The Usefulness Of Dedicated Breast MRI In The Diagnosis And Differential Strategy For Well-circumscribed Mass On Mammography

BackgroundTypical breast cancer is high-density mass with spiculated margin on mammography,such as invasive ductal carcinoma, invasive lobular carcinoma and ductal carcinoma in situ.Well-circumscribed mass is mass with more than75%of mass clear and sharp margin.These masses may be malignant lesions, such as early invasive ductal carcinoma,mucinous carcinoma, metaplastic carcinoma, primary breast lymphoma and medullarycarcinoma; but it may also be benign lesions, such as fibroadenomas, benign phyllodestumor, breast adenosis, fibrocystic changes and fat necrosis. According to Breast ImagingReporting and Data System (BI-RADS)-Mammography, these masses can be classified asBI-RADS3or Category4. It is difficult to distinguish benign with malignant such lesionsbase on breast X-Mammography and ultrasonography. DB-MRI scan sequence is a singlesequence, which features traditional T1WI, but cystic component showed high signal. Itwould be elaboration to be able to divide the masses into solid masses and solid-cysticmasses on the basis of MRI features into parts for analysis.ObjectiveTo investigate the features of dynamic contrast-enhancement dedicated breast MRI(DB-MRI) for the differentiation of malignant from benign lesions which were detect asWell-circumscribed Mass on mammography. This study is to provide radiology evidencefor early treatment of breast cancer.Materials and MethodsTo the examinations of264patients which performed Well-circumscribed Mass onMammography and were checked by dedicated breast MRI in January2010to November2013, Department of Radiology, Ruijin Hospital. Well-circumscribed mass refers to part orall sharp edges. All cases pathological findings were confirmed by pathology. Retrospective analysis of breast Mammography, Well-circumscribed mass were performedby dedicated breast breast imaging MR, clinical examination, surgical and pathologicaldata, the two parts of such signs of solid masses and solid-cystic masses were studied toexplore. Pathological diagnosis of breast cancer based on WHO classification (2003)standards. MRI examinations were dedicated on the Aurora1.5T magnetic resonance(dedicated breast magnetic resonance imaging, DB-MRI, the application of AuroraEDGETM and dedicated breast coil. χ2test or Fisher exact test were analyzed using. Solidmass lesions analyzed morphological features in hemodynamic performance and positivepredictive value (PPV), and calculate the OR values to assess the degree of malignancyrisk and hemodynamic performance of a variety of morphological changes. Analysisestimates the combination of different MRI characteristics determine the positivepredictive value of malignant lesions.ResultsAll264cases of Well-circumscribed Mass on Mammography were confirmed bysurgery. All264cases included188solid mass and76solid-cystic mass in dedicated breastMRI (DB-MRI) and126malignant lesions (48%),138benign lesions (52%).Histopathological diagnosis in188cases showed Well-circumscribed Mass solid masslesions, including74malignant lesions (51non-special type invasive ductal carcinoma,7medullary carcinoma,6primary breast lymphoma,5mucinous carcinoma,4malignantphyllodes tumors,1malignant Adenomyepithelioma);12breast pathology(16%)(medullary carcinoma, mucinous carcinoma);112benign lesions (73cases offibroadenomas, benign phyllodes tumors in17cases,13cases of intraductal papilloma,adenosis seven cases, granular cell tumor in1,2cases of inflammation, fat necrosis in onecase). Morphological characteristics of early intensive mass of188cases of solid masslesions, edge and Time-signal Intensity Curve of MRI, the difference between benign andmalignant lesions were not statistically significant (p=0.453,0.708,0.919);186real TICtypes of strengthening its internal mass enhancement feature; internal characteristics ofbenign and malignant lesions was significantly enhanced (p<0.001). Solid mass in thediagnosis of malignant lesions characterized by meaningful ring enhancement MRI (ORvalue,108.000;95%CI,20.419-571.223); heterogeneous enhancement (OR value,12.800;95%CI,20.419-571.223) and outflows TIC curve type (OR value,15.000;95%CI,6.772-33.226)。76cases showed Well-circumscribed solid-cystic masses on MRI, includingmalignant lesions in54cases (non-special type of invasive ductal carcinoma in21cases, 18cases of mucinous carcinoma, metaplastic carcinoma six cases, five cases of papillarycarcinoma, malignant phyllodes tumor three cases, invasive ductal carcinoma), which is arare type of breast pathology (metaplastic carcinoma, mucinous carcinoma) in24patients(44%); benign lesions in22cases (one case of intraductal papillomatosis,Adenomyepithelioma one case,11cases of fibrocystic changes, hematoma in2cases,fibroadenoma two cases, one case of chronic granulomatous disease, benign mucinoustumors three cases).76cases solid-cystic mass lesions form lumps, bumps edge, thedifference between benign and malignant lesions were not statistically significant (p=0.820,0.260).74cases have enhanced on MRI, Well-circumscribed solid-cystic masslesions and MRI features enhanced internal time-early intensive signal characteristic curve,the difference between benign and malignant lesions were not statistically significant(p=0.257,0.568).74cases have enhanced on MRI, Well-circumscribed solid-cystic masslesions in19cases of TIC types of benign and malignant difference between statisticalsignificance (p<0.05). Solid mass higher degree of risk of malignant lesions MRI ischaracterized by an irregular ring enhancement inner wall (OR value,24;95%CI,2.281-252.490); ring enhancement inner wall nodules (OR value,60;95%CI,3.104-1160.000); hand; ring enhancement wall smooth curves combined with non-flowingtype TIC diagnosis of malignant lesions The positive predictive value is slightly lower(<0.05).ConclusionThis study based on dynamic enhanced MRI features of Well-circumscribed mass onbreast Mammography (such as time-signal intensity curve) and morphological features(shape, margin, etc.) diagnostic criteria of the solid tumor mass and cystic mass analysis.The results show that a dedicated breast MRI for breast Well-circumscribed Mass onMammography between benign and malignant differential diagnosis of high value: BreastMRI showed Well-circumscribed solid mass lesions, ring enhancement or heterogeneousenhancement TIC-merger Type III signs of malignant lesions may prompt large，and whenmass with no enhancement in low signal separator and TIC-I type, the malignant lesionsminimize the possibility; breast MRI showed Well-circumscribed solid-cystic masses,irregular or ring enhancement with nodular lesions in the inner wall of the merger TIC-IIItype of malignant lesions may prompt large，Cystic mass with smooth cystic wall andTIC-I type are all benign disease.