Patent ID: 8335363

Claim:
A method for image reconstruction of moving radionuclide distributions in an unanesthetized living subject comprising: A) imaging a three dimensional phantom including at least three reflective markers and at least three gamma sources with and without motion in a tracking system comprising: I) an imaging volume for limited confinement of the phantom; II) a rotating gantry about said imaging volume; III) at least three optical cameras that scan said three dimensional phantom, to obtain a tracking reference frame, and form an image generated by light reflected from the reflective markers as the optical cameras scan said phantom, to spatially locate the phantom within the imaging volume mounted on the rotating gantry; IV) at least two SPECT and/or PET imaging devices mounted on the gantry, to obtain a gamma reference frame, in positions to permit said optical cameras to view said imaging volume and spatially locate and map the phantom while said SPECT and/or PET imaging devices functionally image the phantom; and V) image processing hardware and software that receive electronic signals from said tracking system and said SPECT and/or PET imaging devices and generate a combined and registered profile and a functional image of the phantom; and B) repeating the process of step A while the living unanesthetized subject labeled with at least three optical reflectors and having previously been injected with a radiopharmaceutical is located in the imaging volume in place of the phantom; and C) obtaining a functional image of the unanesthetized living subject through the application of a vector equation and an iterative list-mode maximum likelihood expectation maximization algorithm that is part of the software; wherein said vector equation is x ( GRF,t )= R TG [R pose ( t ) R −1 pose ( t 0 ){ R −1 TG [x ( GRF,t 0 )− t TG ]−t pose ( t 0 )}+ t pose ( t )]+ t TG and; x(GRF, t) is a 3-D position of a source object point in the gamma reference frame as a function of time t; x(GRF, t 0 ) is a 3-D position of a source object point in the gamma reference frame at a starting time t 0 ; R TG and t TG are a 3-D rotation matrix and a 3-component translation vector describing the transformation from the tracking reference frame to the gamma reference frame; R −1 TG is the matrix inverse of R TG ; R pose (t) and t pose (t) are a time-dependent 3-D rotation matrix and a 3-component translation vector describing a motion of a point in the tracking reference frame from a reference position to a position at time t; R pose (t 0 ) and t pose (t 0 )are a pose rotation matrix and pose translation vector at a time t 0 to be used for the object position for image reconstruction; and R −1 pose (t 0 ) is the inverse of the matrix R pose (t 0 ).