[Values of Minimal Apparent Diffusion Coefficient,Difference between Ratios of Apparent Diffusion Coefficients,and Dynamic Contrast-enhanced Magnetic Resonance Imaging Features in Diagnosing Breast Ductal Carcinoma In Situ with Microinvasion].

Objective To explore the values of minimal apparent diffusion coefficient(ADCMin),difference between ratios of apparent diffusion coefficients(ADCDR),and dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)in the treatment of breast ductal carcinoma in situ with microinvasion(DCIS-Mi).Methods Totally 27 patients with DCIS-Mi and 31 patients with breast ductal carcinoma in situ(DCIS)were collected in our hospital from October,2016 to June,2018.Philips Ingenia 3.0T superconducting magnetic resonance scanner and dedicated phase-controlled array surface coil were used for breast examinations.ADCMin and maximum apparent diffusion coefficient(ADCMax)were selected from multiple regions of interest(ROI)in the apparent diffusion coefficients(ADC)figure,and ADCDR was calculated.In addition,DCE-MRI characteristics were analyzed.Results The ADCMin of DCIS-Mi was significantly lower than that of DCIS[(1.15±0.03)×10 3 mm 2/s vs.(1.34±0.04)×10 -3 mm 2/s,t=-7.192,P=0.002],the ADCDR was significantly higher than that of DCIS[(0.32±0.03)×10 -3 mm 2/s vs.(0.18±0.08)×10 -3 mm 2/s,t=-10.228,P<0.001],and the early enhancement rate of DCIS-Mi was higher than that of DCIS[159.71(157.82,162.49)% vs.147.29(143.59,160.22)%,Z=-3.578,P=0.007].The background parenchymal enhancement of DCIS-Mi was moderate,severe,and non-lump-like,mainly segmental,and the internal enhancement was heterogeneous or clustered circular.Multivariate Logistic regression analysis showed that non-internal characteristics of the mass,the edge of the mass,internal enhancement characteristics of the mass,time-intensity curve,early enhancement rate,ADCMin and ADCDR were the optimal variables for the diagnosis of DCIS-Mi,and the optimal variables were shown by receiver operating characteristic(ROC)curve analysis:the area under curve,sensitivity and specificity of ADCMin,ADCDR,non-tumor internal enhancement,and tumor internal enhancement were higher,with the critical values being 1.12×10 -3 mm 2/s,0.31×10 -3 mm 2/s,1.50,and 1.50,respectively.Conclusion DCE-MRI combined with ADC value(especially ADCMin,ADCDR,non-mass internal enhancement,and mass internal enhancement)is helpful in differentiating breast DCIS-Mi and DCIS.