Evaluation of the accuracy of mammography, ultrasound and magnetic resonance imaging in suspect breast lesions.

Objectives: In breast cancer diagnosis, mammography (MMG), ultrasonography (USG) and magnetic resonance imaging (MRI) are the imaging methods most used. There is a scarcity of comparative studies that evaluate the accuracy of these methods in the diagnosis of breast cancer.

Methods: A cross-sectional study was carried out through the review of electronic medical records of 32 female patients who underwent breast imaging examinations at a imaging diagnostic center in Teresina, State of Piauí, Brazil. Patients who had these three imaging methods at the time of the evaluation of the same nodule were included. The nodule must have been classified as suspect by the BI-RADS® system in at least one of the methods. Data from each method were compared with the histopathological examination. Statistical analysis used the calculation of proportions in Excel 2010.

Results: MMG showed 56.2%, 87.5%, 81.8%, 66.7% and 71.8% of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy, respectively. USG had 75%, 18.8%, 48%, 42.8% and 46.9% of sensitivity, specificity, PPV, NPV and accuracy, respectively. In turn, MRI had 100%, 50%, 66.7%, 100% and 75% of sensitivity, specificity, PPV, NPV and accuracy, respectively.

Conclusion: Thus, MRI and MMG were more accurate in evaluating suspicious breast lumps. MRI had a low specificity, mainly to high breast density, while MMG had also sensitivity limited due to high breast density and USG has been proven to be useful in these patients.