The role of magnetic resonance imaging in diagnosing limb-girdle muscular dystrophy: a descriptive exploratory diagnostic study

Abstract Background Limb-girdle muscular dystrophies (LGMDs) are a heterogeneous group of inherited neuromuscular disorders characterized by progressive weakness of the pelvic and shoulder girdle muscles. Diagnosis typically requires multimodal assessment, including clinical evaluation, laboratory testing, electrophysiology, muscle biopsy, and genetic analysis; however, these approaches may be invasive, resource-intensive, or inconclusive. Muscle magnetic resonance imaging (MRI) provides a non-invasive, radiation-free method for assessing muscle involvement and has increasing relevance in neuromuscular diagnostics. This exploratory diagnostic study evaluated the role of whole-body muscle MRI (WBMRI) in LGMD subtype differentiation. A total of 103 Egyptian patients with suspected LGMD were recruited from the Neuromuscular Unit of our University Hospitals. All participants underwent laboratory investigations, electromyography, muscle biopsy, and WBMRI, which was interpreted independently of histopathological findings. The relation between the clinical picture and the radiological findings were analyzed highlighting the role of WBMRI as a non-invasive diagnostic tool helping in diagnosis of LGMD. Results Seventy-eight patients received confirmed diagnoses. Dysferlinopathy was the most prevalent LGMD subtype, followed by sarcoglycanopathies. WBMRI demonstrated high concordance with clinical assessment and enabled recognition of distinct patterns of muscle involvement across LGMD subtypes. The total Mercuri score of fatty infiltration showed a significant correlation with muscle strength assessed using the Medical Research Council scale. Conclusion Whole-body muscle MRI improves diagnostic accuracy in LGMD, supports subtype differentiation, and represents a valuable adjunct in structured diagnostic pathways.