Abstract: During data acquisition in a tomographic scan of a subject unscattered events and scatter events are collected. The data are corrected for the scatter events and movement of the subject during the scan. A scatter estimate is derived for use in the reconstruction of an image of the subject; a first step in the derivation has a first dependence on the movement of the subject. The image of the subject is derived from the detected events using the scatter estimate; a second step in this derivation has a second dependence on the movement of the subject, the dependence being different from that of the first step.

Abstract: The method calculates a scatter estimate for scatter correction of detection data from a subject in a positron emission tomographic scanner. The detection data represent the scattered events and unscattered events of annihilation photons emitted in the subject. The method uses the following steps: determine an estimate of the unscattered events; determine a simulation of the scattered events; determine a value of a scaling factor by fitting the sum of the estimate of the unscattered events and a product of the scaling factor and the simulation of the scattered events to the detection data; and determine the scatter estimate as the product of the scaling factor having said value and the simulation of the scattered events.

Abstract: A method and apparatus are provided for reducing motion related imaging artifacts. The method includes determining an internal motion for of two regions of the object, each region having a different level of motion, scanning the first region using a first scan protocol based on the motion, scanning a second region using a second different scan protocol based on the motion, and generating an image of the object based on the first and second regions.

Abstract: A method and apparatus are provided for reducing motion related imaging artifacts. The method includes obtaining an image data set of a region of interest in an object, obtaining a motion signal indicative of motion of the region of interest, and determining a displacement and a phase of at least a portion of the motion signal. The method also includes mapping the image data set into a matrix based on the displacement and phase of the motion signal, and generating an image of the region of interest from the matrix.

Abstract: A method of conducting motion correction for a tomographic scanner including a detector array for detecting radiation to generate detector data. The method comprises storing detector data collected during a data acquisition period, the detector data being indicative of directions along which radiation is detected and quantities of radiation detected in different of said directions. The method involves storing movement data representing movement of the subject during the data acquisition period and motion correcting the detector data using the movement data and a motion correction algorithm to calculate motion corrected detector data.

Abstract: The method calculates a scatter estimate for annihilation photons in a subject having a distribution of attenuation. The method can be used for scatter correction of detection data from a positron emission tomographic scanner. The method uses the following steps: —select a first scatter point S1 and a second scatter point S2, —determine a first scatter probability for scattering of a photon at scatter point S1 and a second scatter probability for scattering of a photon at scatter point S2, —determine an integral of the attenuation over a line connecting S1 and S2, —multiply the integral and the scatter probabilities and use the product in the calculation of the scatter estimate.

Abstract: The method calculates a scatter estimate for scatter correction of detection data from a subject in a positron emission tomographic scanner. The detection data represent the scattered events and unscattered events of annihilation photons emitted in the subject. The method uses the following steps: determine an estimate of the unscattered events; determine a simulation of the scattered events; determine a value of a scaling factor by fitting the sum of the estimate of the unscattered events and a product of the scaling factor and the simulation of the scattered events to the detection data; and determine the scatter estimate as the product of the scaling factor having said value and the simulation of the scattered events.

Abstract: An imaging method comprises reconstructing gated emission tomography images for a region of interest, adjusting a mismatch between the gated emission tomography images and a computed tomography image of the region of interest, registering the gated emission tomography images, and combining the registered gated emission tomography images to generate motion corrected images.

Abstract: Detector efficiency data is generated for a positron emission tomography scanner (2) including a single photon source by conducting a blank scan acquisition procedure using the single photon source. The acquired detection count data is processed using an efficiency estimation algorithm to calculate data efficiencies of individual detectors in the detector array (8). In one embodiment, the detection count data is output as artificial coincidence count data and the efficiency estimation algorithm operates on the artificial coincidence count data. The method can be used in a non-rotating scanner or a rotating scanner.

Abstract: During data acquisition in a tomographic scan of a subject unscattered events and scatter events are collected. The data are corrected for the scatter events and movement of the subject during the scan. A scatter estimate is derived for use in the reconstruction of an image of the subject; a first step in the derivation has a first dependence on the movement of the subject. The image of the subject is derived from the detected events using the scatter estimate; a second step in this derivation has a second dependence on the movement of the subject, the dependence being different from that of the first step.

Abstract: The method calculates a scatter estimate for annihilation photons in a subject having a distribution of attenuation. The method can be used for scatter correction of detection data from a positron emission tomographic scanner. The method uses the following steps: —select a first scatter point S1 and a second scatter point S2, —determine a first scatter probability for scattering of a photon at scatter point S1 and a second scatter probability for scattering of a photon at scatter point S2, —determine an integral of the attenuation over a line connecting S1 and S2, —multiply the integral and the scatter probabilities and use the product in the calculation of the scatter estimate.