JPH08131432A - X-ray radiographing device - Google Patents

Abstract

PURPOSE: To provide an X-ray radiographing device extremely effective for blood vessel radiographing. CONSTITUTION: This X-ray radiographing device is equipped with an image intensifier 3 which image-forms an X-ray image obtained by transmitting an X-ray from an X-ray tube system 1 arranged oppositely holding a patient 2 there between, and a moving mechanism 10 which relatively moves a placing board 9 on which the patient is placed to the image intensifier 3. Also. it is equipped with a speed varying means 13 capable of setting moving speed when the relative movement of the placing board 9 to the image intensifier 3 is performed arbitrarily, and a monitor means 7 which monitors an image obtained from the image intensifier 3 by the operation of the speed varying means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray imaging apparatus,
In particular, an X-ray imaging apparatus provided with an image intensifier that forms an X-ray image obtained by transmitting X-rays from X-ray tubes arranged opposite to each other with the subject in between. Regarding

[0002]

2. Description of the Related Art An X-ray radiographing apparatus having such a structure is used for diagnosing the blood vessel, for example, by X-raying a subject into which a contrast medium is injected. ing.

In such imaging, the effective irradiation range of X-rays is limited, and blood vessels extending in the body axis direction of the subject are sequentially imaged along with the flow of the contrast medium. The mounting table on which the subject is mounted is movable relative to the image intensifier.

In this case, for example, the mounting table is moved at a preset speed, but no consideration has been given to freely changing the speed during the movement.

[0005]

However, in the X-ray imaging apparatus configured as described above, for example, when the moving speed of the mounting table is set, the flow rate of the contrast medium injected into the blood vessel is taken into consideration. However, if the setting is incorrect, the mounting table will move without following the flow of the contrast agent.

That is, the image intensifier often captures an X-ray image in a state where it cannot follow the flow of the contrast medium, and therefore its imaging is often not qualified.

The present invention has been made under such circumstances, and an object of the present invention is to provide an X-ray imaging apparatus which is extremely effective for angiography without causing the above-mentioned adverse effects. Especially.

Another object of the present invention is X which is extremely effective for angiography of a so-called subtraction image.
An object is to provide a radiographic apparatus.

[0009]

To briefly explain the summary of typical inventions among the inventions disclosed in this application, they are as follows.

Means 1. An image intensifier that forms an X-ray image obtained by transmitting X-rays from an X-ray tube, which is arranged to face the subject with the subject in between, and a mounting table on which the subject is placed. In the X-ray imaging apparatus provided with a moving mechanism for relatively moving the image intensifier with respect to the image intensifier, the moving speed of the relative movement of the mounting table with respect to the image intensifier can be arbitrarily set during the movement. The present invention is characterized by including speed changing means and monitor means for monitoring an image obtained from the image intensifier when the mounting table is moved.

Means 2. An image intensifier that forms an X-ray image obtained by transmitting X-rays from an X-ray tube, which is arranged to face the subject with the subject in between, and a mounting table on which the subject is placed. In the X-ray imaging apparatus including a moving mechanism that relatively moves the image intensifier with respect to the image intensifier, the moving speed of the relative movement of the mounting table with respect to the image intensifier can be arbitrarily set during the movement. A speed varying means, a storing means for storing a temporal change of relative movement of the mounting table with respect to the image intensifier by the operation of the speed varying means, and an image display of the mounting table based on the information stored in the storing means. A subtraction image is created from the movement reproducing means that reproduces the relative movement with respect to the tensioner, and the respective images of each movement of the mounting table described above. It is characterized in that it comprises a stage, a.

[0012]

According to the configuration described in the above means 1, first, the image obtained from the image intensifier can be monitored by the monitor means when the mounting table is moved.

That is, the flow of the contrast medium injected into the blood vessel can be recognized through this monitor means.

Therefore, if the speed of the relative movement of the mounting table with respect to the image intensifier is changed by the operation of the speed changing means while checking the flow of the contrast agent by the monitor means, the flow of the contrast agent can be followed. You will be able to shoot.

Therefore, it is possible to take a proper blood vessel image.

Further, according to the configuration of the means 2, even if the speed arbitrarily changes during the relative movement of the mounting table with respect to the image intensifier, the speed change with respect to time is stored, and the memory stores the change. Based on this, it becomes possible to reliably reproduce the relative movement of the mounting table with respect to the image intensifier.

This makes it possible to create a so-called mask image (or live image) and a live image (or mask image) from the respective images of each movement of the mounting table without any deviation.

Therefore, it is extremely effective for angiography of a subtraction image.

[0019]

1 is a block diagram showing an embodiment of an X-ray diagnostic apparatus according to the present invention.

In FIG. 1, first, an X-ray tube device 1 for irradiating a subject 2 with X-rays, and an X-ray image obtained by passing through the subject 2 while being irradiated by the X-ray tube device 1. Image intensifier 3 for converting the image into an optical image, a television camera 4 for converting the optical image obtained by the image intensifier 3 into an electric signal, an X-ray tube device 1, an image intensifier 3 and a television camera. 4, a holding device 5 for holding the four facing each other, an image processing device 6 for converting an electric signal from the television camera 4 into image data and storing / calculating the image, an image stored / calculated by the image processing device 6 or A television monitor 7 for observing an X-ray fluoroscopic image, a catheter table 8 for holding the subject 2 in a lying state, and a slide movement in the head-foot direction of the subject 2 on the upper portion of the catheter table 8. And a top plate 9.

Further, a servo motor 10 for driving and operating the top plate 9 and an encoder 1 coupled coaxially with the servo motor 10 for detecting the rotation speed of the servo motor 10.
1 and potentiometer 1 for detecting the current position of the top plate 9
2, a top movement operator 13 that is operated by an operator (not shown) to inform a desired speed by a tilt angle, and a potentiometer 14 that is connected to the top movement operator 13 and outputs a voltage according to the tilt angle of the lever. A multiplexer 15 for switching and inputting the signals of the potentiometer 14 and the potentiometer 12, and an analog / digital converter for converting the analog signals of the potentiometers 12 and 14 input via the multiplexer 15 into digital signals. It is provided with a converter 16 and a CPU 17 which controls the catalog table 8.

Further, the digital / analog converter 18 for converting the digital signal from the CPU 17 into an analog signal is compared with the command value output from the CPU 17 via the digital / analog converter 18 and the output value of the potentiometer 12. A comparator 19 that outputs a difference, an amplifier 20 that amplifies the difference output of the comparator 19, and an encoder 11 that uses the output of the amplifier 20 as a reference speed command value.
The servo driver 21 that drives the servo motor 10 at a rotation speed corresponding to the reference speed command value by comparing the speed feedback value from the camera, and a photographing hand switch that is operated by an operator (not shown) to issue a command through photographing of the entire system. 22
And a contrast agent injector 24 for injecting a contrast agent into the subject 2,
Injection switch 2 for instructing contrast agent injector 24 to start injection
5 and a teaching mode switch 2 for informing the CPU 17 that it is a mode for teaching the moving speed pattern of the tabletop 9.
6, a reproduction operation mode switch 27 for informing the CPU 17 of a mode in which the top plate 9 is reproduced in a taught speed pattern, and a reproduction operation start signal from the switches and the image processing apparatus 6 to the CPU 17 / O
It is provided with a port 28 and an X-ray high voltage device 29 which receives an X-ray irradiation request signal from the image processing device 6 and applies a high voltage to the X-ray tube device 1 to generate X-rays.

The operation of the X-ray diagnostic apparatus thus constructed will be described below.

First, before performing a series of photographing, the operator operates an operator console (not shown) to make X
The X-ray transmission is performed while the X-ray transmission is performed.

By operating the top moving device 13,
The top plate 9 moves to a desired shooting start position.

Here, the method of controlling the top plate operation from the CPU 17 will be described. First, in a steady state (when the top plate is not operating), the detected value of the potentiometer 12 is passed through the multiplexer 15 to the A / D converter. It is digitized by 16, and the digitized value is read by the CPU 17.

Then, the CPU 17 outputs the position command value corresponding to the position data thus read to the D / A converter 18.

The position command value analogized by the D / A converter 18 is compared with the detection value of the potentiometer 12 by the comparator 19.

In the steady state, the two values to be compared are equal, so that the output of the comparator 19 is the logical value '
A signal of 0 'is output. When the output of the comparator 19 is the logical value "0", the output value of the amplifier 20 is also 0 and the reference speed command value input to the servo driver 21 is also 0.

Therefore, the servomotor 10 does not rotate, and the top plate 9 maintains the stopped state.

The output value of the potentiometer 14 is input to the A / D converter 16 via the multiplexer 15 by the operation of the tabletop moving operation device 13, and the CPU is operated.
17 will be read.

Then, the CPU 17 uses the multiplexer 15
The position data from the potentiometer 12 and the operation data from the potentiometer 14 are read by alternately and periodically switching the input channels.

Here, the operator moves the top moving device 13
When is tilted in a desired direction, operation data proportional to the angle of tilt is input to the CPU 17.

The CPU 17 is adapted to add or subtract a value corresponding to the direction and size of the operation data to the position command value output previously, and output it to the D / A converter 18.

As a result, when there is a difference between the inputs of the comparator 19, the difference is amplified by the amplifier 20 and input to the servo driver 21 as a reference speed command value. The rotation starts according to the reference speed command value.

In this way, when the servo motor 10 rotates and the top plate 9 moves, the position data of the potentiometer 12 also changes, and the changed position data is fed back to the comparator 19. Become.

When the speed command value from the CPU 17 becomes equal, the output from the comparator 19 becomes 0 again, and the rotation of the servomotor 10 stops.

In actual operation, the CPU 17 constantly monitors the operation data at a constant period while the top moving operation device 13 is tilted, and adds or subtracts the value corresponding to the operation data to the previously output value. And then output.

Here, when the speed of the tabletop is v, time t ₀
The tabletop position at S _{0 is} the tabletop position at time t _{1
If 1} ,

[0040]

## EQU1 ## S ₁ −S ₀ = v (t ₁ −t ₀ ). Where v is velocity.

Therefore, the general formula is

[Number 2] _{S n -S n-1 = v} (t n -t n-1) n = 1,2,3, ... to become.

In the above equation, t _n -t _n-1 is the update interval (output interval) of the position command value, and S _n -S _n-1 is the value added for each output of the position command value. .

Therefore, if t _n -t _n-1 is made sufficiently small, the top plate 9 will operate as if it were continuous.

When the top 9 (that is, the subject 2) is set at a desired photographing start position, the teaching mode switch 26 is operated, and the subsequent operation of the top moving operation device 13 is the teaching operation of the speed pattern. This will inform the CPU 17 of this.

In the teaching operation, a small amount of a contrast medium is injected into the subject by the contrast medium injector 24 or a syringe (not shown) while performing X-ray fluoroscopy, and the tabletop moving operation device 13 is operated under the fluoroscopy to change the contrast medium. By tracking the flow.

In this case, all the position command values output after the top movement operator 13 is tilted are sequentially stored in the memory 17a on the CPU 17. The position command value is, for example, a speed value of the top 9 over time.

When the teaching operation is completed, shooting is performed for the first time.

When taking a picture, the reproduction operation mode switch 27 is operated, and thereafter, the CPU 17 is informed that the reproduction operation is being performed.

Further, in the image processing device 6, the time for photographing the mask image and the live image, the injection timing of the contrast agent injector, etc. are set in advance, and when the setting is completed, the photographing hand switch 22 is operated.

The photographing hand switch 22 is a two-stage motion switch. When the first stage is depressed, the image processing device 6 outputs a photographing preparation signal 6a to the I / O port 28 and the X-ray high voltage device 29. It has become.

When the I / O port 28 receives this signal, it is transmitted to the CPU 17, and the CPU 17 updates the position command value output so that the top plate 9 reaches the photographing start position. This position command value output is an output value created by a program in advance, regardless of the taught speed pattern.

When the top plate 9 reaches the shooting start position, the CP
The U 17 causes the CPU 17 to output the ready signal 28 a to the image processing apparatus 6 via the I / O port 28.

The image processing apparatus 6 sends the reproduction operation start signal 6a to the I / O port 28 when the preparation completion signal 28a is input and the second stage of the photographing hand switch 28 is pressed. Has become.

Upon receipt of the reproduction operation start signal, the CPU 17 immediately reproduces the position command values obtained by the previous teaching operation and stored in the memory 17a in order from the beginning at the same output intervals as in the teaching operation. It has become.

As a result, the top 9 moves in the same speed pattern as in the teaching operation.

The servo driver 21 sends a rotation start signal 21a to the image processing device 6 when the reference speed command value takes a value other than 0, that is, when the operation is started. ing.

The image processing device 6 receives the rotation start signal 21
Upon receiving a, the irradiation request signal 6 is sent to the X-ray high voltage device 29.
c is output, and the acquisition of image data (mask image) is started.

After that, when the photographing time preset in the image processing device 6 has elapsed, the irradiation request signal 6c output to the X-ray high voltage device 29 is temporarily stopped and the I / O
The reproduction operation start signal 6b output to the O port 28 is stopped.

The CPU 17 completes the reproduction operation, and
The reproduction operation start signal 6b stops, and the shooting preparation signal 6
If a is continuously input, the top plate 9 is made to reach the photographing start position again.

Further, a contrast agent is injected from the contrast agent injecting device 24, and a second reproducing operation is performed in the same manner to capture an image (live image).

When the capture of the live image is completed, the output of the photographing preparation signal 6a is stopped, so that all the operations are completed and stopped.

Since the mask image and the live image thus obtained have the same velocity pattern at the first and second times of the reproducing operation, their positional phases match, and moreover, the flow of the contrast agent is caused by the teaching operation. Therefore, it is possible to obtain a proper subtraction image.

In the above-mentioned embodiment, the embodiment in which the subtraction image of the blood vessel is finally formed is explained, but the contrast agent is injected even if the stage of forming the subtraction image is not reached. It goes without saying that the present invention can also be applied to the case of capturing only a blood vessel image.

As far as the object in this case is achieved, the memory 17 for storing the information showing the speed change of the top 9 is stored.
It goes without saying that a may be omitted.

Further, in the above-described embodiment, when the subtraction image of the blood vessel is created, the mask image is photographed while changing the moving speed of the top plate 9 while observing the monitor 7, but the monitor 7 is not always required. It is needless to say that the mask image may be taken while varying the moving speed of the top 9 according to, for example, an empirical rule, without recognizing it.

Further, for example, according to an empirical rule, the top plate 9
Needless to say, when changing the moving speed of, the live image is not limited to the first capturing of the mask image.

Further, in the above-mentioned embodiment, only the case where the top 9 moves in the head and foot direction of the subject 2 has been described. However, when the top 2 moves in the left-right direction or the height direction of the subject 2. Needless to say, the same can be done.

[0068]

As is apparent from the above description,
The X-ray imaging apparatus according to the present invention can be extremely effective in angiography. In addition, it is extremely effective in angiography of a subtraction image.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an X-ray diagnostic apparatus according to the present invention.

[Explanation of symbols]

 9 Top plate 13 Top moving operation device 17 CPU 17a Memory

Claims (2)

[Claims] 1. An image intensifier for forming an X-ray image obtained by transmitting X-rays from X-ray tubes, which are arranged opposite to each other with the subject in between, and the subject. In an X-ray imaging apparatus having a moving mechanism for moving a mounting table to be mounted relative to the image intensifier, the relative speed of the mounting table with respect to the image intensifier is moved at a moving speed. An X-ray imaging apparatus comprising: a speed varying means capable of arbitrarily setting the above, and a monitor means for monitoring an image obtained from the image intensifier by the operation of the speed varying means. 2. An image intensifier for forming an X-ray image obtained by transmitting X-rays from an X-ray tube disposed opposite to each other with the subject in between, and the subject. In an X-ray imaging apparatus having a moving mechanism for moving a mounting table to be mounted relative to the image intensifier, the relative speed of the mounting table with respect to the image intensifier is moved at a moving speed. Based on the information stored in the storage means for storing the temporal change of the relative movement of the mounting table with respect to the image intensifier by the operation of the speed varying means. The movement reproducing means for reproducing the relative movement of the mounting table with respect to the image intensifier, and the subtraction from the respective photographing at each movement of the mounting table described above. An X-ray imaging apparatus comprising: a means for creating an image.