The Value Of3T Dynamic Contrast-enhanced MRI Of Breast Lesions With BI-RADS Category3～5Microcalcifications Detected On Digital Mammography

Objective To assess the value of3T dynamic contrast-enhanced MRI of breast lesions with BI-RADS category3-5microcalcifications detected on digital mammography.Materials and Methods80patients with mommographically detected BI-RADS category3-5microcalcifications were biopsied or surgeryed after undergoing3T dynamic contrast enhancement MRI. A pathologic result was obtained in all cases. All the lesions were studied form both digital mammography and3T dynamic contrast-enhanced MRI features, according to the IeXicon of Breast Imaging Reporting and Data System(BI-RADS) designed by American College of Radiology(ACR). The morphology, distribution, combination with mass of microcalcification were observed on digital mammography and the morphology, internal enhancement characteristics, time-intensity curve of the lesions were analyzed on3T dynamic contrast-enhanced MRI. SPSS18.0software was used to make the following statistic analysis:(1) The positive predictive values(PPVs) of the morphology, distribution, combination with a mass of microcalcifications were estimated.(2) The positive predictive values (PPVs) of each imaging characteristics on3T dynamic contrast-enhanced MRI were estimated.(3) The sensitivity(SEN), specificity(SPE), positive predictive value(PPV), negative predictive value(NPV) and accuracy(ACC) were calculated in the diagnostic evaluation of microcalcifications on digital mammography and3T dynamic contrast-enhanced MRI. χ2test was used for testing the difference of each group, to P<0.05for the differences were statistically significant.ResultsTotally80suspicious calcified lesions were included, postoperative pathological results showed that40benign lesions and40malignant ones. The morphology (χ2=30.316,P=0.000), distribution (χ2=17.679,P=0.001), combination with a mass of microcalcification (χ2=17.679,P=0.001) had significant value for pathologic analysis.On3T dynamic contrast-enhanced MRI, there were49mass enhancement(61.25%),20 non-mass-like enhancement(25.00%),9punctate progressive enhancement (11.25%) and2no enhancement (2.50%).Combined digital mammography features with time-intensity curve on3T dynamic contrast-enhanced MRI, analyzed morphology show the PPV of fine pleomorphic calcifications and fine linear or linear branching calcifications with Ⅰ, Ⅱ,Ⅲ-type curve was high (100%).The PPV of amorphous or indistinct calcifications with Ⅱ-type curve was high (100%). The PPV of coarse heterogeneous calcifications with Ⅲ-type curve was high (100%). The PPV of amorphous or indistinct calcifications with Ⅲ-type curve was high (87.50%). The PPV of punctate calcifications with Ⅲ-type curve was high (83.33%).Took distribution for analysis, the PPV of segmental calcifications with Ⅱ,Ⅲ-type curve was high (100.00%). The PPV of diffuse, clustered, regional, linear calcifications with Ⅲ-type curve was high (100.00%,88.89%,100.00%and83.33%). The PPV of linear calcifications with Ⅱ-type curve was high (100.00%). Took combination with mass for analysis, the PPV of non-mass calcifications with Ⅲ-type curve was high (77.78%). The PPV of combination with mass calcifications with Ⅰ, Ⅱ,Ⅲ-type curve were44.44%,88.71%and100.00%.The sensitivity, specificity, positive predictive value, negative predictive value and accuracy were as follows, digital mammography:97.50%,67.50%,75.00%,96.43%and82.50%.3T dynamic contrast-enhanced MRI:97.56%,97.44%,97.56%,97.44%and97.50%.Conclusion1. Combined digital mammography features with time-intensity curve on3T dynamic contrast-enhanced MRI, punctuate, diffuse, without mass microcalcifications, with Ⅰ-type curve is typical of imaging findings of benign breast lesions. Fine linear or linear branching,fine pleomorphic, linear or regional, combined with mass microcalcifications, with Ⅲ-type curve is typical of imaging findings of malignant breast lesions.2.3T dynamic contrast-enhanced MRI can not indicate microcalcifications intuitively, but can improve diagnostic specificity, positive predictive value and accuracy, which is helpful in qualitative diagnosis between benign and malignant tumors.