Digital radiographic system and method for adjusting such system

Patent · Tue Sep 25 00:00:00 EDT 1984

OSTI ID:5974027

Bishop, M D; Lucchesi, O J

An X-ray detector receives X-ray radiation from an object under examination and generates a detector image thereof. An image intensifier including a screen enhances the detector image and generates an image intensifier image which emits light. A video camera views the image intensifier image and generates a video signal comprised of frames of digital data. These data describe the signal levels of the image intensifier image. A display device connected to the camera receives the video signal and displays an image in accordance with the distribution of X-ray radiation. An iris is arranged between the image intensifier and the video camera. The iris has an aperture of variable size for controlling the intensity of light transmitted from the image intensifier to the video camera. A control circuit is provided for controlling the aperture of the iris. This control circuit comprises a first storage device receiving the video signal and storing digital data corresponding to one of the frames, a threshold device for determining the maximum signal level of the digital data contained in the stored frame, a second storage device sorting information about parameter values indicative of a plurality of aperture sizes and about maximum image signal levels corresponding to these sizes (''look-up'' table), a device evaluating from the maximum signal level and from the information stored in the second storage device a desired parameter indicative of a desired size of the aperture, and a device for setting the actual size of the aperture, whereby the setting device is responsive to the desired parameter evaluated by the evaluating device.

• Assignee: Siemens Gammasonics Inc.
• Patent Number(s): US 4473843
• OSTI ID: 5974027
• Resource Relation: Patent File Date: Filed date 20 Jul 1982; Other Information: PAT-APPL-400053
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
BIOMEDICAL RADIOGRAPHY
RADIATION DETECTORS
X-RAY RADIOGRAPHY
CAMERAS
CONTROL
DIGITAL SYSTEMS
DISPLAY DEVICES
IMAGE PROCESSING
IMAGE TUBES
RADIATION DOSES
X RADIATION
DIAGNOSTIC TECHNIQUES
DOSES
ELECTROMAGNETIC RADIATION
INDUSTRIAL RADIOGRAPHY
IONIZING RADIATIONS
MEASURING INSTRUMENTS
MEDICINE
NUCLEAR MEDICINE
PROCESSING
RADIATIONS
RADIOLOGY
550602* - Medicine- External Radiation in Diagnostics- (1980-)