Volumetric Layer Segmentation Using Coupled Surfaces Propagation

The problem of segmenting a volumetric layer of nite thickness is encountered in several important ar eas within medical image analysis Key examples in clude the extraction of the cortical gray matter of the brain and the left ventricle myocardium of the heart The coupling between the two bounding surfaces of such a layer provides important information that helps to solve the segmentation problem Here we propose a new approach of coupled surfaces propagation via level set methods which takes into account coupling as an important constraint By evolving two embed ded surfaces simultaneously each driven by its own image derived information while maintaining the cou pling we capture a representation of the two bound ing surfaces and achieve automatic segmentation on the layer Characteristic gray level values instead of image gradient information alone are incorporated in deriving the useful image information to drive the sur face propagation which enables our approach to cap ture the homogeneity inside the layer The level set implementation o ers the advantage of easy initializa tion computational e ciency and the ability to cap ture deep folds of the sulci As a test example we apply our approach to unedited D Magnetic Reso nance MR brain images Our algorithm automati cally isolates the brain from non brain structures and recovers the cortical gray matter