A system and method for imaging by gamma radiation detection having at least one processing unit analyzing at least one signal provided by at least one set of detection modules mounted on a frame and including, on the one hand, at least one module of Compton camera type having a field of view directed towards a volume delimited by the frame and, on the other hand, at least one pair of coincidence detection PET modules, diametrically opposite to each other on the frame and defining an imaging axis, the processing unit analyzing the signal derived from the Compton-type module to determine the intersection of the imaging axis with the field of view and to determine the optimal orientations and/or locations of the various detection modules on the frame so that the imaging axis passes through the source of the gamma radiation in the object to be imaged.

A system and method for imaging by gamma radiation detection having at least one processing unit analyzing at least one signal provided by at least one set of detection modules mounted on a frame and including, on the one hand, at least one module of Compton camera type having a field of view directed towards a volume delimited by the frame and, on the other hand, at least one pair of coincidence detection PET modules, diametrically opposite to each other on the frame and defining an imaging axis, the processing unit analyzing the signal derived from the Compton-type module to determine the intersection of the imaging axis with the field of view and to determine the optimal orientations and/or locations of the various detection modules on the frame so that the imaging axis passes through the source of the gamma radiation in the object to be imaged.

Various aspects include methods compensating for Compton scattering effects in pixel radiation detectors. Various aspects may include determining whether gamma ray detection events occurred in two or more detector pixels within an event frame, determining whether the gamma ray detection events occurred in detector pixels within a threshold distance of each other in response to determining that gamma ray detection events occurred in two or more detector pixels within the event frame, and recording the two or more gamma ray detection events as a single gamma ray detection event having an energy equal to the sum of measured energies of the two or more gamma ray detection events located in a detector pixel having a highest measured energy in response to determining that the gamma ray detection events occurred in detector pixels within the threshold distance of each other.

Various aspects include methods compensating for Compton scattering effects in pixel radiation detectors. Various aspects may include determining whether gamma ray detection events occurred in two or more detector pixels within an event frame, determining whether the gamma ray detection events occurred in detector pixels within a threshold distance of each other in response to determining that gamma ray detection events occurred in two or more detector pixels within the event frame, and recording the two or more gamma ray detection events as a single gamma ray detection event having an energy equal to the sum of measured energies of the two or more gamma ray detection events located in a detector pixel having a highest measured energy in response to determining that the gamma ray detection events occurred in detector pixels within the threshold distance of each other.

An image is reconstituted by iterative approximation, a PET event updated image is produced by updating a current image using a PET event, a Compton event updated image is produced by updating the current image using a Compton event, the PET event updated image and the Compton event updated image that have been independently produced are weighted and added together, and the current image is updated using an image obtained by addition processing. In this way, PET events and Compton events, which have different properties, can be used in combination to efficiently and stably reconstitute images, improving image quality.

An image is reconstituted by iterative approximation, a PET event updated image is produced by updating a current image using a PET event, a Compton event updated image is produced by updating the current image using a Compton event, the PET event updated image and the Compton event updated image that have been independently produced are weighted and added together, and the current image is updated using an image obtained by addition processing. In this way, PET events and Compton events, which have different properties, can be used in combination to efficiently and stably reconstitute images, improving image quality.

A data processing apparatus according to an embodiment includes acquisition circuitry and specification circuitry. The acquisition circuitry is configured to acquire a detector signal containing a first component that is based on Cherenkov light and a second component that is based on scintillation light. The specification circuitry is configured to specify timing information about generation of the detector signal by curve fitting to the first component.

A PET and Compton imaging method implemented by a device including at least two facing PET modules. The device includes a Compton camera arranged outside a plane containing the PET modules for forming a trihedron with the PET modules and producing a Compton view. The acquisition fields of the PET and Compton views having an overlap area covering the object to be imaged. The device allowing the following steps to be carried out: acquisition of a Compton view; location of a dense area and its contour on the Compton view; Computation of the 2D map of the probability of detection of the presence of a source from the Compton view of the Compton camera; Coincidence detection by the PET cameras and association of a response line (LOR); and Segmentation of LORs crossing the dense area by using the detection probability determined by the Compton view.

A PET and Compton imaging method implemented by a device including at least two facing PET modules. The device includes a Compton camera arranged outside a plane containing the PET modules for forming a trihedron with the PET modules and producing a Compton view. The acquisition fields of the PET and Compton views having an overlap area covering the object to be imaged. The device allowing the following steps to be carried out: acquisition of a Compton view; location of a dense area and its contour on the Compton view; Computation of the 2D map of the probability of detection of the presence of a source from the Compton view of the Compton camera; Coincidence detection by the PET cameras and association of a response line (LOR); and Segmentation of LORs crossing the dense area by using the detection probability determined by the Compton view.

A method and apparatus for classifying and/or identifying materials by means of their spectral response to gamma radiation. Classification is carried out by irradiating multiple different samples with gamma radiation, detecting a spectral response in the backscatter direction, sorting the spectral response into energy bands and selecting a combination of energy bands to define a relationship that best distinguishes between clusters of spectral responses for different material classes. Two or more of the energy bands may overlap.