Jimin Ren1,2, A. Dean Sherry1,3, Craig R. Malloy1,4
1Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, USA; 2Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA; 3 Department of Chemistry, University of Texas at Dallas, Richardson, TX, USA; 4VA North Texas Health Care System, Dallas, TX, USA
The phenomenon of exercised-induced muscles intensity increase on T2w images has attracted numerous research interests due to its potential applications in clinical diagnosis of muscle diseases, exercise trainings and assessment of physical therapy. However, the underlying physiological mechanisms are still poorly understood. Traditional explanation is that it is a purely water related phenomenon, possibly resulting from water T2 elongation. MRI and 1H MRS data in this work indicate that calf muscle stretching can amplify the signal intensity of extramyocellular lipid (EMCL), likely due to fat tissue aligning along Bo direction. It may be responsible, at least partly, for the well-known effect.