Magnetic resonance measurement of muscle T2, fat-corrected T2 and fat fraction in the assessment of idiopathic inflammatory myopathies.

Objective: This study examines the utility of MRI, including T2 maps and T2 maps corrected for muscle fat content, in evaluating patients with idiopathic inflammatory myopathy.

Methods: A total of 44 patients with idiopathic inflammatory myopathy, 18 of whom were evaluated after treatment with rituximab, underwent MRI of the thighs and detailed clinical assessment. T2, fat fraction (FF) and fat corrected T2 (fc-T2) maps were generated from standardized MRI scans, and compared with semi-quantitative scoring of short tau inversion recovery (STIR) and T1-weighted sequences, as well as various myositis disease metrics, including the Physician Global Activity, the modified Childhood Myositis Assessment Scale and the muscle domain of the Myositis Disease Activity Assessment Tool-muscle (MDAAT-muscle).

Novel assessment tools to evaluate clinical and laboratory responses in a subset of patients enrolled in the Rituximab in Myositis trial.

Objectives: We aimed to assess changes in myositis core set measures and ancillary clinical and laboratory data from the National Institutes of Health's subset of patients enrolled in the Rituximab in Myositis trial.

Methods: Eighteen patients (5 dermatomyositis, 8 polymyositis, 5 juvenile dermatomyositis) completed more in-depth testing of muscle strength and cutaneous assessments, patient-reported outcomes, and laboratory tests before and after administration of rituximab. Percentage change in individual measures and in the definitions of improvement (DOIs) and standardized response means were examined over 44 weeks.