Tie-Qiang Li1, M. Fukunaga2, K
1Department of Medical Physics, Karolinska University Hospital, S-141 86, Stockholm, Sweden; 2Laboratory of Functional and Molecular Imaging,, National Institute of Neurological Disorders and Stroke, National Institutes of Health,, United States
T2*-weighted MRI at high magnetic field strength has recently been used to reveal cortical layer structures and white matter heterogeneity in vivo. Magnetic susceptibility differences have been widely thought to give rise to most of the contrast but the precise mechanisms underlying the contrast is still poorly understood. Here, we report an interesting finding from microscopic MRI and histological studies of white matter specimens of the human brain, which may provide further clues for better understanding of the mechanisms underlying the T2*-weighted contrast.