CREATING CONNECTED REPRESENTATIONS OF CORTICAL GRAY-MATTER FOR FUNCTIONAL MRI VISUALIZATION

We describe a system that is being used to segment gray matter from ma gnetic resonance imaging (MRI) and to create connected cortical repres entations for functional MRI visualization (fMRI). The method exploits knowledge of the anatomy of the cortex and incorporates structural co nstraints into the segmentation, First, the white matter and cerebral spinal fluid (CSF) regions in the MR volume are segmented using a nove l techniques of posterior anisotropic diffusion, Then, the user select s the cortical white matter component of interest, and its structure i s verified by checking for cavities and handles. After this, a connect ed representation of the gray matter is created by a constrained growi ng-out from the white matter boundary, Because the connectivity is com puted, the segmentation can be used as input to several methods of vis ualizing the spatial pattern of cortical activity within gray matter, In our case, the connected representation of gray matter is used to cr eate a flattened representation of the cortex, Then, fMRI measurements are overlaid on the flattened representation, yielding a representati on of the volumetric data within a single image, The software is freel y available to the research community.