System and method for self-time alignment calibration for a positron emission tomography system
AssigneeSiemens Medical Solutions USA, Inc.
InventorsVladimir Y. Panin, Mehmet Aykac
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Abstract
A method for self-time alignment procedure for a PET scanner system is disclosed. Modeled time-of-flight (TOF) data are compared against the measured TOF data in order to find individual detector's time offsets (TOs). Then the TOs are estimated simultaneously by matching the TOF center of mass between the modeled and measured TOF data.
Claims12
A method for self-time alignment in a positron emission tomography (PET) scanner comprising:
- (a) receiving, at a processing unit, list mode data;
- (b) generating non-time of flight (TOF) projection data, scanner efficiency normalization array n, and attenuation factor a;
- (c) reconstructing image f from the non-TOF projection data, corrected for scanner efficiency by the normalization array n, and for attenuation by the attenuation factor a;
- (d) modeling non-TOF and TOF scatter S and non-TOF and TOF projections p;
- (e) for each line of response, modeling TOF center-of-mass (COM) of true coincidence distribution from zero order and first order moments M0 and M1 of the modeled TOF data;
- (f) for each line of response, computing measured TOF COM;
- (g) determining, by the processing unit, TOF time offsets, to, by taking the difference between the measured TOF COM and the modeled TOF COM;
- and
- (h) performing an imaging operation based on the determined to values.
A method for self-time alignment in continuous bed motion (CBM) positron emission tomography (PET) scanner comprising:
- (a) receiving, at a processing unit, list mode data;
- (b) generating CBM non-time of flight (TOF) projection data, scanner efficiency normalization array n, and attenuation factor a;
- (c) reconstructing image f from the CBM non-TOF projection data, corrected for scanner efficiency by the normalization array n, and for attenuation by the attenuation factor a;
- (d) modeling motion blurred non-TOF and TOF scatter S and motion blurred non-TOF and TOF projections p;
- (e) for each line of response, estimating TOF center-of-mass (COM) of true coincidence distribution acquired in a stationary system of coordinates from zero order and first order moments M0 and M1 of the modeled TOF data;
- (f) for each line of response, computing measured TOF COM;
- (g) determining, by the processing unit, TOF time offsets, to, by taking the difference between the measured TOF COM and the modeled TOF COM;
- and
- (h) performing an imaging operation based on the determined to values.
A non-transitory, machine-readable storage medium encoded with program instructions for controlling a PET scanner, such that when a processor executes the program instructions, the processor performs a method for self-time alignment of the PET scanner, wherein the method comprising:
- (a) receiving, at the processor, list mode data;
- (b) generating non-time of flight (TOF) projection data, scanner efficiency normalization array n, and attenuation factor a;
- (c) reconstructing image f from the non-TOF projection data, corrected for scanner efficiency by a normalization array n, and for attenuation by attenuation factor a;
- (d) modeling non-TOF and TOF scatter S and non-TOF and TOF projections p;
- (e) for each line of response, modeling TOF center-of-mass (COM) of true coincidence distribution from zero order and first order moments M0 and M1 of the modeled TOF data;
- (f) for each line of response, computing measured TOF COM;
- (g) determining TOF time offsets, to, by taking the difference between the measured TOF COM and the modeled TOF COM;
- and
- (h) performing an imaging operation based on the determined to values.
A non-transitory, machine-readable storage medium encoded with program instructions for controlling a continuous bed motion (CBM) PET scanner, such that when a processor executes the program instructions, the processor performs a method for self-time alignment of the CBM PET scanner, the method comprising:
- (a) receiving, at the processor, list mode data;
- (b) generating CBM non-time of flight (TOF) projection data, scanner efficiency normalization array n, and attenuation factor a;
- (c) reconstructing image f from the CBM non-TOF projection data, corrected for scanner efficiency by the normalization array n, and for attenuation by the attenuation factor a;
- (d) modeling motion blurred non-TOF and TOF scatter S and motion blurred non-TOF and TOF projections p;
- (e) for each line of response, estimating TOF center-of-mass (COM) of true coincidence distribution acquired in a stationary system of coordinates from zero order and first order moments M0 and M1 of the modeled TOF data;
- (f) for each line of response, computing measured TOF COM;
- (g) determining TOF time offsets, to, by taking the difference between the measured TOF COM and the modeled TOF COM;
- and
- (h) performing an imaging operation based on the determined to values.
Dependencies are inferred from the claim text.