Quantitative MRI in myositis patients: comparison with healthy volunteers and radiological visual assessment

Abstract

imaging (MRI)-based measurements of T2, fat fraction, diffusion tensor imaging, and muscle volume can detect differences between the muscles of myositis patients and healthy controls, and to identify how they compare with semi-quantitative MRI diagnosis. MATERIALS AND METHODS: Sixteen myositis patients and 16 age-and gender-matched healthy controls underwent MRI of their thigh. Quantitative MRI measurements and radiologists' semi-quantitative scores were assessed. Strength was assessed using an isokinetic dynamometer. RESULTS: Fat fraction and T2 values were higher in myositis patients whereas muscle volume was lower compared to healthy controls. There was no difference in diffusion. Muscle strength was lower in myositis patients compared to healthy controls. In a subgroup of eight patients, scored as unaffected by radiologists, T2 values were still significantly higher in myositis patients. CONCLUSIONS: Quantitative MRI measurements can detect differences between myositis patients and healthy controls. Changes in the muscles of myositis patients, undetected by visual, semi-quantitative scoring, can be detected using quantitative T2 measurements. This suggests that MRI T2 values may be useful for the management of myositis patients.

Quantitative muscle magnetic resonance imaging depicts microstructural abnormalities but no signs of inflammation or dystrophy in post‐COVID‐19 condition

“…Recently, quantitative MRI (qMRI) has been shown to be a sensitive tool in the evaluation of muscle damage in different neuromuscular disorders, for example, in different entities of myositis, muscular dystrophy, and metabolic myopathy [10][11][12][13][14][15]. Results from advanced qMRI techniques like quantitative T2 measures, diffusion tensor imaging (DTI), and Dixon fat fraction (FF) imaging provide additional information about underlying pathophysiology [16].…”

“…Results from advanced qMRI techniques like quantitative T2 measures, diffusion tensor imaging (DTI), and Dixon fat fraction (FF) imaging provide additional information about underlying pathophysiology [16]. Whereas quantitative T2 measures have been shown to reflect the degree of myoedema and inflammation, DTI allows conclusions about muscular micro-and macrostructure [14,17,18]. Most importantly, findings based on both techniques were related to histopathologic features in neuromuscular disorders and were sensitive in detecting subtle changes after physical exertion and in otherwise healthy-appearing, non-fat-infiltrated muscles in neuromuscular disorders [16,19].…”

Idiopathic inflammatory myopathies: one year in review 2022

“…The effectiveness of MRI-based measurements distinguishing IIM patients from healthy controls was also recently assessed. Fat fraction and T2 values were higher in IIM patients, whereas muscle volume was lower than in healthy controls, with no significant differences in diffusion (64). Notably, in a subgroup of patients scored as unaffected by radiologists, T2 values were still significantly higher in IIM patients (64).…”

Checkpoint inhibitor induced myositis – The value of MRI STIR

“…MRI STIR can show inflammation in muscle tissue [ 7 ]. We believe that this imaging method can play an important role in rapid identification of irMyositis.…”