Diffusion tensor imaging and T2 mapping in early denervated skeletal muscle in rats

• Published in: Journal of magnetic resonance imaging 2015-09, Vol.42 (3), p.617-623
• Main Authors: Ha, Dong-Ho, Choi, Sunseob, Kang, Eun-Ju, Park, Hwan Tae
• Format: Article
• Language: English
• Subjects: Animals; Anisotropy; Diffusion Magnetic Resonance Imaging; Diffusion Tensor Imaging; Hindlimb - innervation; Image Processing, Computer-Assisted; Magnetic resonance imaging; Male; Muscle Denervation; Muscle, Skeletal - innervation; Muscle, Skeletal - pathology; Rats; Rats, Sprague-Dawley; Sciatic Nerve - pathology; T2 value
• ISSN: 1053-1807; 1522-2586
• DOI: 10.1002/jmri.24818

Background To evaluate the temporal changes of diffusion tensor imaging (DTI) indices, T2 values, and visual signal intensity on various fat suppression techniques in the early state of denervated skeletal muscle in a rat model. Methods Institutional Animal Care and Use Committee approval was obtained. Sciatic nerves of eight rats were transected for irreversible neurotmesis model. We examined normal lower leg and denervated muscles at 3 days, 1 week, and 2 weeks on a 3 Tesla MR. fractional anisotropy (FA), mean apparent diffusion coefficient (mADC), and T2 values were measured by using DTI and T2 mapping scan. We subjectively classified the signal intensity change on various fat suppression images into the following three grades: negative, suspicious, and definite change. Wilcoxon‐sign rank test and Kruskal‐Wallis test were used for the comparison of FA, mADC, T2 values. McNemar's test was used for comparing signal intensity change among fat suppression techniques. Results FA values of denervated muscles at 3 days (0.35 ± 0.06), 1 week (0.29 ± 0.04), and 2 weeks (0.34 ± 0.05) were significantly (P  0.05) change. T2 values were significantly increased at 1 week (38.11 ± 6.42 ms, P = 0.017) and markedly increased at 2 weeks (46.53 ± 5.17 ms, P = 0.012). The grade of visual signal intensity change on chemical shift selective fat saturation, STIR and IDEAL images were identical in all cases (P = 1.000). Conclusion FA and T2 values can demonstrate the early temporal changes in denervated rat skeletal muscle. J. Magn. Reson. Imaging 2015;42:617–623.