METHOD AND SYSTEM FOR SEGMENTING A BRAIN IMAGE

A method is proposed for segmenting a brain image into a CSF region, a WM region and a GM region. An upper limit for the intensity values of a CSF region in the image is estimated such that the points of the image having an intensity less than this upper limit include a subset of the points which form a spatially connected group and which have a peaked intensity distribution. In other words, the invention exploits both the expected spatial distribution and expected intensity distribution of the CSF region. This makes it possible for the method to provide reliable discrimination of the CSF region even in CT images with poor image quality. Various methods are proposed for using the upper limit, and for improving the segmentation accuracy.