Hokkaido University

Hitachi, Ltd.

Shimadzu Corporation

Masayori Ishikawa

Ryo Ogawara

Naoki Miyamoto

Mitsuhiro Yoshida

Tatsufumi Aoi

Takanobu Handa

Tsuyoshi Sasagawa

Junichi Yamazaki

Masayuki Yamaji

Hirokazu Yamawaki

Seiji Yamanaka

The present invention identifies &#x3b1; decay and other events included in the emission of an LaBrscintillator and only collects &#x3b3; ray events. An LaBrscintillation detector is provided with an LaBr3 scintillator, a photomultiplier tube, an oscilloscope, and a computer. The computerdetects a peak value Vp and a total charge amount Qof a voltage waveform signal and calculates an error propagation expression function for a ratio of the peak value Vp to the total charge amount Q. This error propagation expression function is used as a threshold function for identifying and removing &#x3b1; decay events. The &#x3b1; decay events are identified from the peak value Vp and total charge amount Q, which are measurement values that can be measured in real time.

LABR3 scintillation detector and specific event removal method

A scintillation light detecting device distinguishes between signals from scintillator elements. The device includes a scintillator array. In the scintillator array, the scintillator elements have mutually different decay time constants for emitted light generated as a result of an incident radiation event. A photomultiplier tube that receives light output from the scintillator elements and converts the light into an electrical signal. In relation to the event, an arithmetic processing device detects a peak value and an integrated charge quantity in a voltage waveform of the electrical signal from the photomultiplier tube, and identifies the scintillator element in the scintillator array to which the electrical signal, resulting from the incidence of radiation onto the scintillator element, is attributable, in accordance with a ratio between the detected peak value and integrated electric charge quantity.

Scintillation light detecting device and radiation detecting device

Provided are a scintillator with improved energy sensitivity dependence within the energy range of diagnostic X-rays, more specifically in the range of 40-150 kV, and a radiation dosimeter using same. Due to the scintillator comprising a photopolymer resin that contains a polymerizable monomer, a filler, and a photopolymerization initiator, energy sensitivity dependence within the range of 40-150 kV is improved. Furthermore, changes in relative sensitivity within this energy range can be reduced to 3% or less by containing an inorganic fluorescent substance such as ZnSiO.

Scintillator and radiation dosimeter using same

An X-ray therapy system includes a gantry, a positron emission tomography (PET) detection device in the gantry, and an irradiation unit in the gantry (and configured to radiate X-rays to a patient. The PET detection device has a pair of photon detection units and photon detection unit-moving devices configured to move the pair of photon detection units with respect to the gantry.

X-ray therapy system and irradiation field determining method

An organism is irradiated with therapeutic radiation from a radiation irradiation device. A pair of two-dimensional radiation detectors are arranged so as to face one another with the irradiated therapeutic radiation passing therebetween, and detect the two-dimensional positions irradiated by a pair of annihilation &#x3b3; rays produced when a positron emitted from a positron-emitting radionuclide is annihilated. On the basis of a pair of positions detected by the pair of two-dimensional radiation detectors, a radionuclide position detecting unit detects the position of the positron-emitting radionuclide, and the radiation irradiation device irradiates the position of the positron-emitting radionuclide with therapeutic radiation.

Radiation therapy apparatus

In the case where X-ray tubes and X-ray detectors have fixed directions (directions of irradiation and directions of detecting planes), X-ray fluoroscopy can be carried out from various directions by providing two U-shaped tracks for the X-ray tubes and the X-ray detectors, each having two straight tracks arranged opposite each other, and a curved track connected thereto. An increased number of directions for X-ray fluoroscopy can be secured by arranging a U-shaped track rail for the X-ray tubes and a U-shaped track rail for the X-ray detectors opposite each other when seen in plane view.

Moving object tracking system for radiotherapy

A target tracking device for tracking a moving target, based on X-ray fluoroscopic images from a plurality of directions, the target tracking device may include a plurality of X-ray fluoroscopic devices, an image processing unit, and a position determining unit. The X-ray fluoroscopic devices obtain a plurality of images from a plurality of directions, each of the images in a given direction having a different sensitivity. The image processing unit identifies a position of a target image based on pattern matching between the plurality of images and an image of the target. The position determining unit determines a 3D position of the target based on the position of the target image in the plurality of images from the plurality of directions.

Target tracking device and radiation therapy apparatus

Light emitted in correspondence to ionizing radiation incident from a scintillator is fed through an optical fiber to a photoelectron multiplier tube by which it is converted to an electrical signal. The electrical signal is amplified by a signal amplifying circuit, and any light emission events of given or higher intensity are discriminated by a discriminator and counted by a counter. The count value is fed to a computer. The computer converts the count value to a dosage on the basis of an exponential relationship lying between the light emission intensity and the number of emission events, thereby attaining detection of the dosage.

Growing community of inventors

Sapporo, Japan

Masayori Ishikawa