Peter van Gelderen1, Jacco A. de Zwart1, Jongho Lee1, Pascal Sati2, Daniel S. Reich2, Jeff H. Duyn1
1Advanced MRI section, LFMI, NINDS, National Institutes of Health, Bethesda, MD, United States; 2Translational Neuroradiology Unit, Neuroimmunology Branch, NINDS, National Institutes of Health, Bethesda, MD, United States
A number of methods have been proposed to determine the myelin distribution in human brain, which may report on pathology. One potentially promising method is measurement of the T2* relaxation curve ,which may be affected by restricted mobility of myelin associated water. Here we investigated this possibility using multi-gradient echo MRI at 3T and 7T in normal brain. In myelin-rich regions, we observed relaxation characteristics more consistent with effects from susceptibility variations rather than from mobility restrictions. This may complicate the interpretation, as susceptibility effects are affected by additional factors independent of myelin content.