JPH01211900A - Automatic x-ray exposing device - Google Patents

Abstract

PURPOSE:To obtain an X-ray photograph image with the desired concentration by pairing the initial position of a photographing bed and the position when the interested region is specified, storing them in a memory, detecting the moved position whenever the photographing bed is moved, calculating this position and the position read out from the memory, and correcting the position of the interested region based on the calculated value. CONSTITUTION:X-rays from an X-ray tube 1 permeating an object to be photographed 2 are fed to an image intensifier 5, the generated visible output light is inputted to an image pickup tube 9 via a spectroscope 6 and displayed on a TV monitor 10. On the other hand, the output light separated by the spectroscope 6 is image-formed on multiple detectors 8 via a lens 7, their outputs are inputted to detector selector 16, the position signal detected by a touch sensor 11 is inputted to the selector 16. The position signal detected by the sensor 11 is stored in a memory 13, the position signal read out from it is also inputted to the selector 16. The position signal in the related region is calculated in the selector 16, the displacement of the X-ray tube 1 is corrected and the concentration of X-rays is controlled based on it.

Description

[Detailed description of the invention] [Industrial application field] INDUSTRIAL APPLICATION This invention is utilized in the field of X-ray photography.

The present invention relates to an X-ray automatic exposure apparatus, and more particularly to an X-ray automatic exposure apparatus for automatically controlling film density to an appropriate value during medical diagnostic X-ray photography.

[Conventional technology] Multiple X-ray detectors are placed in the X-ray irradiation field, the amount of X-rays incident on the region of interest is monitored, and when the amount of X-rays reaches a specified level, X-ray radiation is stopped. The film is blocked to obtain the appropriate film density.

[Problem B to be Solved by the Invention] In diagnosis using an X-ray TV apparatus, an imaging table is used to move a subject to a body position suitable for diagnosing a region of interest and perform imaging. Therefore, even if you select the X-ray detector placed in the region of interest before imaging, as you move the imaging table and change the patient's body position, the positional relationship between the region of interest and the X-ray detector will change. As a result, the amount of X-rays incident on the region of interest may not be monitored correctly, and a photograph with the desired density may not be obtained.

An object of the present invention is to specify a region of interest of a subject and, after selecting an X-ray detector for monitoring the amount of incident X-rays to that region, detect the positional relationship between this X-ray detector and the designated region of interest. An object of the present invention is to provide an X-ray automatic exposure device that can automatically correct an initially designated region of interest even if the region of interest deviates, and can correctly monitor the amount of X-rays incident on an X-ray detector.

[X! ! [Means for Solving the Problem] The above object is to separate the output light of an X-ray image intensifier and form an image using a lens, and a plurality of detectors disposed on the imaging plane, An image position detecting means for specifying a region of interest on a TV monitor screen that displays a TV image obtained through an image pickup tube and outputting a position signal thereof; and a position detecting means disposed on a photographing stand. A memory of the initial position signal of the imaging platform detected by the position detection means when specifying the region of interest on the screen, and when the imaging platform moves after specifying the region of interest, the detection value of the position detection means due to the movement and the read value of the memory are moved. means for calculating the corrected image position of the region of interest; detector selection means for selecting a detector corresponding to the detected or corrected image position from a plurality of detectors; and output of the selected detector as an X-ray dose. This is achieved by providing a phototimer circuit that operates by capturing the data.

[Function] The initial position of the imaging platform and the position at the time of specifying the region of interest are made to correspond, the initial position of the imaging platform and the position of the region of interest are stored in memory, and each time the imaging platform is moved thereafter,
The moving position of the photographing table is detected, and the position of the region of interest corresponding to the mobile photographing table is determined by calculation using the initial position of the photographing table and the position of the region of interest read from the memory, and the position of the region of interest is determined according to the calculated value. Corrected.

[Example] A preferred embodiment of the invention will be explained based on the drawings.

FIG. 1 is a configuration block diagram showing one embodiment thereof.

The X-rays that have passed through the subject 2 during fluoroscopy are incident on the image intensifier (1, 1,) 5, and the visible output light is input to the image pickup tube 9 via the spectroscope 6, and is then displayed on the TV monitor 10.
It is displayed as a perspective image above.

On the other hand, the 1 and 1.5 output lights separated by the spectrometer 6 are imaged by the lens 7. A plurality of light receiving elements or detectors 8 are arranged in a plane on this imaging plane.

A touch sensor, a mouse, etc. 11 is provided in front of the screen of the TV monitor 10, and by touching a region of interest on the TV screen, the touched position is input to the CPtJ 14 via the position detector 12, and the touched position is input to the memory 13. to be memorized.

This CPU receives the position signal output from the potentiometer 4 connected to the photographing stand 3 through the interface 1.
It is input via 5.

The CPU 14 receives the output from the position detector 12 and the memory 13.
The region of interest is determined from the position signal of the region of interest on the TV screen stored in the TV screen, the position signal of the imaging stage output from the interface 15, and the position information of the imaging stage when specifying the region of interest stored in the memory 13. The position of the detector located at is calculated, and a detector selection signal corresponding to the position is output to the detector selector 16. The output signal from the detector group 8 arranged on the imaging plane is input to the detector selector 16 . The detector selector 16 outputs to the switch 17 a signal from a detector placed at a position determined by the CPU 14 among the output signals from the detector 8 .

- The switch I7 is a switch that outputs the output signal of the X-ray detector 8 to the phototimer circuit 18 when the imaging state signal is output from the X-ray controller 19. The phototimer circuit 18 outputs an X-ray cutoff signal to the X-ray 'II4 controller 19 when the output signal from the X-ray detector 8 reaches a desired value.

FIG. 2 is a flowchart 1 showing an algorithm for an example of position correction according to the present invention.

When the region of interest (Xo, Yo) on the TV screen is designated, the CPU 14 stores the position of the region of interest in the memory 13;
The position of the imaging platform (xo Sy o ) is read from the potentiometer 4 and recorded in the memory 13 as an offset.

The CPLJ14 constantly compares this offset value with the output value of the potentiometer during fluoroscopy, and calculates the difference between the regions of interest (
Xo % Yo ) is determined as the amount of deviation from the detector 8. The CPU 14 outputs a new signal for selecting the detector placed at this shifted position, so that the amount of X-rays incident on the region of interest can be constantly monitored by the detector.

FIG. 3 is an exemplary view of the screen before and after the photographing stand is moved.

[Effect] During fluoroscopy, even if the X-rays incident on the region of interest shift due to a change in the subject's body position and cannot be monitored by the pre-specified X-ray detector, the X-rays are automatically placed at the shifted position. X
A ray detector is selected to monitor incident x-rays on the region of interest. Therefore, an X-ray photographic image with a desired density can be obtained without worrying about the positional relationship between the region of interest and the X-ray detector during the surgery.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the main components of an embodiment of the present invention, Fig. 2 is a flowchart showing an example of an algorithm for correcting the position of the region of interest and selecting a detector, and Fig. 3 shows before and after moving the imaging platform. It is a screen example figure. 3 is a photographing stand, 4 is a potentiometer, 8 is a detector, 10
is a TV monitor, 12 is a position detector, 13 is a memory, 14
is a CPU, and 16 is a detector selector. Patent applicant: Shimadzu Corporation

Claims (1)

[Claims] 1. The output light of the X-ray image intensifier is divided into two parts, and an image is formed by a lens. A plurality of detectors are placed on the imaging plane, and the output light is passed through an image pickup tube to produce a TV image. An image position detecting means for specifying a region of interest on the monitor screen of a TV monitor to be displayed and outputting a position signal thereof; a position detecting means disposed on the photographing stand; and a position detecting means for specifying the region of interest on the screen. The image position of the region of interest corrected for movement is calculated from the memory of the detected initial position signal of the imaging platform, and when the imaging platform moves after specifying the region of interest, the detected value of the position detection means due to the movement and the read value of the memory. a detector selection means for selecting a detector corresponding to the detected or corrected image position from a plurality of detectors; and a phototimer circuit that operates by taking in the output of the selected detector as an X-ray dose. An automatic X-ray exposure device characterized by: