Study On The Value Of Mr Imaging Features And DWI In Differential Diagnosis Of Benign And Malignant Breast Lesions With Platform-type Curves Of MRI

Objective:To investigate the value of magnetic resonance imaging (MRI)features and DWI-ADC value in differential diagnosis of benign andmalignant breast lesions with platform-type curves of dynamic enhancedMRI.Methods:A total of60patients with68lesions underwent breast dynamicenhanced MRI and obtained platform-type DCE-TIC curves wereenrolled in this study. The selected patients were all pathologicallyconfirmed by surgery or biopsy. Their corresponding unenhanced andenhanced MRI images and diffusion-weighted DWI images as well as theclinical data were collected for retrospective analysis. The differences incharacteristics of all lesions including morphology, boundary and signalwere compared by a comprehensive imaging diagnosis, which were thenclassified according to BI-RADS. The region of interest (ROI) wasselected by post-processing to the location of control platform-type lesion,and the correspondingly apparent diffusion coefficient (ADC) wasmeasured in the breast lesions. The correlation between measured data and histopathological findings was analyzed. The sensitivity, specificity,positive likelihood ratio, negative likelihood ratio and accuracy of ADCvalue in differential diagnosis of benign and malignant breast lesionswere obtained.Result:The pathological findings showed that there were35patients with36lesions of breast cancer (52.9%,36/68) and25patients with32lesions ofbenign breast lesions (47.1%,32/68). All breast lesions showed equal orlow signals in unenhanced T1WI and high signals in unenhanced T2WI.After the dynamic contrast-enhanced imaging, the lesions were observedto find that benign lesions were shown more in round shape(81.3%，26/32)with a clear boundary(87.5%,28/32) and a homogeneous enhancement(78.1%,25/32); malignant lesions were shown more in lobulatedshape(69.4%,25/36) with an obscure boundary(72.2%,26/36) andnonhomogeneous enhancement(44.4%,16/36). In this study, the meanvalue of early-phase enhancement rate of DCE-TIC in the breast lesionwas (78.68±17.02)%in the benign group and (114.40±22.29)%in themalignant group; the early-phase enhancement rate in the benign groupwas obviously lower than the malignant group (P=0.000). When thecut-off value of early-phase enhancement rate of TIC was98.1%, thesensitivity, specificity, positive likelihood ratio and negative likelihoodratio were77.1%,84.9%,5.09and0.27, respectively. The mean value of ADC was (1.05±0.13)×10-3mm2/s in malignant breast group and(1.37+0.31)×10-3mm2/s in benign breast group. The ADC values inbenign breast group were markedly higher than the malignant breastgroup (P=0.000). When the cut-off value of ADC in benign and malignantbreast lesions was1.33×10-3mm2/s, the sensitivity, specificity, positivelikelihood ratio and negative likelihood ratio were92.6%,82.9%,5.42,0.09, respectively. With the cut-off value of ADC as the diagnosticcriterion, the accuracy rate of benign and malignant diagnosis reached88.2%.Conclusion:When DCE-TIC of the breast lesions showed a platform type, it wasbetter to combine with the MRI imaging features and the DWI-ADCvalue. When b value was0,1000s/mm2, the cut-off value of ADC was1.33×10-3mm2/s, and the sensitivity and accuracy of diagnosis of benignand malignant breast were improved.