Abstract #3506

Investigation of Diffusion Tensor Imaging Indices, Mean BOLD Signal and Calf Muscle Cross Sectional Area Following Bed Rest

Alyaa H. Elzibak¹, Michael D. Noseworthy²

¹Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada; ²Electrical and Computer Engineering, School of Biomedical Engineering, Department of Radiology, McMaster University, Hamilton, Ontario, Canada

Changes in posture, from erect to supine, are known to affect muscle cross sectional area (CSA) measurements due to fluid shifts. Diffusion tensor imaging (DTI) and blood oxygen level dependent imaging (BOLD) have been applied to assess muscle microstructure and vasculature, respectively. In this study, we investigated changes in calf muscle DTI indices (λ1, λ2, λ3, apparent diffusion coefficient, and fractional anisotropy) and BOLD signal due to supine rest. These parameters were measured in five calf muscles at three time points: baseline, 30 and 60 minutes of bed rest. We also measured calf muscle CSA at these three times.