Abstract: A pulse Doppler MTI system for equally displaying movements in any directions within a tomographic plane is characterized by creating a bipolar video signal file in which receive signals for one scan serve as one frame and performing a two-dimensional cross-correlation process on the file data after removing components associated with fixed reflecting points.

Abstract: In an X-ray CT which extracts data corresponding to transmitted data of a parallel beam X-ray from transmitted data of an X-ray acquired based on a fan beam X-ray and carries out reconstruction of an image based on the data, the present invention which removes shower-shaped artifacts generated in a reconstructed image by influences of an instantaneous change in strength of an X-ray is characterized in storing output data of a data acquisition device corresponding to a plurality of views in a buffer memory, forming view data from which the influences of a variation in strength of an X-ray are removed by weighted averaging the data corresponding to a plurality of views stored in the buffer memory, and replacing view data at the time when a variation in strength of an X-ray is present with the view data.

Abstract: The image diagnosis apparatus of the present invention is equipped with means for automatically determining a window level and a window width for image displaying in accordance with the value of reconstructed image data. With this window level/window width calculating means (13), the window level is obtained with respect to each reconstructed image on the basis of the virtual average value of its pixel data and the window width is also obtained which has a certain relationship with that window level. When displaying each reconstructed image, a display is made in accordance with each window level and each window width thus obtained. Instead of the obtained window level and window width, those set by a manual setting section (23) may be used by a changeover operation when necessary.

Abstract: A radiant ray CT for reconstructing an image at a high effective rate, high resolution, and high picture quality with a shortened scan time and thus with less exposure. The apparatus comprises a source of radiant ray, such as an X-ray, and a group of detectors disposed in confronting relation with a reconstructive region for accommodating a body to be examined interposed therebetween, wherein scanning is performed according to spatial and timing controls of the radiant ray generating positions so that each of the radiant ray transmitting paths is interpolated with one another substantially at the center of the reconstructive region between adjacent or neighboring view data groups and between confronting view data groups each corresponding to each of the adjacent or neighboring view groups.

Abstract: A received ultrasonic phase matching circuit of the present invention, which utilizes variable delay lines having short delay times as the structural element of variable focus means having a larger aperture and realizes focusing to the regions from the region near the surface of object and to the deeper region thereof, comprises variable attenuators to be controlled individually and variable delay lines having the equal maximum delay times also to be controlled individually to the respective receiving channels forming the maximum aperture for reception of the ultrasonic echoes to form variable aperture by controlling variable attenuators and distribution of delay times for focusing in the aperture using only the variable delay times belonging to such aperture and add and combine the receiving signals delayed by the variable delay lines in the beam steering means.

Abstract: This new invention provides a display device that displays data in multiple areas of the same screen in discrete ranges of gradation while minimizing increased hardware requirements. To apply our new invention in the most preferred application mode, we utilize an image display device that reads one frame of image data written to a first frame buffer (20) in repetition during the display cycle of the display unit (80). The display device writes image data each time to a write enable area of a second frame buffer (50) as specified by a write control circuit (40) after gradation conversion processing is executed using a gradation converting circuit (30). The image data of the second frame buffer is converted into a video signal by a video signal-generating circuit (70) and is displayed on the display unit (80). By repeatedly setting new gradations and write-enable areas, image data having discrete gradations for individual areas is written to the second frame buffer.

Abstract: A pulse Doppler ultrasonic diagnostic system capable of invariably obtaining best Doppler signals with respect to an arbitrary sample volume length under the condition that mean power of transmit ultrasonic waves is restricted to a constant value. The system has a device for making the mean power constant and a device for making a burst wave number variable for transmit ultrasonic signals and also includes a device for making an integration interval length variable for ultrasonic receiving signals, thereby controlling the burst wave number of the transmit ultrasonic waves and the integration interval length of the ultrasonic receiving signals.

Abstract: A video signal processing apparatus for converting an input analog video signal, including a variable-density image signal and a two-state image signal, into an output analog video signal whose number of scanning lines is increased without degrading the visibility of the two-state image; wherein the input video signal is separated into variable-density image data and two-state image data; then, a portion of the variable-density image data from which the two-state image data is removed, is replaced with a variable-density image data portion immediately before the beginning of the two-state image data; then, the variable-density image data and the two-state image data are stored separately in a memory; then, a general analog-mode enlarge interpolation processing, such as a linear interpolation processing, is performed on the variable-density image data; then, a two-state mode enlarge interpolation processing is performed 10 on the two-state image data; and then, the variable-density image data and the two-state

Abstract: A table mechanism for lifting and lowering a table top through a parallel link mechanism. In the table mechanism of the invention, which does not cause an increase in costs even when an initial position of the table top is set low in spite of having a cover for coversing side surfaces of a parallel link mechanism, there is given a difference of elevation in the fitting position of the parallel link mechanism on the sides of the table top and of the floor in combination with front and rear links.

Abstract: A method for correcting distortion of a reconstructed image caused by non-uniformity of a static magnetic field in an NMR imaging apparatus, wherein the non-uniformity of a three-dimensional static magnetic field is measured, and the measurement data is stored in the form of a matrix having a size smaller than the size of a matrix used in image reconstruction; then, data on a two-dimensional plane, corresponding to a slice plane of the reconstruction image, is taken out from the matrix, and based on that data, a distortion correcting table is produced and is enlarged to agree with the size of the matrix used in image reconstruction, so that distortion of the reconstructed image is corrected using the enlarged distortion correcting table.

Abstract: A CAT (computerized axial tomography) scanner having a lightweight rotary portion. The scanner has slip rings through which electric power is supplied to an x-ray tube. The slip rings do not need any special insulating mechanism. The scanner includes an inverter (3) for converting a line voltage into an AC voltage between the line voltage and a high voltage applied to the x-ray tube. The frequency of the AC voltage is between the frequency of the line voltage and radio frequencies. This AC voltage is supplied via the slip rings to the rotary portion and then stepped up and rectified by step-up tanks (7, 8) on the rotary portion to obtain the high DC voltage applied to the x-ray tube.

Abstract: In an ultrasonic diagnostic apparatus of this invention, the dimension of a sample volume can be adjusted both in the depth and azimuth directions in forming a transmission beam for both a B mode and a Doppler mode with the use of a common beam forming data, and an amount of radiation of the ultrasonic wave to a body to be examined can be reduced. In the B mode operation, transmission and reception of a sharply focusing ultrasonic beam are carried out based upon a B mode beam forming data, while in the Doppler mode, transmission and reception of a predetermined blurringly focusing ultrasonic beam are carried out based upon a beam forming data which is obtained by modifying the B mode beam forming data.

Abstract: A scan controller for an NMR imaging device, wherein the scan controller stores control signal waveforms in a waveform memory; stores control signal amplitudes in an amplitude memory; stores data related to the control signal duration in a time memory; reads the waveform memory by using an address counter which operates based on data read out from the time memory and outputs the waveform memory read out value after conversion to analog. The amplitude of the control signal is multiplied by the waveform of the control signal and converted from digital data to analog so that the resulting amplitude is related to the amplitude of the signal stored in the amplitude memory. In this manner high amplitude resolution is attained and requirement for large scale memory capacity is reduced.

Abstract: A gantry for computerized tomographs that can be freely moved up to or away from a patient on an operating table has been developed. It consists of a gantry main body (1) and mobile trolley section (2) that runs along a guideline formed on the floor with the gantry mounted.

Abstract: To apply our new invention in the most preferred application mode, we used an ultrasonic diagnostic system that can instantaneously switch over to the CW Doppler method or B-mode imaging method when both methods are combined using a commonly applicable array probe. The ultrasonic diagnostic system based on this new invention is configured with the following features:Dividing multiple vibrating elements of a commonly applicable array probe (3) into two groups, (3T) and (3R), andconnecting the first vibrating element group (3T) to the first transmitting driver (2T) to which low voltage is supplied by the power supply (4), and connecting the second vibrating element group (3R) to the second transmitting driver (2R) to which high voltage is supplied by the power supply (4).

Abstract: There is disclosed a magnetic resonance imaging method which permits a scan to be made in a short time by collecting only the data that is used to reconstruct an image. The method is initiated by defining a circular region whose center lies at the point in a two-dimensional Fourier plane at which the spatial frequency is zero. The Fourier plane corresponds to a region containing an image to be reconstructed. The spin echo signals emanating from a region inside the circular region are observed by an ordinary Fourier method, said region having a length greater than a predetermined length as measured in the direction in which data obtained by the observation is read out. The spin echo signals emanating from the remaining region inside the circular region are observed while shortening the time for which a reading gradient magnetic field is applied whenever an excitation is effected and, at the same time, effecting an additional phase shift encoding.

Abstract: An improved selective excitation method applicable to NMR imaging, regardless of the NMR signal generation method used, wherein a non-scanned subject area is excited using an RF signal, then the excited area is spoiled with a gradient magnetic field to create an area that receives no other excitation RF signal for a set period, and then NMR signals are collected from the unspoiled area using a conventional method.

Abstract: An X-ray computerized tomographic device of this invention provides images of good quality based on view-interlacing without complicating gantry rotation and scan data sampling control, and which is characterized by setting N.multidot.M-1 units of sampling points (M and N being positive intergers) around a subject over which a rotary scan is performed continuously M times by skipping the M-1 sampling point.

Abstract: This invention is basically, an ultrasonic transducer that can be configured with good reproducibility, that includes an acoustic impedance matching member that gradually changes the acoustic impedance, and which is characterized byAn acoustic impedance matching member(2) configured with multiple unit layers (21, 22, 23, . . . 2n), each layer being thinner than a quarter-wavelength of an ultrasonic wave, andeach unit layer having a laiminated structure make up of heavy metal(52) and plastic(51) layers with a thickness ratio set between them to change gradually from the unit layer close to the ultrasonic oscillator to the unit layer close to the subject.

Abstract: The present invention provides an apparatus for carrying out tomography which is arranged in such a manner that a radiation source and a multichannel radiation detector are rotated about a subject to be examined, the radiation source disposed so as to generate a fan beam of radiant rays such as X-rays, the multichannel radiation detector having an offset arrangement and disposed in opposition to the radiation source with the subject being interposed therebetween; the fan beam of radiant rays being applied in the direction parallel with a chosen section of the subject; the chosen section of the subject being measured in a plurality of directions parallel therewith so as to obtain data representative of the distribution of the intensity of transmitted radiant beams; and an image of the section of the subject being thereby reconstructed on the basis of data having an array corresponding to the fan beam.