301 results about "Pet detector" patented technology

An imaging system comprises: a ring of positron emission tomography (PET) detectors; a PET housing at least partially surrounding the ring of PET detectors and defining a patient aperture of at least 80 cm; a coincidence detection processor or circuitry configured to identify substantially simultaneous 511 keV radiation detection events corresponding to electron-positron annihilation events; and a PET reconstruction processor configured to reconstruct into a PET image the identified substantially simultaneous 511 keV radiation detection events based on lines of response defined by the substantially simultaneous 511 keV radiation detection events. Radiation planning utilizing such an imaging system comprises: acquiring PET imaging data for a human subject arranged in a radiation therapy position requiring a patient aperture of at least about 80 cm; reconstructing said imaging data into a PET image encompassing an anatomical region to undergo radiation therapy; and generating a radiation therapy plan based on at least the PET image.

A combined PET and X-Ray CT tomograph for acquiring CT and PET images sequentially in a single device, overcoming alignment problems due to internal organ movement, variations in scanner bed profile, and positioning of the patient for the scan. In order to achieve good signal-to-noise (SNR) for imaging any region of the body, an improvement to both the CT-based attenuation correction procedure and the uniformity of the noise structure in the PET emission scan is provided. The PET / CT scanner includes an X-ray CT and two arrays of PET detectors mounted on a single support within the same gantry, and rotate the support to acquire a full projection data set for both imaging modalities. The tomograph acquires functional and anatomical images which are accurately co-registered, without the use of external markers or internal landmarks.

Disclosed herein are radiation therapy systems and methods. These radiation therapy systems and methods are used for emission-guided radiation therapy, where gamma rays from markers or tracers that are localized to patient tumor regions are detected and used to direct radiation to the tumor. The radiation therapy systems described herein comprise a gantry comprising a rotatable ring coupled to a stationary frame via a rotating mechanism such that the rotatable ring rotates up to about 70 RPM, a radiation source (e.g., MV X-ray source) mounted on the rotatable ring, and one or more PET detectors mounted on the rotatable ring.

A scintillation block detector employs an array of optically air coupled scintillation pixels, the array being wrapped in reflector material and optically coupled to an array of silicon photomultiplier light sensors with common-cathode signal timing pickoff and individual anode signal position and energy determination. The design features afford an optimized combination of photopeak energy event sensitivity and timing, while reducing electronic circuit complexity and power requirements, and easing necessary fabrication methods. Four of these small blocks, or “miniblocks,” can be combined as optically and electrically separated quadrants of a larger single detector in order to recover detection efficiency that would otherwise be lost due to scattering between them. Events are validated for total energy by summing the contributions from the four quadrants, while the trigger is generated from either the timing signal of the quadrant with the highest energy deposition, the first timing signal derived from the four quadrant time-pickoff signals, or a statistically optimum combination of the individual quadrant event times, so as to maintain good timing for scatter events. This further reduces the number of electronic channels required per unit detector area while avoiding the timing degradation characteristic of excessively large SiPM arrays.

An imaging system comprises: a ring of positron emission tomography (PET) detectors; a PET housing at least partially surrounding the ring of PET detectors and defining a patient aperture of at least 80 cm; a coincidence detection processor or circuitry configured to identify substantially simultaneous 511 keV radiation detection events corresponding to electron-positron annihilation events; and a PET reconstruction processor configured to reconstruct into a PET image the identified substantially simultaneous 511 keV radiation detection events based on lines of response defined by the substantially simultaneous 511 keV radiation detection events. Radiation planning utilizing such an imaging system comprises: acquiring PET imaging data for a human subject arranged in a radiation therapy position requiring a patient aperture of at least about 80 cm; reconstructing said imaging data into a PET image encompassing an anatomical region to undergo radiation therapy; and generating a radiation therapy plan based on at least the PET image.

A medical imaging modality with a PET detector ring for Positron Emission Tomography connected on the data side to a PET image processing unit is to be structured in such a way that, on the basis of the images generated in the modality, a reliable detection and precise localization of metabolism anomalies, especially of malign tissue with tumor incidence is possible. The modality is further intended to offer good access to the patient, so that operative or minimally-invasive interventions on the patient can be undertaken and checked alongside the image recording. To this end there is provision, in accordance with the invention, for an ACT recording device for angiographic computer tomography connected on the data side to an ACT image processing unit to be arranged adjacent to the PET detector, whereby a common display unit for display of PET images and / or ACT images generated in the relevant image processing unit is assigned to the PET image processing unit and the ACT image processing unit.

The present invention is directed to a system, method and software program product for implementing 3-D Complete-Body-Screening medical imaging which combines the benefits of the functional imaging capability of PET with those of the anatomical imaging capability of CT. The present invention enables execution of more complex algorithms measuring more accurately the information obtained from the collision of a photon with a detector. The present invention overcomes input and coincidence bottlenecks inherent in the prior art by implementing a massively parallel, layered architecture with separate processor stacks for handling each channel. The prior art coincidence bottleneck is overcome by limiting coincidence comparisons to those with a time stamp occurring within a predefined time window. The increased efficiency provides the bandwidth necessary for increasing the throughput even more by extending the FOV to over one meter in length and the execution of even more complex algorithms.

A combined PET / MRT unit is disclosed that includes a PET detector which is reduced by comparison with the prior art, and that consists, for example, of a PET detector with a polygonal arrangement of the detector elements or with a PET detector ring. The PET detector is reduced in an axial direction by comparison with the detectors of the prior art, as a result of which the costs for producing the expensive PET detectors are lowered. The reduction of the PET detector is possible because the MR measurement usually lasts longer than the PET measurement, and so a reduced PET detector can be used for the temporally sequential recording of a number of PET tomograms by mechanical displacement of the PET detector. Since the MR measurement lasts substantially longer, this mechanical displacement does not lead to a lengthening of the measuring time. The invention also relates to methods for simultaneously recording MR and PET tomograms in which the PET / MRT units according to the invention are used.

A Positron Emission Tomography (PET) detector assembly includes a cold plate having a first side and an opposite second side, the cold plate being fabricated from a thermally conductive and electrically non-conductive material, a plurality of PET detector units coupled to the first side of the cold plate, and a readout electronics section coupled to the second side of the cold plate. A radio frequency (RF) body coil assembly and a dual-modality imaging system are also described herein.

A positron emission tomography (PET) detector ring comprising: a radiation detector ring comprising scintillators (74) viewed by photomultiplier tubes (72); and a magnetic field shielding enclosure (83, 84) surrounding sides and a back side of the annular radiation detector ring so as to shield the photomultiplier tubes of the radiation detector ring. Secondary magnetic field shielding (76′) may also be provided, comprising a ferromagnetic material having higher magnetic permeability and lower magnetic saturation characteristics as compared with the magnetic field shielding enclosure, the second magnetic field shielding also arranged to shield the photomultiplier tubes of the radiation detector ring. The secondary magnetic field shielding may comprise a mu-metal. The PET detector ring may be part of a hybrid imaging system also including a magnetic resonance (MR) scanner, the PET detector ring being arranged respective to the MR scanner such that a stray magnetic field from the MR scanner impinges on the PET detector ring.

The invention provides signal processing equipment of a PET detector based on a neural network localizer. The equipment integrates and realizes procedures for processing a series of signals from a photoelectric switching signal outputted by a detector to the action position coordinate of the gamma ray counted by a neural network in real time. The equipment comprises a compression read processing circuit to an array pixel signal outputted by a photoelectric switching device, an analog-digital switching circuit, an energy identifying and timing circuit, a proper time judging circuit, a base line recovery circuit, a signal peak value estimating circuit, a neural network real-time computing circuit, a USB interface circuit, etc. Due to the realization of the technology for processing various digital nuclear signals based on FPCA and especially the real-time computing of the neural network, the instantaneity and the integration level of the system are greatly improved. The invention has compact structure, complete performance, strong on-line data processing performance, and can be conveniently assembled into an integral detector module with the PET detector, wherein the detector module is important intermediate equipment for researching and developing novel PET imaging equipment based on neural network positioning.

The invention relates to the field of processing of images, and in particular relates to a counts correcting method for a PET detector. The method comprises the steps of acquiring correction events and acquiring the position information corresponding to reach correction event; acquiring the counts information of each counting area of the PET detector according to the position information corresponding to the correction event; acquiring correction coefficients corresponding to each counting area according to the counting information of each counting area; dividing the PET detector into a plurality of counting areas, wherein the quantity of the counting areas is corresponding to that of a photoelectric multiplying pipe channels of the PET detector; determining whether the correction coefficients of the counting areas are within the preset threshold range; if so, stopping correcting the counts of the PET detector; if not so, adjusting an output signal of the PET detector according to the correction coefficients corresponding to each counting area until the correction coefficients of reach counting area are within the preset threshold range. With the adoption of the method, the counts uniformity can be improved, the imaging uniformity of an image can be improved, and therefore, the high-quality image can be obtained.

The invention relates to an image reconstruction method for a dual panel position-emission tomography (PET) detector. The image reconstruction method for the dual panel PET detector comprises the following steps: conducting simulation on image process of a dual panel PET detection structure by using simulation software; recording line of response (LOR) information corresponding to all coincidence events and voxels where annihilation events lay; judging the type of one coincidence event according to positions of photon pairs in the annihilation events, considering the coincidence event as a true coincidence event if the occurring positions of the pair of photons corresponding to the coincidence event are consistent, considering the coincidence event as a random coincidence event if the occurring positions are inconsistent and removing the random coincidence event; expanding the range of the voxels; obtaining a compressed system response matrix through calculation by using symmetry of the structure the dual panel PET detector; reconstructing an image by using the obtained system response matrix. The image reconstruction method for the dual panel PET detector can be widely in the image reconstruction of the PET detector with the dual panel PET detection structure.

The invention provides a crystal bar position look-up table generation method and device based on a local extremum relocation PET detector. The crystal bar position look-up table generation method is characterize by, to begin with, carrying out statistics on detected photon events to obtain a two-dimension position spectrum; then, obtaining rapid estimation of center positions of crystal bars with arrangement rules of a crystal cell array in actual space being constraint and through performing peak searching operation on projection data of the position spectrum; and at last, taking effective data fragments out of the position spectrum according to the estimation values of the center positions and performing local peak relocation on the effective data fragments to obtain accurate center positions of the crystal bars, and finishing boundary division based on the accurate center positions, and thus a crystal position look-up table is generated. The invention also discloses a PET detector crystal position rapid identification apparatus which comprises a position statistics and preprocessing module, a crystal center position calculating module and a look-up table writing back module. According to the crystal bar position look-up table generation method and device, the crystal position look-up table can be generated online rapidly and effectively, thereby providing accurate and reliable crystal unit position information for follow-up processing.

A helmet-type PET device includes a helmet portion (hemispherical detector) and an added portion (jaw portion detector, an ear portion detector, or a neck portion detector). The helmet portion includes a PET detector so as to cover a parietal region of an examination target. The added portion is positioned to dispose a PET detector at a part other than the parietal region of the examination target. PET measurement is performed using both an output from the PET detector at the helmet portion and an output from the PET detector at the added portion.

A PET / MRI device includes an MRI device that has a measurement port, a PET detector that can be inserted into the measurement port, and a mechanism that can slide the PET detector into and out of the MRI measurement port. Thereby, the PET / MRI device allows MRI measurement during PET measurement.

The invention relates to a photoelectric converter, a detector and scanning equipment. The photoelectric converter comprises a silicon photomultiplier array and a light guide coupled with the silicon photomultiplier array, wherein the silicon photomultiplier array comprises i*j silicon photomultipliers spliced on a horizontal plane, and the i and the j are both integers greater than or equal to 2. The detector comprises a scintillation crystal, an electronic system, a light guide and silicon photomultipliers. The scanning equipment comprises a detection device and a frame, wherein the detection device comprises the detector, and the detector comprises the photoelectric converter. According to the photoelectric converter, the detector and the scanning equipment, a photoelectric conversion scheme of the photoelectric silicon photomultipliers is mainly employed, the silicon photomultipliers have small volumes and are closely arranged, the silicon photomultipliers in proper dimensions and in proper quantity are matched with the light guide in proper shape, a PET detector with high spatial resolution can be established, so the spatial resolution of the whole PET system can be improved, the PET detector having DOI and TOF performances is proper to establish, application to PET / MRI can be realized, and low cost is further realized.

The invention discloses geometric calibration method for a SPECT (single photon emission computed tomography) system. The method comprises the steps as follows: a collimator is measured to obtain geometric parameters of a pinhole or a slot in the collimator; the collimator and a PET (position emission tomography) detector are assembled to form the SPECT system; the collimator is controlled to move, and the PET detector is used for measuring multi-group background coincidence events when the collimator moves to a plurality of target positions; and position coordinates of the collimator in the SPECT system are obtained according to the multi-group background coincidence events. According to the method, the geometric parameters of the SPECT system can be accurately calibrated, accurate geometric parameters are provided for image reconstruction of tomography, and accordingly, the imaging quality of the SPECT system is improved.

A positron emission tomography (PET) detector ring comprising: a radiation detector ring comprising scintillators (74) viewed by photomultiplier tubes (72); and a magnetic field shielding enclosure (83, 84) surrounding sides and a back side of the annular radiation detector ring so as to shield the photomultiplier tubes of the radiation detector ring. Secondary magnetic field shielding (76′) may also be provided, comprising a ferromagnetic material having higher magnetic permeability and lower magnetic saturation characteristics as compared with the magnetic field shielding enclosure, the second magnetic field shielding also arranged to shield the photomultiplier tubes of the radiation detector ring. The secondary magnetic field shielding may comprise a mu-metal. The PET detector ring may be part of a hybrid imaging system also including a magnetic resonance (MR) scanner, the PET detector ring being arranged respective to the MR scanner such that a stray magnetic field from the MR scanner impinges on the PET detector ring.

The present invention relates to a detecting unit for installing in a cylinder type sufferer acceptance cavity (13, 23) of a magnet resonance device (21), which comprises an annular PET detector device (2) with a PET detector component (3), as well as a high frequency coil device (14) of a long conductor (5) setting coaxial in the PET detector device (2), wherein, the long conductor (5) at least sectionally extends along the gaps (9) between the detector components (3) which alternate with certain distance.

A helmet-type PET device includes a helmet portion (hemispherical detector) and an added portion (jaw portion detector, an ear portion detector, or a neck portion detector). The helmet portion includes a PET detector so as to cover a parietal region of an examination target. The added portion is positioned to dispose a PET detector at a part other than the parietal region of the examination target. PET measurement is performed using both an output from the PET detector at the helmet portion and an output from the PET detector at the added portion.

A method of correcting a timing signal that represents an arrival time of a photon at a positron emission tomography (PET) detector includes receiving a timing signal that represents an arrival time of a photon at a PET detector, receiving an energy signal indicative of an energy of the photon, calculating a timing correction using the energy signal, modifying the timing signal using the timing correction, and generating an image of an object using the modified timing signal. A system and non-transitory computer readable medium are also described herein.

A positron emission tomography (PET) detector assembly is provided. The PET detector assembly includes a plate having a first side and an opposite second side, the plate being fabricated from a thermally conductive material. The PET detector assembly also includes multiple PET detector units coupled to the first side of the plate. The PET detector assembly further includes a readout electronics section coupled to the second side of the plate, wherein, during operation, the readout electronics section generates heat that is transferred to the plate. The plate comprises a heat pipe disposed within the plate and configured to extract the heat from the plate and to transfer the heat away from the plate.

Disclosed herein are radiation therapy systems and methods. These radiation therapy systems and methods are used for emission-guided radiation therapy, where gamma rays from markers or tracers that are localized to patient tumor regions are detected and used to direct radiation to the tumor. The radiation therapy systems described herein comprise a gantry comprising a rotatable ring coupled to a stationary frame via a rotating mechanism such that the rotatable ring rotates up to about 70 RPM, a radiation source (e.g., MV X-ray source) mounted on the rotatable ring, and one or more PET detectors mounted on the rotatable ring.

In the integrated PET / MRI scanner provided with an RF coil for MRI and a plurality of PET detectors in the measuring port of the MRI scanner, the PET detectors are disposed with spaces therebetween and at least the transmitting coil elements of the RF coil for MRI are disposed between adjacent PET detectors. Here, the PET detectors are disposed in the circumferential direction of the measuring port with spaces therebetween and the transmitting coil elements are disposed in the axial direction of the measuring port. Alternatively, at least some of the PET detectors are disposed in the axial direction of the measuring port with spaces therebetween and the transmitting coil elements are disposed between adjacent PET detectors. The PET detectors can be DOI-type detectors capable of detecting position in the depth direction.

The invention provides a positron emission tomography (PET) detector, a method for setting the PET detector and a detecting method thereof. The PET detector comprises the components of a crystal array which comprises a plurality of crystal units that are arranged in an array manner and light splitting structures that are arranged on the surfaces of the crystal units, wherein the light splitting structure define the light outlet surface of the crystal array; and a semiconductor sensor array which is arranged relative to the light outlet surface of the crystal array and is suitable for receiving photons from the light outlet surface, wherein the semiconductor sensor array comprises a plurality of semiconductor sensors which are arranged in an array manner. Through arranging the light splitting structures on the crystal units, an effect which is similar with the effect obtained through arranging a light guide plate between the crystal array and the semiconductor sensors is realized. The transmission distance of the photon can be effectively shortened, and furthermore light transmission loss caused by the light guide plate can be prevented, thereby improving resolution of the PET detector.

Disclosed is a topically dedicated flat plate PET imaging device comprising a pair of flat plate PET detectors (200) and a mechanical arm system capable of supporting the detectors (200) to move in three directions, and supporting the detectors (200) to rotate at a certain angle. Also disclosed is a topically dedicated flat plate PET imaging method, comprising: providing a pair of flat plate PET detectors (200) and obtaining the information about regions of interest (400) of an imaging object; determining the imaging field of view of the pair of flat plate PET detectors (200) according to the information about the regions of interest (400), and ensuring that the regions of interest (400) are in the imaging field of view; acquiring corresponding data by means of the pair of flat plate PET detectors (200), performing data correction and calibration, and obtaining a three-dimensional fault activity image through image reconstruction; and completing imaging, and moving the pair of flat plate PET detectors (200) away from the imaging object. The topically dedicated flat plate PET imaging device has a good openness, small size, good mobility, high positional adjustability for the detectors (200), high detection efficiency, and high spatial resolution.

The invention provides a TOF-PET image reconstruction method based on the compressed sensing theory. The method includes the steps that firstly, according to the flight time positioning imaging principle, a first image is reconstructed based on a data set obtained through a TOF-PET detector and an initial image through a TOF reconstruction algorithm; secondly, according to the compressed sensing theory, a sparse representation of the first image is solved with lp norm minimality as the purpose, the first image is updated according to the solution result, and then a second image is obtained; thirdly, whether a stop condition is met or not is judged, if yes, the second image is a final image, if not, the initial image is updated to be the second image, and the first step is executed again. By means of the TOF-PET image reconstruction method, given time information can be completely utilized, acquisition time is shortened, and the drug dose is reduced; meanwhile, the image signal to noise ratio can be increased, noise can be remarkably suppressed, and therefore better image quality can be acquired.

Systems and methods for integration of a PET detector with a CT gantry are provided. One system includes an x-ray computed tomography (CT) gantry having a rotating portion and a stationary portion within a housing, and including a bore volume therethrough. The system also includes an x-ray source and an x-ray detector coupled to the rotating portion. The system further includes a positron emission tomography (PET) detector, wherein the PET detector is coupled to the stationary portion of the CT gantry, such that the PET detector extends at least partially into the CT gantry with at least a portion of the PET detector within the housing of the CT gantry.