Abstract: A first image collection memory collects two-dimensional image data within a predetermined energy window to constitute a fine matrix. A second image collection memory collects three-dimensional image data, including energy spectral information, to constitute a coarse matrix. Each pixel of the data collected in the second image collection memory is subjected to a scatter correction with energy weighted acquisition using a weight function. Correction coefficients are derived from a ratio between data before the correction and data after the correction, and by interpolation processing for each pixel in the fine matrix, and are applied to the image data collected in the first image collection memory. The data collected in the second image collection memory is subjected to two-dimensional low-pass filter processing.

Abstract: In an apparatus for automatically stabilizing the amplification degrees of photomultipliers (PMT's) in a detector having a scintillator and a plurality of PMT's, the PMT's (3) are classified into groups (A, B, C and D) and arranged such that the PMT's of the same group are not disposed adjacent to each other. Outputs taken from the PMT's (3) are classified according to the groups and summed in adders (6) allotted to the respective groups. A sum signal taken from a group which includes a PMT disposed closest to a scintillation is analyzed by a pulse height analyzer (14). The outputs from the pulse height analyzer are collected in a counter memory (15) as statistical data on a change in the amplification degrees of PMT's. Data on the high voltage to be applied to each PMT (3) is recorded beforehand in a register (17) and this data is corrected by a data processing circuit (16) in accordance with the statistical data.

Abstract: Semiconductor radiation detector comprising a radiation detecting element made of a compound semiconductor and operable at room temperature in response to a radiation event to produce a corresponding output signal; a preamplifier for preamplifying the output from the detecting element to produce a corresponding signal; and pulse shaping amplifier including a quasi-gaussian filter comprising a combination of a first differentiator and an integrator to shape and amplify the signal from the preamplifier; means for obtaining information about charge collection time at each radiation event by comparing the pulse height of a signal caused by the output from the differentiator and the pulse height of the output from the shaping amplifier; and means for correcting the pulse height of the output signal form the shaping amplifier in accordance with the information about charge collection time at each radiation event, thereby to improve the deterioration of the energy resolution caused by incomplete charge collection.

Abstract: A radiation imaging apparatus provided with a pulse height analyzer for checking whether the pulse height of the energy signal produced in response to each scintillation event falls within an energy window set for the particular (x,y) coordinate position of the scintillation. The pulse height analyzer has a memory for storing a plurality of energy windows each for a particular one of the coordinate positions in the scintillator and each having a particular central level and a particular width such that the nonuniformity of the sensitivity of the detector due to the position-dependency of the energy signal and/or other causes can be corrected. A preliminary pulse height analyzer may be provided to increase the counting rate of energy signals useful for image production.