Juvenile dermatomyositis (JDM) is a rare connective tissues disorder characterized by chronic inflammation that primarily affects the skin and skeletal muscles. Although during the past decade the prognosis of JDM has markedly improved, there are still patients with persistent active disease leading to potential irreversible damage and permanent disability. One of the major challenges in the clinical management of JDM is to accurately assess disease activity and to discriminate it from chronic damage, especially in patients with longstanding disease, whose muscle weakness may be due to a combination of ongoing muscle inflammation, necrosis, muscle atrophy and fatty replacement. The potential of musculoskeletal MRI for defining the contribution of each of these components to the patients weakness is well established. Water-sensitive sequences are very sensitive to the presence of inflammation and have the potential to support diagnosis, to guide muscle biopsy in an area of active disease and to monitor treatment response; T1 weighted images are suitable to visualize sign of chronic damage such AS muscle atrhophy and/or fatty infiltration of the muscles.
Main indications for musculoskeletal MRI in JDM, technical issues and diagnostic accuracy, and newer MRI scanner techniques (i.e whole-body MRI) will be discussed thus providing an overview of the potential advantages of this imaging modality in estimating total disease burden, tailoring treatment and monitoring its efficacy.
Disclosure of Interest None declared