Electrical impedance myography for the in vivo and ex vivo assessment of muscular dystrophy ( mdx ) mouse muscle

: Sensitive, non‐invasive techniques are needed that can provide biomarkers of disease status and the effects of therapy in muscular dystrophy. Methods : We evaluated electrical impedance myography (EIM) to serve in this role by studying 2‐month‐old and 18‐month‐old mdx and wild‐type (WT) animals (10 animals in each of 4 groups). Results : Marked differences were observed in EIM values between mdx and WT animals; the differences were more pronounced between the older age groups (e.g., reactance of 92.6 ±4.3 Ω for mdx animals vs. 130 ± 4.1 Ω for WT animals, P  < 0.001). In addition, in vivo EIM parameters correlated significantly with the extent of connective tissue deposition in the mdx animals. Conclusions : EIM has the potential to serve as a valuable non‐invasive method for evaluating muscular dystrophy. It can be a useful biomarker to assist with therapeutic testing in both pre‐clinical and clinical studies. Muscle Nerve 49 : 829–835, 2014