MR扩散加权成像对Ⅰ型与Ⅱ型子宫内膜癌的鉴别诊断价值

The value of MR diffusion-weighted imaging in differentiating type Ⅰ from type Ⅱ endometrial carcinoma

目的:探讨表观扩散系数(ADC)对Ⅰ型与Ⅱ型子宫内膜癌的鉴别诊断价值。方法:回顾性分析93例经手术病理证实的I型(71例)与II型(22例)子宫内膜癌患者的病例资料。所有患者均行常规MRI及DWI检查,b值为0,1000 s/mm^2。由两位医师在ADC图上分别测量ADC值,并比较Ⅰ型与Ⅱ型子宫内膜癌的ADC值。统计学分析采用Mann-Whitney U检验、Fisher确切概率法、ROC曲线分析及组内相关系数(ICC)。结果:Ⅱ型子宫内膜癌ADC中位数值为0.73[0.626,0.868]×10^(-3)mm^2/s,显著低于I型子宫内膜癌的ADC中位数值0.876 [0.813,0.972]×10^(-3)mm^2/s,两组间差异具有统计学意义(Z=-3.982,P<0.001)。ROC曲线显示ADC值鉴别Ⅱ型与Ⅰ型子宫内膜癌的曲线下面积为0.782,当ADC阈值为0.743×10^(-3)mm^2/s时,敏感度为64%,特异度为90%,符合率为84%。结论:ADC值有助于鉴别Ⅰ型与Ⅱ型子宫内膜癌。

Objective:The aim of this study was to determine the feasibility of apparent diffusion coefficient (ADC) for differentiating type Ⅰ from type Ⅱ endometrial carcinoma. Methods:93 patients with endometrial carcinoma proved by surgery and pathology were retrospectively evaluated.All patients underwent conventional MRI and DWI scan with b factors of 0 and 1000s/mm^2.ADC values were measured and compared between type Ⅰ and Ⅱ endometrial carcinomas independently by two radiologists on ADC maps.Statistical analysis were performed using Mann-Whitney U-test,Fisher exact test,receiver operating characteristic (ROC) curve and intraclass correlation coefficient. Results:The median ADC value for type Ⅱ was 0.73×10^-3mm^2/s,which was significantly lower than that of type Ⅰ(0.876×10^-3mm^2/s).There was a significantly statistical difference between type Ⅰ and Ⅱ endometrial carcinomas ( Z =-3.982, P <0.001).ROC curve analysis showed the area under the ROC was 0.782 when the threshold of ADC was at 0.743×10^-3mm^2/s,with sensitivity,specificity,and accuracy of 64%,90%,and 84% for the characterization between type Ⅰ and Ⅱ. Conclusion:MR ADC value is useful for differentiating type Ⅰ from Ⅱ endometrial carcinomas.