AUTOMATIC SEGMENTATION OF BRAIN TISSUE AND WHITE MATTER LESIONS IN MRI

A method to automatically segment cerebrospinal fluid, gray matter, white matter and white matter lesions is presented. The method uses magnetic resonance brain images from proton density, T1-weighted and fluid-attenuated inversion recovery sequences. The method is based on an automatically trained k-nearest neighbour classifier ex-tended with an additional step for the segmentation of white matter lesions. On six datasets, segmentations are quantitatively compared with manual segmentations, which have been carried out by two ex-pert observers. For the tissues, similarity indices between method and observers approximate those between manual segmentations. Reasonably good lesion segmentation results are obtained compared to interobserver variability. Index Terms — Automatic image segmentation, Brain tissue, White matter lesions, Magnetic resonance imagin