• mdx;
  • mouse imaging;
  • muscular dystrophy;
  • skeletal muscle;
  • small animal imaging

Introduction: The ability to view individual myofibers is possible with many histological techniques, but not yet with standard in vivo imaging. Optical coherence tomography (OCT) is an emerging technology that can generate high resolution 1–10 μm cross-sectional imaging of tissue in vivo and in real time. Methods: We used OCT to determine architectural differences of tibialis anterior muscles in situ from healthy mice (wild-type [WT], n = 4) and dystrophic mice (mdx, n = 4). After diffusion tensor imaging (DTI) and OCT, muscles were harvested, snap-frozen, and sectioned for staining with wheat germ agglutinin. Results: DTI suggested differences in pennation and OCT was used to confirm this supposition. OCT indicated a shorter intramuscular tendon (WT/mdx ratio of 1.2) and an 18% higher degree of pennation in mdx. Staining confirmed these architectural changes. Conclusions: Architectural changes in mdx muscles, which could contribute to reduction of force, are detectable with OCT. Muscle Nerve, 2013