The Study Of Different Diffusion Models Of Magnetic Resonance Imaging In Breast Disease

Purposes To evaluate the diagnostic value of mono-exponential,intravoxel incoherent motion,diffusion kurtosis imaging models of DWI in characterizing benign and malignant breast lesions.Methods The inclusion criteria concluded:(1)patients who diagnosed as Breast Imaging Reporting and Data System(BI-RADS)category 4 or higher at mammography or ultrasonography were seleted for breast MR imaging.The exlusion criteria included(1)patients who had undergone core-needle biopsy or preoperative chemotherapy or surgery(2)patients whose MR images had substantial motion artifacts.TIRM,multi-b DWI(readout-segmented echo-planar imaging)and dynamic contrast-enhanced T1 WI were performed in all patients.ROIs were drawn on ADC maps on the slice with the largest tumor area using b=50 and 1000s/mm2,avoiding necrotic or cystic parts.The parameters of mono-exponential(ADC),IVIM [molecular diffusion coefficient(Dt),perfusion-related diffusion coefficient(D*)and perfusion fraction(f)]and diffusion kurtosis model[Diffusivity(Dk),Kurtosis(K)]were measured by two radiologists.The difference of the parameters between malignant tumors and benign lesions was analyzed by independent sample t test.ROC curve was performed to compare the diagnosis value of different parameters based on the AUC(area under the curve),Z test was performed to compare the difference of each AUC.Results 80 patients(83 lesions)were included in our study,there were 38 breast benign lesions and 45 malignant lesions.ADC,Dt,K and Dk value were all statistically significant in the differential diagnosis of malignant and benign breast lesions(P < 0.05),the optimal threshold value were ADC 1.08 ×10-3mm2/s ?Dt value 1.06 × 10-3mm2/s ?K value 0.756 and Dk value 1.36×10-3mm2/s.The D* and f value between benign and malignant lesions had a large overlap,the difference was not statistically significant(P > 0.05).The ROC curve area showed that the AUC of K and Dt value in differential diagnosis of benign and malignant breast lesions were the highest,respectively 0.956 and0.947,the sensitivity and specificity were 91.1% and 89.5%,93.3% and 84.2%,respectively;the AUC of ADC and Dk value were 0.933 and 0.923,the sensitivity and specificity were 88.9% and 84.2%,91.1% and 84.2%,respectively.Finally,the AUC of ADC,Dt,K and Dk value in the differential diagnosis of benign and malignant breast lesions were not statistically different.(P>0.05).Conclusions The three models all had good performance in differential diagnosis of benign and malignant breast lesions.IVIM and DKI showed higher AUC,but the AUC of all had no statistically different.The mono-exponential model had good clinical value at the advantage of short detection time and easy post-processing.Purpose To evaluate the diagnostic value of ADC?IVIM and DKI derived parameters in differential diagnosis of breast ductal carcinoma in situ and invasive ductal carcinoma.Methods The inclusion criteria concluded:(1)patients who diagnosed as Breast Imaging Reporting and Data System(BI-RADS)category 4 or higher at mammography or ultrasonography were seleted for breast MR imaging.(2)patients who pathologically confirmed ductal carcinoma in situ or invasive ductal carcinoma The exlusion criteria included(1)patients who had undergone core-needle biopsy or preoperative chemotherapy or surgery(2)patients whose MR images had substantial motion artifacts.TIRM,multi-b DWI(RS-EPI)and dynamic contrast-enhanced T1 WI were performed in all patients.All data was transferred to MATLAB post processing software.ROIs were drawn on the slice with the largest tumor area avoiding necrotic or cystic parts The parameters of apparent diffusion coefficient(ADC)?Tissue diffusivity coefficient(Dt)?kurtosis coefficient(K)and diffusivity coefficient(Dk)were measured by two radiologists(with 9 and 7 years of seniority).ROC curve was performed to compare the diagnosis value of ADC?Dt ?K and Dk value based on the AUC.Z test was performed to compare the difference of each AUC.Results a total of 29 lesions were included in the study,of which there were 9 DCIS and 20 IDC.The ADC Dt and Dk value of DCIS group were significantly higher than those of IDC group(0.99±0.11×10-3mm2/s vs0.88±0.13×10-3mm2/s,P=0.032;0.95±0.11×10-3mm2/s vs0.85±0.10×10-3mm2/s,P=0.033;1.24±0.15×10-3mm2/s vs1.08±0.17×10-3mm2/s,P=0.027).The K value of DCIS group was significantly lower than that of IDC group(0.80±0.03 vs0.89±0.07,P=0.001).In the differential diagnosis,the area under ROC curve of K value was the highest,which was 0.878.But,the AUC ofADC,K and D value in the differentiation of two groups were not statistically different.(P>0.05).Conclusion ADC?Dt?K and Dk were all helpful for the differential diagnosis between DCIS and IDC,but the AUC of all the three models had no statistically different.