Systems and methods for correcting mismatch induced by respiratory motion in positron emission tomography image reconstruction

A system, comprising:

• at least one processor;
• and
• at least one storage medium for storing instructions, the instructions, when executed by the at least one processor, causing the system to perform a method including:
• obtaining an anatomical image of a subject;
• obtaining positron emission tomography (PET) data of the subject;
• gating the PET data into a plurality of bins, the plurality of bins corresponding to a plurality of respiratory phases;
• reconstructing, based on the gated PET data, a plurality of gated PET images, each gated PET image of the plurality of gated PET images corresponding to a respiratory phase of the plurality of respiratory phases;
• determining, based on the plurality of gated PET images and the anatomical image, a motion vector field corresponding to a target respiratory phase with respect to a reference respiratory phase relating to the anatomical image;
• obtaining a respiratory phase-matched anatomical image for the target respiratory phase by transforming a volume of interest (VOI) in the anatomical image based on the motion vector field corresponding to the target respiratory phase with respect to the reference respiratory phase;
• and
• reconstructing an attenuation corrected PET image corresponding to the target respiratory phase based on the respiratory phase-matched anatomical image and the gated PET data.

A non-transitory computer-readable storage medium storing instructions that, when executed by at least one processor of a system, cause the system to perform a method, the method comprising:

• obtaining an anatomical image of a subject;
• obtaining positron emission tomography (PET) data of the subject;
• gating the PET data into a plurality of bins, the plurality of bins corresponding to a plurality of respiratory phases;
• reconstructing, based on the gated PET data, a plurality of gated PET images, each gated PET image of the plurality of gated PET images corresponding to a respiratory phase of the plurality of respiratory phases;
• determining, based on the plurality of gated PET images and the anatomical image, a motion vector field corresponding to a target respiratory phase with respect to a reference respiratory phase relating to the anatomical image;
• obtaining a respiratory phase-matched anatomical image for the target respiratory phase by transforming a volume of interest (VOI) in the anatomical image based on the motion vector field corresponding to the target respiratory phase with respect to the reference respiratory phase;
• and
• reconstructing an attenuation corrected PET image corresponding to the target respiratory phase based on the respiratory phase-matched anatomical image and the gated PET data.