A protocol for a scoping review on the role of whole-body and dedicated body-part magnetic resonance imaging for assessment of adult and juvenile idiopathic inflammatory myopathies

Background. Currently, there is lack of standardization of magnetic resonance imaging (MRI) scoring systems and protocols for assessment of idiopathic inflammatory myopathies (IIMs) in children and adults among treatment centres across the globe. Therefore, we will perform scoping reviews of the literature to inform available semi-quantitative and quantitative MRI scoring systems and protocols for the assessment and monitoring of skeletal muscle involvement in patients with IIMs with the final goal of providing evidence-based information for the future development of a universal standardized MRI scoring system in specific research and clinical settings in this population. Methods. Electronic databases (PubMed, EMBASE, and Cochrane) will be searched to select relevant articles published from January 2000 to October 2023. Data will be synthesized narratively. Discussion. This scoping review will extensively map evidence on the indications, utility for diagnosis and assessment of disease activity and damage using skeletal muscle MRI in IIMs. The results will allow the development of consensus recommendations for clinical practice and enable the standardization of research methods for MRI assessment of skeletal muscle changes in patients with IIMs.