Elastic properties of skeletal muscle and subcutaneous tissues in Duchenne muscular dystrophy by magnetic resonance elastography (MRE): A feasibility study

Abstract

Objectives: Increasing fibrosis of skeletal muscle is a hallmark of the dystrophic process in Duchenne muscular dystrophy (DMD) and is a hindrance to functional muscle regeneration. We sought to evaluate the capacity of magnetic resonance elastography (MRE) to characterize the elastic properties of the vastus medialis (VM) muscle as well as that of its adjacent subcutaneous tissue in relaxed and exercised states.Material and Methods: Six healthy controls and six ambulant DMD boys underwent a MRE test. The shear stiffness (μ) and cartographies of stiffness were generated.Results: At rest, the DMD stiffness of the VM was higher than the healthy control muscle, suggesting altered elastic properties of the DMD muscle, most likely due to muscle fibrosis. In a contracted state, the VM stiffness of the DMD was lower than that found in healthy muscle, due to a lack of the muscle contractile properties. The results further showed a stiffer subcutaneous adipose tissue for the DMD compared to the healthy participants at rest.Conclusion: This is the first study to demonstrate muscle altered elastic properties of dystrophic muscle in DMD by MR elastography. Surprisingly, subcutaneous tissue in DMD also showed dramatically altered elastic properties, a new observation which will need further investigation.