The Applications Of3.0T DCE-MRI And DW-MRI In The Diagnosis Of Benign And Malignant Breast Lesions

Part1The study of semi-quantitative assessment of the kinetic curvetype for the breast lesionsObjedive:To assess the diagnostic value of the kinetic curve type withsemi-quantitative method for the breast lesions.Methods:Seventy-two women with breast diseases(81lesions),mean[±SD] age48.05±12.59years underwentv dynamic contrastenhancement.Four cutoff values (0.03%/s average washout slope,0.06%/saverage washout slope,the percentage-enhancement difference after enhancinginitial stage5%and the percentage-enhancement difference after enhancinginitial stage10%)were designed for the kinetic curve type withsemi-quantitative method. Fischer scoring system was used to analyze andcompare the sensibility, specificity and accuracy for the differentiation ofbenign and malignant breast lesions.Results:The areas under the curve (AUCs) of0.03%/s average washoutslope,0.06%/s average washout slope, the percentage-enhancement differenceafter enhancing initial stage5%and the percentage-enhancement differenceafter enhancing initial stage10%were0.724,0.696,0.716and0.678,respectively. Combined the categorization using the four different cutoffpoints(0.03%/s average washout slope,0.06%/s average washout slope, thepercentage-enhancement difference after enhancing initial stage5%and thepercentage-enhancement difference after enhancing initial stage10%) andother indexes of Fischer scoring system, the sensibility of the differentiationof benign and malignant lesions were93.18%,90.91%,88.64%,86.36%;the specificity were67.57%,59.46%,67.56%,59.46%and the accuracy were81.48%,76.54%,79.01%and74.07%, respectively.Conclusion: It was the most useful for the differentiation of benign andmalignant breast lesions in3.0T DCE-MRI when we used the0.03%/saverage washout slope as cutoff value to assess the kinetic curve type. Part2Objectivity study in focal breast lesions using3.0T magneticresonance imaging diffusion-weightedObjedive: Objectivity and repeatability study in focal breast diseasesusing3.0T magnetic resonance diffusion-weighted imaging (DWI) bydesigning different apparent diffusion coefficient (ADC) measurementinfluential factors.Methods: Fifty-three women with breast diseases(61lesions), mean[±SD]age47.6±13.1years underwent3T DWI.. Two observers measured the ADCvalues of breast focal lesions by DW images with diffrent b-values (500,700and1,000s/mm2) and two different ROIs(ROI and ROI/2). Observer Arepeated the measurement ADC of all breast focal lesion after6months.Results:(1) There were no significant differences in the result of ADCvalues between both the interobserver and the intraobserver(P value was0.957and0.547, respectively). The mean of the interobserver differences was0.00×10-3mm2/s (limits of agreement:-0.32×10-3mm2/s-0.32×10-3mm2/s), andthe mean intraobserver difference was0.08×10-3mm2/s (limits ofagreement:-1.26×10-3mm2/s-1.41×10-3mm2/s), respectively.(2) There were nosignificant difference of ADC value between the ROI and the ROI/2in thethree b value groups (P>0.05).(3) In ROI group, the ADC value of theb=500s/mm2was significantly higher than that of the b=700s/mm2(P<0.05),while in ROI/2group, the ADC value of the b=500s/mm2was significantlyhigher than that of the b=1000s/mm2(P<0.05). Conclusion: The ADC value of3.0T MRI-DWI was repeatable andobjective for the diagnosis of breast diseases. And using the same b value ofDWI would be more objectivity for the clinical application. Part3The diagnostic value of3.0T diffusion-weighted magneticresonance imaging with different b values in the differentiation of benignand malignant breast lesionsObjedive: To evaluate the ability of DWI with different b values in thedifferentiation between benign and malignant breast lesions at3T MRI.Methods:Fifty-three women with breast diseases(61lesions),mean[±SD] age47.6±13.1years underwent3T DWI.ADC values of breastfocal lesions were measured by DW images with diffrent b-values (500,700and1,000s/mm2). The sensitivity and specificity of DWI and the thresholdADC value with different b values were evaluated by Receiver OperatingCharacteristic curve (ROC).Results: The ADC value of benign lesions was significantly higherthan that of malignant lesions in the three b groups(P<0.05). There were nosignificant differences of ADC value during the three different b value in thebenign and the malignant (P>0.05)，while there were significant differences ofADC value between the b=500s/mm2and the b=1000s/mm2(P<0.05).Whenb=500s/mm2,The ADC value of1.8×103mm2/s as cut-off score provided68%sensitivity and73%specificity for the classification of benign andmalignant lesions.While b=700s/mm2and b=1000s/mm2，the cut-off ADCvaluewas1.445×103mm2/s、1.44×103mm2/s，the corresponding sensitivityand specificity was80%、66.7%and72%、80%, respectively. Conclusion: DWI was important for the differentiation between benignand malignant breast lesions, and it would be more helpful for the detection oflesion by using b=700s/mm2.