MRI Features And Quantitative Parameters Of Breast X-ray BI-RADS4 Mass Lesions

Objective:To analyze the application value of MRI morphological features and quantitative parameters of BI-RADS 4 breast mass lesions in the differential diagnosis of benign and malignant lesions.Metheds:179 cases of BI-RADS 4 breast mass lesions diagnosed by mammography and underwent MRI in our hospital from January 2015 to June 2017 were enrolled,including 97 benign lesions and 82 malignant lesions.The MRI images of all cases were reviewed,and six features including the affected side,quadrant,maximum diameter,shape,margin and internal enhancement of the lesions were extracted.The Functool software was used to manually delineate the lesion's region of interest?ROI?on the GE AW 4.4 workstation.The signal intensity of the ROI was measured and the time-signal intensity curve?TIC?was automatically generated and the curves were classified into types I,II,and III.The diffusion weighted imaging?DWI?sequence was imported into the workstation to measure the apparent diffusion coefficient?ADC?value of the lesion.The dynamic enhancement sequence and pre sequence classified by DCM software were imported into Omni-Kinetics software of GE company and the pharmacokinetic model was selected.Functional parameters of the lesions were measured,including volume transfer constant?Ktrans?,plasma fraction?Vp?,and rate constant?Kep?.SPSS 20.0 statistical software was used for data analysis.Chi-square test was used for counting data analysis,Mann-Whitney U test was used for measurement data analysis,and Logistic regression analysis was used for multivariate analysis.Subject operating characteristic curve?ROC?was drawn for image features and parameters with statistical differences.The area under ROC curve?AUC?was used to evaluate the differential diagnostic efficacy of various features and parameters for benign and malignant lesions.The sensitivity,specificity and coincidence rate of X-ray and MRI in the diagnosis of breast cancer were compared according to the gold standard of pathological results.All statistical analyses were based on P<0.05.Results:1.Univariate analysis of MRI features showed that the shape,margin and TIC curve types of lesions were significantly different between benign and malignant groups ?P<0.01?.Multivariate logistic regression analysis showed that the shape,margin and TIC curve types of lesions on MRI were the influencing factors of benign and malignant lesions,and their relative risk?OR?values were 4.566,6.024 and 4.892,respectively.The AUC values of ROC curves were 0.708,0.768 and 0.776,respectively.The combined regression model of all features had the highest diagnostic efficacy for benign and malignant lesions,and its AUC values,sensitivity and specificity were 0.888,0.753 and 0.854,respectively.2.Quantitative parameter analysis showed that K^transmin value(0.000?0.000;0.510?,K^transmax value(1.848?1.183;4.760?,and K^transmean value(0.545?0.336;1.527? were larger in malignant group than in benign group;ADCmin value(0.828?0.709;0.916?,ADCmax value(1.412?1.303;1.596?,and ADCmean value(1.122?1.075;1.165?were smaller in malignant group than in benign group,and the difference was statistically significant?P<0.01?.The K_epmax value(1.825?0.685;5.836?,V_pmax value(2.583?1.617;5.370?,and V_pmean value(0.270?0.151;0.801?were larger in malignant group than in benign group,while the K_epmean value(0.104?0.046;0.862?in malignant group was smaller than that in benign group,and the difference was not statistically significant?P>0.05?.3.The ROC curves were drawn to evaluate the diagnostic efficacy of the corresponding parameters in differentiating benign from malignant lesions.The UC values of K^transmax,K^transmean,ADCmin,ADCmax and ADCmean orresponding to ROC curves are 0.642,0.748,0.817,0.629 and 0.902,respectively,and ADCmean has the highest diagnostic efficacy among them.When ADCmean>1.210 mm2/s was used as the critical value for the diagnosis of malignant lesions, he sensitivity and specificity were 81.40%and 90.20%respectively.4.The sensitivity,specificity and coincidence rate of X-ray examination in the diagnosis of breast cancer were respectively 75.61%,68.04%and 71.51%,and the sensitivity,specificity and coincidence rate of MRI examination in the diagnosis of reast cancer were respectively 91.46%,89.69%and 90.50%.The sensitivity,specificity and coincidence rate of MRI examination were significantly higher than hose of X-ray examination,and the differences were statistically significant?P<0.01?.Conclusion:1.In the analysis of MRI features of BI-RADS 4 breast mass lesions,the shape,margin nd TIC curve type of lesions are the influencing factors of benign and malignant esions.Malignant lesions are irregular in shape and edge,and the TIC curve type re mostly type II,while benign lesions are regular in shape and smooth in edge, nd the TIC curve are mostly type I.2.DCE-MRI parameters can quantitatively reflect the hemodynamic changes of the esions.The K^trans value of BI-RADS 4 malignant lesions increased significantly nd was evidently higher than that of benign lesions,and the K^transmean value was f high value in qualitative diagnosis of the lesions.3.The diffusion of water molecules in the BI-RADS 4 malignant lesions was ignificantly limited.The ADC value of malignant lesions decreased and was lower than that of benign lesions,and ADCmean value had the highest efficacy in differential diagnosis of benign and malignant lesions among them.4.The efficacy of MRI in the diagnosis of breast cancer is superior to X-ray examination.Analyzing the MRI morphological features and quantitative parameters of BI-RADS 4 breast mass lesions comprehensively and extracting the corresponding influencing factors are helpful to the accurate diagnosis of breast lesions and provide guidance for further clinical diagnosis and treatment.