Retrospective Evaluation of Magnetic Resonance Imaging Findings for BI-RADS 5 Lesions: A 5-year Clinical Experience

<p>Abstract<br>Objectives: This study aimed to evaluate the diagnostic utility of magnetic resonance imaging (MRI) for breast cancer detection, focusing specifically on Breast<br>Imaging-Reporting and Data System (BI-RADS) 5 lesions. The study investigated the morphological and dynamic characteristics of these lesions using MRI to<br>identify features associated with malignancy.<br>Methods: A retrospective analysis was conducted on breast MRI scans performed between January 2019 and December 2023. The study included 120<br>patients with BI-RADS 5 lesions who underwent biopsy or surgical excision. MRI images were evaluated for breast parenchymal patterns, T2-weighted<br>signal characteristics, lesion size, location, enhancement kinetics, and morphological features using a standardized protocol. Histopathological results were<br>correlated with MRI findings.<br>Results: Among the 120 BI-RADS 5 lesions, 109 were malignant and 11 benign. Malignant lesions predominantly exhibited heterogeneous enhancement<br>patterns (69.7%) and hypointense T2-weighted signals (56%). Most malignant lesions (82.3%) showed washout enhancement kinetics. Benign lesions, on the<br>other hand, exhibited predominantly hyperintense T2-weighted signals (63.6%) and heterogeneous enhancement patterns (54.5%). Due to the small number<br>of benign lesions, statistical comparisons between the malignant and benign groups were limited.<br>Conclusion: Breast MRI, particularly for BI-RADS 5 lesions, plays a critical role in the detection and characterization of breast cancer. The detailed assessment<br>of morphological and dynamic features by MRI aids in accurate diagnosis and treatment planning. Understanding these MRI findings will enhance clinical<br>decision-making and reduce unnecessary surgical interventions in patients with suspicious breast lesions.<br>Keywords: Breast cancer, magnetic resonance imaging, BI-RADS 5, lesion characterization, dynamic contrast-enhanced MRI</p>