Abstract: A cap comprising a cap body including a top plate portion which is disk-shaped, and a skirt portion which is cylindrical and provided at a peripheral edge portion of the top plate portion, the top plate portion including a substrate and a resin coating film provided on a cap inner surface side of the substrate, the resin coating film including a polyester-based resin and a lubricant, and a sealing member provided in the cap body separately from the cap body so as to face the top plate portion, and having an outer diameter smaller than an inner diameter of the skirt portion.

Abstract: The present invention aims to optimize image quality for a conventional scan (axial scan) or a cine scan or a helical scan of an X-ray CT apparatus by a data acquisition system having a limited number of channels. The optimum view numbers determined or defined by image quality to be determined depending upon the positions of the respective channels at image reconstruction are determined by a sampling theorem. Thus, the optimum view numbers, which depend upon the respective channel positions, are allocated. The data acquisition system performs data acquisition in accordance with the views to make it possible to obtain a tomographic image having the optimum image quality. Thus, the number of A/D converters of the data acquisition system and its performance can also be optimized.

Abstract: Enhancement of the resolution of tomograms obtained by conventional scanning (axial scanning), cine-scanning, helical scanning or variable-pitch helical scanning by the X-ray CT apparatus using a multi-row X-ray detector or a two-dimensional X-ray area detector of a matrix structure is to be realized by a simple method. An X-ray CT apparatus is realized in which a multi-row X-ray detector or a two-dimensional X-ray area detector of a matrix structure with a small amount of processing work, and image reconstructing device capable of providing high-resolution tomograms by image reconstruction is provided.

Abstract: In order to control a collimator so that an X-ray impingement position on an X-ray detector is kept constant, an error of the impingement position of a fan-shaped beam (400) in the direction of side-by-side arrangement of a plurality of detector element rows in a detector element array (24) is detected (101), and the collimator is controlled (103) based on the detected error so that the impingement position of the fan-shaped beam is kept at a constant position.

Abstract: In order to control a collimator so that an X-ray impingement position on an X-ray detector is kept constant, an error of the impingement position of a fan-shaped beam (400) in the direction of side-by-side arrangement of a plurality of detector element rows in a detector element array (24) is detected (101), and the collimator is controlled (103) based on the detected error so that the impingement position of the fan-shaped beam is kept at a constant position.