Abstract: An image correction method according to an aspect of the present disclosure includes receiving an input of selecting one of a first method for correcting a shape of an image projected from a projector onto a projection surface and a second method that is a method for correcting the shape of the image and is different from the first method, outputting a signal for causing the projector to project a first pattern image when the first method is selected, generating first correction data for correcting the shape of the image using the first method based on a first captured image that is acquired by imaging the projection surface and includes the projection surface and a first projection image appearing on the projection surface by projecting the first pattern image, outputting a signal for causing the projector to project a second pattern image different from the first pattern image when the second method is selected, and generating second correction data for correcting the shape of the image using the second met

Abstract: It is an object of the present invention to eliminate windmill artifacts that inevitably occurs when a helical scan is performed with an X-ray CT system. To this end, the present invention is equipped with an X-ray source, and an X-ray detector having a plurality of detector elements arranged two-dimensionally, and disposed opposite to the X-ray source with a predetermined rotation center axis therebetween. The invention further includes reconstruction means for performing an arithmetic operation, in which two-dimensional projection data obtained based on X-ray detection data detected by the detector elements while rotating the X-ray source around the rotation center axis are back projected along a path different in a Z-axis direction extending along the rotation center axis from the X-ray path of the projection data, to reconstruct an image.

Abstract: An X-ray CT apparatus is provided which can be suppressed or eliminated of aliasing occurrence in the R-R scheme. The X-ray CT apparatus has a reconstructing device for processing the collected data on each view to thereby obtain projection data and making a backprojection operation on the projection data to thereby reconstruct an image. In the reconstructing device, when the X-ray detector element closest to a rotation center of the detector system determines that an X-ray path for detecting the X-ray irradiated is in a position deviated by a sampling offset (first value) from the rotation center, projection data of the X-ray detector element at least in a vicinity of the rotation center upon the backprojection operation is backprojected to a position deviated by a backprojection offset (second value: different from the first value) from the rotation center.

Abstract: It is an object of the present invention to eliminate windmill artifacts that inevitably occurs when a helical scan is performed with an X-ray CT system. To this end, the present invention is equipped with an X-ray source, and an X-ray detector having a plurality of detector elements arranged two-dimensionally, and disposed opposite to the X-ray source with a predetermined rotation center axis therebetween. The invention further includes reconstruction means for performing an arithmetic operation, in which two-dimensional projection data obtained based on X-ray detection data detected by the detector elements while rotating the X-ray source around the rotation center axis are back projected along a path different in a Z-axis direction extending along the rotation center axis from the X-ray path of the projection data, to reconstruct an image.

Abstract: A radiological image diagnostic system is provided with a radiation generating unit, a radiation detecting unit, a clipping-correction unit and an image reconfiguration unit. The radiation generating unit generates a radiation. The radiation detecting unit detects the radiation from the radiation generating unit. The clipping-correction unit applies a clipping process to a radiation detected value by the radiation detecting unit and applies a mean value correction process to data acquired based upon the radiation detected value so that the separation of the local mean of the data acquired based upon the radiation detected value before and after the clipping process is reduced. The image reconfiguration unit generates an image using data acquired based upon a radiation detected value after the clipping process and after the mean value correction process.

Abstract: A radiological image diagnostic system is provided with a radiation generating unit, a radiation detecting unit, a clipping-correction unit and an image reconfiguration unit. The radiation generating unit generates a radiation. The radiation detecting unit detects the radiation from the radiation generating unit. The clipping-correction unit applies a clipping process to a radiation detected value by the radiation detecting unit and applies a mean value correction process to data acquired based upon the radiation detected value so that the separation of the local mean of the data acquired based upon the radiation detected value before and after the clipping process is reduced. The image reconfiguration unit generates an image using data acquired based upon a radiation detected value after the clipping process and after the mean value correction process.

Abstract: An X-ray CT apparatus is provided which can be suppressed or eliminated of aliasing occurrence in the R-R scheme. The X-ray CT apparatus has a reconstructing device for processing the collected data on each view to thereby obtain projection data and making a backprojection operation on the projection data to thereby reconstruct an image. In the reconstructing device, when the X-ray detector element closest to a rotation center of the detector system determines that an X-ray path for detecting the X-ray irradiated is in a position deviated by a sampling offset (first value) from the rotation center, projection data of the X-ray detector element at least in a vicinity of the rotation center upon the backprojection operation is backprojected to a position deviated by a backprojection offset (second value: different from the first value) from the rotation center.

Abstract: An X-ray CT scanner comprises an X-ray source generating an X-ray, detector detecting the X-ray transmitted through an object, processor to produce projection data, and reconstruction unit to reconstruct an image using the projection data. The processor produces the projection image by applying, to an output signal from the detector, logarithm conversion processing on a function deviating from an ideal logarithm function. The ideal logarithm function is a logarithm function defined by a mathematical formula of y=K·log [b, x] (wherein a variable x is an input, a variable y is an output, and a reference K shows a scaling constant). The function deviating from the ideal logarithm function has an input/output characteristic deviating from that of the ideal logarithm function. Such deviating function is for example a linear function and applied to a conversion of only low-count data into its projection data to suppress low-count artifacts on reconstructed CT images.

Abstract: An X-ray CT scanner comprises an X-ray source generating an X-ray, detector detecting the X-ray transmitted through an object, processor to produce projection data, and reconstruction unit to reconstruct an image using the projection data. The processor produces the projection image by applying, to an output signal from the detector, logarithm conversion processing on a function deviating from an ideal logarithm function. The ideal logarithm function is a logarithm function defined by a mathematical formula of y=K·log [b, x] (wherein a variable x is an input, a variable y is an output, and a reference K shows a scaling constant). The function deviating from the ideal logarithm function has an input/output characteristic deviating from that of the ideal logarithm function. Such deviating function is for example a linear function and applied to a conversion of only low-count data into its projection data to suppress low-count artifacts on reconstructed CT images.

Abstract: The RF coil is an 8-shaped coil applied to a receiving coil, for example, of a so-called vertical field magnetic resonance imaging apparatus, and comprises a central conductor which is wide in a y-axis direction and a return path connected to the central conductor and provided to bypass the central conductor. The central conductor has an magnetic field sensitivity of interest in a y-axis direction orthogonal to a static magnetic field B0 direction (a z-axis direction). Since the return path has no magnetic field sensitivity of interest, the return path is provided to bypass the central conductor in order to prevent the magnetic field of the return path from interfering with the interest magnetic field of the central conductor.

Abstract: A pair of 8-shaped coils vertically sandwiches an object to be examined for providing a magnetic field in the horizontal direction perpendicular to the body axis in the object. A pair of rectangular coils also vertically sandwiches the object for providing a magnetic field in the vertical direction in the object. The pair of 8-shaped coils is connected for detecting a first magnetic resonance signal from the object and the pair of rectangular coils is connected for detecting a second magnetic resonance signal from the object. A phase of one of an output of the pair of 8-shaped coils and an output of the pair of rectangular coils is shifted by 90.degree. and summing a shifted output and the other output. An upper coil assembly of the 8-shaped coil pair and the rectangular coil pair is connected to a lower coil assembly at one end thereof in the lateral direction of the object and is pivotal to be freely opened and closed.

Abstract: Four QD surface coil assemblies each constituted by an 8-shaped coil and a rectangular coil are one-dimensionally arranged under the spine array of a patient in the direction of the body axis of the patient. Each 8-shaped coil senses an RF magnetic field in an x direction near the spine array of the patient, and each rectangular coil senses an RF magnetic field in a y direction. Outputs from the 8-shaped coils and the rectangular coils are input to 90.degree. hybrid combiner circuits through pre-amplifiers, the phase of any one of the outputs is shifted by 90.degree., and then the outputs are added to each other. Outputs from the 90.degree. hybrid combiner circuits are supplied as raw data, through receiver/data acquisition systems, to a data processing unit (computer). In the data processing unit, raw data are two-dimensionally Fourier-transformed to form image signals p.sub.i (x,y,z) (i=1 to 4). The signals p.sub.1 (x,y,z) are squared, the sum of p.sub.

Abstract: In a multiple coil type magnetic resonance imaging system, MR signals can be obtained at high S/N ratio and over a large image region. The magnetic resonance imaging system includes: a plurality of receiving coils for receiving a plurality of MR signals generated from plural portions of an object under medical examination; a plurality of filters coupled to the plural receiving coils, for filtering the plurality of MR signals to obtain a plurality of filtered MR signals; a processor and a filter passband setting circuit for setting passbands of the plurality of filters in such a manner that the plurality of filtered MR signals have preselected frequency bands different from each other; and, an adder for adding the filtered MR signals with each other which are derived from the filters coupled to at least two receiving coils selected from the plurality of receiving coils.

Abstract: In a magnetic resonance imaging apparatus, there are provided plural receiver coils over a portion of a biological body. Data on a coil energizing sequence is previously stored in a memory. An only limited number of receiving coils are sequentially energized based on the coil energizing sequence data.

Abstract: There is provided a rotate-rotate type X-ray computerized tomographic imaging apparatus having a plurality of pairs of mutually facing X-ray sources and multichannel X-ray detectors, wherein a high-resolution scan mode or a high-speed scan mode is selected. The apparatus includes a stationary body, a rotational body arranged rotatably in the stationary body and having an insertion section in which a subject is inserted, a K-number of X-ray sources provided on the rotational body, a K-number of multichannel X-ray detectors movably mounted on the rotational body, data processing means for collecting data from the K-number of multichannel X-ray detectors and for carrying out processing relating to image reconstruction, and control means for performing at least a control of rotation of the rotational body, a control of the data collection, and a control of the processing relating to the data reconstruction.

Abstract: A computed tomography method and system for performing dynamic scans of objects undergoing cyclic displacement, for example a human heart. Characteristic curves are generated from images reconstructed from projection data synchronized with the cyclic displacement of the object. Each image reflects one displacement cycle of the object, and consists of projection data collected, in one case, within a phase window centered on a specified phase of cyclic displacement of the object, and in another case, consists of projection data collected between two specified phases of cyclic displacement.

Abstract: An X-ray CT apparatus, in which a plurality of dynamic tomographic images obtained by repeatedly photographing a region of interest of a subject under examination are stored in an image memory, for subsequent display on a display device. A processing device extracts data of pixels along a certain line common to all of the tomographic images, and stores the pixel data in the image memory, in the order of photographing time of the tomographic images, thus forming a time sequence image formed of picked-up pixels. The processing device reduces a tomographic image and the time sequence image, and rearranges the reduced images in one frame area of the image memory for simultaneous display thereof on the display device.

Abstract: An X-ray CT system includes an X-ray source, a drive device, an X-ray detector, a data acquisition system, a reconstruction processor and a delay circuit. The X-ray source emits an X-ray fan beam onto an object and is rotated by the drive device on substantially the same plane as the fan beam. A graticule sensor detects an angular position of the X-ray source. The X-ray detector consists of detector elements fixed concentrically with a relative rotational path of the X-ray source. The data acquisition system responds to a position signal from the graticule sensor and samples the output data from the detector for each predetermined angular position of the X-ray source to obtain projection data. The projection data is reconstructed by the reconstruction processor to obtain a tomographic image of the object.

Abstract: In a computerized tomographic CT apparatus, X-rays penetrated from a slice of an object are computer-processed so as to reconstruct a tomographic image of the imaginary slice of the object. The CT apparatus is comprised of a table couch for supporting the object to be examined, a table couch drive control circuit for controlling a continuous transportation of the table couch along a longitudinal axis of the object, an X-ray source for irradiating fan-shaped X-rays toward the imaginary slice of the object, a detector array for detecting the fan-shaped X-rays which have penetrated throught the slice of the object. It further comprises a gantry for mounting the X-ray source and the detector array in such a manner that the X-ray source is positioned opposite from the detector array with respect to the slice of the object and for performing a relative movement between the X-ray source and the detector array in a plane which is perpendicular to the longitudinal axis of the object.

Abstract: A radiation measuring device comprising a radiation detector for detecting radiation quantum arriving in the Poisson distribution, a phase height analyzer for analyzing a height of an output signal from the detector to extract signal components at a level within a predetermined level, converter for integrating an output signal from the detector to produce pulses of which the number corresponds to the integrated value, a switch for selecting the output signal from the analyzer when the number of arrival photons is smaller than a predetermined value and for selecting the output signal from the converter when the number of photons is larger than the predetermined value and a counter for counting output pulses of the selected analyzer or counter.