Reconstruction with Partially Known Attenuation Information In Time of Flight Positron Emission Tomography

摘要

Reconstruction in positron emission tomography is performed with partially known attenuation. A PET-CT scanner is used to generate a PET image with time of flight emission information. To limit x-ray dose while providing increased sensitivity at the ends of the CT volume in the PET image, attenuation coefficients for oblique LORs passing outside the CT volume are determined from the time of flight emission information. The attenuation coefficients for LORs within the CT volume are derived from the CT data. An objective function may be maximized for the emission distribution without reconstructing the attenuation distribution.

主权项

1. A method for reconstructing in positron emission tomography with partially known attenuation, the method comprising:
acquiring, with a computed tomography (CT) scanner, attenuation information for a CT volume of a patient; acquiring, with a positron emission tomography (PET) scanner having a plurality of detectors, time of flight data along lines-of-response from emissions; converting the attenuation information into attenuation coefficients along only a first subset of a plurality of the lines of response, a second sub-set of the lines of response missing attenuation information; reconstructing an image of the patient from the time of flight data including the lines of response of the first and second subsets, the reconstructing being a function of the attenuation coefficients along the lines of response of the first subset and a model of attenuation coefficients along the lines of response of the second subset, the model being a function of the corresponding time of flight data for the lines of response of the second sub-set; and displaying the image.