Quantitative muscle MRI depicts microstructural abnormalities but no signs of inflammation or dystrophy in Post COVID-19 condition

Patients with post COVID-19 condition (PCC) often suffer from musculoskeletal pain with unknown pathophysiology. qMRI of the lower limbs was used to unravel the underlying mechanisms. 20 PCC were compared to 20 age and gender matched controls with regard to muscle fatfraction (revealed by Dixon imaging) water T2 time (using T2-mapping) and structural alterations (using DTI). Quantitative MRI did not depict any signs of ongoing inflammation or dystrophic process of the skeletal muscles in PCC patients. However, differences observed in muscle DTI depicts microstructural abnormalities, which may reflect potentially reversible fiber hypotrophy due to deconditioning.