SU466842A1 - Gammatomograf - Google Patents

Description

one

The invention relates to medical technology and is used to study human internal organs using radioisotopes.

Gammatomographs containing the detector portion of an amplitude analyzer, a photographic recording system, a scanner, a scanning mechanism, a buffer memory, and a clock generator are known. However, such devices do not provide accuracy in the detection of pathological foci.

In order to increase the accuracy of detecting pathological foci by registering the distribution of radioactive radiation in given planes of the studied organ, a synchronous generator is installed in the device, made in the form of a master oscillator, an intermediate register and polling and control descriptors, and the polling decoder is connected to a buffer memory, and control decoders with an image scanner. A set of scintillation sensors is made with non-parallel central axes.

In addition, the buffer memory device can be performed on bistable elements according to the number of scintillation sensors, and the number of switched-on electron-beam tubes of the recording unit can be compared with the number of studied planes.

The drawing shows a functional diagram of the proposed gammatomograf.

The device contains a series of detector units 1, made in the form of a set of scintillation sensors 2, 3, 4 and 5, a series of amplitude analyzers 6, 7, 8

and 9 according to the number of sensors, a buffer memory 10, a registration unit 11, including electro-radiation tubes 12 and 13, an image scanning unit 14 of the cathode-ray tubes, and a scanning mechanism 15 of the detector unit 1, a synchronous generator 16, made in the form of a master oscillator 17, an intermediate register 18, the interrogator 19 of the interrogation, the decoder 20 of the control is coordinated and the decoder 21 is controlled in the Y coordinate of the block 11 of the register. The polling decoder 19 is connected to the buffer storage device 10, and the decoder 20 and 21 controls to the image scanning unit 14. The set of sensors of sensors is made with non-parallel central axes. The buffer memory 10 is arranged on the bistable elements 22, 23, 24, 25 by the number of scintillation sensors. The number of included electron-beam tubes of the registration unit is equal to the number of studied planes.

The device works as follows.

When block 1 of detectors and a right-angle raster over a patient's body under study is transferred, the necessary amount of radioactive iairata is injected, scintillation sensors 2, 3, 4, 5 register gamma rays in the form of electrical pulses entering the corresponding amplitude analyzers 6, 7, 8, 9 where pulses are produced that correspond to the photopeak region of the energy spectrum of a given radioisotope.

The output pulses of the amplitude analyzers are stored by the bistable elements 22, 23, 24, 25 of the buffer storage device, and the pulses are read by sequential polling of the bistable elements by the signals of the decoder 19. Thereafter, the pulses are fed to the imager 26, where they are summed, normalized and their duration, amplitude and delay. time, after which they are applied to the control electrodes 27, 28, producing illumination of the screens of the electron-beam tubes at certain points. The duration of the pulses at the output of the imager is half the period of the frequency of the master oscillator 17, and the time delay is a quarter of the neorode of the same frequency from the beginning of the reading of the pulses from the bistable elements 22, 23, 24, 25.

The synchronization of the decoders 19, 20, 21 is carried out by means of an intermediate register 18 controlled by pulses of the master oscillator 17.

The signals produced by the sweep unit 14 are stepwise varying voltages, with the duration of the step being equal to the frequency of the reference drive,. nerator, and the number of steps is - + i, where

N is the number of sensors 2, 3, 4, 5.

The output signals of the scanner unit 14 are fed to the deflecting plates 29, 30, 31, 32 of the electron-beam tubes, and the deflecting plates 33, 34, 35, 36 are fed to the signals generated by the scanning mechanism 15 and representing linearly varying voltages proportional to the current coordinates of the position of the detector 1 block as it moves along a rectangular raster.

As a result of the total action of the voltages on the deflecting plates, the electron beam moves across the screens of the cathode ray tubes synchronously with sensors 2, 3, 4, 5 along a predetermined raster, and the amplitudes of the steps of the output voltages of the scanning unit 14 are such that the allowed flash points on the screens of the electron beam tubes They are located in geometrical similarity with the points of intersection of the axes of the sensors 2, 3, 4, 5 with the marked planes in the patient's examined organ.

Through the lens 37, light points on the screens of the electron beam tubes are projected onto the film 38, on which images of the distribution of radioactivity in the distinguished planes — gammatomograms — are formed.

Thus, as a result of a single scan cycle of patientitis, several gammatomograms are obtained. In this case, if in one of the planes to be selected there is, for example, a “hot focus, then on the gammatomogram, relating to this plane, it will be depicted as a single section with a significant optical slope of the black film 38, and on all other gammatomograms, this hot spot will be depicted in the form of several sections (by the number of sensors 2, 3, 4, 5) with optical density blackened several times smaller (in accordance with the number of sensors).

The proposed gammatomograph allows to increase the accuracy and efficiency of detection of pathological foci.

Subject invention

Claims (2)

1. A gammatomograph, including successively included detector unit, made up of a set of scintillation sensors, a number of amplitude analyzers by the number of sensors, a buffer memory, a registration unit, including electron beam tubes, a scanner image of the electron beam tubes, and a detector unit scanning mechanism, characterized in that, in order to increase the accuracy of detection of pathological foci by recording the distribution of radioactive radiation in given planes of research of the organ, a synchro generator is installed in the form of a master oscillator, an intermediate register and the deferrer of the oiros and control of the coordinate axis of the registration unit, the decoder of the poll with a buffer bothering device, the control decoders with the scanner of the image, and a set of scintillation sensors made with non-parallel to each other central axes. 2. The gammatomograph according to claim 1, characterized in that the buffer memory in it is made on bistable elements by scintillation sensors, and the number of switched-on electron-beam tubes of the recording unit is equal to the number of studied planes.