Esmaeil Davoodi-Bojd1, 2, Michael Chopp3, 4, Hamid Soltanian-Zadeh, 25, Shiyang Wang1, 6, Guangliang Ding1, Quan Jiang1
1Neurology, Henry Ford Health System, detroit, MI, United States; 2Electrical and Computer Engineering, University Of Tehran, Tehran, Iran; 3Neurology, Henry Ford Hospital, detroit, MI, United States; 4Physics, Oakland University, Rochester, MI, United States; 5Radiology, Henry Ford Health System, detroit, MI, United States; 6Radiology , University of Chicago, Chicago, IL, United States
In this work, a new model is proposed to estimate Water Exchange Ratio (WXR) the ratio of exchanged spins during diffusion time, Δ, between intra and extra axonal space using multi-shell DWMR imaging. Injury (such as MS, stroke, and TBI) to the axonal membrane or myelin sheath will likely change WXR. By measuring this parameter, the proposed model can discriminate between normal and injured fiber tracts induced by TBI or other diseases which affect the exchange parameters of the tissue. This model also may be used to estimate other micro-structural parameters like radius, density, and diffusion coefficients.