Hamamatsu-Photonics K.k.

Hamamatsu Photonics Kabushiki Kaisha

Research Development Corporation of Japan

Keiji Shimizu

Takaji Yamashita

Hiroyuki Okada

Hiroshi Uchida

Mitsuo Watanabe

Eiichi Tanaka

Tomohide Omura

Nakahiro Satoh

A positron CT scanner includes a plurality of detectors arranged in a generally cylindrical multi-layers of rings, and slice septa for restricting visual fields of the detectors so that the visual fields intersect a set axis. An interval of the slice septa is substantially corresponds to a plural number of detector cells each of which can determine positions of .gamma. rays incident in the direction of the set axis. The slice septa are movable relatively to the detector cells in the direction of the set axis during a .gamma. ray counting operation.

Positron computed tomography scanner

A data correcting device is intended to be used with a CT apparatus for obtaining a tomographic image with a subject holding means being adapted to be slidable into or out of the tunnel in a gantry. The device includes a body movement sensor for detecting a movement of a subject under examination; a body movement data processing unit for converting body movement data from the body movement sensor into address correcting data; a tomographic data processing unit for processing tomographic data obtained in the gantry; an address converting unit for correcting the address of the tomographic data with the address correcting data; and a memory for storing data.

Data correcting device for use with computed tomography apparatus

A method and an apparatus for performing address transformation of projection data for use in a positron CT system, where plural detectors are classified into plural detector groups. In this system, a polar coordinate of the addresses assigned to paired detectors which detect coincident events of gamma-ray emission is determined by adding a first encoded signal representing a first polar coordinate of the line joining the reference points of the paired detector groups including the paired detectors and a second encoded signal representing a second polar coordinate of the deviation of the line joining the two detectors from the line joining the reference points. The second encoded signal is obtained on the basis of address signals representing the addresses of the two detectors and a third encoded signal representing the angle relationship of the paired detector groups which is preliminarily stored in a memory. The polar coordinate thus obtained is outputted as a fourth encoded signal and used in a image reconstruction process of the positron CT system.

Method and apparatus for performing address transformation of projection

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.

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Shizuoka, Japan

Keiji Shimizu