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Diffusion tensor imaging assesses triceps surae dysfunction after achilles tenotomy in rats
Author(s) -
Hara Yusuke,
Ikoma Kazuya,
Kido Masamitsu,
Sukenari Tsuyoshi,
Arai Yuji,
Fujiwara Hiroyoshi,
Kawata Mitsuhiro,
Kubo Toshikazu
Publication year - 2015
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.24707
Subject(s) - fractional anisotropy , diffusion mri , tenotomy , medicine , achilles tendon , triceps surae muscle , muscle belly , ankle , anatomy , atrophy , muscle atrophy , heel , tendon , skeletal muscle , magnetic resonance imaging , radiology
Purpose To elucidate the relationship of diffusion tensor imaging (DTI) with structural changes and muscle function in skeletal muscle. Materials and Methods The subjects were 21 12‐week‐old male rats. Achilles tenotomy was performed on the right legs. Proton density‐weighted images and DTI (7.04T) of the triceps surae at 2 and 4 weeks posttenotomy were obtained. Eigenvalues (λ) and fractional anisotropy (FA) were calculated from the muscle images. After imaging, histological specimens of the triceps surae were prepared. The long axis and cross‐sectional area of the triceps surae were measured 2 and 4 weeks postoperatively. The strength of ankle plantar flexion was measured. Correlations of DTI parameters with morphological values and muscle strength were analyzed. Results λ 1 declined after tenotomy ( P < 0.01), and λ 2 and λ 3 declined at 4 weeks posttenotomy ( P < 0.01). FA increased at 4 weeks posttenotomy ( P < 0.01). Atrophy of the triceps surae was observed in the tissues images of the treatment group. The muscle belly significantly shortened postoperatively, and a decline in plantar flexion force was observed after tenotomy. Positive correlations were observed between λ 1 and muscle strength ( r = 0.89) and between λ 1 and the length of the long axis of the muscle belly ( r = 0.81). Conclusion DTI may serve as a marker of muscle function. J. Magn. Reson. Imaging 2015;41:1541–1548 . © 2014 Wiley Periodicals, Inc .