Abstract: A neural network is initially trained to remove errors and is later fine tuned to remove less-effective portions (e.g., kernels) from the initially trained network and replace them with further trained portions (e.g., kernels) trained with data after the initial training.

Abstract: The present disclosure is related to removing scatter from a SPECT scan by utilizing a radiative transfer equation (RTE) method. An attenuation map and emission map are acquired for generating scatter sources maps and scatter on detectors using the RTE method. The estimated scatter on detectors can be removed to produce an image of a SPECT scan with less scatter. Both first-order and multiple-order scatter can be estimated and removed. Additionally, scatter caused by multiple tracers can be determined and removed.

Abstract: A guided pairing method includes generating a singles list by detecting a plurality of singles at a plurality of detector elements in a detector array, the plurality of singles falling within a plurality of detection windows; for each detection window of the plurality of detection windows in the singles list having exactly two singles of the plurality of singles, determining the line of responses (LORs) for each of the two singles of the plurality of singles; for each detection window of the plurality of detection windows in the singles list having more than two singles of the plurality of singles, determining all coincidences possible based on the more than two singles; generating a weight for said each coincidence of the coincidences based on the determined LORs for said each of the two singles of the plurality of singles; and pairing the more than two singles based on the generated weight for said each coincidence of the coincidences.

Abstract: Existing, low quality images can be restored using reconstruction or a combination of post-reconstruction techniques to generate a real patient phantom. The real patient phantom (RPP) can then be simulated in Monte Carlo simulations of a higher performance system and a lower performance system. Alternatively, the RPP can be simulated in the higher performance system, and a real scan can be performed by an existing, lower performance system. The higher performance system can be differentiated from the lower performance system in a variety of ways, including a higher resolution time of flight measurement capability, a greater sensitivity, smaller detector crystals, or less scattering. A neural network can be trained using the images produce by the higher performance system as the target, and the images produced by the lower performance system as the input.

Abstract: A method of normalizing detector elements in an imaging system is described herein. The method includes a line source that is easier to handle for a user, and decouples the normalization of the detector elements into a transaxial domain and an axial domain in order to isolate errors due to positioning of the line source. Additional simulations are performed to augment the real scanner normalization. A simulation of a simulated line source closely matching the real line source can be performed to isolate errors due to physical properties of the crystals and position of the crystals in the system, wherein the simulated detector crystals are otherwise modeled uniformly. A simulation of a simulated cylinder source can be performed to determine errors due to other effects stemming from gaps between the detector crystals.

Abstract: The present disclosure relates to an apparatus for estimating scatter in positron emission tomography, comprising processing circuitry configured to acquire an emission map and an attenuation map, each representing an initial image reconstruction of a positron emission tomography scan, calculate, using a radiative transfer equation (RTE) method, a scatter source map of a subject of the positron emission tomography scan based on the emission map and the attenuation map, estimate, using the RTE method and based on the emission map, the attenuation map, and the scatter source map, scatter, and perform an iterative image reconstruction of the positron emission tomography scan based on the estimated scatter and raw data from the positron emission tomography scan of the subject.

Abstract: A method of normalizing detector elements in an imaging system is described herein. The method includes a line source that is easier to handle for a user, and decouples the normalization of the detector elements into a transaxial domain and an axial domain in order to isolate errors due to positioning of the line source. Additional simulations are performed to augment the real scanner normalization. A simulation of a simulated line source closely matching the real line source can be performed to isolate errors due to physical properties of the crystals and position of the crystals in the system, wherein the simulated detector crystals are otherwise modeled uniformly. A simulation of a simulated cylinder source can be performed to determine errors due to other effects stemming from gaps between the detector crystals.

Abstract: The present disclosure relates to an apparatus for estimating scatter in positron emission tomography, comprising processing circuitry configured to acquire an emission map and an attenuation map, each representing an initial image reconstruction of a positron emission tomography scan, calculate, using a radiative transfer equation (RTE) method, a scatter source map of a subject of the positron emission tomography scan based on the emission map and the attenuation map, estimate, using the RTE method and based on the emission map, the attenuation map, and the scatter source map, scatter, and perform an iterative image reconstruction of the positron emission tomography scan based on the estimated scatter and raw data from the positron emission tomography scan of the subject.

Abstract: A positron emission tomography scanner includes a plurality of gamma-ray detector rings that form a bore through which an imaging subject is translated, each of the plurality of gamma-ray detector rings being in a first axial position, and processing circuitry configured to receive attenuation data associated with a plurality of transaxial slices of the imaging subject, determine a second axial position of each of the plurality of gamma-ray detector rings based on the received attenuation data, and adjust a position of each of the plurality of gamma-ray detector rings from the first axial position to the second axial position. The processing circuitry may further be configured to calculate an attenuation metric based on the received attenuation data, and determine the second axial position such that the attenuation metric calculated for each pair of adjacent gamma-ray detector rings is equal.

Abstract: A method of normalizing detector elements in an imaging system is described herein. The method includes a line source that is easier to handle for a user, and decouples the normalization of the detector elements into a transaxial domain and an axial domain in order to isolate errors due to positioning of the line source. Additional simulations are performed to augment the real scanner normalization. A simulation of a simulated line source closely matching the real line source can be performed to isolate errors due to physical properties of the crystals and position of the crystals in the system, wherein the simulated detector crystals are otherwise modeled uniformly. A simulation of a simulated cylinder source can be performed to determine errors due to other effects stemming from gaps between the detector crystals.

Abstract: A time of flight positron emission tomography apparatus (100) includes a detector (106), a data acquisition system (120), a coincidence system (122) and a reconstructor (129). Various elements of an imaging chain influence the temporal resolution of the system (100) so that positron data collected along different lines of response is characterized by different temporal resolutions. The different temporal resolutions are used to estimate the positions of detected events along their respective lines of response.

Abstract: In accordance with one aspect of the invention a method and apparatus for utilizing time of flight information to detect motion during a medical imaging acquisition, such as a PET imaging acquisition, is provided. In accordance with another aspect of the invention, a method and apparatus for detecting and correcting for respiratory motion and cardiac motion in medical images, such as PET images, is provided.

Abstract: A method and system for use in positron emission tomography, wherein a list-based reconstructor means (129) is configured to generate first portion volumetric data responsive to a first portion of a plurality of positron annihilation events detected during a positron emission tomography scan; generate a human-readable image indicative of the first portion volumetric data; use a list-based reconstruction technique to generate composite volumetric data responsive to the first portion volumetric data and a second portion of the plurality of positron annihilation events; and generate a composite human-readable image indicative of the composite volumetric data. In another aspect the reconstructor (129) is configured to selecting first or second portion event quantities responsive to one or more parameters including image definition requirements and processing time requirements.

Abstract: An imaging system includes storage (12) for storing radionuclide imaging data including quantitative radiation detection event energy values, the radionuclide imaging data having been acquired of a subject by a radionuclide imaging device (10); an energy window selection module (20) selecting an energy window and a data filtering module (14) configured to filter the stored radionuclide imaging data respective to the stored quantitative radiation detection event energy values using the selected energy window to generate a filtered radionuclide imaging data set; and a reconstruction module (30) configured to reconstruct the filtered radionuclide imaging data set to generate a reconstructed image of the subject.

Abstract: In accordance with one aspect of the invention a method and apparatus for utilizing time of flight information to detect motion during a medical imaging acquisition, such as a PET imaging acquisition, is provided. In accordance with another aspect of the invention, a method and apparatus for detecting and correcting for respiratory motion and cardiac motion in medical images, such as PET images, is provided.

Abstract: An imaging system includes storage (12) for storing radionuclide imaging data including quantitative radiation detection event energy values, the radionuclide imaging data having been acquired of a subject by a radionuclide imaging device (10); an energy window selection module (20) selecting an energy window and a data filtering module (14) configured to filter the stored radionuclide imaging data respective to the stored quantitative radiation detection event energy values using the selected energy window to generate a filtered radionuclide imaging data set; and a reconstruction module (30) configured to reconstruct the filtered radionuclide imaging data set to generate a reconstructed image of the subject.

Abstract: A time of flight positron emission tomography apparatus (100) includes a detector (106), a data acquisition system (120), a coincidence system (122) and a reconstructor (129). Various elements of an imaging chain influence the temporal resolution of the system (100) so that positron data collected along different lines of response is characterized by different temporal resolutions. The different temporal resolutions are used to estimate the positions of detected events along their respective lines of response.

Abstract: A method and system for use in positron emission tomography, wherein a list-based reconstructor means (129) is configured to generate first portion volumetric data responsive to a first portion of a plurality of positron annihilation events detected during a positron emission tomography scan; generate a human-readable image indicative of the first portion volumetric data; use a list-based reconstruction technique to generate composite volumetric data responsive to the first portion volumetric data and a second portion of the plurality of positron annihilation events; and generate a composite human-readable image indicative of the composite volumetric data. In another aspect the reconstructor (129) is configured to selecting first or second portion event quantities responsive to one or more parameters including image definition requirements and processing time requirements.