Patent ID: 7737406

Claim:
A process for generating an adjusted attenuation map from a truncated transmission scan of an imaged object using a non-truncated emission scan of the imaged object having an outline, comprising the steps of: performing a transmission scan of the imaged object about a plurality of projection angles to collect transmission projection data having a field of view (FOV) inside the outline of the imaged object, resulting in truncated transmission projection data; performing an emission scan of the imaged object about a plurality of projection angles to collect emission projection data having a FOV including the outline of the imaged object; reconstructing non-truncated emission image volume data; generating transmission data missing from said collected transmission projection data as a result of said truncation, based on the reconstructed non-truncated emission image volume data wherein the emission scan from the reconstructed non-truncated emission image volume data includes the imaged object outline data needed to generate the data missing from the truncated transmission data; adding said generated transmission data to said collected transmission data to obtain truncation-compensated transmission data using differential attenuation information (DAI) and CT template matching, wherein DAI exists in the emission scan data extracted from dual or multiple energy acquisitions where multi-emission isotopes are used, and further wherein the CT template matching involves a search of registered images to reveal a CT template dataset for the best matched CT template within the FOV of the truncated transmission projection data; converting the truncation-compensated transmission data to linear attenuation coefficient data for generating an attenuation map; and registering the attenuation map with the reconstructed non-truncated emission image volume date to correct said reconstructed non-truncated emission image volume data for effects of attenuation wherein reconstructing non-truncated emission image volume data includes tomographic reconstruction of emission scan data to generate image volume data.