34 results about "Compton camera" patented technology

The invention provides novel Compton camera detector designs and systems for enhanced radiographic imaging with integrated detector systems which incorporate Compton and nuclear medicine imaging, PET imaging and x-ray CT imaging capabilities. Compton camera detector designs employ one or more layers of detector modules comprised of edge-on or face-on detectors or a combination of edge-on and face-on detectors which may employ gas, scintillator, semiconductor, low temperature (such as Ge and superconductor) and structured detectors. Detectors may implement tracking capabilities and may operate in a non-coincidence or coincidence detection mode.

The invention consists in structuring scintillation radiation detectors as Photonic Bandgap Crystals or 3D layers of thin filaments, thus enabling extremely high spatial resolutions and achieving virtual voxellation of the radiation detector without physical separating walls. The ability to precisely measure the recoil electron track in a Compton camera enables to assess the directions of the gamma rays hitting the detector and consequently dispensing with collimators that strongly reduce the intensity of radiation detected by gamma cameras. The invention enables great enhancements of the capabilities of gamma cameras, SPECT, PET, CT and DR machines as well as their use in Homeland Security applications. Methods of fabrication of such radiation detectors are described.

An approach for the selection of Compton camera shapes, configurations, positions, orientations, trajectory paths, and detector element sets is provided for collecting data for analysis using the surface integral and integral-of-line-integral methods of reconstruction Compton data. Methods are introduced for (1) selecting one or more imaging lines through a radioactive distribution for which approximations of integrals of radioactivity are to be derived, (2) selecting and using Compton camera relative positions, relative orientations, and detector element sets that “correspond to” the selected imaging lines to collect the needed data; and (3) deriving approximations of integrals of radioactivity along those imaging lines. This methodological approach is used to reconstruct line integrals, cross-sections, local volumes, parallel projections, and cone-beam projections of radioactive distributions.

The invention discloses a multi-gamma photon coincidence imaging system and a multi-gamma photon coincidence imaging method, and belongs to the technical field of emission computed tomography. The system comprises a time coincidence module, a computer platform, at least one first probe consisting of a collimator and a gamma photon detector as well as at least one second probe consisting of front and back Compton camera detectors; and each probe detects multiple gamma photons radiated by radionuclide to form a multi-gamma photon coincidence event. According to the imaging method, the range of the position where the radionuclide decays is shrunk into a plurality of intersection points of a projection line determined by the gamma photon event detected by the first probe in the multi-gamma photon coincidence event as well as a protection conical surface determined by the gamma photon event detected by the second probe, and a certain number of multi-gamma photon coincidence events are accumulated to obtain the images, distributed in the detected range, of the radionuclide. The reconstruction algorithm is simplified, the detection efficiency is improved, the signal-to-noise ratio of thereconstructed image is increased, and demand on the total count of the gamma photons is reduced.

The invention provides novel Compton camera detector designs and systems for enhanced radiographic imaging with integrated detector systems which incorporate Compton and nuclear medicine imaging, PET imaging and x-ray CT imaging capabilities. Compton camera detector designs employ one or more layers of detector modules comprised of edge-on or face-on detectors or a combination of edge-on and face-on detectors which may employ gas, scintillator, semiconductor, low temperature (such as Ge and superconductor) and structured detectors. Detectors may implement tracking capabilities and may operate in a non-coincidence or coincidence detection mode.

A method for the conversion of Compton camera data into a 2D image of the incident-radiation flux on the celestial sphere includes detecting coincident gamma radiation flux arriving from various directions of a 2-sphere. These events are mapped by back-projection onto the 2-sphere to produce a convolution integral that is subsequently stereographically projected onto a 2-plane to produce a second convolution integral which is deconvolved by the Fourier method to produce an image that is then projected onto the 2-sphere.

Systems and methods are described for image reconstruction. A set of conical integrals are calculated to satisfy a completeness condition and are related to a distribution of radioactivity.

The present invention relates to an imaging system and method based on gamma radiation detection, comprising at least one processing unit (5) which analyses at least one signal supplied by at least one set of detection modules (CP, P) mounted on a frame and comprising: at least one Compton-camera-type module having a field of view (CV) directed towards a volume defined by the frame, and at least one pair of coincidence-detection PET modules, positioned diametrically opposite one another on the chassis and defining an imaging axis (A), said processing unit (5) analysing the signal from the Compton-type module in order to determine the intersection between the imaging axis (A) and the field of view (CV) and to determine the optimal locations and / or orientations for the different detection modules (CP, P) on the chassis so that the imaging axis (A) passes through the gamma radiation source in the object (O) to be imaged.

The invention discloses a method and device for realizing Compton camera reconstruction by constructing a sparse source set matrix, electronic equipment and a storage medium, and the method comprises the steps: converting a high-dimensional space voxel of a radioactive source of a Compton camera into a one-dimensional row vector tag of a corresponding photon event; constructing a two-dimensional sparse source set matrix of all photon events and corresponding one-dimensional row vector labels; and performing iterative reconstruction of one-dimensional random sampling on the two-dimensional sparse source set matrix to obtain a Compton camera reconstruction result. According to the embodiment of the invention, the calculation amount of Compton camera reconstruction is greatly reduced, the calculation complexity is lower, and the time consumption in the high-dimension and high-precision reconstruction of the Compton camera is shorter. Therefore, the problems of large calculation amount, high calculation complexity, long time consumption in calculation and low calculation precision during Compton camera reconstruction in the prior art are solved.

Methods are presented that increase the position resolution and granularity of double sided segmented semiconductor detectors. These methods increase the imaging resolution capability of such detectors, either used as Compton cameras, or as position sensitive radiation detectors in imagers such as SPECT, PET, coded apertures, multi-pinhole imagers, or other spatial or temporal modulated imagers.

The present disclosure concerns a charge-accumulation radiation detector that includes a semiconductor device and specifies an incident time and energy of radiation from a transferred image signal. The radiation detector includes a semiconductor substrate and electrodes disposed on both sides of the semiconductor substrate, and includes a plurality of charge accumulation units inside the semiconductor substrate. The plurality of charge accumulation units is each configured to accumulate charges generated by radiation incident on the semiconductor substrate. The charges accumulated in the charge accumulation units are readable to outside through at least one of the electrodes.

The invention discloses a multi-gamma photon coincidence imaging system and a multi-gamma photon coincidence imaging method, and belongs to the technical field of emission computed tomography. The system comprises a time coincidence module, a computer platform, at least one first probe consisting of a collimator and a gamma photon detector as well as at least one second probe consisting of front and back Compton camera detectors; and each probe detects multiple gamma photons radiated by radionuclide to form a multi-gamma photon coincidence event. According to the imaging method, the range of the position where the radionuclide decays is shrunk into a plurality of intersection points of a projection line determined by the gamma photon event detected by the first probe in the multi-gamma photon coincidence event as well as a protection conical surface determined by the gamma photon event detected by the second probe, and a certain number of multi-gamma photon coincidence events are accumulated to obtain the images, distributed in the detected range, of the radionuclide. The reconstruction algorithm is simplified, the detection efficiency is improved, the signal-to-noise ratio of thereconstructed image is increased, and demand on the total count of the gamma photons is reduced.

A radiation measuring apparatus (20) includes a scatterer detector (10A), an absorber detector (10B) and a processing unit (12). Pixel electrodes (2) of the scatterer detector (10A) and the absorber detector (10B) are arranged such that a distance between centers of two neighbor pixel electrodes (2) is smaller than a mean free path of a recoil electron generated in the Compton scattering of an electromagnetic radiation. The processing unit (12) specifies and incidence direction of the electromagnetic radiation based on a recoiling direction to which the recoil electron recoils. In this way, an electron tracking-type Compton camera is realized which confines the incidence direction of the electromagnetic radiation by using the recoiling direction of the recoil electron in a Compton camera using a semiconductor detector.

A Compton camera system and method for detecting gamma radiation, comprising a gamma radiation source, at least one fast scintillator plate P1 of which the rise time to peak light is less than 1 ns, having a thickness greater than or equal to 5 mm, equipped with an array of segmented photodetectors (5) and a dedicated fast-reading microelectronic means. The system is characterised in that it is capable of measuring the spatial and temporal coordinates (X, Y, Z, T) and energy E at at least two successive positions of a gamma photon when said photon undergoes Compton scattering at a first point A before being absorbed at a second point B, by recognising circles of non-scattered photons corresponding to each scintillation interaction. The system has a module for estimating a valid Compton event. The detection system has two scintillator plates P1 and P2.

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.