title: Magnetic resonance elastography of skeletal muscle.
abstract: While the contractile properties of skeletal muscle have been studied extensively, relatively little is known about the elastic properties of muscle in vivo. Magnetic resonance elastography (MRE) is a phase contrast-based method for observing shear waves propagating in a material to determine its stiffness. In this work, MRE is applied to skeletal muscle under load to quantify the change in stiffness with loading. A mathematical model of muscle is developed that predicts a linear relationship between shear stiffness and muscle load. The MRE technique was applied to bovine muscle specimens (N = 10) and human biceps brachii in vivo (N = 5). Muscle stiffness increased linearly for both passive tension (14.5 +/- 1.77 kPa/kg) and active tension, in which the increase in stiffness was dependent upon muscle size, as predicted by the model. A means of noninvasively assessing the viscoelastic pro-perties of skeletal muscle in vivo may provide a useful method for studying muscle biomechanics in health and disease.
authors.affiliation: Magnetic Resonance Laboratory, Department of Diagnostic Radiology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Dresner
authors.forename: G H
authors.initials: GH
authors.lastname: Rose
authors.forename: P J
authors.initials: PJ
authors.lastname: Rossman
authors.forename: R
authors.initials: R
authors.lastname: Muthupillai
authors.forename: A
authors.initials: A
authors.lastname: Manduca
authors.forename: R L
authors.initials: RL
authors.lastname: Ehman
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002417:Cattle; D004548:Elasticity; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D018482:Muscle, Skeletal / Q000473:pathology / Q000502:physiology*; D012016:Reference Values; D016474:Weight-Bearing / Q000502:physiology*