VALUE OF MUSCLE MAGNETIC RESONANCE IMAGING IN COMPARISON WITH MUSCLE BIOPSY FOR DIFFERENTIATING VARIOUS TYPES OF LGMD

Abstract Background Limb Girdle Muscular Dystrophies (LGMD) are a clinically and genetically heterogeneous group of disorders which share progressive muscle weakness and degenerative muscle changes involving the shoulder and pelvic girdle muscles. The diagnostic approach is based on a comprehensive clinical history, a thorough physical examination, laboratory data, electrophysiological investigations, and particularly the histologic and immunoanalysis of a muscle biopsy, followed by a genetic confirmation of the diagnosis. Magnetic Resonance Imaging (MRI) complements clinical examination by delineating characteristic disease specific patterns of muscle involvement which helps in differentiation of individual LGMD subtypes. It is used to demonstrate the severity and distinguish between dystrophic and non-dystrophic diseases. Objective Identification of the value, sensitivity of Muscle MRI to be used as a tool for diagnosis and differentiation of patients with LGMD and as a guidance for the needed immunological and genetic studies to confirm their diagnosis. Patients and methods This study was conducted on 71 patients with clinical criteria of LGMD diagnosed by clinical, laboratory and dystrophic muscle biopsy from Myology Clinic and Neuromuscular Unit, Ain Shams University Hospitals, Muscle MRI was done blind from the results of muscle biopsy, immunohistochemistry and genetic studies. MRI muscles was done at mid-thigh, mid-leg levels. MRI Equipment was 1.5 Tesla in the Radiology department, Ain Shams University Hospitals (T1, Fat subtraction). MRI T1 images were obtained and muscle fatty infiltration in every single muscle was graded on a 5 point rating scale. Results The results showed that the diagnostic performance of muscle MRI in LGMD is most sensitive when calculated in examined Thigh muscles, followed by Leg muscles in comparison with muscle biopsy. Conclusion Muscle MRI is a practical, reproducible and valid tool that can be used in assessment of suspected LGMD patients.