Abstract: A PET apparatus and a timing correction method of this invention select two target gamma-ray detectors which count coincidences, select a reference detector which is one detector out of the two selected gamma-ray detectors, select a gamma-ray detector different from the other, opposite detector, and when repeating the selection, make a time lag histogram concerning two gamma-ray detectors selected in the past a reference, and correct a time lag histogram concerning gamma-ray detectors selected this time based on the reference. By repeating an operation to make the corrected time lag histogram concerning the two gamma-ray detectors a new reference, an optimal time lag histogram can be obtained without repeating many measurements and computations.

Abstract: A PET apparatus and a timing correction method of this invention select two target gamma-ray detectors which count coincidences, select a reference detector which is one detector out of the two selected gamma-ray detectors, select a gamma-ray detector different from the other, opposite detector, and when repeating the selection, make a time lag histogram concerning two gamma-ray detectors selected in the past a reference, and correct a time lag histogram concerning gamma-ray detectors selected this time based on the reference. By repeating an operation to make the corrected time lag histogram concerning the two gamma-ray detectors a new reference, an optimal time lag histogram can be obtained without repeating many measurements and computations.

Abstract: A display device, a display method, and a display program used in a measurement system capable of facilitating positioning in a measurement information image by displaying an IP (imaging plate) image having measurement information for ?+ rays contained in blood to be measured and appending a guide G based on design information of a disc housing the blood to an IP image and displaying the image. The guide G is appended to an IP image in which a guide is not originally reflected, which makes it possible to visually discern a reference position (for example, the central position of the disc) in the IP image based on design information. As a result, it is possible to facilitate positioning in the IP image based on the guide G indicating the reference position (central position of the disc).

Abstract: A radiation detector includes two reflecting plate lattices that are combined into a single reflecting plate lattice. The use of such a structure simplifies the manufacturing of a scintillator. The radiation detector reduces the number of reflecting plate lattices that are stacked when manufacturing the scintillator, enabling the scintillator to be manufactured easily. Moreover, the number of reflecting plate lattices to be manufactured is reduced, reducing commensurately the number of components required for manufacturing the scintillator. The scintillator may be manufactured more easily and an inexpensive radiation detector may be obtained.

Abstract: Disclosed is a radiation detector signal processor that allows accurate identification of a variation in fluorescence detection intensity. With a construction of the disclosure, the variation is obtainable in accordance with detection data (a peak value) of fluorescence and a specified number of light spread indicating how the fluorescence generated in a scintillator spreads spatially until reaching each of detecting elements. Such a construction allows accurate obtainment of the variation in the radiation detector in which the fluorescence is detected with a plurality of light detecting elements while spreading. A radiation detector is adjusted in accordance with the variation, achieving more accurate positional identification by the radiation detector.

Abstract: Even when areas delimited by delimiting points are not appropriate and area division has failed, success or failure of area division in such areas can easily be determined by applying a map determination condition in the map determining step (step S50). And since the areas delimited by the delimiting points are changed and the map determining step (step S50), including also steps S22 and S23 and steps S30 and S40, is repeated until the map determination condition is satisfied, the areas satisfying the map determination condition are determined appropriate and the area division in such areas can be carried out accurately. Even when there is distortion, a two-dimensional position map can be corrected accurately.

Abstract: Disclosed is a radiation detector signal processor that allows accurate identification of a variation in fluorescence detection intensity. With a construction of the disclosure, the variation is obtainable in accordance with detection data (a peak value) of fluorescence and a specified number of light spread indicating how the fluorescence generated in a scintillator spreads spatially until reaching each of detecting elements. Such a construction allows accurate obtainment of the variation in the radiation detector in which the fluorescence is detected with a plurality of light detecting elements while spreading. A radiation detector is adjusted in accordance with the variation, achieving more accurate positional identification by the radiation detector.

Abstract: A radiation detector includes two reflecting plate lattices that are combined into a single reflecting plate lattice. The use of such a structure simplifies the manufacturing of a scintillator. The radiation detector reduces the number of reflecting plate lattices that are stacked when manufacturing the scintillator, enabling the scintillator to be manufactured easily. Moreover, the number of reflecting plate lattices to be manufactured is reduced, reducing commensurately the number of components required for manufacturing the scintillator. The scintillator may be manufactured more easily and an inexpensive radiation detector may be obtained.

Abstract: The display apparatus of this invention, even when edges of an IP image with measurement information on ?+ rays are indistinct and an area to be measured is unclear, includes a main screen for displaying in superimposition the IP image and a scanner image with morphological information on blood, whereby an area measured of the scanner image can be grasped visually from the IP image. Even if traces of movement of the blood appear on the IP image, the position of an object to be measured can be determined by displaying the IP image and the scanner image in superimposition.

Abstract: According to a method of manufacturing a light guide of this invention, a shaping member is provided that covers a molding frame. In a releasing step, when the shaping member is lifted up in a direction apart from the molding frame, the light guide is lifted and pulled out from an aperture of the molding frame accordingly. As a result, there is no need to pull out the light guide by conventionally providing a pressing plug on a bottom of the molding frame and pressing the plug in a direction. In addition, there is no need to perform a grinding process to the light guide.

Abstract: Even when areas delimited by delimiting points are not appropriate and area division has failed, success or failure of area division in such areas can easily be determined by applying a map determination condition in the map determining step (step S50). And since the areas delimited by the delimiting points are changed and the map determining step (step S50), including also steps S22 and S23 and steps S30 and S40, is repeated until the map determination condition is satisfied, the areas satisfying the map determination condition are determined appropriate and the area division in such areas can be carried out accurately. Even when there is distortion, a two-dimensional position map can be corrected accurately.

Abstract: A PET apparatus and a timing correction method of this invention select two target gamma-ray detectors which count coincidences, select a reference detector which is one detector out of the two selected gamma-ray detectors, select a gamma-ray detector different from the other, opposite detector, and when repeating the selection, make a time lag histogram concerning two gamma-ray detectors selected in the past a reference, and correct a time lag histogram concerning gamma-ray detectors selected this time based on the reference. By repeating an operation to make the corrected time lag histogram concerning the two gamma-ray detectors a new reference, an optimal time lag histogram can be obtained without repeating many measurements and computations.

Abstract: A boundary calculating unit is provided for determining boundaries between separated plasma and blood cell or air and plasma whose image is picked up by an image pickup unit. With such boundary calculating unit provided, the boundaries between the separated plasma and blood cell or air and plasma can be determined, and areas of the separated air, plasma, and blood cell can be determined accurately. Particularly, a straight line drawing unit is provided for drawing, on the image picked up, a plurality of straight lines parallel to grooves in a disk which performs plasma separation. The boundary calculating unit can easily determine the boundaries by determining the boundaries based on a profile of the plurality of straight lines drawn by the straight line drawing unit.

Abstract: In a scintillator of a radiation detector according to this invention, first reflectors provided in first scintillation counter crystal layer adjacent to one another have gaps wider than first reflectors provided in second scintillation counter crystal layer such that an overall width of the first reflectors in the first scintillation counter crystal layer in an arranging direction is identical to an overall width of the first reflectors in the second scintillation counter crystal layer in an arranging direction. Such construction improves spatial resolution at a side end of the scintillator.

Abstract: In a DOI radiation detector, scintillation crystals are arranged in three dimensions on a light receiving surface of a light receiving element, and a response of a crystal having detected a radiation ray can be identified on the light receiving surface. Thereby, a position at which the radiation ray is detected is determined in three dimensions. In this DOI radiation detector, regular triangular prism scintillation crystals are used, and response positions of the respective crystals are shifted for each set. This allows crystal identification without loss even with a structure such as a three-layer or six-layer structure hard to achieve by a quadrangular prism scintillation crystal.

Abstract: According to a method of manufacturing a light guide of this invention, a shaping member is provided that covers a molding frame. In a releasing step, when the shaping member is lifted up in a direction apart from the molding frame, the light guide is lifted and pulled out from an aperture of the molding frame accordingly. As a result, there is no need to pull out the light guide by conventionally providing a pressing plug on a bottom of the molding frame and pressing the plug in a direction. In addition, there is no need to perform a grinding process to the light guide.

Abstract: A radiation detector according to this invention has a first reflector frame and a second reflector frame. Each of scintillation counter crystals is inserted in a direction through the first reflector frame and the second reflector frame, whereby two or more scintillation counter crystals are arranged in a first direction and a second direction to form a scintillation counter crystal layer. A position of the first reflector frame provided in the scintillation counter crystal layer differs from a position of the second reflector frame provided in the scintillation counter crystal layer. With such construction, the radiation detector may be provided of significantly suppressed manufacturing costs without reducing spatial resolution and detecting sensitivity.

Abstract: In a scintillator of a radiation detector according to this invention, first reflectors provided in first scintillation counter crystal layer adjacent to one another have gaps wider than first reflectors provided in second scintillation counter crystal layer such that an overall width of the first reflectors in the first scintillation counter crystal layer in an arranging direction is identical to an overall width of the first reflectors in the second scintillation counter crystal layer in an arranging direction. Such construction improves spatial resolution at a side end of the scintillator.

Abstract: An emitted light in a scintillator element is sufficiently diffused in the scintillator array to be inputted into a photo multiplier tube (PMT) using a side face light guide that is optically coupled with respect to a side face of a scintillator array, except for in an end area. In the end area, the emitted light in the scintillator element is sufficiently diffused also in the side face light guide to be inputted into the PMT. In this way, also in the scintillator element in the end area, the emitted light is sufficiently diffused in the side face light guide, and thereby the precision of separation of a position calculation map in the end area may be improved, resulting in improved discriminating ability of a position in the end area.

Abstract: A positron emission tomography (PET) scanner is provided which uses information on the time-of-flight difference (TOF) between annihilation radiations for image reconstruction. The scanner has detection time correction information (memory) corresponding to information on coordinates in a radiation detection element (e.g., scintillator crystal), in the depth and lateral directions, at which an interaction has occurred between an annihilation radiation and the crystal. Reference is made to the detection time correction information, thereby providing information on time-of-flight difference with improved accuracy. As such, an improved signal to noise ratio and spatial resolution are provided for image reconstruction using time-of-flight (TOF) difference.