JPH07265286A - X-ray diagnostic system - Google Patents

Abstract

PURPOSE:To provide an X-ray diagnostic system capable of outputting an image in the actual size. CONSTITUTION:This X-ray diagnostic system is provided with an X-ray tube, a top plate, an image intensifier, a TV camera photographing the optical image from the image intensifier, an output device 3 outputting the image photographed by the TV camera, an SID measurement section 13 determining the first distance from the X-ray tube to the image intensifier, an FSD measurement section 14 determining the second distance from the X-ray tube to the center of an object, magnification factor calculation sections 11, 12, 6 calculating the magnification factors from the first distance, second distance, image output size, and the size of the X-ray incidence face, and an image processing section 2 expanding the image from the TV camera based on the magnification factor and feeding it to the output device 3 so that the image photographed by the TV camera is magnified to the same size as the object and outputted from the output device 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray diagnostic apparatus for picking up an X-ray image transmitted through a subject with a TV camera through an image intensifier.

[0002]

2. Description of the Related Art Conventionally, an X-ray diagnostic apparatus of this type has a TV
A monitor or an imager is provided as an output device that outputs an image captured by a camera. An imager is a TV that scans film with a laser beam, for example.
This is a device for imprinting an image captured by a camera on a film. Image processing for appropriately enlarging or reducing the image captured by the TV camera so that the image captured by the TV camera is displayed and imprinted on the entire range of the angle of view of the monitor or film on the X-ray diagnostic apparatus. A device is provided. Due to such enlargement / reduction, an image displayed on a monitor or imaged on a film by an imager is often not in actual size. Therefore, the conventional X-ray diagnostic apparatus has a problem in that it is difficult for the radiologist to intuitively grasp the size of the region of interest when the image is interpreted.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to address the above-mentioned circumstances, and an object thereof is to provide an X-ray diagnostic apparatus capable of outputting an image at an actual size.

[0004]

According to a first aspect of the present invention, there is provided an X-ray generating means for irradiating X-rays from a focal point, a top plate on which a subject is placed, and the X-ray generating means. X-ray light conversion means that are arranged so as to face each other with the subject in between and that convert the transmitted X-rays of the subject that have entered from the X-ray incident surface into light.
An image pickup unit for picking up an optical image output from the X-ray light conversion unit, an output device for outputting the image picked up by the image pickup unit, and the X-ray from the focus of the X-ray generation unit.
The means for obtaining a first distance to the X-ray incident surface of the line light converting means, the means for obtaining a second distance from the focus of the X-ray generating means to the center of the subject, and the imaging means. The magnification ratio is calculated from the first distance, the second distance, the image output size, and the size of the X-ray entrance surface so that the captured image is output from the output device at the same magnification as the subject. The X-ray diagnostic apparatus is characterized in that the X-ray diagnostic apparatus is provided with: a magnifying power calculation means; and an image processing means for magnifying the image from the image pickup means based on the magnifying power and supplying the image to the output device.

According to a second aspect of the present invention, X-ray generating means for irradiating X-rays from a focal point, a top plate for mounting a subject, and the X-ray generating means via the subject are provided. X-ray light conversion means arranged facing each other and converting transmitted X-rays of the subject incident from the X-ray incident surface into light, and imaging means for capturing an optical image output from the X-ray light conversion means. An output device for outputting an image picked up by the image pickup means, and a distance from the focal point of the X-ray generation means to the X-ray incident surface of the X-ray light conversion means from the focal point of the X-ray generation means. First magnifying power calculating means for calculating a first magnifying power by dividing by the distance to the center of the subject, and an image output size specific to the output device, the X-ray incident surface of the X-ray light converting means. Second to calculate the second magnification by dividing by the size of
An enlargement ratio calculating means, a third enlargement ratio calculating means for calculating the third enlargement ratio by multiplying the first enlargement ratio by the second enlargement ratio, and an image picked up by the image pickup means. In order to output from the output device at the same size as the sample, the third
The X-ray diagnostic apparatus is characterized by further comprising image processing means for enlarging an image from the image pickup means at a magnification of a reciprocal of the enlargement ratio and supplying the image to the output device.

According to a third aspect of the present invention, the X-ray generating means for irradiating X-rays, the top plate for mounting the subject, and the X-ray generating means are opposed to each other via the subject. Placed
The size of the X-ray incident surface is variable, and the X-ray light converting means for converting the transmitted X-rays of the subject incident from the X-ray incident surface into light is output from the X-ray light converting means. An image pickup means for picking up an optical image, an output device for outputting the image picked up by the image pickup means, and a distance from the focus of the X-ray generation means to the X-ray incident surface of the X-ray light conversion means are set as above. First magnifying power calculation means for calculating a first magnifying power by dividing by the distance from the focus of the X-ray generating means to the center of the subject, and an image output size specific to the output device, the X-ray light Second magnifying power calculation means for calculating a second magnifying power by dividing by the size of the X-ray incidence surface of the converting means, and third magnifying power obtained by multiplying the first magnifying power by the second magnifying power. The rate is 1 and the image taken by the imaging means is at the same size as the subject. An X-ray diagnostic apparatus characterized by comprising a means for varying the size of the X-ray incidence plane of the X-ray light conversion means so as to be outputted from the serial output device.

According to a fourth aspect of the present invention, X-ray generating means for irradiating X-rays, a top plate on which a subject is placed, and the X-ray generating means are opposed to each other via the subject. Placed
It has an X-ray entrance surface whose size can be changed in stages
X-ray light conversion means for converting the transmitted X-rays of the subject incident from the ray incident surface into light, imaging means for imaging the optical image output from the X-ray light conversion means, and imaging by the imaging means. An output device for outputting an image and a distance from the focus of the X-ray generation means to the X-ray incident surface of the X-ray light conversion means from the focus of the X-ray generation means to the center of the subject. First magnification factor calculating means for calculating a first magnification factor by dividing by distance, and image output size specific to the output device is obtained by dividing by the size of the X-ray incident surface of the X-ray light converting means. So that the third enlargement ratio obtained by multiplying the second enlargement ratio by the first enlargement ratio is closest to 1.
The selecting means for selecting the size of the X-ray incident surface of the X-ray light converting means, and the X-ray light converting means for the image output size peculiar to the output device are selected by the selecting means.
The above 1st to 4th magnification factor divided by the size of the plane of incidence
Of the fifth magnification ratio so that the image captured by the imaging means is output from the output device at the same magnification as the subject. And an image processing means for enlarging the image from the image pickup means and supplying the image to the output device.

[0008]

According to any of the above-mentioned inventions, the image picked up by the image pickup means is output in actual size. According to the third aspect of the invention, the deterioration of the spatial resolution peculiar to the image pickup means is suppressed. Further, according to the invention described in claim 4, the spatial resolution peculiar to the image pickup means is not lowered.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the X-ray diagnostic apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the X-ray diagnostic apparatus according to the first embodiment. FIG. 2 is a side view showing the structure of the X-ray imaging system of FIG. In this embodiment, T
The image captured by the V camera is output from the output device at the same magnification as the subject.

As shown in FIG. 2, the X-ray imaging system 1 includes an X-ray tube 21, a diaphragm device 22, a top plate 23, an image intensifier 24, an optical system 25, and a TV camera 26.
The X-ray tube 21 and the image intensifier 24 are independently held by an elevating mechanism (not shown) so as to be vertically movable, and are set to arbitrary heights desired by an inspector. The X-ray tube 21 emits X-rays from the focal point F. The X-rays are applied to the subject P mounted on the top plate 23 via the diaphragm device 22. The diaphragm device 22 normally provides two X-ray shielding plates so that they can approach and separate in the same plane, and changes the distance between the two X-ray shielding plates (opening of the slit) to open the X-ray irradiation field. It is for limiting. The image intensifier 24 as an X-ray light converting means for converting X-rays into light has an input fluorescent screen as an X-ray incident surface of a predetermined diameter and a photocathode behind the input fluorescent screen at the input part, and an output part at the output part. It is a vacuum tube having an output fluorescent screen for light emission, and the transmitted X-rays that have passed through the subject P are reduced to form an input fluorescent screen image on the output fluorescent screen by an electronic lens system, and the input fluorescent screen image is displayed with its brightness. Is amplified and output from the output phosphor screen. The diameter of the image intensifier 24 is, for example, 12 inches, 9 inches, 7
Inches are common and are fixed to one of these sizes here. Image intensifier 2
The optical image output from 4 is captured by the TV camera 26 via the optical system 25. The TV camera 26 may be either an image pickup tube or a CCD camera.

The image signal output from the TV camera 26 is output from the output device 3 via the image processing section 2.
The image processing unit 2 receives the total expansion rate MA from the total expansion rate calculation unit 6.
G.total is supplied. The image processing unit 2 uses this magnifying power MAG.
The image from the TV camera 26 is enlarged by the reciprocal of total. The output device 3 includes a monitor 4 and an imager 5. The imager 5 is, for example, a device for scanning a film with a laser beam and imprinting an image captured by the TV camera 26 on the film. The monitor 4 is generally size-expressed in inches such as 14 inches or 20 inches, and displays an image at an angle of view of, for example, 14 inches × 0.9. The imager 5 is loaded with films of various sizes, and a film of any film size can be selected as a film on which an image is projected. Further, the imager 5 can arbitrarily select the number of divisions of the film when a plurality of images are printed on one film. 1 for the film loaded in the imager 5
There are various sizes such as 4 inches, and the imager 5 projects an image at an angle of view of 14 inches × 0.9, for example.

The output image size input section 7 is for inputting the size of the output image, and includes a film size input section 8 for inputting the film size selected by the imager 5 and an imager 5 for the imager 5. A division number input unit 9 for inputting the division number of the selected film and a monitor size input unit 10 for inputting the size of the monitor 4 are included.

The output image size input from the output image size input unit 7 is sent to the system system enlargement ratio calculation unit 11. The system magnifying power calculation unit 11 divides the output image size by the size (diameter) of the X-ray incident surface specific to the image intensifier 24 to calculate the system magnifying power MA.
Find G.sys. The system expansion rate MAG.sys is sent to the total expansion rate calculation unit 6.

An SID measuring unit 13 and an FSD measuring unit 14 are connected to the geometrical enlargement ratio calculating unit 12. The SID measuring unit 13 measures the distance from the X-ray tube 21 to the X-ray incident surface of the image intensifier 24 (generally called “SID”; see FIG. 2). Therefore, the SID measuring unit 13 is provided with a sensor such as a rotary encoder that detects the vertical position of the X-ray tube 21, and a sensor such as a rotary encoder that detects the vertical position of the image intensifier 24. The SID is measured from the detection result of. Further, the FSD measurement unit 14 measures the distance from the center of the subject P to the X-ray incident surface of the image intensifier 24 (generally called “FSD”; see FIG. 2). Therefore, the FSD measuring unit 14 has a top plate 23.
A sensor such as a rotary encoder for detecting the vertical position of the image intensifier 24 is provided, and a sensor such as a rotary encoder for detecting the vertical position of the image intensifier 24 is provided.
The FSD is measured from the detection results of both sensors. Subject P
There is a slight distance between the center and the top plate 23. The FSD measurement unit 14 holds the standard value of this distance and adds it to the position of the table 23 to estimate the vertical position of the center of the subject P.

The geometrical enlargement ratio calculator 12 obtains the geometrical enlargement ratio MAG.geo by MAG.geo = SID / (SID-FSD). The geometric expansion rate MAG.geo is sent to the combined expansion rate calculation unit 6.

The total expansion rate calculation unit 6 calculates the geometric expansion rate MAG.geo calculated by the geometric expansion rate calculation unit 12 and the system expansion rate calculated by the system expansion rate calculation unit 11.
Multiply with MAG.sys to obtain the total expansion rate MAG.total. The total enlargement ratio MAG.total is sent to the image processing unit 2. The image processing unit 2 uses T as the reciprocal of this magnification MAG.total.
The image from the V camera 26 is enlarged and supplied to the output device 3.

Next, the operation of this embodiment will be described. Prior to the X-ray photography, the X-ray tube 21 and the image intensifier 24 are set to the examiner's arbitrary height. SI
The D measurement unit 13 measures the distance (SID) from the X-ray tube 21 to the X-ray incident surface of the image intensifier 24, and the FSD measurement unit 14 makes the X-ray incidence of the image intensifier 24 from the center of the subject P. The distance to the surface (FSD) is measured.

The geometrical enlargement ratio calculator 12 obtains the geometrical enlargement ratio MAG.geo by MAG.geo = SID / (SID-FSD). The geometric expansion rate MAG.geo is sent to the combined expansion rate calculation unit 6. Further, the size of the output image is input from the output image size input unit 7 prior to the X-ray imaging. Specifically, the film size selected by the imager 5 is input from the film size input section 8,
The division number of the film selected by the imager 5 is input from the division number input unit 9, and the size of the monitor 4 is input from the monitor size input unit 10. 3 (a) and 3 (b) show a film divided into four and six parts, respectively. The output image size S in the case of film output is calculated by S = a × α, where a is the film size and α is a coefficient corresponding to the number of divisions. α is set to 2 for 4 divisions, 2 for 4 divisions, and 3 for 9 divisions. The output image size S thus obtained is calculated by the system system enlargement ratio calculation unit 11,
System intensification ratio divided by the inch size, which indicates the aperture of the X-ray entrance surface specific to the image intensifier 24.
MAG.sys is required. This system expansion rate MAG.sys
Is sent to the total enlargement ratio calculation unit 6.

FIG. 4 (a) shows an image from the TV camera 26, FIG. 4 (b) shows a state in which the image from the TV camera 26 is displayed at all angles of view of the film, and FIG. 4 (c). To T
The image from the V-camera 26 is added by the image processing unit 2 to the total magnification MA
It shows the state of being enlarged and imprinted on the film according to the reciprocal of G.total. The image from the TV camera 26 is enlarged in the image processing unit 2 by the reciprocal of the total enlargement ratio MAG.total, and is displayed on the monitor 4 of the output device 3 in the actual size, or is copied from the imager 5 to the film in the actual size. Get caught. Therefore, the image interpretation doctor can interpret the image output at the actual size. As a result, it is possible to proceed with the interpretation quickly. Further, the interpreting doctor does not need to manually adjust the enlargement ratio so that the image is output in actual size, and the burden on the interpreting doctor is reduced.

Now, let us consider concrete numerical values. SI
D = 1100 mm, FSD = 220 mm, image intensifier 24 aperture 12 inches, film size 14 inches, angle of view 0.9, division number 1. MAG.geo = 1100 / (1100-220) = 1.2 MAG.sys = (14 x 0.9 x 1) / 12 = 1.05 MAG.total = MAG.geo x MAG.sys = 1.26 Therefore, the TV camera in the image processing unit 2 By enlarging (reducing in practice) the image from 26 by the reciprocal 1 / 1.26 = 0.79 of MAG.total, the image is output at the actual size.

In the above description, in order to measure the distance FSD from the center of the object P to the X-ray incident surface of the image intensifier 24, the FSD measuring unit 14 measures the distance from the center of the object P to the top plate 23. By holding the standard value of the distance and adding it to the position of the top plate 23, the vertical position of the center of the subject P is estimated, and the FSD is measured by subtracting the vertical position of the image intensifier 24 from this vertical position. However, instead of such a method, the following method may be adopted. In this method, the X-ray tube 21 side is equipped with a non-contact type distance meter using ultrasonic waves, laser, or the like as a medium. The distance D1 from the focus F of the X-ray tube 21 to the body surface of the subject P is measured by the non-contact distance meter. The SID-FSD is obtained by adding the distance D2 from the body surface of the subject P to the center to this distance D1. The distance D2 from the body surface of the subject P to the center is measured from the vertical position of the X-ray tube 21 and the vertical position of the top plate 23.
When the distance from the top plate 23 to the top plate 23 is D3, D2 = (D3-D1) / 2 is obtained. With this method, the geometrical enlargement ratio can be accurately obtained corresponding to the individual difference in physique.

Next, the second embodiment will be described. FIG. 5 is a block diagram of the X-ray diagnostic apparatus according to the second embodiment. The same parts as those in FIG. In this embodiment, as the image intensifier, an image intensifier having a caliber of 12 inches, 9 inches, and 7 inches is used. The geometric magnification MAG.geo from the geometric magnification calculation unit 12 and the output image size input unit 7
The output image size from the above is supplied to the II size setting unit 30. The II size setting unit 30 sets the aperture of the image intensifier as X, and the aperture geometrical enlargement ratio MAG.ge.
From o and the output image size S, the aperture of the image intensifier whose MAG.total by MAG.total = MAG.geo × (S / X) is closest to 1 is selected.

For example, assuming that the geometrical enlargement ratio is MAG.geo = 1.2, the film size is 14 inches, the angle of view is 0.9, and the number of divisions is 2, then MAG.total = 1.2 x ((14 x 0.9 x 0.5) / X) is the most An image intensifier caliber close to is selected, in this example a 7 inch caliber.

The aperture information of the image intensifier selected by the II size setting unit 30 is sent to the II size switching unit 31, and the aperture of the image intensifier is 7
Switched to inches.

Further, the aperture information of the image intensifier selected by the II size setting unit 30 is also sent to the system magnification ratio calculating unit 11. The subsequent processing is the same as in the case of the first embodiment described above, and the system magnification ratio calculation unit 11 calculates the system magnification ratio from the aperture of the selected image intensifier and the output image size. The system system enlargement ratio is multiplied by the geometrical enlargement ratio, the combined enlargement ratio calculation unit 6 calculates the combined enlargement ratio, and the image processing unit 2 enlarges the image from the TV camera 26 according to the reciprocal of the combined enlargement ratio. And output from the output device 3. In the above numerical example, the total enlargement ratio is 1.08, and the image is enlarged (reduced in this case) by the reciprocal 1 / 1.08 = 0.93 of this total enlargement ratio.

According to this embodiment, the effect of the first embodiment can be obtained, and since the enlargement ratio in the image processing unit 2 is close to 1, the effect of suppressing the decrease in the spatial resolution peculiar to the TV camera can be obtained. is there.

If an image intensifier with a continuously variable aperture is used, the MA
You can select the aperture of the image intensifier that makes G.total the most 1. In this case, it is possible to output at the actual size without performing the enlargement processing in the image processing unit 2, and the spatial resolution peculiar to the TV camera can be maintained.

The present invention is not limited to the above-described embodiments, but can be implemented with various modifications. In the above description, it is stated that the image is always output at the actual size, but it is possible to switch between this actual size function and the conventional normal function in which an image captured by a normal TV camera is output to the front of the output image size. Good.

[0029]

As described above, according to any one of the first, second, third and fourth aspects of the present invention, the image picked up by the image pickup means can be output in actual size. A line diagnostic device can be provided. According to the third aspect of the invention, it is possible to provide the X-ray diagnostic apparatus in which the deterioration of the spatial resolution peculiar to the imaging means is suppressed. Further, according to the invention described in claim 4, it is possible to provide an X-ray diagnostic apparatus in which the spatial resolution inherent in the imaging means is not deteriorated.

[Brief description of drawings]

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

FIG. 2 is a side view showing the structure of the X-ray imaging system shown in FIG.

FIG. 3 is a diagram showing an example of film division.

FIG. 4 is a diagram showing an output example of a film.

FIG. 5 is a block diagram showing a configuration of an X-ray diagnostic apparatus according to a second embodiment.

[Explanation of symbols]

1 ... X-ray imaging system, 2 ... Image processing unit,
5 ... Imager, 6 ... Combined enlargement ratio calculation unit, 7 ... Output image size input unit, 8 ... Film size input unit, 9 ... Division number input unit,
10 ... Monitor size input unit, 11 ... System system enlargement ratio calculation unit, 12 ... Geometric enlargement ratio calculation unit, 13 ... SID
Measuring unit, 14 ... FSD measuring unit.

Claims (4)

[Claims] 1. An X-ray generation unit that irradiates X-rays from a focal point, a top plate on which a subject is placed, and an X-ray generation unit that is disposed so as to face the X-ray generation unit with the subject interposed therebetween. Transmission X of the subject incident from the ray incident surface
X-ray light converting means for converting rays into light, image pickup means for picking up an optical image output from the X-ray light converting means, an output device for outputting an image picked up by the image pickup means, and the X-ray A means for obtaining a first distance from the focal point of the generating means to the X-ray incident surface of the X-ray light converting means, and a second distance from the focal point of the X-ray generating means to the center of the subject. The first distance, the second distance, the image output size, and the X-ray incidence so that the image captured by the image capturing unit is output from the output device at the same magnification as the subject. It is characterized by further comprising: an enlargement ratio calculating means for calculating an enlargement ratio from the size of the surface; and an image processing means for enlarging the image from the image pickup means based on the enlargement ratio and supplying the image to the output device. X-ray diagnostic device. 2. An X-ray generation unit that irradiates X-rays from a focal point, a top plate on which a subject is placed, and an X-ray generation unit that is arranged to face the X-ray generation unit with the subject interposed therebetween. Transmission X of the subject incident from the ray incident surface
X-ray light converting means for converting rays into light, image pickup means for picking up an optical image output from the X-ray light converting means, an output device for outputting an image picked up by the image pickup means, and the X-ray The first magnification is calculated by dividing the distance from the focus of the generating means to the X-ray incident surface of the X-ray light converting means by the distance from the focus of the X-ray generating means to the center of the subject. And a second magnification calculation for calculating a second magnification by dividing an image output size specific to the output device by the size of the X-ray incident surface of the X-ray light conversion means. Means, third enlargement ratio calculation means for calculating a third enlargement ratio by multiplying the first enlargement ratio by the second enlargement ratio, and the image taken by the imaging means is the subject or the like. Of the third enlargement ratio so that the output device outputs the output image at the third magnification ratio. X-ray diagnostic apparatus characterized by comprising an image processing means for supplying the output device by enlarging processing the image from the imaging unit by the number of magnifications. 3. An X-ray generation unit for irradiating X-rays, a top plate for mounting a subject, and an X-ray incidence unit which are arranged so as to face the X-ray generation unit with the subject therebetween. The size of the surface is variable, and
X-ray light conversion means for converting the transmitted X-rays of the subject incident from the ray incident surface into light, image pickup means for picking up an optical image output from the X-ray light conversion means, and an image picked up by the image pickup means. An output device for outputting an image, and a distance from the focus of the X-ray generation means to the X-ray incident surface of the X-ray light conversion means from the focus of the X-ray generation means to the center of the subject. A first magnification calculating means for calculating a first magnification by dividing by a distance; and an image output size peculiar to the output device, divided by a size of the X-ray incident surface of the X-ray light converting means. Second enlargement ratio calculation means for calculating an enlargement ratio of 2, and a third enlargement ratio obtained by multiplying the first enlargement ratio by the second enlargement ratio becomes 1 and the image taken by the imaging means is The output device outputs the same size as the subject. X-ray diagnostic apparatus characterized by comprising a means for varying the size of the X-ray incidence plane of the line light conversion means. 4. An X-ray generation unit that irradiates X-rays, a top plate on which a subject is placed, and an X-ray generation unit that are arranged so as to face the X-ray generation unit with the subject in between and have a step size. And an X-ray light conversion unit for converting the transmitted X-rays of the subject incident from the X-ray incidence surface into light, and the X-ray light conversion unit outputs the X-ray light conversion unit. An image pickup unit that picks up an optical image, an output device that outputs the image picked up by the image pickup unit, and a distance from the focus of the X-ray generation unit to the X-ray incident surface of the X-ray light conversion unit are described above. First magnifying power calculating means for calculating a first magnifying power by dividing by a distance from the focus of the X-ray generating means to the center of the subject; and an image output size specific to the output device, the X-ray light The second magnification obtained by dividing by the size of the X-ray incidence surface of the conversion means A selection unit that selects the size of the X-ray incident surface of the X-ray light conversion unit so that the third magnification ratio obtained by multiplying the first magnification ratio is closest to 1; The fifth enlargement ratio is obtained by multiplying the fourth enlargement ratio obtained by dividing the image output size of the above by the size of the X-ray incident surface of the X-ray light conversion unit selected by the selection unit by the first enlargement ratio. And enlarging the image from the image pickup means by a reciprocal magnification of the fifth enlargement ratio so that the image picked up by the image pickup means is output from the output device at the same magnification as the subject. And an image processing unit for supplying the output device to the output device.