1.  Volume Preprocessing
Intensity normalization Ð critical for segmentation
¥Inhomogeneities in scanner fields cause gray and white matter intensities to vary as a function of their spatial location.
¥Removes residual non-uniformities in gray and white matter intensity values.











¥Increases gray and white matter contrast.
¥Sharpens the peaks of the two tissue classes.
¥Makes the intensity distribution of gray and white matter spatially uniform.
BEFORE
BEFORE
AFTER
AFTER