Hitachi Medical Corporation

Hitachi, Ltd.

Nippon Telegraph and Telephone Public Corporation

Hitachi, Ltd. , Hitachi Medical Corporation

Hisatake Yokouchi

Yoichi Onodera

Fumitaka Takahashi

Ken Ueda

Keiji Umetani

Masayuki Tsuneoka

Ryuichi Suzuki

Koichi Koike

Rika Baba

Mitsuru Ikeda

Hideyuki Horiuchi

Shinji Yamamoto

Akihide Hashizume

Kouichi Koike

Takakazu Funo

Tetsuhiko Takahashi

Tadaaki Hirai

Yukio Takasaki

Masahide Okumura

Masanori Maruyama

Kenichi Okajima

Susumu Ozasa

Yasuo Kato

Saburo Ataka

Tadahito Matsuda

Hideyuki Sakai

Tsuyoshi Kano

Kenji Umetani

Akiho Takahashi

Sadao Takahshi

Tomoharu Kajiyama

Shigekazu Hara

Takakazu Huno

A digital radiography system having an X-ray source irradiating an object to be inspected with X-ray, an X-ray image intensifier tube which receives the X-rays which pass through the object and converts the received X-rays into an optical image, a video camera which picks up the output image and has different modes, an optical system including a plurality of lenses and disposed between the X-ray image intensifier tube and the video camera, an image processor which converts an output from the video camera into a digital image data, and an image display for displaying an X-ray image by reading out the digital image data from the image processor.

Digital radiography system having an X-ray image intensifier tube

A digital radiography system obtaining x-ray images of a patient body through an X-ray image intensifier tube and a video camera optically coupled with the X-ray image intensifier tube. The diameter of an input imaged size of the X-ray image intensifier tube is ranged from 254 to 457 mm, the diameter of an output image size of the X-ray image intensifier tube is ranged from 50 to 90 mm, and the ratio of the diameter of the output image size against the diameter of the input image size is ranged from 4 to 8.

A digital radiography system obtaining X-ray images of a patient body through an X-ray image intensifier tube and a video camera optically coupled with the X-ray image intensifier tube. The diameter of an input imaged size of the X-ray image intensifier tube is ranged from 254 to 457 mm, the diameter of an output image size of the X-ray image intensifier tube is ranged from 50 to 90 mm, and the ratio of the diameter of the output image size against the diameter of the input image size is ranged from 4 to 8.

In order to image an object larger than a field of view for observation, imaging is effected by dividing it into several times and pictures thus imaged are synthesized to constitute a whole image. In order to image several times, only a detecting unit is moved and an X-ray source is substantially fixed with respect to the object. Images thus obtained include a common part of the object and are joined so that the common part are overlapped on each other. In case where an image pick-up tube is included in the detecting unit, the image pick-up tube is made operable, after a period of time necessary for attenuation of microphonic noise has lapsed, measured from a point of time where the detecting unit has been stopped.

X-ray imaging system and method therefor

A radiologic three-dimensional imaging apparatus comprises a device for generating an X-ray, a two-dimensional X-ray image detector including an avalanche multiplication image pickup tube for detecting an image of an object with the X-ray transmitted therethrough, a device for producing an average intensity distribution from a plurality of intensity distributions of the X-ray transmitted image, and a device for setting the target voltage applied to the photoconductive layer of the avalanche multiplication image pickup tube for each electron beam scanning position in such a manner the target voltage is high at the central portion of the visual field of the object and low at the peripheral portion thereof.

Method and apparatus for producing radiologic three-dimensional image

An X-ray radiography method and apparatus in which a phantom such as a chart having elements arranged in predetermined positions is irradiated with X-rays and an X-rays detection unit detects signals thereof. An image of the chart is obtained and a center position of each of the elements in the image of the chart is obtained as well as for those elements which are not within the imaging field of view. Pixel positions for a distortion free image is obtained and a transform table is prepared making each of the pixel positions in the image of the chart correspond to each of the pixel positions in the distortion free image. A plurality of digital images of a subject to be examined are obtained and the digital images are corrected in accordance with the transform table. The corrected digital images are then joined together and a digital image is displayed, wherein common portions in the corrected images are in accordance with each other.

X-ray radiography method and system

A digital X-ray imaging system having an X-ray generator, an X-ray generator controller for controlling the X-ray generator, an X-ray detecting unit for detecting an X-ray transmitted through a subject, the X-ray detecting unit having an X-ray grid for shielding a scattered X-ray, a signal processor for acquiring a signal from the X-ray detecting unit and processing the signal to obtain a digital X-ray image of the subject, and a display device for displaying an image of the subject obtained by the signal processor. The system is provided with a position changing unit for changing a relative position between the X-ray detecting unit and the subject, a position change controller for controlling the position changing unit, and an imaging-sequence controller for controlling the position change controller and the X-ray generator controller. The imaging controller controls setting of each of a plurality of target imaging regions of the subject to generally a central area of an X-ray detecting plane of the X-ray detector, the X-ray detecting plane being an incident plane of the transmitted X-ray, and to set at least one imaging view field to contain an intermediate region between target imaging regions. The whole or part of a plurality of obtained digital X-ray images is used to join a single or a plurality of digital X-ray images for display.

Digital x-ray imaging system and method

An X-ray TV camera apparatus having a function to switch a visual field of an X-ray image, comprising an X-ray generating apparatus, an image intensifier for converting X-ray information by an X-ray which was generated from the X-ray generating apparatus and passed through an object to be examined into an optical image, a TV camera for converting the optical image from the image intensifier into the video signal, a switch to switch the visual field of the X-ray image on the image intensifier, and a correcting circuit to shading correct the video signal so that the video signal from the TV camera gives a uniform image in accordance with the visual field switched by the switch.

X-ray TV camera having function to switch a visual field of X-ray image

An X-ray imaging apparatus is constructed with a combination of an X-ray image intensifier, a relay optical system, and a video camera with avalanche multiplication camera tube. The video camera is controlled by an image acquisition circuit, a synchronizing signal generation circuit, and an applying voltage control circuit. The applying voltage control circuit for controlling the voltage to be applied to the video camera with avalanche multiplication camera tube controls the applying voltage on the basis of image data in an image memory so that the gray scale level of a detected visible image is corrected.

Apparatus and method for radiation imaging

An X-ray fluorograph and radiograph apparatus including an X-ray television camera having an avalanche multiplication operation type image pick-up tube having an input/output characteristic in which increment of an output reduces gradually against increase of dose of incident X-rays and a unit for setting X-ray latitude and a multiplication factor of an image pick-up tube to optimum values for inputted radiograph conditions by controlling a voltage value applied to the image pick-up tube and a value of a stop of an optical system, and making it possible to obtain X-ray latitude at 1,000 or more.

X-ray fluorograph and radiograph apparatus for obtaining X-ray image

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.

Real-time digital radiography system

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. A beam current control circuit is further added, if necessary, for generating a control voltage and applying the control voltage to the control electrode to control the beam current of the electron beam such that the electron beam does not collide with the frame of the mesh electrode during a period in which the electron beam scans the area outside the restricted scanning area.

Image input apparatus

An X-ray television apparatus applies an X-ray to an object to be inspected, converts the X-ray projection image of the object into an optical image by a fluorescent screen or an X-ray image intensifier, picks up the optical image by a TV camera, displays the video signal obtained by a TV monitor for fluoroscopic monitoring, and records radiograph of the object by using the video signal. Avalanche multiplication is caused on the photoconductive layer of the image pick-up tube of the TV camera so as to enable monitoring or imaging with high sensitivity at a low X-ray dose rate.

X-ray television apparatus

In a real-time digital radiographic apparatus, an image is picked up by means of a TV camera. In a fluoroscopic monitoring mode, an output of the TV camera is displayed on a display in real time. In a radiographic imaging mode, the output of the TV camera is A/D converted, subjected to a necessary image processing and held as image data for diagnosis. In the fluoroscopic monitoring mode, a beam scanning for an image pickup tube corresponding to an NTSC system is performed whereas in the radiographic imaging mode a high-density and low-speed beam scanning can be selected in which the number of scanning lines is increased and the frame rate is lowered. In order to suppressing the lowering of the maximum signal current derivable from the image pickup tube which may occur in such a high-resolution scanning, a target voltage of the image pickup tube in a high-resolution mode is changed to a value higher than a standard value of the target voltage, thereby acquiring an image which has a wide dynamic range and a high S/N ratio.

Multiple-mode scanning and beam current control x-ray TV apparatus

In an image input device, in which an image is photographed by a television camera using a plurality of operational modes having numbers of scanning lines different from each other, a video signal thus obtained is subjected to an analogue to digital conversion and a digital image signal is stored, one of a plurality of sampling clocks obtained by dividing a main clock is selected; the analogue to digital conversion is effected by using the sampling clock thus selected; and at the same time synchronization signals of the horizontal and the vertical scannings of the television camera are formed by counting the selected sampling clock.

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Tokyo, Japan

Hisatake Yokouchi