title: Demyelination reduces brain parenchymal stiffness quantified in vivo by magnetic resonance elastography.
abstract: The detection of pathological tissue alterations by manual palpation is a simple but essential diagnostic tool, which has been applied by physicians since the beginnings of medicine. Recently, the virtual "palpation" of the brain has become feasible using magnetic resonance elastography, which quantifies biomechanical properties of the brain parenchyma by analyzing the propagation of externally elicited shear waves. However, the precise molecular and cellular patterns underlying changes of viscoelasticity measured by magnetic resonance elastography have not been investigated up to date. We assessed changes of viscoelasticity in a murine model of multiple sclerosis, inducing reversible demyelination by feeding the copper chelator cuprizone, and correlated our results with detailed histological analyses, comprising myelination, extracellular matrix alterations, immune cell infiltration and axonal damage. We show firstly that the magnitude of the complex shear modulus decreases with progressive demyelination and global extracellular matrix degradation, secondly that the loss modulus decreases faster than the dynamic modulus during the destruction of the corpus callosum, and finally that those processes are reversible after remyelination.
authors.affiliation: Institute of Neuroradiology,  University Luebeck, 23568 Luebeck,  Germany.
authors.forename: Katharina
authors.initials: K
authors.lastname: Schregel
authors.forename: Eva
authors.initials: E
authors.lastname: Wuerfel
authors.forename: Philippe
authors.initials: P
authors.lastname: Garteiser
authors.forename: Ines
authors.initials: I
authors.lastname: Gemeinhardt
authors.forename: Timour
authors.initials: T
authors.lastname: Prozorovski
authors.forename: Orhan
authors.initials: O
authors.lastname: Aktas
authors.forename: Hartmut
authors.initials: H
authors.lastname: Merz
authors.forename: Dirk
authors.initials: D
authors.lastname: Petersen
authors.forename: Jens
authors.initials: J
authors.lastname: Wuerfel
authors.forename: Ralph
authors.initials: R
authors.lastname: Sinkus
mesh_terms: D000818:Animals; D001369:Axons; D001921:Brain / Q000473:pathology*; D002614:Chelating Agents / Q000008:administration & dosage / Q000737:chemistry; D003300:Copper / Q000737:chemistry; D003471:Cuprizone / Q000008:administration & dosage / Q000737:chemistry; D003711:Demyelinating Diseases / Q000473:pathology*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D002614:Chelating Agents; D003471:Cuprizone; D003300:Copper