36 results about "Portal imaging" patented technology

The invention provides methods and apparatus for detecting radiation including x-ray, gamma ray, and particle radiation for nuclear medicine, radiopaphic imaging, material composition analysis, high energy physics, container inspection, mine detection and astronomy. The invention provides detection systems employing one or more detector modules (102) comprising edge-on scintillator detectors (101) with sub-aperture resolution (SAR) capability employed, e.g., in nuclear medicine, such as radiation therapy portal imaging, nuclear remediation, mine detection, container inspection, and high energy physics and astronomy. The invention also provides edge-on imaging probe detectors for use in nuclear medicine, such as radiation therapy portal imaging, or for use in nuclear remediation, mine detection, container inspection, and high energy physics and astronomy.

The present invention provides a practical design of a megavoltage x-ray detector with both high quantum efficiency (QE) and high resolution. The x-ray detector disclosed herein has a QE that can be an order of magnitude higher than that of current flat panel systems and yet has a spatial resolution equivalent to that of current flat panel systems used for portal imaging. The x-ray detector includes a large number of micro-structured electrically conducting plates, packed together with thin spacers placed between neighboring plates with the micro-structured plates oriented to be parallel to the incident x-rays in operation. Each plate includes an electrically conductive substrate with a first planar surface, elongate electrically conductive strip electrodes separated from each other with strip spacers placed in between and sitting on an insulating layer interposed between the first planar surface of the electrically conductive substrate and the strip electrodes. A power supply applies a bias voltage between each electrically conductive substrate and the electrically conductive strip electrodes, whereby x-rays absorbed in the conductive substrate generates high energy electrons which produce ions in an ionization medium located in spaces between the conductive substrate and the electrically conductive strips. A detector detects an electrical current generated in the electrically conductive strip electrodes and a 2D active readout matrix is coupled to the detector.

The invention aims at providing a method for collecting spatial population distribution in real time on the basis of mobile phone big data and realizing large passenger flow early warning. The method is characterized by comprising the following steps of obtaining real-time mobile phone big data from a mobile phone communication operator at each statistics moment; dividing a target region into different space regions; at the current statistics moment, mapping the latest space position of each EPID (Electronic Portal Imaging Device) obtained in the first step to each space region of the target region; and obtaining the real population size (the distribution condition of the total population in the whole target region) in each space region at the current statistics moment. The method has the advantages that the sufficient relying on the existing mobile phone big data resources is realized; the continuous encrypted position information of the existing mass anonymous mobile phone users in the mobile communication network is used; the low-cost high-frequency and automatic implementation can be realized; and the popularization distribution data in a large-range urban space range can be continuously obtained in a fast deploying way.

The present invention provides a practical design of a megavoltage x-ray detector with both high quantum efficiency (QE) and high resolution. The x-ray detector includes an optical-fiber taper (OFT) made from a large number of optical fibers, each of which is aligned with the incident x-rays from an x-ray source hitting a top surface of the optical fiber taper. The optical-fiber taper is a matrix of optical fibers with the core material made of, e.g., silica and coated with a cladding glass or polymer such that light created within the core of each optical fiber will be guided to the bottom ends of the fiber with the ends of the fibers at the bottom being optically coupled to and optical image read-out device. Each optical fiber in the optical fiber taper is fully aligned with the incident x-ray source so that x-rays entering the top of the fiber travel directly towards the bottom of the same fiber. This alignment (or focusing) of the optical-fiber taper towards the x-ray source can be achieved by an extra coating at the bottoms of the optical fibers so they have a larger diameter than the other top ends of the fibers.

Systems and methods for determining beam asymmetry in a radiation treatment system using electronic portal imaging devices (EPIDs) without implementation of elaborate and complex EPID calibration procedures. The beam asymmetry is determined based on radiation scattered from different points in the radiation beam and measured with the same region of interest ROI of the EPID.

Image storage assemblies comprise thin metal screens adjacent phosphor storage screens. The thin metal screen is from about 0.01 to about 0.75 mm in thickness when composed of copper and from about 0.05 to about 0.4 mm when composed of lead. These image storage assemblies can be used in portal imaging whereby imaging radiation is directed through the thin metal screens before the phosphor storage screens. Stimulating radiation can then be directed to the phosphor storage screen before it reaches the thin metal screen.

X-ray therapy EPI artifact reduction and control of imaging is provided. Scanning of images is synchronized with the pulse rate of the x-rays. The scanning period is longer than the pulse rate period, so artifacts are generated within the resulting images. Due to the synchronization, the pulse variation artifacts are aligned across multiple images. The synchronization and resulting alignment of linear artifacts allows for gain correction as a function of lines within the image. Such gain correction reduces or removes non-linearities associated with pulse rate variation.

A radiation therapy system produces a treatment beam that is detected by an electronic portal imaging device (EPID) after it passes through the subject being treated. A chopper wheel modulates low energy components of the beam while leaving the higher energy components substantially unmodulated. Modulated components in the image signals produced by the EPID are detected and used to produce portal images.

A radiation dose received by a patient 110 from a radiation therapy system 100 can be verified by acquiring a cine stream of image frames from an electronic portal imaging device (EPID) 108 that is arranged to detect radiation exiting the patient during irradiation. The cine stream of EPID image frames can be processed in real-time to form exit images providing dose measurements at the EPID (e.g., absolute dose as dose-to-water values), which can be representative of the characteristics of the radiation received by the patient. Compliance with predetermined characteristics for the field can be determined during treatment by periodically comparing the dose measurements with the predetermined characteristics, which can include a predicted total dose in the field after full treatment and/or a complete irradiation area outline (CIAO). The system operator can be alerted or the irradiation automatically stopped when non-compliance is detected.

The present invention is a method or system for acceptance testing and commissioning of a LINAC and treatment planning system (TPS). For a LINAC commissioning, the present invention collects reference data from a fully calibrated LINAC and compares the reference data with machine performance data collected from a testing LINAC. The compared results are analyzed to assess accuracy of the testing LINAC. For a TPS commissioning, the present invention collects standard reference data from standard treatment plans and standard input data and compares the standard reference data with results from standard tests that are performed by a testing treatment plan system. The compares results are analyzed to assess accuracy of the testing treatment plan system.

The invention relates to a novel high-resolution portal imaging system, belongs to the field of medical instruments, and is applied to tumor radiotherapy. The novel high-resolution portal imaging system comprises a multi-blade collimator comprising multiple blades which are installed in a box body. The box body is installed on a slide block of a linear guide rail and can move along the linear guide rail. Each blade can move along blade guide grooves of the box body. The box body moves in a dragging way via a leading screw transmission mechanism. The blades move in the dragging way via leading screw nuts. A required portal shape is formed by positions of the multiple blades and the box body via positioning and controlling, and dimension of a dose calculation matrix unit of the portal imaging system is 2.5mm*2.5mm. The novel high-resolution portal imaging system is characterized in that the blades comprise a group of intermediate blades, a second group of blades and a third group of blades. The second group of blades are arranged at the two sides of the group of intermediate blades. The third group of blades are arranged at the two sides of the second group of blades. The novel high-resolution portal imaging system has characteristics of being high in performance, low in cost and high in practicality.

The invention discloses an accelerator-based energy spectrum computed tomography (CT) implementation method and device and radiotherapy equipment. The energy spectrum CT implementation method comprises the following steps: S1, CT scanning parameter information of a patient is received, and an accelerator rotating rack and a treatment bed are moved to preset initial positions; S2, the rack is enabled to start to rotate, the treatment bed cooperates to correspondingly move a patient, meanwhile, an energy spectrum CT control unit enables an MV-level imaging system and a kV-level imaging system to carry out portal imaging and records rack angle information and treatment bed position information at the moment, and all dual-energy projection images and corresponding angle information of the patient are obtained; S3, image registration is performed on the dual-energy projection image; S4, a two-dimensional projection image of the material coefficient of the patient is solved; S5, a three-dimensional image of the material coefficient of the patient is reconstructed; and S6, various functional images are calculated and displayed. According to the invention, by adding the energy spectrum CT control unit and the corresponding control method, the purpose of realizing the energy spectrum CT is achieved.

The invention discloses an electronic portal imaging device positioning device used for a medical accelerator, which belongs to the technical field of radiation treatment instruments. An overturn mechanism in the device is installed on a base, the overturn mechanism achieves rotation around a mounting axis, an overturn positioning mechanism mounted on the overturn positioning mechanism performs mechanical limit on an overturn angle of the overturn mechanism, and a rotating positioning clearance eliminating mechanism mounted on the overturn mechanism performs elimination on a transmission sidegap of the overturn mechanism; and a linear motion mechanism is mounted on the overturn mechanism, a ray detection device is mounted on the linear motion mechanism, a linear positioning mechanism mounted on the overturn mechanism performs the mechanical limit on a linear motion of the linear motion mechanism, and a linear positioning clearance eliminating in the linear motion mechanism performs the elimination on the transmission side gap of a linear transmission mechanism. The device can quickly, reliably and repeatedly position a position of the ray detection device by the overturn mechanismand the linear motion mechanism.