Integrated region/edge framework for multimodality target delineation

A new methodology is proposed for the delineation of anatomical or physiological target regions utilizing a rich set of multimodality imagery. The proposed technique is unique in that it allows the integration of anatomical cues from transmission tomography (MRI/CT) with more fuzzy, physiological information derived from emission tomography (PET/SPECT). This approach allows for the delineation of regions of homogeneous tracer uptake constrained by the boundaries of anatomical structures, and vice versa. An extension of deformable model segmentation techniques is presented which integrates both region and edge information from registered scans in a competitive manner. The proposed technique has been implemented for two-dimensional deformable models. Results are presented for the cases of unimodal MRI in which region and edge information is integrated, and for a multimodal case employing a registered MRI and PET scan.