Segmentation of the brain from 3D MRI using a hierarchical active surface template

The accurate segmentation of the brain from three-dimensional medical imagery is important as the basis for visualization, morphometry, surgical planning and intraoperative navigation. The complex and variable nature of brain anatomy makes recognition of the brain boundaries a difficult problem and frustrates segmentation schemes based solely on local image features. We have developed a deformable surface model of the brain as a mechanism for utilizing a priori anatomical knowledge in the segmentation process. The active surface template uses an energy minimization scheme to find a globally consistent surface configuration given a set of potentially ambiguous image features. Solution of the entire 3D problem at once produces superior results to those achieved using a slice by slice approach. We have achieved good results with MR image volumes of both normal and abnormal subjects. Evaluation of the segmentation results has been performed using cadaver studies. 1. INTRODUCTION The rapi..

Segmentation of Cortical Surface and Interior Brain Structures Using Active Surface / Active Volume Templates

Advanced applications such as neurosurgical planning and simulation require both surface and interior anatomical information in order to be truly effective. We are developing a segmentation scheme based on collections of active surface templates embedded within an active volume. This composite system encodes high-level anatomical knowledge of both cortical surface and interior brain structures in a self-assembling model of a reference, or atlas brain. Following initialization of the surface templates in the test brain volume, the cortical surface templates deform to achieve a segmentation of the surface of the brain. The displacements of the cortical surface templates cause an increase in the potential elastic energy of the active volume, and a subsequent minimization of this elastic energy is used to define a volumetric warp between the reference brain and the test data. This warp is used to deform the active surface models of the deep structures in the brain to their approximate fina..