title: Changes in diffusion tensor imaging (DTI) eigenvalues of skeletal muscle due to hybrid exercise training.
abstract: Several studies have proposed the cell membrane as the main water diffusion restricting factor in the skeletal muscle cell. We sought to establish whether a particular form of exercise training (which is likely to affect only intracellular components) could affect water diffusion. The purpose of this study is to characterise prospectively the changes in diffusion tensor imaging (DTI) eigenvalues of thigh muscle resulting from hybrid training (HYBT) in patients with non-alcoholic fatty liver disease (NAFLD). Twenty-one NAFLD patients underwent HYBT for 30 minutes per day, twice a week for 6 months. Patients were scanned using DTI of the thigh pre- and post-HYBT. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), the three eigenvalues lambda 1 (λ1), λ2, λ3, and the maximal cross sectional area (CSA) were measured in bilateral thigh muscles: knee flexors (biceps femoris (BF), semitendinosus (ST), semimembranous (SM)) and knee extensors (medial vastus (MV), intermediate vastus (IV), lateral vastus (LV), and rectus femoris (RF)), and compared pre- and post-HYBT by paired t-test. Muscle strength of extensors (P<0.01), but not flexors, increased significantly post-HYBT. For FA, ADC and eigenvalues, the overall picture was of increase. Some (P<0.05 in λ2 and P<0.01 in λ1) eigenvalues of flexors and all (λ1-λ3) eigenvalues of extensors increased significantly (P<0.01) post-HYBT. HYBT increased all 3 eigenvalues. We suggest this might be caused by enlargement of muscle intracellular space.
authors.affiliation: Department of Radiology, Institute of Clinical Medicine, University of Tsukuba Hospital, Ibaraki, Japan. Electronic address: yokamoto72429@gmail.com.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Okamoto
authors.affiliation: Department of Musculoskeletal Biology, Faculty of Health & Life Sciences, University of Liverpool, Liverpool, Merseyside, United Kingdom.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Kemp
authors.affiliation: Department of Radiology, Institute of Clinical Medicine, University of Tsukuba Hospital, Ibaraki, Japan.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Isobe
authors.affiliation: Department of Radiology, University of Kitasato, Tokyo, Japan.
authors.forename: Eisuke
authors.initials: E
authors.lastname: Sato
authors.affiliation: Department of Radiology, Institute of Clinical Medicine, University of Tsukuba Hospital, Ibaraki, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hirano
authors.affiliation: Department of Gastroenterology, Institute of Clinical Medicine, University of Tsukuba Hospital, Ibaraki, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Shoda
authors.affiliation: Department of Radiology, Institute of Clinical Medicine, University of Tsukuba Hospital, Ibaraki, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Minami
mesh_terms: D000328:Adult; D016880:Anisotropy; D004058:Diffusion; D056324:Diffusion Tensor Imaging; D015444:Exercise; D005081:Exercise Therapy / Q000379:methods; D006801:Humans; D006984:Hypertrophy / Q000473:pathology; D007866:Leg; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000473:pathology*; D065626:Non-alcoholic Fatty Liver Disease / Q000473:pathology*; D013848:Thigh / Q000473:pathology
keywords: Difusion tensor imaging; Eigenvalue; Hybrid training; Skeletal muscle