Diagnostic Evaluation Of Dynamic Contrast-enhanced MR Imaging And Diffusion-weighted Imaging For Benign And Malignant Breast Lesions

Objective1. To approach the value of MRI dynamic contrast-enhanced MRI, diffusion-weighted MRimaging and the combination of the two methos for diagnosis of breast lesions.2. To evaluate the feasibility of DWI in breast lesions, and to choose the best optimal bvalue for detecting the lesions. To determine whether the ADC value have significantdiscrepancies among the normal breast, the benign lesions and the malignant lesions whenusing the same b value, and whether the ADC value have significant discrepancies for thesame group when using different b values.Metiarials and MethodsThere were77women patients including84lesions and84normal volunteers, all thecases were divided into three groups:54malignant lesions,30benign lesions and84normal breast. All the cases were underwent conventional MRI(T1WI, T2WI, SPAIR),dynamic contrast-enhanced MRI and diffusion-weighted MR imaging (b value) using thePhillips Achieva3.0T MRI. When using DWI, we choose four b values(0,500,800,1000s/mm~2). The raw data of DWI were transmitted to the workstation for generating the mapsof ADC, then the ADC value and the rADC were determined. The conventional imageswere reviewed and made consensus on the shape and margin. irregular shape or burr finwas thought malignant features. Otherwise, round shape or clear margin was generally viewed as benign characters. For dynamic contrast-enhanced images, the enhancementmode, intensity and the time-intensity curve(TIC) were calculated, obvious enhancement,Ⅱor III curve style all stand for malignant lesions, oppositely, homogeneous enhancementand I curve style are always the prognostication of benign lesions. For diffusion-weightedMR images, with the same b value, The ADC values of normal breast, benign lesions andmalignant lesions were analyzed using one-factor analysis of variance. The ADC values ofevery group among different b values were analyzed using one-factor analysis of variance.Regard pathological results as golden criteria, the ROC could be drawn, in this way, wecan get the threshold ADC value and rADC for every b value, and calculate thecorresponding sensitivity and specificity. So we could learn which is the beat optimal bvalue for diagnosis efficacy of breast lesions. Moreover, compared to the pathologicalresults, the sensitivity and specificity for diagnosing breast lesions of every method and thecombined methods can be got.ResultsThe sensitivity and specificity for MR morphology were88.9%and73.3%; fordynamic contrast-enhanced MR were92.6%and66.7%, combined the two methods, we gotthe sensitivity90.7%and the specificity70.0%. When b value is500s/mm~2,the ADC ofmalignant lesions, benign lesions and normal breast are1.029±0.160mm~2/s,1.323±0.370mm~2/s and1.790±0.159mm~2/s，rADC of malignant lesions and benign lesions are0.624±0.011and0.794±0.213; when b value is500s/mm~2, the ADC of malignantlesions, benign lesions and normal breast are0.869±0.164mm~2/s,1.172±0.322mm~2/sand1.596±0.121mm~2/s, rADC of malignant lesions and benign lesions are0.663±0.012and0.853±0.024; when b value is1000s/mm~2, the ADC of malignant lesions, benignlesions and normal breast are0.793±0.163mm~2/s,1.128±0.327mm~2/s and1.555±0.101mm~2/s, rADC of malignant lesions and benign lesions are0.682±0.012and0.899±0.025. The ADC and rADC of the same lesions group has significant deviation amongdifferent b values(P<0.05). The ADC and rADC of the three lesions group with the same bvalue are significantly deviated(P<0.05). As the ROC indicated, when b value is1000 s/mm~2, the area under the curve is largest, the threshold rADC is0.701, the diagnosticsensitivity is90.7%, the specificity is86.7%. Combined above methods, the diagnosticsensitivity and specificity are92.6%and90.0%.Conclusion1Though the diagnostic sensitivity of3.0T conventional MR combining withdynamic enhanced-contrast scanning is high, the specificity is a little low.2ADC value of DWI could be an index for diagnosing breast benign and malignantlesions.3Combined dynamic contrast-enhanced scanning and diffusion-weighted imagingcan enhance the diagnostic efficacy for breast lesions, especially can improve thespecificity.