Value of magnetic resonance imaging for evaluating muscle inflammation: insights from a new mouse model of myositis

Inflammatory myopathies or myositides represent a group of severe skeletal muscle diseases characterized by muscle weakness, elevation of serum creatine kinase levels and muscle inflammatory cell infiltrates. Despite the contribution of a growing number of myositis-specific autoantibodies and the existence of characteristic dermatological features in dermatomyositis, the definitive diagnosis of myositis requires pathological examination of a muscle biopsy [1, 2]. To limit false negatives, this biopsy should be performed in an area of active disease [2]. In this context, magnetic resonance imaging (MRI) has gained interest since T1-weighted images are able to determine muscle damage such as atrophy, fatty infiltration and their distribution [3, 4] while T2-weighted images help to detect edema and thus may inform on the activity of the disease, i.e. muscle inflammatory infiltrates. This article is protected by copyright. All rights reserved.