Muscle imaging technologies have become more sophisticated over the years. Among them, magnetic resonance imaging (MRI) plays a role not only in establishing the diagnosis of a good number of acquired or hereditary neuromuscular diseases but also in the evolutionary monitoring of the patient, whether in an individual setting or in a therapeutic protocol. The precise quantification of muscle damage using this method nevertheless remains complex and is based on analyzes most often targeted on regions of interest (ROI).
In an article published in November 2020, researchers from the Institut de Myologie de Paris succeeded in demonstrating the value of a more comprehensive approach, at scale, for example, of a whole limb segment. To achieve this, the images obtained by MRI one year apart from 102 patients with neuromuscular pathology (21 cases of inclusion myositis (IBM), 19 of GNE myopathy, 19 of Duchenne muscular dystrophy, 12 of dysferlinopathy, etc.) were compared taking special note of the sensitivity to change in the measurement of the muscle fat fraction. Using the SRM (standardized mean response) parameter in particular, the authors demonstrate that a more global approach at the scale of a limb segment is better than the muscle by muscle approach in most aetiologies studied (except for GNE and IBM).
