Henry H. Ong1, Felix W. Wehrli1
1Laboratory for Structural NMR Imaging, Departement of Radiology, University of Pennsylvania School of Medicine, Philadelphia, PA, United States
Q-space imaging offers potential for indirect assessment of white matter architecture but is complicated by signal from both extra- and intra-cellular spaces (ECS and ICS). Here, we use an empiric method to separate ECS and ICS signals based on different characteristics of hindered and restricted diffusion in white matter tracts of healthy mouse spinal cords. This method circumvents problems with modeling or multi-exponential fitting to distinguish the two signals. The measured mean axon diameter show excellent agreement with histology. The results demonstrate the feasibility of this method to accurately separate and characterize diffusion in the ECS and ICS.