Hamamatsu-photonics K.k.

Research Development Corporation of Japan

National Institute of Radiological Sciences

Hitachi Chemical Company, Ltd.

Hamamatsu Photonics Kabushiki Kaisha

Hamamatsu Photonics Kabushiki

Tomohide Omura

Takaji Yamashita

Hiroshi Uchida

Mitsuo Watanabe

Hideo Murayama

Takahiro Moriya

Naoko Inadama

Kenshi Fukumitsu

Taiga Yamaya

Hiroyuki Ishibashi

Keiji Sumiya

Eiichi Tanaka

Ryosuke Ota

Keiji Shimizu

Ryoko Yamada

A PET device includes detectors including detector signal processing units and a data processing circuit configured to acquire a gamma ray generation position. The detector signal processing unit includes a Compton cone estimating unit configured to estimate incidence directions of gamma rays detected by a pair of detectors as a first and second Compton cones. The data processing unit includes: a coincidence acquiring unit; a scattering surface estimating unit; an intersection line determining unit; an intersection point determining unit; and a gamma ray generation position.

PET device and method of acquiring gamma ray generation position using scattered coincidence with PET device

A scintillator array including a plurality of scintillators, an optical detector array corresponding to the scintillators, an AD conversion unit configured to convert an analog signal output from each optical detector into digital data, and a position detection processing unit configured to specify a position of the scintillator on which the radiation is incident are provided. If there are two different pieces of digital data at the same time, the position detection processing unit determines that radiation is incident on two scintillators when energy value data of the two pieces of digital data is greater than an energy value of a Compton edge and specifies the address of the scintillator on which the radiation is incident by comparing the energy values of the two pieces of digital data when at least one of the two energy values is less than the energy value of the Compton edge.

Radiation position detector, PET device, and recording medium

A three-dimensional position-sensitive radiation detector is provided which has a three-dimensional array of photodetectors disposed on the surface of a scintillator block and which is capable of three-dimensionally identifying the position of light emission at which radiation has been detected within the detector. The three-dimensional position-sensitive radiation detector includes: a scintillator block including a central portion which restricts the direction of diffusion of light so as to direct the light in three axial directions and which has an optically discontinuous region, and an outer portion which is disposed on the outside of the central portion and which does not restrict the direction of diffusion of light; and photodetectors disposed on at least two outer circumferential surfaces of the scintillator block. The detector identifies three-dimensionally the position of light emission, thereby preventing deterioration in position discrimination performance even when inner scintillator elements are smaller than the photodetectors.

Three-dimensional position-sensitive radiation detector and method of identifying radiation detected positions therein

A depth of interaction detector with uniform pulse-height comprises a multi-layer scintillator obtained by coupling at least two scintillator cells on a plane and then stacking the planar coupled scintillator cells, in layers, up to at least two stages and a light-receiving element connected to the bottom face of each scintillator cell of this multi-layer scintillator, wherein the detector is provided with a means for discriminating the position of a scintillator cell, which receives radiant rays and emits light rays and a means for making, uniform, the quantity of the light emitted from each scintillator cell and received by the light-receiving element. The detector can provide precise detection information even when radiation is absorbed by and emitted from a scintillator layer positioned above the scintillator layer optically coupled to the light-receiving element, permits the production of a depth of interaction detector having a three-dimensional depth of interaction-detecting function and can provide the same total output signal, which is independent of the position or a specific scintillator cell practically emitting light if the radiation energy is identical.

Depth of interaction detector with uniform pulse-height

The energy E of a signal pulse P inputted to an energy measurement apparatusfor measurement, and corresponding to the total integrated intensity, is calculated in an energy calculation unitfrom the integrated signal intensity Q acquired by a gate integrator, and from the pulse interval T measured by a pulse interval measurement unit. At this time, pileup correction is performed using at least one of the integrated signal intensity or the energy, and the pulse interval of the signal pulse inputted prior to the signal pulse for measurement. By this means, the correct energy E, with the effect of pileup eliminated, can be determined with good precision. Hence a method and apparatus for energy measurement are realized which enable correct and precise measurement of the energy of individual signal pulses, even when the pulse interval between signal pulses is short.

Method and apparatus for measuring signal pulse energy

A high resolution scintillation camera includes a scintillator which generates scintillation light having a light amount proportional to the energy value of incident radiation at the radiation incident position. The generated scintillation light is supplied to several of a plurality of photodetectors forming a detector array. These photodetectors output electrical signals proportional to the supplied light amounts, respectively. The output electrical signals are supplied to a selector to select a photodetector arranged at the radiation incident position and a plurality of photodetectors adjacent to this photodetector. A detection unit detects the radiation incident position on the scintillator on the basis of output signals from a plurality of segments of each photodetector selected by the selector.

Scintillation camera using a photomultiplier having a plurality of anodes

A radiation detector comprising a scintillator array for emitting scintillation light upon incidence of radiation to a scintillator and distributing the scintillation light to the other scintillators at a predetermined distribution ratio and plural photomultiplier tubes optically coupled to the scintillator array for converting the scintillation light into an amplified electrical signal representing an incident position of the radiation to the scintillator array. The scintillator array comprises plural scintillators, and each pair of neighboring scintillators have coupling surface on both of confronting surfaces thereof for optically coupling the neighboring scintillators therethrough, each of the coupling surfaces having at least one of a roughened surface and a mirror-polished surface having different transmissivities to light passing therethrough to thereby adjust the distribution ratio of the scintillation light transmitted from one of the scintillators to another.

Radiation detector using scintillator array

A radiation detector for detecting the axial position of radiation incident to a scintillation element. Roughened surface portions are selectively configured and interstitially positioned relative to mirror-polished surface portions at discrete intervals along the axis of the element for optimizing the position resolution by varying the light reflection characteristics of the element.

Radiation detector

A scintillation detector for three-dimensionally measuring the absorption position of the gamma-rays entering the detector and a positron computed tomography apparatus employing as a gamma-rays detector plural scintillation detectors arranged in the form of a ring are provided which can prevent the degradation of the spatial resolution in the peripheral region of the visual field and uniformly detect a positron distribution over the entire visual field with high resolution. The scintillation detector comprises a bundle of pillar-shaped scintillator elements and position detecting photodetectors coupled to the end surfaces of each scintillator element, and the apparatus comprises a plurality of scintillation detectors formed in a ring, each of which includes a bundle of scintillator elements, and plural position detecting photodetectors each of which is connected to both ends of the scintillator bundle.

Growing community of inventors

Hamamatsu, Japan

Tomohide Omura