Assessment of Axon Diameter Distribution in Mouse Spinal Cord with q-Space Imaging

Henry H. Ong¹, Felix W. Wehrli¹

Knowledge of axon morphology would provide important insight into neural function, anatomy and pathology. Q-space imaging (QSI) offers potential for indirect assessment of WM architecture and already has been used to measure intra-cellular volume fraction and mean axon diameter. Here, we examine the feasibility of QSI to measure axon diameter distribution (ADD) from white matter tracts in healthy mouse spinal cords using the displacement probability density function. The results show that QSI-derived ADDs semi-quantitatively agree with histologic ADDs and consistently illustrate the relative differences in ADD between WM tracts.