Hitachi Medical Corporation

National Institute of Radiological Sciences

Tokyo Shibaura Denki Kabushiki Kaisha

Tokyo Shibaura Electric Co., Ltd.

The Director of the National Institute of Radiological Sciences, Science

Eiichi Tanaka

Katsumi Takami

Kenji Ishimatsu

Takehiro Tomitani

Norimasa Nohara

Yoshitoshi Ito

Hideo Murayama

Mineki Nishikawa

Makoto Kakegawa

Akira Ogushi

Nobuo Kumano

Mikio Yamamoto

A plurality of input signals are applied to input terminals of first and second priority encoders according to the order of priority in ascending and descending orders, respectively. The encoded output signals of the first and second priority encoders are exclusive-ORed for each corresponding pair of significant bits. A single event detection is executed only if exclusive OR is effected for all the corresponding pairs of significant bits.

Apparatus for detecting single event

An apparatus for a detecting the location of incident radiation comprises at least one pair of assembly comprised of a scintillation crystal consisting of a plurality of crystal segments, a pair of photo-multiplier tubes optically coupled to the scintillation crystal so as to be able to detect a scintillation produced in any one of these crystal segments. These plural crystal segments are coupled to each other in such manner that any scintillation produced in any single crystal segment will cause the photo-multiplier tubes to deliver substantially a same output irrespective of the illuminating position within this crystal segment, and also that scintillations produced in the respective crystal segments will cause the photo-multiplier tubes to deliver outputs which are different in level for the respective crystal segments.

Apparatus for detecting the location of incident radiation

An apparatus for effecting positron emission computed tomography comprises rows of a plurality of arrays of detectors arranged rotatably around a center of rotation in such way that at least one of the detectors in each array is disposed at an irregular position relative to the rest of detectors in the array, and that, for each revolution of the row through an angle of 360.degree./n (wherein: n represents an odd number of 3 or larger), each array of detectors will assume exactly the position occupied by its adjacent array till the revolution takes place.

Apparatus for performing positron emission computed tomography

An apparatus for optically transmitting signals from a rotatable body to a stationary side or vice versa in a non-contact manner, includes a plurality of light emitting elements excited by a PCM signal from a signal source and a plurality of light receiving elements disposed in opposition with the light emitting elements for receiving light therefrom. A plurality of sets each including plural light receiving or emitting elements are provided at the stationary side in association with the respective light emitting or receiving elements disposed at the rotatable body side. Alternatively, a plurality of sets each including plural light emitting elements are provided at the rotatable body side in association with the respective light receiving elements disposed at the stationary side. The elements in such plural sets are selected in accordance with the rotation of the rotatable body.

Optical signal transmission apparatus

In a radiation detector including a radiation sensitive scintillator and a photo-electric conversion element, a film of silicon nitride providing a modified refractive index is interposed between the scintillator and the photo-electric conversion element.

Radiation detector having refractive index matching means

A scanner for positron emission computed tomography comprising a rotary member rotatable within the plane of a slice about an axis lying perpendicular to this plane and having means for accommodating a subject for examination, a drive means for rotating this rotary member within the plane of slice, and a plurality of radiation detectors provided on the rotary member so as to substantially face each other relative to the subject to be examined, in which the radiation detectors are disposed so that at least some of them are either positioned with irregular spacing relative to each other, or positioned at irregular distances from the axis of rotation.

Scanner for positron emission computed tomography

A scintillation type radiation-measuring apparatus comprising a radiation-detecting scintillator, wherein a scintillation given off from the scintillator is converted into current by a photomultiplier tube; a current amplifier generates a plurality of pulses each proportional to the intensity of said converted current; the pulses have the width clipped by a clipped pulse generating circuit; the clipped form of the pulses is delayed by a delay circuit and integrated by an integrator; the wave height value of the outputs from the integrator is sampled by a sampling circuit to provide a sampled output; and means are provided to supply instructions to start and reset the operation of the integrator and to commence the operation of the sampling circuit in accordance with the interval between successively detected current pulses.

Growing community of inventors

Mitaka, Japan

Eiichi Tanaka