T2 Hyperintensity in Breast MRI: a Useful Marker in Lesion Characterization?
Author Block: E. Rubino1, C. M. L. Trombadori1, C. Boldrini1, A. Marra1, A. D'Angelo1, P. Belli1, P. Clauser2; 1Rome/IT, 2Vienna/AT
Purpose: In breast magnetic resonance imaging (MRI), T2-weighted (T2w) hyperintensity is typically observed in benign lesions but can also occur in some malignant tumors. The aim of our study was to retrospectively evaluate the association between T2 hyperintensity and histopathological and molecular features of breast lesions.
Methods or Background: We retrospectively analyzed 1387 breast MRIs performed between 2022 and 2024. For each lesion, a breast radiologist assessed signal intensity on T2w images using non-fat suppressed T2-TSE sequences, enhancement pattern, histology, molecular subtype (Luminal A, Luminal B, HER2+, triple-negative), and Ki67 proliferation index. Associations among these variables were analyzed using Pearson’s chi-squared test, Fisher’s exact test, Mann-Whitney U test, and Spearman’s correlation.
Results or Findings: Out of 1387 patients, 779 lesions were hyperintense on T2w images. No statistically significant association was found between T2 hyperintensity and lesion benignity or malignancy, with similar proportions of hyperintensity in both groups. Analysis of malignant histological subtypes revealed that tumors with an in situ component (DCIS and DCIS + IDC) were more frequent among non-hyperintense lesions, while rare tumor subtypes - such as mucinous, papillary, and metaplastic carcinomas - were significantly more frequent among T2-hyperintense lesions (p<0.001). Molecular subtype analysis showed that Luminal A tumors were underrepresented among T2-hyperintense lesions, whereas Luminal B and triple-negative tumors were more common (p<0.05). Spearman’s correlation indicated that higher T2 signal intensity was associated with higher Ki67 levels (p<0.001).
Conclusion: In our cohort, T2 hyperintensity showed significant associations with rare tumor subtypes (mucinous, papillary, and metaplastic carcinomas), Luminal B and triple-negative molecular subtypes, and high proliferative activity. These preliminary findings suggest that T2w signal characteristics may contribute to refining lesion interpretation in breast MRI and highlight their potential role in lesion characterization.
Limitations: Retrospective single-study center, single reader
Funding for this study: No
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics Committee Territorial Lazio Area 3, protocol no. 00000883/24, ID 6699, non-profit study.