Phase Image Display Settings for Paramagnetic Rim Lesion Detection in Multiple Sclerosis: A Practical Guide

The 2024 revisions of the McDonald criteria incorporate the paramagnetic rim lesion (PRL) into the diagnostic framework of multiple sclerosis, and PRL evolution is increasingly recognized as a marker of disease progression. PRLs are detected on phase images of susceptibility-sensitive sequences, but their visibility depends critically on display settings. Current consensus recommendations provide detailed guidance on acquisition parameters yet do not address the phase-image window/level applied at the reading workstation; an inappropriate phase window can render rims invisible. We discuss practical tips for reliable PRL detection, including awareness of vendor-specific phase conventions, windowing to optimize conspicuity, and hands-on training, to support accurate and reproducible PRL assessment in routine clinical practice.