Method and apparatus for scatter correction in position emission tomography (PET) imaging by performing a short PET scan in an extended region to estimate scatter coming from outside of the field of view (FOV)

An apparatus, comprising:

• a display configured to display a reconstructed image;
• a bed configured to accommodate a subject that emits gamma rays, the bed being configured to move to respective bed positions;
• a plurality of detector elements arranged around the bed and configured to
• detect, within a field of view, coincident gamma rays from respective positron emissions within the subject, and
• generate positron emission tomography (PET) data representing coincident gamma-ray detection events at the plurality of detector elements;
• and
• circuitry configured to
• obtain PET data including
• first emission data of a region of interest (ROI) including one or more full PET scans performed at respective FOVs with respect to the subject, the FOVs spanning the ROI, and each of the one or more full PET scans having a full-scan time duration,
• second emission data of a short PET scan performed with the FOV including a first extended region, which is next to the ROI in a first direction, the short PET scan having a short-scan time duration, which is less than the full-scan time duration, and
• third emission data of another short PET scan performed with the FOV including a second extended region, which is next to the ROI in an opposite direction to the first direction, the another short PET scan having a duration of the short-scan time duration,
• perform single-bed scatter correction on the PET data,
• perform, based on the second emission data and the third emission data, outside-the-FOV scatter correction on the first emission data to generate twice-corrected first emission data, and
• reconstruct, based on the twice-corrected first emission data, a PET image of the ROI.

A method, comprising:

• obtaining positron emission tomography (PET) data representing gamma rays detected at a plurality of detector elements of a PET scanner, which has field of view (FOV) with respect to coincidence pairs of gamma rays from positron emission, the PET scanner being configured to move a subject with respect the FOV, the PET data including
• first emission data of a region of interest (ROI) including one or more full PET scans performed at respective FOVs with respect to the subject, the FOVs spanning the ROI, and each of the one or more full PET scans having a full-scan time duration,
• second emission data of a short PET scan performed with the FOV including a first extended region, which is next to the ROI in a first direction, the short PET scan having a short-scan time duration, which is less than the full-scan time duration, and
• third emission data of another short PET scan performed with the FOV including a second extended region, which is next to the ROI in an opposite direction to the first direction, the another short PET scan having a duration of the short-scan time duration,
• performing single-bed scatter correction on the PET data;
• performing, based on the second emission data and the third emission data, outside-the-FOV scatter correction on the first emission data to generate twice-corrected first emission data;
• and
• reconstructing, based on the twice-corrected first emission data, a PET image of the ROI.