0.80±0.12）；P=0.35]. ROC analysis showed that the area under curve （AUC） of ADC value were higher than that of T2WI-SSI（0.942 vs. 0.859）. Conclusion: Both ADC value and T2WI-SSI are helpful for differentiating renal oncocytoma from chromophobe renal cell carcinoma，with ADC showing higher diagnostic value.