JPH04208140A - X-ray diagnosis equipment - Google Patents

Abstract

PURPOSE:To prevent an object of inspection from being exposed to unnecessary X-rays and enhance the operability of a diaphragm opening by controlling the diaphragm opening of a rectangular diaphragm on a second power and controlling the diaphragm opening of a circular diaphragm on a first power. CONSTITUTION:An X-ray diagnosis equipment is provided with a circular diaphragm 21, a rectangular diaphragm 22, a variable power means and an optical system 5, etc. The circular diaphragm 21 limits circularly the X-rays incident on an object of inspection 3 according to diaphragm opening. The rectangular diaphragm 22 limits retangularly the X-rays incident on the object of inspection 3 according to the diaphragm opening. The variable power means varies a first power between an X-ray image on an input face 41 of an light image covering means 4 and an optical image of an output face 46. The optical system 5 varies a focal distance to vary a second power between an optical image of the light image converting means 4 and an optical image surrounded with an image pickup means 6. On the second power varied by the optical system 5, the diaphragm opening of the rectangular diaphragm 22 is so controlled as to control the diaphragm opening of the circular diaphragm 21 on the first power. This enhances the operability of the diaphragm opening without exposing the object of inspection 3 unnecessarily to X-rays.

Description

DETAILED DESCRIPTION OF THE INVENTION "First aspect of the invention" (field of use in PR business) The present invention is a system for converting X-rays transmitted from an X-ray source through a subject into an optical image by an image intensifier. The present invention relates to an X-ray diagnostic apparatus that manually displays an optical image on a TV right camera and displays a fluoroscopic image on a TV monitor.

(Prior Art) In an X-ray diagnostic apparatus, fluoroscopy and imaging are performed on a subject as follows. The X-rays emitted from the X-ray source and the X-ray tube at l~ are limited to a predetermined amount by the aperture opening of the X-ray diaphragm, and the limited X-rays pass through the subject. The transmitted X-rays are then converted into an optical image by an image intensifier (hereinafter referred to as 1.1.) as a light image conversion means. After that, the light amount of the optical image is adjusted by an optical system consisting of, for example, a lens and an optical diaphragm, and the optical image is displayed on a TV.
The right camera converts it into a video signal. Then, the video signal output from the TV right camera is used as a fluoroscopic image of the subject.
Displayed on a monitor, etc.

When it is desired to enlarge or reduce the 'C1 field of view in the X-ray diagnostic apparatus configured in this way, the optical image, that is,
, (2) A variable focus lens (zoom lens) is provided in the optical system for forming the output image into the TV right camera. That is, in this zoom lens, the focal position can be changed by changing the L/lens position. If you use this zoom lens, 1.1. The output image from the TV camera is enlarged/reduced on the input surface of an image pickup tube provided in the TV camera, and an enlarged/reduced image can be obtained.

On the other hand, 1.1. In terms of human power, for example, the size (hereinafter referred to as input size) for taking in transmitted X-rays using high voltage from a high voltage power supply can be changed by two or three. By changing the size of this human power, the total input X-ray energy amount changes, so 1.1. The amount of light of the optical image obtained on the output surface of the lens changes.

Furthermore, conventionally, 1.1. The transparency corresponding to the input size of
The aperture opening of the X-ray diaphragm was controlled so that the X-rays were emitted from the X-ray tube, and the X-rays were not applied to the subject more than necessary.

(Problem to be solved by the invention) On the other hand, if it is possible to obtain an enlarged image using a zoom lens in an optical system, when the field of view is reduced with a zoom lens]7, conventional methods Adjust the X-ray aperture [2. I.

When imaging a region smaller than the effective surface having a circular shape, the subject (for example, a patient) will be unnecessarily exposed to X-rays corresponding to the portion of the effective surface excluding the above-mentioned region. Alternatively, in order to prevent unnecessary radiation exposure, it is necessary to manually set the aperture opening according to the magnification of the zoom lens, resulting in poor operability.

Therefore, the purpose of the present invention is to provide an X-ray diagnostic device that improves the operability of the aperture opening, reduces the operational burden on the operator, and improves inspection efficiency, without exposing the subject to X-rays unnecessarily. It's about doing.

[Structure of the invention] (Means for solving the problem) The present invention solves the above problems [7] In order to achieve the object, the following measures have been taken. The optical image converted by the optical image converting means is converted into a video signal by the imaging means. In an X-ray diagnostic apparatus that displays a fluoroscopic image of the subject in steps 1 to 1, the X-rays to the subject are limited to a circular shape by the aperture opening degree. an aperture, a rectangular aperture that limits X-rays to the subject to a rectangular shape depending on the aperture opening, and a first magnification of the X-ray image on the input surface and the optical image on the output surface of the optical image conversion means is changed by 6■ means, an optical system for changing the focal length in order to change the second magnification of the optical image of the light image converting means and the optical image taken into the imaging means; The present invention is characterized in that it includes means for controlling the opening degree of the rectangular diaphragm based on the magnification and means for controlling the opening degree of the circular diaphragm based on the first magnification.

In addition, in an X-ray diagnostic apparatus that converts the X-rays into an optical image (17) using an optical image converting means (17) and displays a fluoroscopic image of the subject through an optical system (7) converting the optical image into an image (5) using an imaging means (17), means for varying the first magnification of the X-ray image on the input surface of the means and the optical image on the output surface; An optical system that changes a focal length to vary a second magnification between the optical image of the image converting means and the optical image taken into the imaging means, and the second magnification and the first magnification varied by this optical system are used. The present invention is characterized by comprising means for determining the amount of light incident on the photographing means using an optical system and controlling the aperture opening of the optical diaphragm based on the amount of incident light.

In addition, in an X-ray diagnostic apparatus in which an optical image obtained by converting X-rays by a light image converting means is converted into a video signal by an imaging means via an optical system 17 to display a fluoroscopic image of a subject, the human power of the light image converting means is means for changing a first magnification between the X-ray image of the optical image converting means and the optical image on the output surface, and a second magnification between the optical image on the output surface of the light image converting means and the optical image taken into the imaging means. The present invention is characterized in that it includes an optical system and a means for determining an enlargement factor of an image based on first and second magnification factors and generating a scale for display from the enlargement factor, and displays the scale on a perspective image.

In addition, in an X-ray diagnostic apparatus that converts an optical image of X-rays by an optical image converting means into an image fi by an imaging means through an optical system (7) and displays a fluoroscopic image of a subject at °C, a desired field of view is used. Based on the means for setting and the visual field information from this means,
Determine a first magnification between the X-ray image on the input surface of the light image conversion means and an optical image on the output surface, and a second magnification between the optical image on the output surface of the light image conversion means and the optical image taken into the imaging means. and the means to
It is characterized by comprising means for setting the input size for inputting the transmitted X-rays of the optical image conversion means based on the first magnification, and means for changing the focal length of the optical system based on the second magnification. .

(Effects) By taking such measures, the following effects are achieved. A first magnification between the X-ray image on the input surface of the light image converting means and an optical image on the output surface is varied, and a second magnification between the optical image of the light image converting means and the optical image taken into the imaging means is varied. The focal length can be changed to make it variable. The aperture opening of the rectangular diaphragm is controlled based on the second magnification, and the aperture opening of the circular diaphragm is controlled based on the first magnification, so the X-ray irradiation field is set optimally, eliminating unnecessary X-rays. It is possible to prevent radiation exposure of the subject to radiation.

Further, the first magnification between the X-ray image on the input surface and the optical image on the output surface of the light image conversion means is varied, and the second magnification between the optical image of the light image conversion means and the optical image taken into the imaging means is varied. The focal length can be changed to make it variable.

In Step 17, the amount of light incident on the photographing means is determined by the optical system using the second magnification and the first magnification, and the aperture opening of the optical diaphragm is controlled based on this amount of incident light, so that an image with good resolution can be obtained. can get.

Also, the first magnification of the X-ray image on the input surface of the light image conversion means and the optical image on the output surface is changed by iiJ, and the first magnification of the 2 (H
The S rate is varied. Then, the magnification factor of the image is determined based on the first and second magnification factors, a scale for display is generated from the magnification factor, and the scale is displayed on the perspective image, so the image can be easily displayed using the scale. It can be measured.

Also, when you set the desired field of view, based on the field of view information,
A first magnification between the X-ray image on the input surface of the optical image conversion means and an optical image on the output surface, and a second magnification between the optical image on the output surface of the first stage of optical image conversion and the optical image taken into the imaging means. It is determined. Part 1
7) The input size of the optical image converting means is set based on the first magnification, and the focal position of the optical system is changed based on the second magnification, so that an image with good resolution corresponding to the observation field of view can be obtained.

(Embodiment) FIG. 1 is a diagram showing the configuration of an embodiment of an X-ray diagnostic apparatus according to the present invention. The X-ray diagnostic apparatus is configured as follows. The X-ray generator for generating X-rays consists of an X-ray tube 11 as an X-ray source and a high-voltage generator 12, and the high voltage generated by the high-voltage generator 12 is transferred to the X-ray tube 1.
X-rays are applied between the anode and cathode of X-ray tube 11, and X-rays are generated by X-ray tube 11.

The high voltage generator 12 sets conditions to be applied to the X-ray tube 11, such as tube voltage (KV), tube current (mA), and application time (s e
c) can be set and controlled respectively. The amount of X-rays generated by varying the tube voltage (KV) changes in proportion to the n-th power (n>1) of the tube voltage, and the amount of xia generated by varying the tube current (mA) and application time (s e c) varies in proportion to the tube current and application time, respectively.

An X-ray diaphragm 2 is installed at the radiation opening of the X-ray tube 11 to narrow down the irradiation field to only the necessary area.
Inside the line diaphragm 2, as shown in FIG. 2, there is provided a circular diaphragm 21 made of a material 2 with high X-ray absorption, such as lead, for narrowing down the irradiation field. X
Behind the circular diaphragm 21 in the line diaphragm 2, a rectangular diaphragm 22 is provided to narrow down the irradiation field to a rectangular shape, as shown in FIG.

The circular aperture 21 has a plurality of aperture blades 21-1 to 21--n.
The rectangular diaphragm 22 is a movable diaphragm whose size can be varied by rotating the diaphragm 22-1.
~22-4 is a movable diaphragm whose size can be varied by moving it vertically, horizontally, and horizontally as shown by the arrows. The circular apertures 21 and 22 each have a drive motor 21:1. ．． 2
21, and detectors 212 and 222 for detecting the aperture position corresponding to the aperture opening degree.

The aperture opening controller 23 controls the aperture openings of the circular aperture 21 and the rectangular aperture 22 by driving and controlling the drive motors 211 and 221, respectively.

As shown in detail in FIG. 4, the aperture opening controller 23 includes a subtractor 23-1. Control circuit 23-11. Motor driver 23
-12, and a circular aperture opening signal 84 from an irradiation field control unit 84, which will be described later, is detected by a subtractor 23-1.
2, the control circuit 23-11 drives and controls the motor driver 23-12 based on the subtracted output, and the motor driver 23-12 supplies the circular diaphragm motor signal to the motor 211. The motor 2]1 is driven to control the opening degree of the circular diaphragm 2].

Further, the aperture opening controller 23 includes a subtracter 23-2° control circuit 23-21. A motor driver 2B-22 is provided, and a subtracter 23-2 subtracts a detected rectangular aperture vertical opening degree signal from a detector 222 from a rectangular aperture vertical opening degree signal 842 from an irradiation field control unit 84, which will be described later, to obtain a subtracted output. Based on the control circuit 23
-21 drives and controls the motor driver 23-22, and the motor driver 23-22 supplies a rectangular aperture vertical motor signal to the motor 221 to drive the motor 221, and the rectangular aperture 2
2. Controls the vertical opening of the rectangular diaphragm.

Furthermore, the aperture opening controller 23 includes a subtracter 23-3,
Control circuit 23-31. A motor driver 23-32 is provided, and a subtracter 23-3 subtracts a detected rectangular diaphragm lateral opening signal from the detector 222 from a rectangular diaphragm lateral opening signal 843 from an irradiation field control unit 84, which will be described later, to obtain a subtracted output. Based on this, the control circuit 23-31 drives and controls the motor driver 23-32, and the motor driver 23-32 supplies a rectangular diaphragm lateral motor signal to the motor 221 to drive the motor 221, thereby controlling the rectangular diaphragm lateral opening of the rectangular diaphragm 22. control.

In such a configuration, the X-rays generated by the X-ray generating device are limited to a necessary size irradiation field by the X-ray diaphragm 2, and are irradiated onto the subject 3, with the transmitted X-rays being 1.1 .4
1, 1.4 absorbed by the input surface 4]- of the input surface 41. Electrodes 42, 43, 44, 45, each having high voltage electrodes on the left and right sides.
Output fluorescent screen 46 provided at the bottom. It consists of a high voltage power supply 47 for applying high voltage to the high voltage electrode.

When the input surface 41 is irradiated with X-rays, electrons are emitted inside the input surface 41. The emitted electrons are accelerated and focused by the high voltage applied to each of the -14=electrodes 42.43 and 44.45, resulting in output fluorescence 1I.
The image is formed on IJ46. The output phosphor screen 46 is coated with phosphor, and electrons are emitted as an output image (optical image).

Electrode 42.43°44.4 from high voltage power supply 47
By varying the high voltage applied to 5, the electron focusing distance (I
, I. Focusing point of electrons F, , F2. from the input surface 41. Since the distance (to F3) is variable, the input size for three Is, for example 9 inches, 6 inches, and 4.5 inches, can be selected. Even if the same X-ray dose is incident on the input surface 41, the input size can be selected, so 1. Since the total amount of X-ray energy input to I, 4 changes approximately in proportion to the area of the input size, 1. I, the brightness of the output image changes.

The optical system 5 is provided behind 1.1.4 of the output fluorescent screen 46 . The output image is optically formed on the input surface of a photographing tube 61 provided at the rear of the optical system 5.

The optical system 5 includes a lens 51. provided on the 1.14 side. TV
Lens 52 provided on the left camera side. Lens 51.52
An optical aperture 53 provided between the Zoom motor 511
．． , detector 512. Zoom magnification controller 54. It consists of an optical aperture drive controller 55.

The lens 51 is a variable focus lens (so-called zoom lens). The zoom motor 511 drives the lens 51 to change the focal length f51 of the lens 51, and the detector 512 detects the lens position corresponding to the focal length f5+. The zoom magnification controller 54 drives and controls the zoom motor 511 to change the focal lengths f and I of the lens 51. The focal length of the lens 52 is f,2, which is a constant value. The zoom magnification controller 54 also controls the lens position (corresponding focal length f 5 ) detected by the detector 512.
+D) and the target lens position (target focal length f51), and set the lens position (which is always 1") as the target lens position (target focal length f51).
By controlling the focal length f, 1), the target zoom magnification is obtained.

Here, the zoom magnification is 1.1.4 output phosphor screen 4
It is the ratio of the size of the output image at 6 and the size of the image formed on the input surface of the image pickup tube 61, k, s'' f 52/
It is f51.

By changing the focal length f51 of the lens 51, the magnification of the image is varied in inverse proportion to this. Focal length f5 of lens 51
1 changes, the brightness of the lens changes and the amount of light incident on the input surface of the image pickup tube 61 changes.

Optical aperture 53 is provided between lens 51 and lens 52 and controls the amount of light that enters the input surface of image pickup tube 61 . The optical diaphragm 53 can be opened and closed by driving the optical diaphragm motor 531, and the detector 522 detects the diaphragm position corresponding to the aperture opening degree of the optical diaphragm 53. Optical aperture opening controller 55
drives and controls an optical diaphragm mode 531 to control the opening degree of the optical diaphragm 53.

The TV left camera having the image pickup tube 61 captures an image formed on the input surface of the image pickup tube 61 by the optical system 5. The camera controller 62 controls the image pickup tube 61 by controlling the image pickup tube 61 and converts the image signal from the image pickup tube 61 into an image signal (video signal). The video signal output from the camera controller 62 is sent to an image processing device 91, digitized by an A/D converter inside the device, and subjected to image processing such as subtraction and edge enhancement processing. The monitor processing unit 92 superimposes text and graphic information such as the patient's name and conditions at the time of imaging on the image-processed digital image. Furthermore, this information is D/A converted and sent to the monitor 93 as a video signal, so that the photographed image and text/graphic information can be superimposed and observed on the monitor 93.

On the other hand, 1. I, controller 81 is connected to an external device such as 1.1. Take in the size designation signal 721, 1.1. I, I based on the size designation signal 721
, 4 of the high voltage power supply 47, for example, any one of the three. I, and change it to the size 1. I.

The size signal 811 is supplied to the irradiation field control section 84 and the dotted magnification rate meter circuit 86 .

Here, the incident X-ray dose is expressed as m R / min 111, the brightness at the output phosphor screen 46 is expressed in units of Cd / m 2, and the ratio is 1. It is called the conversion coefficient Gx of I,4.

G x ((Cd/m′) /
(mR/min)) - Luminance (C
d/m')/incident X-ray t'il (m R/rn i
n) If the input size in 1.1.4 is reduced by changing the high voltage of the high voltage power supply 47, the total energy of the incident X-rays will be 1, which is calculated by the square of the input size
, 1. The energy corresponding to the manpower area is reduced. On the other hand, since the size of the output phosphor screen 46 is the same, the brightness decreases by the amount that the size is reduced. (7 Therefore, the conversion coefficient Gx is proportional to the manpower area of I, 1.4.

1, I, the controller 81 is 1. The value of the square of the input size of I, 4 is not sent to the light amount control unit 85 as the brightness signal 812 of I, I.

The zoom lens controller 82 takes in the zoom magnification designation signals 7', 2', ) from the magnification distribution circuit 72, and uses the zoom magnification designation f,; Set the position. At the same time, the zoom lens controller 82 supplies the zoom magnification signal 821 at this time to the irradiation field control unit 84 and the 1-tal magnification distribution circuit 86 (j+4), and also supplies the lens brightness F value at this time. , I-nons brightness signal 822 and +7 are supplied to the 1-tal light amount control section 85.

The optical aperture control section 83 is, for example, a 1-tal light amount control section 8.
A light amount instruction signal 852 is taken in from the optical aperture opening controller 55 to set eleven aperture positions for the optical aperture opening controller 55, and at the same time, a brightness signal 831 of the optical aperture 53 is supplied to the total light amount controller 85.

Next, in the device configured as above, the circular diaphragm 2
], the control of the rectangular diaphragm 22 will be explained.

■、1. The control unit 81 performs 1.1. Take in the high voltage of the high voltage power supply 47 for setting the size, and generate the size signal 811 based on this high voltage. The irradiation field control unit 84 controls the above-mentioned I, I.

The output I, ■, and size signal 811 are taken in from the controller 81, and 1. I, distance to input surface 41 14. and a circular aperture 2 from the focal point Fo of the X-ray tube 11.
Based on the distance 12+ to 1, the X-ray field is 1.1
．． Circular aperture opening (11
No. 84] is supplied to the aperture opening controller 23. 1. I, 4
The input size is d811, and the circular aperture opening is d2+
Then, as shown in FIG.
Based on this signal, the motor 211 is driven by the diaphragm opening controller 23, and the opening of the circular diaphragm 21 is set to 621 by the motor 21].

On the other hand, regarding the setting of the rectangular aperture opening, the irradiation field control unit 84
are the distance 141 from the focal point Fo of the X-ray tube 11 to the 1.1° input surface, the distance 12□ from the focal point FO of the X-ray tube 11 to the vertical and horizontal rectangular apertures 22-1 to 22-4, respectively. , I
, I. Based on the size signal 811 and the zoom magnification signal 821, the aperture opening controller 23 outputs a rectangular aperture vertical 1'yij Ift signal 842 and a rectangular aperture horizontal opening signal 843.

Here, the opening degree of the rectangular diaphragm is Ij 22A X d 22
Images at [] and +1.1.1.4 are d8□ and 17, I,
Assume that the size of the output phosphor screen 46 of 1.4 is d, +6. Further, the image reduction ratios of 1, I, and 4 are set to 4, the zoom magnification is set to , and the imaging area of the image pickup tube 61 is set to AXB. Further, I, I, and the size of the output phosphor screen 46 are d, which is the size of the image formed by the optical system 5. , then k 4- d 46/ d s++ as shown in FIG.

k 5- d b+/ d 46= f 52/ f
5+d2□A ”= 121X k4 X k5 xA
/ 14Hd2□B -12+Xk4 Xk5 xB/
141, a rectangular diaphragm vertical opening signal 842 and a rectangular diaphragm lateral opening signal 843 are generated. These signals 842
．． Based on 843, the motor 22 is controlled by the throttle opening controller 23.
1 is driven, the rectangular diaphragm 22 is driven by the motor 221.
The opening degree is set to d22A x d22B.

In this way, the circular aperture 21. Since the rectangular diaphragm 22 is controlled by the diaphragm opening controller 23 via the motors 211 and 221, as shown in FIG. 7, <1.1. Circular irradiation field A1 according to input size
An overlapping area (shaded area) between the rectangular irradiation field A2 and the imaging area, that is, a necessary and sufficient irradiation field to be captured as an image is obtained.

Therefore, in the image pickup tube 61, the parts B, ~B4, which are in the imaging area but where no image appears due to 1.1.4,
In 1.1.4, it can be output as an image, but in the imaging tube 61, it is possible to prevent unnecessary irradiation of X-rays to the parts C, C2 that are not photographed and do not become an image, and this allows unnecessary X-rays to be output to the subject 3. There is no need to expose the patient to X-rays. Also 1, 1.
Since the input size (4) and the opening of the aperture (2) are automatically set, inspection time can be shortened.

Next, control of the total light amount will be explained.

1.-tal light amount control section 85 performs 1.1. 1 from the controller 81. I brightness signal 812 and zoom lens controller 8
2 and the optical aperture controller 8.
The brightness signal 831 of the optical aperture 53 from 3 is taken in,
Calculate the amount of light at the input surface of the image pickup tube 61 by
Determine whether the optimum operating light intensity is achieved. If the image pickup tube 61 is not within the optimal operating light amount range, the optimal X-ray conditions for the optimal operating light meter are determined, and an X-ray condition signal 851 is generated at a high voltage to change the X-ray conditions. A light quantity instruction signal 852 is supplied to the optical diaphragm controller 83.

Here, methods for estimating the amount of light on the human-powered side of the image pickup tube 61 include (a) a method of estimating the deviation from the optimum operating condition by calculation, and (b) a method of installing a monitoring optical detector in the optical system. (c) A method of determining from the output signal from the image pickup tube 61 whether the amount of light is optimal for operating the image pickup tube.

First, the method for estimating the amount of light on the input surface according to (a) will be explained. 1.1. Incident X-ray dose is X (mR/'m1n)
1. I, the brightness at the output phosphor screen 46 is B (Cd/m
2) Toshi 1. Let the focal length of the lens 51 be f51. In addition, the F number is set to F5+7, and the transmittance of the lens is ε, l.
and the focal length of the lens 52 is f52. Further, the opening degree of the optical diaphragm 53 is set to d53, the light amount at the input surface of the image pickup tube 61 is set to E(lx), and the conversion coefficient at the selected input size in 1.1.4 is set to Gx ((Cd/m2 ) / (mR/m1n)l
Then, E=ε5. ×ε, 2×π×B / [14 (f51/d5g)2+11 X (f52
/ f, +) 2]...(1) The following relationship holds true: B=GxXX.

By calculating the above equation, the light ff1E(lx) can be obtained. However, when calculating with two formulas,
1.1. The incident X-ray dose X must be known, 1.1
．． The incident x-ray dose must be kept constant by other means.

Next, the method of estimating the amount of light on the human power side according to (b) will be explained. A device to which this method is applied is shown in FIG. In the optical system 5 shown in the figure, a small mirror 56 is provided behind the optical diaphragm 53 to extract a portion of the light from the optical path to the outside.

Then, the extracted light passes through a small lens 57 that is conjugate with the lens 52 to form an image. A photodetector 58 is provided at the position where the image is formed, and the light taken out by the photodetector 58 is detected to estimate the amount of light on the human-powered surface of the image pickup tube 61.

This makes it possible to obtain a signal proportional to the image pickup tube input surface illuminance E. In this case, the output signal of the photodetector 58 and the image pickup tube manual illuminance E are measured in advance, and the proportionality constant 1 (,
Find 6.

Next, a method for estimating the amount of light on the input surface according to (C) will be explained. The output signal corresponding to the amount of light incident on the image pickup tube 61 is the ninth
As shown in the figure, it is a linear function. Thereby, by detecting the output signal of the image pickup tube 61, it can be determined whether the amount of human light is within the optimum operating light amount range.

Next, consider the light intensity of the image pickup tube 16, or the optimum operating light intensity range.
6 - Explain how to control the amount of light when there is no. Substituting the optimal operating light 1Eopt into equation (7), the optical aperture opening d5
Solving for 3, d 53- f 51/ [ε, 1×ε52XπxB
/...(2) By calculating this formula, the optimum optical aperture opening can be determined.

However, since equation (2) requires a fairly complicated calculation, the following method is used in a simplified manner.

In order for the operating light itE to remain constant even if the input size and zoom magnification in 1.1.4 change, GX/[+4
(f5+/d, 3)2+1)XI/(f51)
2] “”const is sufficient.

Therefore, 1.1.4 conversion coefficient Gx changes depending on the human power size, f changes depending on the zoom magnification, 1. Calculate in advance dq3, which changes depending on the optical aperture opening,
The result is stored in a memory etc., and the conversion coefficient Gx,
It is advisable to have a lookup table for determining the optical aperture opening d53 from the values of f and +.

When the amount of deviation in the amount of incident light E is small, the optical aperture opening d5
You only need to change 3. However, when the amount of deviation becomes large, the optical diaphragm opening d53 alone cannot cover the amount of deviation, so at this time, the X-ray conditions are also changed.

According to the control of the total light amount as described above, 1.1.4
Even if you change the input size or the magnification of the zoom lens, the aperture opening of the optical diaphragm 53 is appropriately controlled.
The amount of light incident on the input surface of the image pickup tube 61 can be kept constant, so that images with good resolution can always be obtained. Furthermore, even if the adjustment range of the optical diaphragm 53 is exceeded, the X-ray conditions are automatically and appropriately adjusted, so that images with good resolution can always be obtained.

Next, image scale display will be explained.

The total magnification calculation circuit 86 performs 1.1. Control unit 8]-
The I, I size signals 811 from the zoom lens controller 82 and the magnification signal 821 from the zoom lens controller 82 are taken in, and the total magnification factor 1 (8b) is calculated based on these signals as shown in the following equation.

k B6 = k 4 X k 5 The scale generation circuit 87 is the total magnification calculation circuit 86
Based on the total magnification factor from 86, set the scale to 2.
It is generated as a value image, and a vertical scale 931 and a horizontal scale 932 matching the dimensions of the monitor processing unit 92 are displayed.

Therefore, since the scale can be displayed on the image, when measuring, for example, the size of arteriopathy, the image can be easily measured using the scale, and the accuracy can be improved by t1Δ1. Furthermore, since there is no need to consider the magnification rate, diagnosis time can be shortened. However, when using the scale, if you need the dimensions of the subject 3" which is the dimension on the human force plane 41, enter 3 in the subject magnification rate in advance and use the ks
6 = 3xk4Xk.

It's fine if you do this.

Next, the image display of the observation field included in the above embodiment will be explained.

The operating unit 71 of the system can set various conditions of the system. The operating section 71 includes one operating device for setting the field of view desired for observation, and a field of view setting signal is sent to the magnification distribution circuit 72.

The magnification distribution circuit 72 is provided with a memory storing a lookup table, and based on the field of view setting signal, 1. l 4
The input size selection signal 721 of 1.1. The zoom magnification setting signal 722 is supplied to the control section 81 and the zoom magnification setting signal 722 is supplied to the zoom lens control section 82 . And 1.1. Since the high voltage signal corresponding to the input size selection signal 721 is supplied from the control section 81 to the high voltage power supply 47, this high voltage
．． The size is set appropriately.

On the other hand, the zoom motor 511 is driven by the zoom magnification controller 54 based on the zoom magnification setting signal 722, and the focal length of the zoom lens 51 is optimally set, thereby setting the optimal magnification.

In general, the magnification factor in 1.1.4 is 4. The larger the magnification rate of the zoom lens, the greater the M T F of the resulting image.
will get better.

However, 1. I, M when increasing the magnification rate of 4 to 4
The degree of improvement in TF is different, and the combination a) Zel 1, I
,4. It also differs depending on the performance of each optical system 5. Also, the magnification rate is 4. When 5 is increased, the amount of light input to the image pickup tube decreases. 1. Increasing the magnification ratio of I, 4 to 4 will result in a smaller amount of light than increasing the magnification ratio of 1 (,) using a zoom lens.These characteristics are combined 1, I, 4. Optical system 5 Since this differs depending on the performance of the system, an optimal lookup table for magnification distribution is set depending on the system combination.

In this way, depending on the observation field, 1. I. Size.

By appropriately combining zoom lens magnifications, you can always obtain images with good resolution. Furthermore, since it can be performed automatically, fewer operations are required and inspection time can be shortened.

Note that the present invention is not limited to the embodiments described above. In the embodiment described above, the X-ray diaphragm is controlled, the total amount of light is controlled, and the scale is displayed on the second screen.

Although four types of image display in the observation field have been described, a device may be a combination of these four types, or a device may use each of the four types independently. It goes without saying that various other modifications can be made without departing from the scope of the present invention.

[Effects of the Invention] According to the present invention, the first magnification of the X-ray image on the input surface of the light image conversion means and the optical image on the output surface is varied, and the optical image of the light image conversion means and the optical image captured in the imaging means are The focal length is changed to vary the second magnification of the optical image. The aperture opening of the rectangular diaphragm is controlled based on the second magnification, and the aperture opening of the circular diaphragm is controlled based on the first magnification, so the X-ray irradiation field is set optimally, eliminating unnecessary X-rays. It is possible to prevent the subject from being exposed to radiation from the radiation beam, and since there is no need to perform a diaphragm operation, the burden on the operator can be reduced and the examination time can be shortened.

Further, the first magnification of the X-ray image on the input surface of the light image conversion means and the optical image on the output surface is varied, and the first magnification of the optical image of the light image conversion means and the optical image taken into the imaging means is 32 = 2. The focal length can be changed to vary the magnification.

The amount of light incident on the photographing means is determined by the optical system using the second magnification and the first magnification, and the aperture opening of the optical diaphragm is controlled based on this amount of incident light, so that an image with good resolution can be obtained.
This reduces the burden on the operator and shortens the inspection time.

Further, the first magnification between the X-ray image on the input surface of the light image conversion means and the optical image on the output surface is varied, and the second magnification between the optical image on the output surface of the light image conversion means and the optical image taken into the imaging means is The magnification of is variable. Then, the magnification factor of the image is determined based on the first and second magnification factors, a scale for display is generated from the magnification factor, and the scale is displayed on the perspective image, so the image can be easily visualized using the scale. It can be measured and inspection time can be shortened.

Also, when you set the desired field of view, based on the field of view information,
A first magnification between the X-ray image on the input surface of the light image conversion means and an optical image on the output surface, and a second magnification between the optical image on the output surface of the light image conversion means and the optical image taken into the imaging means are determined. be done. Then, the input size of the optical image conversion means is set based on the first magnification, and the focal position of the optical system is changed based on the second magnification, so an image with good resolution can be obtained according to the observation field of view, and the operation is easy. Because of this, it is possible to provide an X-ray diagnostic apparatus that can reduce the burden on the operator and shorten the examination time.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an embodiment of the X-ray diagnostic apparatus according to the present invention, FIG. 2 is a diagram showing details of a circular diaphragm, FIG. 3 is a diagram showing details of a rectangular diaphragm, and FIG. 4 is a diagram showing details of a rectangular diaphragm. A diagram showing details of the aperture opening controller, FIG. 5, is shown in 1.1. Figure 6 is a diagram showing how to determine the aperture opening of a rectangular diaphragm based on the input size of the zoom lens. Figure 7 is a diagram showing how to determine the aperture opening of a rectangular diaphragm based on the input size of the zoom lens. FIG. 8 is a diagram for explaining the X-ray irradiation range depending on the magnification of the lens, FIG. 8 is a diagram for explaining the operating light amount, and FIG. 9 is a diagram for explaining the optimum operating light amount range. ]...X-ray generator, 2...X-ray diaphragm, 3...subject, 4...image intensifier, 5...optical system, 6...imaging tube, ]1...X Wire tube, 12... High voltage generator, 21... Circular diaphragm, 22... Rectangular diaphragm, 23... Aperture opening controller, 41... Human power side, 4
2 to 45...electrode, 46...output surface, 4
7...High voltage power supply, 51.53...Lens, 53...
- Optical aperture, 54... Zoom magnification controller, 55... Optical aperture opening controller, 62... Camera control, 71...
・Operation unit, 72... Magnification distribution circuit, 8J...I,
l, controller, 82...zoom lens controller, 83...
・Optical aperture controller, 84... Irradiation is performed by field control section, 85.
...Total light amount control unit, 86...1 - Total expansion rate calculation circuit, 87... Scale generation circuit, 91... Image processing device, 92... Monitor processing unit, 93...T
V monitor. Applicant's Representative Patent Attorney Takehiko Suzue Figure 2 η Figure 3 Figure 5 Figure 6 Figure 7 Figure 8 Human Light Level Figure 9

Claims (4)

[Claims] (1) In an X-ray diagnostic apparatus that displays a fluoroscopic image of a subject by converting an optical image obtained by converting X-rays by a light image converting means into a video signal by an imaging means, the X-rays to the subject are apertured. a circular diaphragm that limits the X-rays to the subject to a rectangular shape depending on the diaphragm opening; an optical system that changes a focal length to vary a second magnification between the optical image of the optical image converting means and the optical image taken into the imaging means; an X-ray device comprising means for controlling the aperture opening of the rectangular diaphragm based on the second magnification; and means for controlling the aperture opening of the circular diaphragm based on the first magnification. Diagnostic equipment. (2) In an X-ray diagnostic apparatus in which an optical image obtained by converting X-rays by a light image converting means is converted into a video signal by an imaging means via an optical system and a fluoroscopic image of a subject is displayed, the optical image converting means means for varying a first magnification of the X-ray image on the input surface and the optical image on the output surface; an optical diaphragm provided in the optical system for limiting the amount of light from the light image conversion means by an aperture opening; an optical system that changes a focal length to vary a second magnification between the optical image of the light image converting means and the optical image taken into the imaging means; An X-ray diagnostic apparatus characterized by comprising means for determining the amount of light incident on the photographing means by the optical system using a magnification and controlling the aperture opening of the optical diaphragm based on the amount of incident light. (3) In an X-ray diagnostic apparatus in which an optical image obtained by converting X-rays by a light image converting means is converted into a video signal by an imaging means via an optical system and a fluoroscopic image of a subject is displayed, the optical image converting means means for varying a first magnification between an X-ray image on an input surface and an optical image on an output surface; and a second magnification between an optical image on an output surface of the optical image converting means and an optical image taken into the imaging means. an optical system that varies the magnification of the image; and a means for determining an image magnification based on the first and second magnifications and generating a scale for display from the magnification, and displaying the scale on the perspective image. An X-ray diagnostic device characterized by: (4) Setting a desired field of view in an X-ray diagnostic device that displays a fluoroscopic image of a subject by converting an optical image of X-rays by an optical image conversion device into a video signal by an imaging device via an optical system. and a first magnification between an X-ray image on the input surface and an optical image on the output surface of the light image conversion means, and an optical image on the output surface of the light image conversion means based on the field of view information from the means. means for determining a second magnification of the optical image taken into the imaging means; and means for setting an input size for inputting the transmitted X-rays of the optical image conversion means based on the first magnification; An X-ray diagnostic apparatus comprising: means for changing the focal length of the optical system based on the second magnification.