SU519887A1 - Gamma ray beam pointing device at the irradiated area - Google Patents

Description

The ionizing radiation converter 5 is positioned so that its center is always located on the main ontic axis of the operating (switched on) gamma radiation source 1. In this case (by irradiating with a vertical beam), the task of pointing is to locate the target of object pickup just above the center of the transducer 5 (see Fig. 1). The X-ray tube 2 is at the point from which it is intended to conduct irradiation (eg, extreme upper position). The irradiation object 8 is positioned so that the area of the intended irradiation is approximately above the center of the converter. An x-ray pulse with a duration of several tens of milliseconds shines through the object. The video signal received at the output of converter 5 enters the input of block 3 for recording and replaying image frames, is stored there and is continuously reproduced on the screen of video control device 6. For what purpose, from the output of block 3, the video signal is sent to block 4 combining images and from its output without the changes are fed to the input of the video monitoring device 6, on the screen of which the X-ray television image of the irradiated object 8 is continuously reproduced. The center of the screen corresponds to the center of the transducer. If the irradiation target visible on the screen is not in the center, the value and direction of the required displacement of the object table 7 with the object 8 is determined on the screen grid, this movement is performed and, if necessary, the irradiation direction and the position of the object 8 are changed The irradiation of the object is then repeated with the following x-ray impulse, making a control x-ray television image.

At the second stage, the source / gamma radiation is moved to the working site (see Fig. 2) and the shutter is opened. Video signal

from the output of the converter 5, carrying information about the position, shape and size of the gamma-ray beam, is fed to the input of the image registration unit 4.

This unit lowers (raises) the video signal read from the recording-reproducing unit 3 to the black (white) level in accordance with changes in the video signal output from the converter 5. The combined video signal is fed to the input of the video monitor 6. The corresponding image on the screen of this device has view of a television radiograph with a beam contour marked on it

gamma quanta. If necessary, adjust the shape and size of the beam.

Formula of the invention

A gamma-ray beam pointing device at the irradiated area containing gamma and X-ray sources, an ionizing radiation intensity converter into a video signal, a video monitoring device and a movable subject table, characterized in that, in order to reduce the X-ray dose absorbed by an object in the targeting process, and improve the hovering accuracy, the device contains a pulsed x-ray

a tube, an X-ray image recording-reproducing unit, and an X-ray image combining unit with an image of a projection path of a gamma-quanta beam, with the inputs of the playback recording unit

and the X-ray image registration unit with the image of the projection path of the gamma-ray beam is connected to the output of the ionizing radiation converter into the video signal, the output of the recording-reproducing unit is connected to the second input of the image-matching unit, the output of which is connected to the video monitoring device.

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