A positron emission tomography (PET) data processing method comprises obtaining PET data from a PET detector, wherein the PET detector comprises an array of detector elements, and wherein the PET data is representative of a PET measurement of at least part of a subject. The method comprises identifying in the PET data a plurality of paired events, wherein each paired event comprises a first photon event in a first region of the PET detector and a second photon event in a second region of the PET detector. The first photon event comprises an energy deposition in a first detector element of the array or in a first detection region of the first detector element due to a scattering of a first photon at a first azimuthal scattering angle and an associated energy deposition by the scattered first photon in a second detector element of the array or in a second detection region of the first detector element or of the second detector element. The second photon event comprises an energy deposition in a third detector element of the array or in a third detection region of the third detector element due to a scattering of a second photon at a second azimuthal scattering angle and an associated energy deposition by the scattered second photon in a fourth detector element of the array or in a fourth detection region of the third detector element or of the fourth detector element. The method further comprises processing the PET data in dependence on the first and second azimuthal scattering angles for the paired events.

A flat pixel (20) is a single unit composing a radiation detector and is configured so as to be divided into at least four subpixels (21) such that even if a prescribed number of subpixels (21) are removed from each pixel (20) in order of largest effective area, the centroid (51) of the effective area of the entirety of the remaining subpixels (21) is positioned within a similar-shape region (30) having the same centroid (50) as the pixel (20) and having sides of lengths that are half those of the pixel (20).

The present invention is an X-ray system having a source-detector module, which includes X-ray sources and detectors, for scanning an object being inspected, a scan engine coupled to the source-detector module for collecting scan data from the source detector module, an image reconstruction engine coupled to the scan engine for converting the collected scan data into one or more X-ray images, and a scan controller coupled with at least one of the source detector module, the scan engine, and the image reconstruction engine optimize operations of the X-ray system.

A method and system are provided for elementally detecting variations in density. The method includes providing a computed tomography device, comprising a radiation source, a detector, and at least one grating between the radiation source and the detector, positioning the component between the radiation source and the detector, directing radiation from the radiation source to the detector to acquire information from the component, generating at least one phase contrast image and at least one dark field contrast image of the component corresponding to variations in density with the information from the component, correlating the variations in density to a foreign mass, and displaying foreign mass distribution within the component. The system includes a radiation source, a detector, a component, a first grating, a second grating, and an analysis device capable of determining total variation of density in response to radiation received by the detector, and correlating the variation of density to free element distribution in the component.

A device for generating one or more images of a source distribution of a gamma radiation field in the near and far field can include a detector system that includes several synchronized detectors for detecting radiation, system electronics that registers coincidence events, a data acquisition system that stores the measurement data of the coincidence events, and an analysis unit that performs an image reconstruction, which reconstructs one or more images of the source distribution of the radiation field.

A method and apparatus is provided to perform dead-time correction in a positron emission tomography (PET) by estimating a full singles spectrum using a scatter model. The scatter model can use a Monte Carlo method, a radiation transfer equation method, an artificial neural network, or an analytical expression. The scatter model simulates scatter based on an emission image/map and an attenuation image/map to estimate Compton scattering. In the full singles spectrum, the singles counts with energies less than 511 keV are determined from the simulated scatter. The attenuation image can be generated based on X-ray computed tomography or based on applying a joint-estimation to PET data.

A coded mask apparatus is provided for gamma rays. The apparatus uses nested masks, at least one of which rotates relative to the other.

A method of investigating a specimen using a tomographic imaging apparatus comprising: A specimen holder, for holding the specimen; A source, for producing a beam of radiation that can be directed at the specimen; A detector, for detecting a flux of radiation transmitted through the specimen from the source; A stage apparatus, for producing relative motion of the source with respect to the specimen, so as to allow the source and detector to image the specimen along a series of different viewing axes; A processing apparatus, for assembling output from the detector into a tomographic image of at least part of the specimen,
which method comprises the following steps: Considering a virtual reference surface that surrounds the specimen and is substantially centered thereon; Considering an incoming point of intersection of each of said viewing axes with this reference surface, thereby generating a set of such intersection points corresponding to said series of viewing axes; Choosing discrete viewing axes in said series so as to cause said set to comprise a two-dimensional lattice of points located areally on said reference surface in a substantially uniform distribution.

This disclosure describes an imaging radiation detection module with novel configuration of the scintillator sensor allowing for simultaneous optimization of the two key parameters: detection efficiency and spatial resolution, that typically cannot be achieved. The disclosed device is also improving response uniformity across the whole detector module, and especially in the edge regions. This is achieved by constructing the scintillation modules as hybrid structures with continuous (also referred to as monolithic) scintillator plate(s) and pixellated scintillator array(s) that are optically coupled to each other and to the photodetector. There are two basic embodiments of the novel hybrid structure: (1) the monolithic scintillator plate is at the entrance for the incoming radiation, preferably gamma rays, and the pixellated array placed behind the plate, all in optical contact with the photodetector, (2) the order of the scintillator components is reversed with the pixellated scintillation plate placed in front of the monolithic plate.

An X-ray detector is positioned relative to an X-ray source such that at least a part of a region between the X-ray source and the X-ray detector is an examination region for accommodating an object. The X-ray source and X-ray detector are controlled by a processing unit in order to operate in a first imaging operation mode, a second imaging operation mode, and/or a third imaging operation mode. The detector comprises a first scintillator, a second scintillator, a first sensor array, and a second sensor array. The first scintillator is disposed over the second scintillator such that X-rays emitted from the X-ray source first encounter the first scintillator and then encounter the second scintillator.