Abstract: In order to construct a radiotherapy apparatus which can irradiate a point in the body of a patient in an optional direction with high accuracy, an accelerated electron beam is controlled electrically by using deflectors so as to irradiate a plurality of radioactive ray generating positions, a collimator is provided so that a radioactive ray generated from the positions can irradiate one point of a portion of the patient's body to be treated, and a gantry can be rotated mechanically.

Abstract: A phase adjustment circuit for use in an ultrasonic apparatus which respectively time-adjusts a plurality of received signals from an ultrasonic transducer array and sets wave fronts of the reflected waves from particular positions into an in-phase state and adds the in-phase signals, thereby obtaining a received beam. The received signals are mixed with phase-controlled reference signals. The low frequency component of the mixed wave is sequentially sampled and stored in a memory which is controlled by a clock signal of a predetermined period, and thereafter, the stored sampled signals are read out. Most of the necessary time adjustment results from the difference between the writing time and the reading time. The remaining micro time adjustment is performed by phase control of the reference signals.

Abstract: In ultrasonotomography, ultrasonic transducers are divided in the scanning direction and in a direction (elevation direction) orthogonal to the scanning direction and by changing the aperture in the elevation direction through focus in elevation direction, a tomogram and a Doppler signal of a blood flow can be obtained and displayed two-dimensionally. Doppler data is obtained by effecting slight angle scan of the ultrasonic beam mechanically or electronically in the elevation direction. Data pieces for the same raster of a plurality of Doppler data pieces obtained through the slight angle scan in the elevation direction are added/averaged or added to improve the S/N ration. By effecting the slight angle scan of the ultrasonic beam in the elevation direction orthogonal to a tomogram plane, a vessel at a position deviant form the tomogram plane can be found.

Abstract: An ultrasonic flow mapping apparatus transmits and reflects waves from sampling points on a two-dimensional cross-section. The waves are detected while transmitting repeatedly ultrasonic pulses. The phase shifts of different reflected waves are calculated, and displayed in color to show a distribution of blood flow velocity. Artifact due to reflected waves from body organs, which remain even by using MTI filters, is detected from phase signals, which have not passed through the MTI filters, and the artifact is removed by lowering display brightness for a sampling point corresponding to a relevant detection output.

Abstract: The present invention includes an ultrasonic diagnostic apparatus for forming differential image data by performing differential operation among topographic image data obtained in time series, an apparatus for giving color codes which designate display colors to differential image data, an apparatus for cumulating a plurality of frames of differential image data, and an apparatus for displaying respective cumulated differential images in colors designated by the color codes in which motion of a moving portion of a patient's body is displayed in colors by superposing a plurality of differential images.

Abstract: An ultrasonic diagnostic apparatus operates such that the ultrasonic beam transmission and reception is made in the same scanning direction twice at intervals shorter than the frame rate. A subtraction operation is performed between line data obtained by the successive transmissions and receptions. A subtraction image is formed by subtraction image data obtained by scanning in a plurality of scanning directions.

Abstract: An image displaying method in an ultrasonic diagnostic apparatus obtains differential image data between first image data and second image data in image data sequentially obtained from an echo signal received by transmitting an ultrasonic wave to a body to be examined. A time difference between a point of time, where the first image data are measured, and another point of time, where the second image data are measured is determined. A synthesized image data capable of displaying simultaneously a differential image and the time difference by combining the differential image data and data representing the time difference is obtained and displayed.

Abstract: A method for correcting phase errors in a nuclear magnetic resonance signal is disclosed, by which central frequencies of NMR signals are measured directly before and directly after or in addition in a course of a normal measurement for obtaining an NMR signal for imaging and an amount of phase error is obtained for each of the NMR signals for imaging by using a difference between the central frequencies and a measurement time for each of the NMR signals for imaging.

Abstract: A method and apparatus for compensating for nonuniformity of a static magnetic field in a MRI system wherein one of X-, Y- and Z-axes of a Cartesian coordinate system is selected as a phase encoding direction, a region of a field of view is selectively excited by applying a high frequency pulse of a predetermined angle to an object under inspection, and an NMR signal is measured by applying a phase encoding gradient magnetic field and a frequency encoding gradient magnetic field after application of the high frequency pulse for a plurality of times while changing the phase encoding gradient magnetic field.

Abstract: A real-time digital radiography system operates to introduce a X-ray image on a real-time basis and process the image for clinical diagnosis. The system provides for additional inputs, for example, clinical information material, which are also subject to digital image conversion. The system is designed to connect several TV cameras to an A/D converter which digitally converts the produced image to digital information, with one of the TV cameras for imaging the output image of an X-ray image intensifier, and the output of the one TV camera is selectively connected to the A/D converter. The output image of the X-ray image intensifier and other output images produced by separate TV cameras are connected to the A/D converter through a switching apparatus, and subsequently the digital output is processed.

Abstract: A projection detecting apparatus for use in a third generation X-ray computer tomography includes an X-ray source and a detector array both mounted on a rotatable gantry for detecting X-ray projections of an object under inspection sequentially at a plurality of angles of the gantry, respectively. The detector array is formed by disposing consecutively a plurality of detector element blocks each constituted by a photodiode array and a scintillator array laminated together. The element blocks are so disposed as to be asymmetric to the center line of a fan-like radiation beam which line extends through the position of the X-ray source and the center of rotation of the gantry.

Abstract: Method and apparatus of stabilizing uniformity of a static magnetic field in a magnetic resonance imaging apparatus, wherein before adjustment of uniformity of the static magnetic field and before each actual imaging operation, pulse-like gradient magnetic fields are applied to a static magnetic field generating magnetic circuit at a maximum output level of power supplies for generation of gradient magnetic fields so as to magnetize the static magnetic field generating magnetic circuit to constant magnetization intensity.

Abstract: Disclosed is an automated image gray level transformation system applied to a medical image processing work station for the purpose of dispensing with the prior art manual complex processing thereby improving the accuracy of diagnosis. The system carries out, in addition to its fundamental step of equalizing a histogram of image data of an input image, the steps of suppressing an adverse effect of a background region of the image so as to obtaining an intensity transformation function, constraining the intensity transformation function and modifying a bias value used for the function constraining.

Abstract: A delay circuit of ultrasonic diagnostic apparatus comprising a delay line consisting of a plurality of unit portions connected in cascade, in each of which an anode of a first variable capacitance diode and a cathode of a second variable capacitance diode are connected with a connecting point of two inductors connected in series, or a delay line obtained by replacing capacitances in a second order all pass type delay line by variable capacitance diodes, or a delay line, in which variable capacitance diodes and inductors form a balanced circuit; and control circuit for applying a reverse bias voltage to each of the variable capacitance diodes; and an amplifier or a variable resistance circuit using FETs serving as a matching circuit for the delay line, capable of varying continuously an input impedance by using a control voltage from the exterior.

Abstract: An image input apparatus including a camera tube having a photoconductive layer onto which an optical image is to be projected, a cathode for emitting an electron beam for scanning the photoconductive layer, a control electrode for controlling a beam current of the electron beam emitted from the cathode in accordance with a control voltage, and a mesh electrode having a frame, the apparatus further including a deflecting circuit for periodically deflecting the electron beam to scan the photoconductive layer. The deflecting circuit periodically deflects the electron beam to scan an area outside a restricted scanning area determined by the frame of the mesh electrode.

Abstract: In one aspect of correcting phase distortion in an MR imaging system at high speed and with high precision, partial regions having any shapes are established on a complex image reconstruction, linear phase distortion is estimated for every partial region and the phase distortion of the whole image is corrected by use of the estimated phase distortion. In another aspect, a plurality of phase distortion patterns are measured in advance through phantom imaging and stored. The phase distortion pattern is invariable and hence it is not necessary to perform the measurement for each impage processed. Phase distortion included in data acquired through imaging is corrected by representing it as a summation of the plurality of phase distortion patterns with weighting factors.

Abstract: A flow meter for detecting a flow speed in such a manner that an ultrasonic pulsed continuous wave is repeatedly transmitted toward an object at predetermined intervals T, a phase vector indicative of the phase of a reception signal due to the reflected wave is produced at the predetermined intervals, the phase difference between the present phase vector and the preceding phase vector is detected, and a Doppler frequency is calculated from the average value of a plurality of phase difference values to obtain the speed of the object.

Abstract: A radiation detection circuit integrates output currents of a plurality of X-ray CT scanner radiation detectors, which are combinations of scintillators and photodiodes, during a short period to convert them to charge information in order to collect data for reproducing a tomogram. A current amplifier is connected to the output terminal of the photo-diode, and an output current of the current amplifier is charged in an integration capacitor. In this manner, the radiation detection circuit enables reduction of the measurement period.

Abstract: A flow meter for detecting the average speed of an object in such a manner that an ultrasonic pulsed continuous wave is repeatedly transmitted toward the object to obtain a phase vector from the reception signal of the wave reflected from the object, the phase difference between consecutive ones of phase vectors obtained at an interval T equal to the period of transmitted wave is detected, a plurality of phase difference values are added and averaged to obtain an average phase difference value, and a Doppler frequency is calculated from the average phase difference value to obtain the average speed of the object, in which in order to remove an error caused by aliasing of an angle in the course of the arithmetic operation for obtaining the average phase difference value, a plurality of presumed average phase difference values having the error are calculated from the average phase difference value, the difference between the change of a phase caused by adding the phase difference values successively and the cha

Abstract: In an imaging apparatus using the nuclear magnetic resonance, a solenoid coil and a slot-resonator coil are combined with each other so as to constitute a quadrature-phase detection probe. In order to operate the slot-resonator coil at low frequency, inductance is added to the slot-resonator coil. Further in order to cut the coupling between a transmitting coil and a receiving coil in a cross coil system, a capacitor together with the added inductance to form a resonant circuit is connected in parallel to the inductance. A favorable probe can be obtained in a vertical-magnetic field type imaging apparatus.