MRI Characteristics of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: A Review.

IMPORTANCE: Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a demyelinating disease distinct from multiple sclerosis (MS) and aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD). Magnetic resonance imaging (MRI) is central to confirming attacks, defining lesion distribution, and excluding alternative diagnoses and is a key component of the 2023 MOGAD diagnostic criteria. However, its imaging spectrum and lesion evolution remain underrecognized in practice, and variability in imaging parameters can contribute to delayed diagnosis and suboptimal treatment. OBSERVATIONS: This article summarizes the hallmark MRI features of optic nerve, brain, and spinal cord involvement in MOGAD, including key findings from the 2023 diagnostic criteria, supported by illustrative figures and detailed tables. The characteristic evolution of MRI abnormalities in MOGAD is highlighted, including radiologic lag, lesion dynamics during acute attacks, and frequent T2-lesion resolution, contrasting with the persistent lesions typical of MS. A recommended MRI protocol for acute attacks is proposed, and the timing and utility of rebaselining MRI (ie, repeating the MRI to establish a new baseline) after onset are reviewed. The clinical course of MOGAD is of attack-related neuroinflammation evident clinically and radiologically, and asymptomatic radiological activity is rare, suggesting that surveillance MRI has less clinical utility than in MS and less value as a surrogate biomarker in clinical trials. MRI features that differentiate MOGAD from MS and AQP4+NMOSD are summarized and imaging red flags suggestive of alternative diagnoses are highlighted. Finally, emerging advanced imaging, artificial intelligence in MOGAD imaging, and the link between imaging and immunopathogenesis are reviewed. CONCLUSIONS AND RELEVANCE: MRI is central to MOGAD evaluation, and recognition of the characteristic imaging features and lesion dynamics outlined in this review can aid diagnosis. Application of the standardized MRI protocol summarized here can optimize use in clinical practice and promote harmonization across research studies. Future imaging and artificial intelligence applications may improve diagnosis, disease monitoring, and understanding of MOGAD pathogenesis.