Contrast-enhanced mammography and breast magnetic resonance imaging in invasive lobular carcinoma: a comparative analysis of morphological features and enhancement kinetics.

PURPOSE: This study aimed to compare the diagnostic performance of contrast-enhanced mammography (CEM) and dynamic contrast-enhanced breast magnetic resonance imaging (MRI) in the preoperative evaluation of invasive lobular carcinoma (ILC) in terms of lesion size measurement, morphological characteristics, and enhancement kinetics. METHODS: In this retrospective single-center study, 62 lesions from 46 patients with histopathologically confirmed ILC who underwent both CEM and MRI between February 2021 and December 2024 were analyzed. Lesion size was measured based on the maximum diameter of the index lesion on both modalities. Morphological patterns, including architectural distortion, mass and non-mass enhancement (NME) patterns, and lesion conspicuity, were analyzed according to the American College of Radiology Breast Imaging Reporting and Data System v2025 lexicon. Enhancement kinetics on CEM were categorized as persistent, plateau, or washout based on visual assessment of early- and delayed-phase images and compared with MRI kinetic curve types. The sensitivity of CEM was 94.1% for type 1, 89.2% for type 2, and 62.5% for type 3 enhancement patterns. Architectural distortion was significantly more frequent in type 2 and type 3 patterns. High conspicuity was the most common finding on CEM, whereas low conspicuity was predominantly observed in type 1 lesions. MRI was superior for the evaluation of extra-mammary extension, soft tissue involvement, and axillary lymph nodes. CONCLUSION: CEM demonstrates diagnostic performance comparable with MRI in assessing lesion size, morphology, and enhancement kinetics in ILC. It represents a valuable alternative imaging modality in cases where MRI is contraindicated or limited in availability. However, MRI remains the gold standard for investigating NME and extra-mammary disease extension. CLINICAL SIGNIFICANCE: CEM provides diagnostic accuracy comparable with MRI in assessing lesion size, morphology, and additional lesions in ILC. Its high sensitivity, shorter examination time, and cost-effectiveness make it a valuable alternative imaging modality, particularly in cases where MRI is contraindicated or limited in availability. Furthermore, the integration of CEM into clinical practice may contribute to improved preoperative assessment.