Objectives: To characterize diffusion tensor imaging (DTI) tensor eigenvalues (λ1, λ2, λ3), fractional anisotropy, mean diffusivity, and radial diffusivity in healthy lumbar musculature.
Methods: Seventeen healthy subjects (10 men, 7 women; mean age, 28 ± 7 years) were scanned using a 3.0-T magnetic resonance imaging. Axial DTI was performed using 15 diffusion directions (b = 400 mm2/s) at the L4 level. Oswestry Low Back Pain and Godin Physical Activity questionnaires were administered to rule out underlying lower back problems.
Results: Skeletal muscle DTI metrics were similar to those previously published. All measurements showed low coefficients of variation, except for quadratus lumborum. Laterality was not significant. Significant sex differences were observed in the quadratus lumborum (P < 0.05). Significant correlations were found between subjects’ weight and body mass index with fractional anisotropy and λ1 of the multifidus muscles.
Conclusions: The DTI metrics in paraspinal muscles can be reliably measured and are influenced by body mass index and weight but not by age or physical activity.
From the *McMaster School of Biomedical Engineering, McMaster University; †Imaging Research, and ‡Department of Rehabilitation Medicine, St. Joseph’s Healthcare; §Department of Radiology, McMaster University; ∥Department of Diagnostic Imaging, St. Joseph’s Healthcare; and ¶Departments of Electrical and Computer Engineering, and #Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada.
Received for publication July 8, 2012; accepted October 2, 2012.
Reprints: Michael D. Noseworthy, PhD, PEng, Imaging Research Center, Fontbonne Bldg, F-126-4 St. Joseph’s Healthcare, 50 Charlton Ave East, Hamilton, Ontario, Canada L8N 4A6 (e-mail: firstname.lastname@example.org).
The authors do not have conflicts of interest.