1Department of Medical and Health
Sciences, Division of Radiation Physics, Linkping, stergtland, Sweden; 2Center
for Medical Imaging Science and Visualization, Linkping, stergtland,
Sweden; 3Department of Medicine and Health, Division of Clinical
Physiology, Linkping, stergtland, Sweden
Using
an MR quantification sequence; specific brain-tissues typically exhibit a
narrow range of R1, R2 and PD values, and thus the tissues in the brain can
be identified as clusters in the three dimensional R1-R2-PD space. In partial
volume voxels (voxels containing two or more tissue types) the R1-R2-PD
values are a combination of the values from the contributing tissues. By
using a partial volume model a segmentation method to assess fractional
brain-tissue volumes of white matter (WM), grey matter (GM) and CSF for the
complete brain on a sub-voxel basis was created and validated on 7 normal
subjects.