Temporal changes in magnetic resonance imaging in the mdx mouse
Open Access
- 9 July 2013
- journal article
- Published by Springer Science and Business Media LLC in BMC Research Notes
- Vol. 6 (1), 262-5
- https://doi.org/10.1186/1756-0500-6-262
Abstract
Background Duchenne muscular dystrophy (DMD) is characterized clinically by severe, progressive loss of skeletal muscle. The phenotype is much less severe in the mdx mouse model of DMD than that seen in patients with DMD. However, a “critical period” has been described for the mdx mouse, during which there is a peak in muscle weakness and degeneration/regeneration between the 2nd and 5th weeks of life. A number of studies have employed small animal magnetic resonance imaging (MRI) to examine skeletal muscle in various dystrophic models, but such studies represent a snapshot in time rather than a longitudinal view. Results The in vivo cross-sectional T2-weighted image of the healthy (wild type, WT) muscles is homogeneously dark and this homogeneity does not change with time, as there is no disease. We, and others, have shown marked changes in MRI in dystrophic muscle, with multiple, unevenly distributed focal hyperintensities throughout the bulk of the muscles. Here we monitored an mdx mouse using MRI from 5 to 80 weeks of age. Temporal MRI scans show an increase in heterogeneity shortly after the critical period, at 9 and 13 weeks of age, with a decrease in heterogeneity thereafter. The 4.3-fold increase in percent heterogeneity at week 9 and 13 is consistent with the notion of an early critical period described for mdx mice. Conclusions Age is a significant variable in quantitative MR studies of the mdx mouse. The mdx mouse is typically studied during the critical period, at a time that most closely mimics the DMD pathology, but the preliminary findings here, albeit based on imaging only one mdx mouse over time, suggest that the changes in MRI can occur shortly after this period, when the muscles are still recovering.Keywords
This publication has 33 references indexed in Scilit:
- Early metabolic changes measured by 1H MRS in healthy and dystrophic muscle after injuryJournal of Applied Physiology, 2012
- Diffusion Tensor MRI to Assess Damage in Healthy and Dystrophic Skeletal Muscle after Lengthening ContractionsJournal of Biomedicine and Biotechnology, 2011
- Chronic heart failure reduces Akt phosphorylation in human skeletal muscle: relationship to muscle size and functionJournal of Applied Physiology, 2011
- Location of myofiber damage in skeletal muscle after lengthening contractionsMuscle & Nerve, 2009
- Malformedmdxmyofibers have normal cytoskeletal architecture yet altered EC coupling and stress-induced Ca2+signalingAmerican Journal of Physiology-Cell Physiology, 2009
- Mammalian animal models for Duchenne muscular dystrophyNeuromuscular Disorders, 2009
- Dystrophin‐deficient mdx mice display a reduced life span and are susceptible to spontaneous rhabdomyosarcomaThe FASEB Journal, 2007
- Magnetic resonance imaging of regenerating and dystrophic mouse muscleBiochemistry and Cell Biology, 1998
- Magnetic Resonance Imaging and Magnetization Transfer in Experimental Myonecrosis in the RatMagnetic Resonance in Medicine, 1995
- Serum CK, calcium, magnesium, and oxidative phosphorylation in mdx mouse muscular dystrophyMuscle & Nerve, 1988