Revised recommendations of the Polish Medical Society of Radiology and the Polish Neurological Society for a protocol concerning routinely used magnetic resonance imaging in patients with multiple sclerosis.

Multiple sclerosis (MS) is a chronic immune-mediated inflammatory demyelinating disease of the central nervous system (CNS), the exact etiology of which remains unknown. The pathological hallmark of MS involves CNS tissue damage characterized by dissemination in space (DIS) and dissemination in time (DIT). Magnetic resonance imaging (MRI) represents the most sensitive paraclinical tool for detection, diagnosis, and longitudinal monitoring of MS, playing a crucial role in treatment decision-making. The recently published 2024 McDonald criteria, incorporating advances in MR acquisition and post-processing techniques, necessitate revision of current MRI protocols used in routine clinical practice. These updated criteria expand the definition of typical MS lesion locations to include the optic nerves and introduce novel MRI biomarkers - the central vein sign (CVS) and paramagnetic rim lesions (PRLs) - which enhance diagnostic specificity and differential diagnosis. This manuscript presents the third version of recommendations developed by the Polish Medical Society of Radiology and the Polish Neurological Society for standardized MRI examination protocols in patients with MS. These evidence-based recommendations incorporate contemporary technical advances, provide practical guidance for radiographers and radiologists, and aim to standardize imaging procedures across all MRI departments in Poland. Implementation of this protocol is essential for establishing reliable diagnoses, ensuring adequate disease monitoring, and supporting critical clinical decisions regarding treatment initiation and modification.