磁共振扩散加权成像定量参数对宫颈癌的诊断效能及其一致性的多中心评价

Evaluation of diagnostic efficacy and consistency for cervical cancer based on quantitative parameters from DWI:a multicenter study

目的:基于多中心数据分析MR扩散加权成像(Diffusion weighted imaging,DWI)表观扩散系数(Apparent diffusion coefficient,ADC)单指数模型及体素内不相干运动(Intravoxel incoherent motion,IVIM)模型的定量参数对宫颈癌诊断及病理分级的价值,并进一步探讨DWI定量参数在不同临床中心间的一致性。方法:回顾性分析3个临床中心经手术病理证实的170例宫颈癌及12例宫颈平滑肌瘤患者的资料,术前均行多b值DWI扫描。所有DWI图像通过后处理获得相应DWI定量参数,包括IVIM模型的纯扩散系数(D)、伪扩散系数(D*)、灌注分数(f)、fD*及ADC单指数模型的ADC值。采用受试者工作特征(Receiver operating characteristic,ROC)曲线及Man-Whitney U检验分析DWI定量参数诊断宫颈癌的效能及术前对宫颈癌病理分级的价值,采用Kruskal-Wallis单因素ANOVA(多样本)方法分析DWI定量参数在不同临床中心间的一致性,P<0.05为差异有统计学意义。结果:宫颈癌病灶的DWI定量参数(D、D*、f、fD*、ADC值)均明显小于正常宫颈组织(P<0.05)。定量参数D、f及ADC值的曲线下面积(Area under the curve,AUC)值均大于0.95,其诊断宫颈癌的敏感度、特异度、阳性预测值及阴性预测值均大于90%。低分化(G3)宫颈癌的D和ADC值低于中高分化(G1~G2)宫颈癌(P<0.05)。在宫颈癌病灶中,临床中心2的设备2与临床中心3之间各DWI定量参数(D、f、D*、fD*、ADC值)无明显差异(P>0.05)。宫颈癌灌注相关参数(f、D*、fD*)在不同临床中心不同设备之间无明显差异(P>0.05)。结论:DWI定量参数D、f及ADC值在宫颈癌的诊断方面取得了良好的诊断效能(AUC值均大于0.95)。DWI定量参数D和ADC值可以区分宫颈癌的病理分级,且在不同临床中心相同型号的MRI设备中具有较好的一致性。

Objective:To investigate the diagnostic efficacy of apparent diffusion coefficient(ADC) mono-exponential model and intravoxel incoherent motion(IVIM) model’s quantitative parameters for cervical cancer diagnosis and its pathological differentiation.And the consistency of DWI parameters among different centers were further analyzed.Methods:All of 170 cases of cervical cancer and 12 cases of cervical leiomyoma confirmed by histology in 3 centers were retrospectively analyzed.DWI parameters were obtained,including pure diffusion coefficient(D),pseudo diffusion coefficient(D*),perfusion fraction(f),fD* of IVIM and ADC value.Receiver operating characteristic(ROC) curve and Man-Whitney U test were used to evaluated the diagnostic efficacy of DWI parameters and the preoperative diagnostic value of cervical cancer differentiation.DWI parameters of cervical cancer between four scanners from three centers were compared by Kruskal-Wallis one-way ANOVA(k samples).(P<0.05).There were no significant differences in the perfusion related parameters(D*,f,fD*) between varoius scanners(P>0.05).Conclusion:DWI parameters D,f and ADC values obtained very good diagnostic efficacy in cervical cancer diagnosis(AUC values>0.95).Diffusion related parameters D and ADC values were significantly important in evaluating the pathological differentiation of cervical cancer,and got good consistency in the same type of scanners in different centers.