34 results about "Compton camera" patented technology

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 decribed.

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.

A single plane Compton telescope uses a coplanar array of detectors to determine the direction of a radiation source. Detector materials and dimensions may have comparable Compton scattering and photoelectric absorption probabilities, so scattered photons have a high probability of escape from the detector in which the initial interaction occurs, while being absorbed in adjacent detectors. Energy information from coincident interactions between two detectors defines a bearing plane that contains the radiation source; by comparing these interactions in two non-parallel directions, the source is localized to a line representing the intersection of two bearing planes. Energies may be summed to determine the initial photon energy. The array may be of a single detector type or an arrangement of different detector types. The array may be a stationary, planar configuration of at least three detectors, or a linear array of at least two detectors that is rotatable within a selected plane.

The present invention provides methods and apparatuses for constructing observed data from a Compton camera in order to provide a three-dimensional image of a radiopharmaceutical source distribution within a patient. No intermediate two-dimensional images are formed. Observed data may be analyzed by a processor in order to construct a three-dimensional image representing the source distribution. An idealized mathematical model may express the observed Compton camera data in terms of an integral over the source distribution. An exact analytic inversion is then found for this idealized model. The new analytic solutions arise from a generalization of the integral equation used to model the Compton camera. The kernel of the integral equation is modified by the introduction of an index p that describes the effect of source distance from the camera.

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 scintillator array detector and a three-dimensional position resolution method in Compton scattering imaging. The method comprises the following steps: 1) enabling gamma photons to be incident to the scintillator array detector; 2) determining two-dimensional coordinate information (X, Y) of the action position of the gamma photons in the scintillator array according to the number of the responded photodetector pixel in the photodetector array; and 3) determining third-dimensional coordinate information Z of the action position of the gamma photons in the scintillatorarray according to the amplitude ratio f=X1/(X1+X2) of output signals (X1, X2) of the responded light detector and a lookup table obtain three-dimensional coordinates (X, Y, Z) of the action positionof the gamma photons, wherein X1 and X2 are corresponding top surface and bottom surface optical detector output signals when gamma photons act on the scintillator strip detection unit i. According to the invention, the detection efficiency of a Compton camera and the imaging precision of the nuclear radiation hot spot are improved.

Method and system for generating an image of the radiation density of a source of photons located in an object wherein Compton scattering and non-Compton scattering events are detected and contained within data used for image reconstruction. The system includes a multiple pinhole collimator, a position sensitive scintillation detector as used in standard Gamma cameras, and a silicon pad detector array inserted between the collimator and the scintillation detector. The problem of multiplexing, normally associated with multiple pinhole systems, is reduced by using the extra information from the detected Compton scattering events. For properly selected pinhole spacing, this leads to a significantly improved image quality. A valuable enhancement can be achieved when adding only a small fraction of gamma rays with reduced angular ambiguity. The system does not require a highly optimized Compton camera behind the collimator.

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.

The present invention concerns a device, system and method of use of a multi-capture Compton camera, characterised by the use of at least two capture centres having separate positions.

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 Compton camera for medical imaging is divided into segments (11) with each segment (11) including part of the scatter detector (12), part of the catcher detector (13), and part of the electronics (14). The different segments (11) may be positioned together to form the Compton camera arcing around part of the patient space. By using segments (11), any number of segments (11) may be used to fit with a multi-modality imaging system.

To optimize image quality and/or sensitivity, a Compton camera is adaptable. The scatter and/or catcher detectors (12, 13) may move closer to and/or further away from a patient and/or each other. Thisadaptation allows a balancing of image quality and sensitivity by altering the geometry.

The invention discloses a cadmium zinc telluride/silicon gamma ray X-ray detector and a preparation method thereof. The detector provided by the invention has high detection sensitivity and high detection efficiency, and is a composite cadmium zinc telluride-silicon detector with absorption and multiplication region separation. According to the invention, a CZT wafer and SiPM are bonded together,the CZT wafer is used as an absorption region for detecting nuclear radiation, the SiPM is used as a multiplication and amplification region of a carrier, and the CZT/Si nuclear radiation detector with an absorption region and a multiplication region separated and high detection sensitivity is formed. When a SiPM structure is adopted, the whole device is used as a high-sensitivity detector; and when a single APD unit or a part of APD units are used as pixel units, the detector can be used as a high-sensitivity pixel detector. A detection device with single photon counting capability, high energy resolution, high spatial resolution, high time resolution, high detection sensitivity and high detection efficiency is provided for imaging instruments of a next generation Compton gamma camera, asingle photon emission computed tomography instrument and a positron emission tomography instrument.

To capture more emitted photons with a Compton camera, the scatter detector (12) is tilted (non-orthogonal angle) relative to a radial from the isocenter of the imaging system. The tilt creates a greater volume for scatter interaction. To capture more scatter photons, the catcher detector (13) is non-planar, such as a multi-faced detector at least partially surrounding a volume behind the scatterdetector (12). The tilted scatter detector (12) alone, the non-planar catcher detector (13) alone, or the tilted scatter detector (12) and the non-planar catcher detector (13) are used in the Comptoncamera.

The invention discloses a method for radionuclide identification by utilizing Compton scattering case statistics. The method comprises the following steps: 1) measuring and generating a nuclide library to be identified of target equipment by utilizing the characteristics of a Compton scattering case statistical array determined by the target equipment, wherein the target device is a device capableof obtaining Compton scattering cases; 2) testing unknown nuclide contained in the to-be-identified nuclide library by utilizing the target equipment to obtain a to-be-tested Compton scattering casestatistical array; 3) calculating the probability density vi of the counting rate of each element i in the to-be-tested Compton scattering case statistical array relative to the multiple of the background condition; 4) obtaining the type and quantitative component rate of the nuclide to be measured according to a maximum likelihood expectation maximization method. According to the invention, quantitative identification of unknown radionuclides by the Compton camera can be realized.