不同扩散模型对Ⅰ期子宫内膜癌肌层浸润深度的诊断价值

The value of different diffusion models in the depth of myometrial invasion of stage Ⅰ endometrial cancer

目的评估单指数、双指数、拉伸指数模型各参数对诊断Ⅰ期子宫内膜癌肌层浸润深度的价值。材料与方法收集Ⅰ期子宫内膜癌53例,行常规MRI和多b值扩散加权成像(diffusion weighted imaging,DWI)扫描,在各参数伪彩图上测量表观扩散系数(apparent diffusion coefficient,ADC)、真扩散系数(D)、假扩散系数(D*)、灌注分数(f)、分布扩散系数(distribution diffusion coefficient,DDC)、水扩散异质性指数(α)值。根据子宫全切术后病理结果分为Ⅰa期和Ⅰb期。使用两独立样本t检验进行两组间差异性比较。绘制受试者工作特征(receiver operating characteristic,ROC)曲线,评价各参数对诊断Ⅰ期子宫内膜癌肌层浸润深度的效能。结果Ⅰb期D、f、DDC、ADC值小于Ⅰa期,且差异均有统计学意义(P<0.05),Ⅰb期D*值大于Ⅰa期,差异无统计学意义(P>0.05),Ⅰb期α值小于Ⅰa期,差异无统计学意义(P>0.05)。D、f、DDC、ADC值对诊断Ⅰ期子宫内膜癌肌层浸润深度的曲线下面积(area under curve,AUC)分别为0.867、0.762、0.794、0.774。结论单指数模型对诊断Ⅰ期子宫内膜癌肌层浸润深度有一定帮助,双指数、拉伸指数模型较之价值更高。

Objective: To evaluate the value of monoexponential, biexponential, and stretched exponential diffusion-weighted imaging models in diagnosing the depth of myometrial invasion of stage Ⅰ endometrial cancer. Materials and Methods: 53 cases of stage Ⅰ endometrial cancer were collected, and conventional MRI and multi-b value DWI scan were performed.The apparent diffusion coefficient(ADC), true diffusion coefficient(D) and pseudo-diffusion coefficient(D*) were measured on the pseudo-color map of each parameter, perfusion fraction(f), distribution diffusion coefficient(DDC), water diffusion heterogeneity index(α) value.According to the pathological results after total hysterectomy, it was divided into stage Ⅰa and stage Ⅰb. Differences between the two groups were compared using two independent sample t-tests. The receiver operating characteristic(ROC) curve was plotted to evaluate the efficacy of each parameter in diagnosing the depth of myometrial invasion of stage Ⅰ endometrial cancer.Results: The values of D, f, DDC and ADC in Ⅰb phase were less than Ia, and the differences were statistically significant(P<0.05). The D* value in Ⅰb phase was greater than that in Ia, the difference was not statistically significant(P>0.05),Ⅰb phase the α value was less than stageⅠa, and the difference was not statistically significant(P>0.05). The area under the curve(AUC)of D, f, DDC, and ADC values for the diagnosis of myometrial invasion of stage Ⅰ endometrial cancer were 0.867, 0.762, 0.794, and 0.774, respectively. Conclusions: The monoexponential model can help to diagnose the depth of myometrial invasion of stage Ⅰ endometrial cancer.The biexponential, and stretched exponential models are superior to the monoexponential model.