Improved diagnosis of adnexal lesions by integrating intra-tumoral hemorrhage detection with non-contrast MRI scoring (NCMS) using susceptibility-weighted sequences
Background
Dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) protocol was included into the Ovarian-Adnexal Reporting & Data System (O-RADS) MRI scoring system. To avoid the administration of contrast medium, the non-contrast MRI scoring (NCMS) system was proposed.
Purpose
To evaluate the contribution of detecting intra-tumoral hemorrhage in the solid tissue of adnexal masses to improve tumor characterization and enhance the risk stratification of adnexal lesions using the NCMS system.
Material and Methods
MRI findings including susceptibility-weighted sequences (T2*-weighted MR angiography [SWAN]) were retrospectively analyzed in 126 surgically confirmed adnexal tumors with solid tissue components (20 benign, 106 malignant). Solid tissue was classified as malignant based on the NCMS criteria, defined by intermediate intensity on T2-weighted (T2W) imaging, and corresponding diffusion restriction. Hemorrhage was assessed based on high intensity on T1-weighted (T1W) imaging and susceptibility-related signal voids on SWAN.
Results
The NCMS solid tissue criteria identified malignancy with a sensitivity of 94.3%, specificity of 60%, and accuracy of 88.9%. High intensity on T1W imaging and signal voids on SWAN were observed in 23.6% and 72.6% of malignant lesions, compared to 0% and 5% in benign lesions, respectively. Hemorrhage was frequently observed in high-grade malignant tumors, or hemorrhagic subtypes. The combination of NCMS criteria and/or presence of intra-tumoral hemorrhage was associated with malignancy, yielding a sensitivity of 98.1%, specificity of 60%, and accuracy of 92.1%.
Conclusion
The inclusion of intra-tumoral hemorrhage enhances the diagnostic accuracy of the NCMS for characterizing adnexal lesions. SWAN may also aid in estimating tumor grade and identifying hemorrhagic subtypes.