Optimizing the MRI Pelvis Protocol for O-RADS MRI.

Adnexal lesions seen on US images are referred for MRI when there is a need for further characterization and more accurate cancer risk score assessment. MRI can help expedite referral to gynecologic oncologists when ovarian cancers are suspected and avoid unnecessary, overextensive surgery or unnecessary follow-up when benign lesions are identified. The Ovarian-Adnexal Reporting and Data System (O-RADS) MRI was developed to provide standardized lexicon terminology and to allow predicting the risk of cancer when the appropriate MRI protocol is used. Only when the MRI protocol with the minimum technical requirements and dynamic contrast-enhanced imaging is used can the positive predictive values listed in the O-RADS MRI table be obtained. The O-RADS MRI recommended protocol includes multiplanar T2-weighted imaging, diffusion-weighted imaging, in- and opposed-phase imaging, and pre- and postcontrast imaging, including dynamic contrast-enhanced imaging. Optimizing each MRI sequence may be challenging but will lead to accurate risk stratification of adnexal lesions. It is also important to understand how each sequence is used to assess adnexal lesion characteristics for accurate risk scoring. This article reviews the necessary sequences in the recommended O-RADS MRI protocol and offers tips and tricks that can be used to optimize images, negate common artifacts, and avoid common errors in interpretation, including when the MRI examination is suboptimal. ©RSNA, 2026 See the invited commentary by Lakhman and Rakow-Penner in this issue.