Andrew D. Davis1,2, Greg D. Wells3,4, Bereket Falk5, Michael D. Noseworthy6,7
1Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ontario, Canada; 2Medical Physics and Applied Radiation Sciences, St. Joseph's Healthcare, Hamilton, Ontario, Canada; 3Department of Anesthesia, University of Toronto, Toronto, Ontario, Canada; 4Physiology and Experimental Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada; 5Department of Physical Education and Kinesiology, Brock University, St. Catharines, Ontario, Canada; 6Electrical and Computer Engineering, School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada; 7Brain-Body Institute, St. Joseph's Healthcare, Hamilton, Ontario, Canada
BOLD data was acquired at 3T in skeletal muscle of the lower leg during an on/off isometric exercise paradigm. This was compared to data taken by substituting a twisting motion for the exercise. Both data sets were analysed using a square wave based GLM. The twisting data was found to mimic the exercise data, confounding the analysis. In-plane twists must therefore be eliminated from during-exercise BOLD scans, since the motion effects may be mistaken for true changes in perfusion and oxygenation.