Diagnostic contributions of abbreviated breast magnetic resonance imaging before biopsy for BI-RADS 4c and 5 breast lesions

Breast magnetic resonance imaging (MRI) has the highest sensitivity for diagnosing and detecting breast pathologies. However, today's common usages of breast MRI are limitted as a second-line imaging method because of its long acquisition and evaluation time, directly or indirectly associated with a higher cost. These usages are solving diagnostic problems on mammography (MG) or ultrasound (US), improving the primary tumor staging, evaluation of the response to therapy. The abbreviated protocol breast MRI terminology was first defined by Kuhl et al. The abbreviated protocol allows for more widespread use of breast MRI by reducing image acquisition and reporting time. The purpose of this study is to evaluate the contribution to biopsy management of abbreviated protocols (AP) breast MRI compared to standard full protocol(FP) breast MRI protocol and breast ultrasound. We conducted a retrospective study of breast MRI images of 133 patients who had been biopsy indication with BI-RADS 4C-5 categorization on US examination and diagnosed breast cancer histopathologically. All MRI examinations were performed using a 1.5 Tesla (T) system (Siemens, Magnetom Aera Syngo MR, Erlangen, Germany) and 3 T system (GE Healthcare, The Discovery™ MR750w, United States) dedicated breast coil between January 2016 and December 2018. The first abbreviated protocol (AP1) consists of the second post-contrast images and its subtracted images and the second abbreviated protocol (AP2) consists the same as sequences with AP1 and DWI images additionally. Two protocol sets of images were reviewed separately and blindly by two radiologists. The full diagnostic protocol (FP) set consisted of a common consensus of two radiologists. Malignant lesion number, lesion site, long axle size, presence of axillary metastatic lymphadenopathy were recorded for both AP1 and AP2. Ultrasound reports and histopathology data were analyzed by third another radiologist without knowledge of MRI data. The relationship between protocols' agreement and background enhancement and breast parenchymal density was evaluated. The obtained data were compared with the full protocol and US data. All statistical calculations were done with the computer program IBM SPSS (Statistical Package for the Social Science; Chicago,) release 20.0 for Microsoft Windows. 133 women patients with a mean age of 54.77±12.6 years (age range: 20-85 years) viii were included in our study. In the AP1 and AP2 evaluations of both readers, the lesion location, number, and size were substantial and almost perfect compared to FP (all Kappa values> 0.61, p <0.05). In both AP1 and AP2 assessments, inter-rater agreements were substantial and almost perfect (Kappa values> 0.7, p <0.05). Although there was no statistically significant difference, more malignant foci were detected in all MRI protocols compared to US Therefore, the compatibility of MRI protocols with US in terms of lesion detection was found to be fair and moderate agreement (Kappa values: 0.25-0.44 p <0.001). In all MRI protocols, the lesions' sizes were measured approximately 5 mm larger than the US (p <0.05). In all MRI protocols, metastatic lymphadenopathy detection sensitivity was higher and specificity was lower than US data (p <0.05). Abbreviated Breast MR imaging and reporting can turn into cost savings, resulting in more frequent use. When a lesion with a suspicion of malignancy above 50% is detected by US, the abbreviated protocol MRI examination obtained before the biopsy will contribute to the biopsy management by showing other suspicious foci and the extent of the lesion. With an effective biopsy approach and correct preoperative evaluation, the rate of recurrence and residual disease can be reduced, and disease-free survival can increase. Limitations of our study are retrospectivity and no correlation with second-look ultrasound. Key Words: Breast Neoplasms, Ultrasonography, Magnetic Resonance Imaging