121 results about "Positron" patented technology

A positron emission tomography (PET) scanner includes a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module includes an array of scintillator detectors. Each scintillator detector comprises a monolithic scintillation crystal and a plurality of photodetector arrays, such as silicon photomultipliers (SiPMs). A photodetector array is positioned on at least two nonparallel faces of each scintillation crystal. In some examples, a photodetector array is positioned on each of three orthogonal faces of each scintillation crystal.

The invention belongs to the technical field of vacuum coating, and relates to an electron gun and ion source collaborative evaporation coating method, a control method and a control system. The electronic gun and ion source collaborative evaporation coating control method comprises the steps that key parameters in the coating process are continuously collected, and an electronic gun beam initial value and an ion source gas flow initial value are dynamically generated according to state diagnosis results of all the parameters; the beam current value of the electron gun and the gas flow value of the ion source are corrected in real time to inhibit the disturbance of the ion source to the beam current of the electron gun, and the electron gun and the ion source are cooperatively regulated and controlled to ensure the precise control of the coating uniformity; the invention further discloses an electron gun and ion source collaborative evaporation coating method, local hot spot compensation and global uniformity compensation are carried out by adopting a film thickness compensation mechanism so as to accurately control the film thickness. According to the invention, the cooperative control of the electron gun evaporation and ion bombardment process is realized, the film adhesion is enhanced, the evaporation coating rate is improved, and the film thickness uniformity is improved.

The invention relates to an oxidase response type molecular probe as well as a preparation method and application thereof, and belongs to the technical field of medical imaging. Aiming at the problem that the inflammation activity is difficult to accurately evaluate in the prior art, the invention provides a molecular imaging probe capable of responding to the activity of in-vivo myeloperoxidase (MPO), and the molecular imaging probe can be used for real-time and non-invasive imaging monitoring of the activity of the in-vivo MPO, so that the activity of the inflammatory reaction of a focus is accurately evaluated. The invention provides a chelating agent with structural characteristics of a chelating unit and an enzyme response unit, and is characterized in that the enzyme response molecular probe is constructed by taking rigid framework cyclohexanediamine (CDTA) as a transition metal chelating unit and taking electron-rich functional groups (such as phenol, catechol or 5-hydroxytryptamine) as the enzyme response unit. The probe is chelated with paramagnetic metal (such as Mn < 2 + >) for magnetic resonance imaging (MRI) or radioactive metal (such as 68Ga) for positron emission tomography (PET), so that specific response to MPO activity is realized. The dynamic stability of the probe is remarkably improved; after the MPO is responded, the relaxation efficiency is improved by 2-3 times, and the sensitivity is optimized; the cytotoxicity is low; in an acute pancreatitis model, the MRI contrast noise ratio (delta CNR) reaches 77.39 + / -7.04 and is 4.2 times that of a control group, the PET uptake rate is remarkably improved, bimodal imaging is supported, and accurate positioning and quantitative evaluation of the inflammation activity are achieved.

A multiplexing scheme for both energy and timing information is provided for a particle detection system having a photosensor array with multiple photosensors. Each photosensor is associated with multiple scintillator modules. The system has a segmented pseudo-prismatic light guide with multiple pseudo-prismatic segments. Each segment is associated with multiple photosensors, and the photosensors are adjacent. Each scintillator module contacts its associated photosensor at one end and its associated segment at the other end. Each of the multiple photosensors may be connected to an energy readout channel, such that photosensors associated with the same segment are not connected to the same energy readout channel. Each energy readout channel has at least two timestamps associated therewith.

A positron emission tomography (PET) scanner may include a plurality of gamma radiation detector modules arranged to form a detector ring. Each detector module may include an array of elongated scintillation crystals. With respect to the detector ring, each elongated scintillation crystal includes a proximal end-face, two axially oriented lateral faces, two transaxially oriented lateral faces, and a distal end-face radially oriented into the detector ring to receive a gamma photon. An array of photosensors is positioned along a first of the axially oriented lateral faces of each elongated scintillation crystal to detect scintillation photons. A reflective material is positioned on the proximal end-face, the distal end-face, the transaxially oriented lateral faces, and a second of the axially oriented lateral faces of each elongated scintillation crystal to internally reflect scintillation photons. In various embodiments, a dual-channel processing circuit provides distinct timing and energy signals from the photosensors.

Disclosed herein are methods and apparatus for acquiring positron emission (or PET) data in the presence of ionizing radiation causing PET detector afterglow. In one variation, the method includes adjusting a coincidence trigger threshold of a PET detector during a treatment session. In one variation, the method includes adjusting a gain factor used in positron emission data acquisition (e.g., a gain factor used to multiply and / or shift an output(s) of a PET detector(s)) during a treatment session. In some variations, a method for acquiring positron emission data during a radiation treatment session includes suspending communication between a PET detector and a signal processor of a controller for a predetermined period of time after a radiation pulse is emitted by a linear accelerator.

A positron emission tomography (PET) scanner includes multiple gamma radiation detector modules arranged to form a detector ring. Each detector module includes an array of elongated scintillation crystals. With respect to the detector ring, each elongated scintillation crystal includes a proximal end face, two axially-oriented side faces, two cross-axially-oriented side faces, and a distal end face oriented radially into the detector ring to receive gamma photons. An array of photosensors is disposed along a first of the axially-oriented side faces of each elongated scintillation crystal to detect scintillation photons. Reflective material is disposed on a second of the proximal end face, the distal end face, the cross-axially-oriented side face, and the axially-oriented side face of each elongated scintillation crystal to internally reflect scintillation photons. In various embodiments, a dual-channel processing circuit provides separate timing and energy signals from the photosensors.

A method for estimating noise equivalent counts includes one or more times during a scan of an object with a positron emission tomography (PET) scanner, wherein a plurality of coincidence events are detected by a detector array of the PET scanner, performing the following actions. The actions include obtaining a total of the plurality of coincidence events, estimating random coincidence events, and estimating scatter coincidence events. The actions include estimating true coincidence events based on the total of the plurality of coincidence events, the estimated random coincidence events, and the estimated scatter coincidence events. The actions include determining a scatter fraction based on the estimated scatter events and true coincidence events. The actions include estimating the noise equivalent counts based at least on the scatter fraction, the total of the plurality of coincidence events, the estimated true coincidence events, the estimated scatter coincidence events, and the estimated random coincidence events.

This invention relates to a convolution-based method for noise suppression in positron emission tomography (PET) flow field images, comprising the following steps: S1, obtaining consistent data through CFD flow field simulation and GATE detection system simulation, and reconstructing a low-resolution initial image of the PET flow field containing noise using the OSEM algorithm; S2, constructing a noise suppressor model, inputting the low-resolution initial image into the model, and outputting a noise-suppressed flow field feature image using a deep convolutional network and multi-scale feature fusion technology; S3, constructing a multi-loss fusion evaluation system, using mean squared error loss, minimum absolute value deviation loss, and perceptual loss to jointly constrain model training, and iteratively updating the weights using the Adam optimizer. This invention not only improves the enhancement model's ability to distinguish noise information, thereby enhancing the model's ability to remove noise information from PET images, but also significantly improves evaluation metrics such as PSNR and SSIM.

The invention belongs to the technical field of inorganic scintillator materials, and particularly relates to a multi-element co-doped yttrium lutetium silicate scintillator and a preparation method and application thereof, and the material has excellent comprehensive performance of high light output, short decay time, high radiation hardness, high matching degree of emission spectrum and novel photoelectric sensors and the like. The invention further relates to a preparation method of the scintillator material and application of the scintillator material in radiation detection fields such as positron emission tomography (PET), time flight PET (TOF-PET), interaction depth PET (DOI-PET), single photon emission computed tomography (SPECT), high-energy physical experiments, nuclear medicine imaging, industrial nondestructive inspection, safety detection (such as luggage and cargo container inspection) and the like.

The current disclosure provides systems and methods for increasing a quality of positron emission tomography (PET) images generated by a PET system with detectors including bismuth germinate (BGO) crystals. In one example, a method for the PET system comprises extracting a higher-quality 2-D image from a first image volume reconstructed using higher-quality time-of-flight (TOF) data acquired from a subject during a scan performed using the PET system, the TOF data based on Cherenkov radiation detected at the BGO crystals; extracting a lower-quality 2-D image from a second image volume reconstructed using lower-quality TOF data acquired from the subject by the PET system; generating an enhanced-quality 2-D image from the lower-quality 2-D image using a trained image quality enhancement model; merging the enhanced-quality 2-D image with the higher-quality 2-D image; and displaying the merged 2-D image on a display device of the PET system.

Methods and apparatus are disclosed for concurrent digital autoradiography of alpha-particle events and positron events using a spatially resolving charged particle detector and a gamma-ray detector. Alpha particles and positrons are detected by the charged particle detector. Positrons are identified based on coincidence with gamma-ray events. A positron-emission autoradiograph is formed based on positron positions. Alpha particles, both coincident and anticoincident with positrons, are identified based on energy deposition patterns. An alpha-emission autoradiograph is formed based on alpha-particle positions and energies. Separation of coincident alpha and positron events recorded by the charged particle detector improves position detection accuracy. Validation of positron imaging for alpha-emitter distribution or dosage, based on correlation of respective autoradiographs, is described. Variations for particle identification based on isotropy, energy, coincidence, or anticoincidence are presented. Disclosed techniques are applicable to alpha-emitting radionuclides with complex decay chains.

The present disclosure provides a modular radiation therapy apparatus comprising a plurality of modules configured to sequentially interlock within one another in an annular arrangement, wherein the plurality of modules are individually extractable from the annular arrangement and at least a subset of the plurality of modules comprise computing elements configured to communicate with one another, the plurality of modules comprising a collimator module comprising a multi-leaf collimator (MLC) and at least one sensor, a linear accelerator (LINAC) module comprising at least one of a magnetron or a klystron, at least one imaging module comprising at least one of an image detector, an imaging source, a magnetic imaging system, a single photon emission computed tomography (SPECT) system, or a positron emission tomography (PET) system, a patient tracking module, a cooling module, and a vacuum module, and performing at least one of: monitoring a respective status of the plurality of modules via onboard sensors and computing elements to determine whether any module is in an error state and provisioning status information and module identifiers to a remote computing environment; or distributing computational workloads among the plurality of modules and communicating with a remote computing environment to offload processing tasks using federated processing operations.

A holding device (3) for a medical imaging device, in particular in the form of a positron emission tomography (PET) scanning device (1), is provided. A holding device (3) is used to hold a medical imaging phantom (2) in a defined position inside a detector ring (11) of a medical imaging device. The retaining device (3) is adapted to be attached to an axial end face (113; 114) of the detector ring (111). The invention further relates to a phantom unit comprising such a holding device (3) and a medical imaging phantom (2) and to a method for securing a quality standard for a medical imaging device (1) and for calibrating a medical imaging device (1).

The invention belongs to the technical field of PET (positron emission tomography), and relates to a PET probe extensive field image multi-model adaptive deformation and FPGA (field programmable gate array) curing method, which comprises the following steps of: acquiring single-lift event data of a PET probe; generating an original extensive field image based on the single-lift event data; performing coordinate traversal transformation on the original extensive field images by adopting an image deformation model in a preset multi-model transformation library; performing off-line analysis on each model and the parameters thereof in the multi-model transformation library by utilizing a preset evaluation index, and screening out an optimal model and an optimal parameter; and transforming the original pan-field image by using the optimal model and the optimal parameters to generate an enhanced image and a crystal position lookup table, and solidifying the enhanced image and the crystal position lookup table to the FPGA. The method has the beneficial effects that the local adhesion area can be stretched in a targeted manner through the nonlinear transformation model, the distinction degree of crystal event clusters is remarkably improved, and the LUT calibration precision is fundamentally improved.

A method for determining a convolution kernel for an iterative statistical algorithm based on a continuous-to-continuous data model. The method is used for image reconstruction from radiation measurements obtained in emission tomography, specifically in a Time-of-Flight Positron Emission Tomography (TOF PET) scanner. The presented method is a non-list-mode solution that reduces the computational complexity of the reconstruction problem, improves the resolution of reconstructed images, reduces the radiation dose absorbed by patients during TOF PET examinations, and / or shortens the measurement acquisition time without significantly compromising the quality of the diagnostic images. Notably, the quality of the functional images remains at the same level. These improvements are achieved by designing the convolution kernel to account for the statistical properties of the measurement signals registered during the TOF PET scanner's acquisition process.

To provide both good time-of-flight resolution and interaction depth information. [Solution] The positron emission tomography apparatus according to the embodiment comprises a scintillation array and a photosensor array. The scintillation array includes a plurality of scintillator crystal units individually separated by a reflective material, and each scintillator crystal unit is configured to generate scintillation light in response to gamma-ray interactions within the scintillator crystal unit caused by gamma-ray irradiation from a subject, and has a substructure for decoding two or more depths within the scintillator crystal unit such that gamma-ray interactions at different depths cause scintillation light to escape from the photo-escape plane of the scintillator crystal unit in different patterns. The photosensor array converts the scintillation light received from the scintillation array into an electrical signal.

There is provided a positron source (10; 1000) for generating a positron beam (180), wherein the positron source (10; 1000) includes: a laser arrangement (50) configured to generate a pulsed beam (70) of photons; a target (30) configured to receive the beam (70) of photons, wherein the target (30) is arranged for the photons of the beam (70) to generate a photon plasma at a surface layer (40) of the target (30), wherein the surface layer (40) is configured to preferentially absorb electrons from the photon plasma to generate corresponding free positrons; and an electrode arrangement (160) comprising one or more electrodes (160A, 160B, 160C) that are configured to apply an electric field to the photon plasma to extract the free positrons therefrom and to guide the positrons to form the positron beam (180). At least the target (30) and the electrode arrangement (160) are included within a vacuum chamber (20) configured in use to provide a vacuum condition in which the target (30) and the electrode arrangement (160) are arranged to function. Optionally, the surface layer (40) is configured to include a doped semiconductor material for providing the surface layer (40). More optionally, the doped semiconductor includes at least one of: p-doped Silicon, p-doped Gallium Arsenide, p-doped Graphene, Graphene, p-doped Silicon Carbide.

The invention discloses a reactor base slow positron source, a control method and a reactor and belongs to the field of nuclear power. The stack-based slow positron source comprises a slow positron generating assembly, an outer sleeve, a heavy water tank sleeve and a sealing assembly; the outer sleeve is inserted into the heavy water tank through the heavy water tank sleeve, and the tail end of the outer sleeve is immersed in the heavy water; the slow positron generation assembly is arranged at the tail end of the outer sleeve and is sealed in the outer sleeve; the sealing assembly comprises a heavy water sealing mechanism and a light water sealing mechanism, the heavy water sealing mechanism seals a gap between the heavy water tank sleeve and the outer sleeve, and the light water sealing mechanism seals a gap in the pool wall sleeve. The stack-based slow positron source can cool the slow positron generation assembly through heavy water convection, effectively improves the heat dissipation efficiency, and improves the upper limit of the slow positron beam intensity.

The application relates to the field of positron emission tomography technology, in particular to a multi-channel high-precision PET circuit acquisition system and a use method thereof, and the system comprises the following: an FPGA control board, which is used for controlling bias voltage programming output voltage values, controlling current programming output voltage values and current values according to DAC bias voltage values received from an upper computer, and sending DUT board configuration information received from the upper computer to a DUT board; and the DUT board, which comprises multi-channel high-precision PET circuits, each circuit is configured through an SPI protocol according to DUT board configuration information received from the upper computer, 16 channels are adopted to collect time electric signal information output by a PET detector, and 64 channels are adopted to collect energy electric signal information output by the PET detector. In the application, the multi-channel high-precision PET circuit acquisition software and the hardware of the control system are portable, the upper computer software program is programmable, and the operation is simple.

The application discloses a method for imaging airtight inner cavity of an aero-engine by using a low-cost positron emission tomography device with good imaging quality, and the gamma photon detection mechanism of the positron emission tomography device comprises an embedded rotary flat plate detection device and a ring-shaped detection device; the ring-shaped detection device comprises a cylindrical mounting frame, and the inner wall of the cylindrical mounting frame is covered with second gamma photon detection crystals; the embedded rotary flat plate detection device comprises a mounting flat plate and a driving device for driving the mounting flat plate to rotate around the central axis of the ring-shaped detection device, and the mounting flat plate is provided with a plurality of first gamma photon detection crystals; the central angle of the cylindrical mounting frame corresponding to the first gamma photon detection crystals of the first detection crystal array is 60-90 degrees; and the diameter of the second detection crystal array is 1.6-2.6 times the distance between the first detection crystal array and the central axis of the ring-shaped detection device.

The invention provides a preparation method of alpha-type 2-amino-dihydrotetrabenazine, which comprises the following steps: 1) reacting raw materials containing tetrabenazine, ammonium acetate and sodium cyanoborohydride, and post-treating a reaction mixed solution to obtain a crude product; (2) carrying out column chromatography on the crude product in the step (1), and separating to obtain alpha-type 2-amino-dihydrotetrabenazine; a stationary phase used by the column chromatography is silica gel; the diameter-height ratio of the stationary phase is 1: (6-8), a mixed solution of dichloromethane and methanol is adopted as an elution system, and the volume ratio of dichloromethane to methanol is (9-11): 1; the elution flow rate is 4 to 6 mL / min. Radioactive labeling of the alpha-type 2-amino-dihydrotetrabenazine is realized through a fluorine [< 18 > F] labeling technology, a key technical support is provided for development of a novel positron emission tomography (PET) specific tracing probe based on a molecular skeleton, and an important technical foundation is laid for development of a novel VMAT2 targeted tracing probe based on a compound skeleton.

A system and method for simultaneous imaging of multiple positron emission tomography (PET) tracers in which digital data including PET information associated with at least two time points is received, where the digital data is generated by PET scans of a region of interest of a physiologic body which has been administered at least two PET tracers that differ from one another at least in their radioactive decay constant. At least one set of output digital data is determined based on the radioactive decay constants of each PET tracer, the at least one set of output digital data corresponding to at least one of the at least two PET tracers. The determination of at least one set of output digital data includes at least one of regularizing to account for statistical noise, preconditioning the digital data to be more amenable to signal separation, applying feature preservation techniques, or accounting for late tracer kinetics.

An image acquisition apparatus includes a measurement unit and a processing unit. The processing unit, for each coincidence event in which a first detector and a second detector perform coincidence detection of a pair of gamma-ray photons generated by an electron positron annihilation event in a positron emitting radionuclide, assuming that the gamma-ray photon arriving at one detector is a gamma-ray photon arriving without being Compton scattered in a subject, and the gamma-ray photon arriving at another detector is a gamma-ray photon arriving after being Compton scattered in the subject, determines a position at which the gamma-ray photon is Compton scattered in the subject based on a detection position and a detection time of the gamma-ray photon by each of the first detector and the second detector and a position of the positron emitting radionuclide.

The application provides a simulation prediction method and system for slow positron source intensity in a research reactor, comprising the following steps: S1, reading arrangement information of components in a reactor core of the research reactor; S2, constructing a Monte Carlo model of the reactor core containing a slow positron source device, and obtaining neutron multi-group angular flux and photon multi-group angular flux information near the slow positron source generating device; S3, constructing a slow positron Monte Carlo model; S4, performing energy-angle double sampling to obtain an incident neutron energy probability density distribution function f n,ig,ia , an angle probability density distribution function f n,ia , an incident photon flux energy probability density distribution function f g,ig,ia , an angle probability density distribution function f g,ia , and a neutron-photon weight factor; S5, performing function sampling of particle types, energy and angle; and S6, obtaining slow positron distribution information generated in the slow positron generating device. The application accurately considers the whole life cycle of slow positron generation and transportation through multi-stage coupling, and realizes accurate prediction of slow positron source intensity.

A method and a system for limiting coincidence data includes detecting a plurality of coincidence events during a scan of a subject with a detector array of a positron emission tomography (PET) scanner, wherein the PET scanner includes a plurality of detector rings disposed along a longitudinal axis of the PET scanner, and each detector ring includes a plurality of detectors. The method also includes limiting data associated with the plurality of coincidence events from the scan so that the data varies in a radial extent relative to a center of a field of view of the scan.

The present invention facilitates manufacturing of a scintillator array, a radiation detection device, and a positron emission tomography device. A scintillator array (11) is provided with at least one pair of scintillators (11Uia, 11Uib), a light reflection member (LA) disposed in a first location between the scintillators for preventing light from passing between the scintillators, and an air layer (LB) disposed in a second location between the scintillators for allowing light to pass between the scintillators.

A system for the safe preparation and injection of the radioisotope H2 15 O for use in positron emission tomography (PET). The invention also relates to a safety valve for controlling the flow of H2 15 O for use in PET, the use of said safety valve, and a method for preparing and injecting H2 15 O.

A housing in an imaging apparatus is provided. The imaging apparatus may include a Magnetic Resonance (MR) component and a Positron Emission Tomography (PET) component that includes a plurality of detectors. The housing may include one or more enclosed spaces configured to accommodate the plurality of detectors of the PET component. Each of the one or more enclosed spaces is defined by one or more walls.