JPS6116370A - X-ray picture processor - Google Patents

Abstract

PURPOSE:To make a three-dimensional vision possible by storing alternately X-ray pictures, which are obtained by the stereo photographing method and subjecting these X-ray pictures to subtraction and outputting subtraction results. CONSTITUTION:X-ray pictures photographed at right and left focuses before and after injection of a contrast medium with respect to a body 4 to be examined are stored in the first - the fourth frame memories 11-14. X-ray pictures of the body 4 to be examined which are stored in four frame memories 11-14 are subjected to the subtraction processing by an arithmetic unit 10 to obtain subtraction video signals. Subtraction video signals are stored alternately in the fifth frame memory 16 and the sixth frame memory 17 and are converted to analog signals by D/A converters 18 and 19 and are supplied to two properly arranged monitors 20 and 21. Pictures on monitors 20 and 21 are observed to attain the three-dimensional vision of a subtraction image.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention converts X-ray images in xi diagnosis into video output using an X-ray television camera, and digitalizes the X-ray images before angiography and the X-ray images after contrast. The present invention relates to an X-ray image processing apparatus that performs subtraction after conversion to extract only a contrasted region, and particularly relates to an X-ray image processing apparatus that enables stereoscopic viewing.

[Technical background of the invention and its problems] In X-ray diagnosis, especially in angiography, X-ray images taken using an X-ray television camera are
A digital subtraction method is now used that performs /D conversion, digital subtraction, and extracts only the contrast area.

In this digital subtraction method, a contrast medium is injected into a blood vessel + i6 state X-ray image @ (hereinafter referred to as a mask image) is subjected to △/D conversion, one screen of information is stored, and then the contrast medium is An X-ray image (hereinafter referred to as a contrast image) of the state in which the injection is performed is stored.

These two X-ray images are digitally subtracted, and in areas not affected by the contrast agent, both the mask image and the contrast image have the same video signal level value, and the subtraction result is zero. On the other hand, at the site where the contrast agent was injected, the contrast image shows XI compared to the mask image.
! Absorption increases, causing a difference in the video signal, and an image of the signal level difference appears as a subtraction image. By D/A converting this subtraction image and recombining it on a television monitor, the contrast region can be extracted and information useful for diagnosis can be obtained.

However, in the case of imaged areas, especially areas with intricate structures of thin blood vessels such as the head and abdomen, it is difficult to recognize the three-dimensional positional relationship even when observing the extracted blood vessel images. .

On the other hand, as a means of X-ray diagnosis, stereo imaging using X-ray film is used, which enables stereoscopic viewing and greatly contributes to the recognition of three-dimensional positional relationships. In general imaging methods, the X-ray tube and the subject are arranged perpendicularly, whereas in stereo imaging, two It has two X-ray focal points, and two X-ray films taken at each focal point and developed are placed on the left and right, and stereoscopic viewing is possible by observing from a required distance. However, in the above-mentioned conventional digital subtraction method, since the mask image and contrast image storage means have a one-to-one configuration, it is not possible to employ the stereo imaging method.

[Object of the Invention] The present invention was made based on the above-mentioned circumstances, and an object of the present invention is to provide an image processing device that enables stereoscopic viewing using left and right subtraction images.

[Summary of the Invention] The present invention provides an X-ray image processing device that digitally subtracts a pre-contrast X-ray image and a post-contrast X-ray image to extract only a contrast area. The first step is to store images alternately. a second storage means; The first feature is that it is equipped with a calculation means for alternately subtracting each of the xm images from the second storage means, and a means for simultaneously outputting the subtracted images from this calculation means. A combined subtraction image is projected to enable stereoscopic vision, and the second feature is polarized glasses having the configuration of the first feature with transmittance switched independently on the left and right sides;
By adding a means to control the transmission state of the polarized glasses in synchronization with the image switching, subtraction images of two planes are projected alternately, and the transmittance is switched alternately between the left and right sides in synchronization with the image switching. Observations are made using a polarizing camera that allows stereoscopic viewing.

[Embodiment of the Invention] A digital fluorography apparatus according to the present invention will be described below according to an embodiment shown in FIG. In Figure 1, 1
1 is an X-ray tube for stereo imaging, and this xi tube 1 is of a twin-focus type having two sets of filaments at the cathode and two focal points spaced a predetermined distance apart on the anode. Reference numeral 2 denotes a high voltage generator that supplies high voltage power to the X-ray tube 1. 3 is XI! This is an image intensity 1 ear (hereinafter abbreviated as 1.1.) that converts the transmitted X-rays xgl irradiated onto the subject 4 from the IL tube 1 into an optical image. 5 is an optical system that forms the optical image from 1.1.3. Reference numeral 6 denotes a television camera that converts the output optical image from T, 1.3 through the optical system 5 into a video signal using a built-in image pickup tube. 7 inputs the video signal from this television camera 5,
This is an image processing device that converts into digital data, performs subtraction processing on images of the subject 4 before and after injection of a contrast medium, and then outputs the images again as analog images (video output).

This image processing device 7 includes a logarithmic converter 8 that logarithmically converts and amplifies the video signal from the television camera 6, an A/D converter 9 that converts the output of the logarithmically converter 8 into a digital quantity, and this A/D converter 9 that converts the output of the logarithmic converter 8 into a digital quantity. A calculation unit 10 performs subtraction image processing on the output of the /D converter 9, and a first unit stores an X-ray image taken at the left focal point before injecting the contrast agent into the subject 4.
a second frame memory 12 that stores an X-ray image taken with the right focus before injection, and a third frame memory 13 that stores an X-ray image taken with the left focus after injection. , a fourth frame memory 14 for storing an X-ray image photographed by the right focus of the injection, and an automatic focus switching command for giving a command to the high voltage generator 2 to select the left focus and right focus of the X-ray tube 1. Vessel 15. And the first. a fifth frame memory 16 in which the subtraction image at the left focus generated by the X-ray image from the third frame memory 11.13 is stored; Xf from fourth frame memory 12.14! A sixth frame memory 17 stores a subtraction image at the right focus generated by the image, and a first frame memory 17 converts the outputs of these 5° and 6th frame memories 16 and 17 into analog quantities.
It is composed of a second D/A converter 189.

20.21 are respectively the 1st. Second D/A converter 18.19
This is a television monitor that displays subtraction images of the left focus and right focus using the output of the .

Next, the operation of this embodiment configured as described above will be described. That is, when the high voltage generated by the high voltage generator 2 is applied to the XM tube, X-rays are first emitted from the left focal point.

This X-ray is irradiated to the subject 4, and the transmitted X-ray is 1
．． 1.3, it is converted into an optical image. The optical image from 1.1.3 passes through the optical system 5, is projected onto the image pickup tube in the television camera 6, is converted into a video signal, and is output. This video output is input to the image processing device 7.

The video signal input to the image processing device 7 is converted into a digital signal by an A/D converter 9 via a logarithmic converter 8 as required. This digital video signal is subjected to appropriate arithmetic processing in the arithmetic unit 10 and stored in the first frame memory 11. What is stored in this first frame memory is an X-ray image taken at the left focal point of the subject 4 before contrast medium injection.

Next, the focus switching command device 15 issues a right focus selection command to the high voltage generator 2. The high voltage generator 2 switches the X-ray tube focal point selection to the right focal point, so that the high voltage
When applied to the ray tube 1, X-rays are emitted from the right focal point.

This X-ray goes through the same process as the left focal point and is stored in the second frame memory 12. What is stored in this second frame memory 12 is an X-ray image taken at the right focal point of the subject 4 before injection of the contrast medium.

Next, after the contrast medium is injected into the blood vessel, the focus switching command device 15 issues a left focus selection command to the high voltage generator 2 again. The high voltage generator 2 switches the X-ray tube focal point selection to the left focal point, and when high voltage is applied to the X-ray tube 1, X-rays are emitted from the left focal point again. This X-ray is stored in the third frame memory 13 through the above-described process. This third
What is stored in the frame memory 13 is an X-ray image photographed at the left focal point of the subject 4 after the contrast medium has been injected.

The focus switching command device 15 issues a right focus selection command to the high voltage generator 2 again. The high voltage generator 2 is
When the X-ray tube focal point selection is switched to the right focal point and a high voltage is applied to the X-ray tube, X-rays are emitted from the right focal point again. This X-ray undergoes the above process and is stored in the fourth frame memory 14. What is stored in this fourth frame memory 14 is an X-ray image taken at the right focal point of the subject 4 after the contrast agent has been injected.

The X-ray images of the subject 4 stored in these four frame memories 11, 12, 13 and 14 are subjected to subtraction processing in the calculation unit 10 to obtain subtraction video signals.

First, the focus switching command unit 15 sends the first frame memory 1
A command is issued to read the X-ray images stored in the first and third frame memories 13. As a result, the mask image and contrast image photographed at the left focal point are input to the arithmetic unit 10, subjected to subtraction processing, and then stored in the fifth frame memory 16.

Next, from the focus switching command device 15, the second frame memory 1
A command is issued to read the X-ray images stored in the second and fourth frame memories 14. As a result, the mask image and contrast image photographed at the right focal point are input to the arithmetic unit 10, subjected to subtraction processing, and then stored in the sixth frame memory 17. D/A converters 1 provided after the fifth frame memory and the sixth frame memory, respectively.
8.19, the above-mentioned subtraction images are converted into analog signals and output from the image processing device 7, respectively.

This analog signal is displayed on television monitors 20 and 21. Therefore, by arranging these two monitors at necessary positions and observing them, it becomes possible to view the subtraction image stereoscopically.

Next, another embodiment of the present invention will be described with reference to FIG. 2, in which parts common to those in FIG. 1 are given the same reference numerals. In the embodiment shown in Fig. 2, the process up to the synthesis of subtraction images is the same as that in Fig. 1, but when displaying the subtraction images on a television monitor, the left and right A switch 22 is provided at the output stage so that images depending on the focus are displayed alternately, and the input signal of the switch 22 is alternately switched in response to a command from the focus switching command device 15.

Furthermore, at the same time, this switching command signal is sent to the polarized glasses 23 whose transmittance is alternately switched between left and right.

According to such a configuration, when the TV monitor 20 is observed while wearing the polarized glasses 23 and the sub-1-raction image photographed with the left focal point is displayed on the TV monitor 20, the left side of the polarized glasses 23 The transmittance is high, and the transmittance for the right side is low, and the subtraction image is observed only with the left eye.

Conversely, when a subtraction image photographed with the right focus is displayed on the television monitor 20, the transmittance of the right side of the polarized glasses 23 is high and the transmittance of the left side is low, and the subtraction image is visible only to the right eye. Observe. With the above, stereoscopic viewing is possible with the display on one television monitor 20.

In the embodiment shown in FIGS. 1 and 2, one screen of the output image of the television camera 6 was explained when storing the X-ray image in the frame memory, but in reality, the output image from the television camera 6 is In order to improve the signal-to-noise ratio of the video signal, several screens are added and normalized by the number of additions.
A method of storing data in frame memory is adopted. In addition, in the above addition method, X-rays are emitted at the same focal point for a period corresponding to the necessary screen addition, and then the focus is switched and X-rays are exposed at the same focal point again for a period corresponding to the necessary screen addition. There is a method in which the focus is alternately switched and the required screen addition is performed based on the focus set by the 111eA.

Here, a specific example of implementing the latter method using three frame memories will be described with reference to the timing chart for writing to and reading from the frame memories shown in FIG. First, at the timing shown in FIG. 3(b), the first image shown in FIG. 3<a> is written by a write command to the first frame memory 11. Next, the R1 image is written into the second frame memory 12 at the timing shown in FIG. 3(d). Next, at the timing shown in FIG. 3(C), the L1 image of the first frame memory 11 is read out, and at the same time, it is added to the L2 image, and at the timing shown in FIG. 3(f), the L1 image is read out from the third frame memory Write to 13. Next, at the timing shown in FIG. 3(e), at the same time as reading out the R1 image from the second frame memory 12,
It is added to the R2 image and written into the first frame memory 11 at the timing shown in FIG. 3(b). In this process,
Currently, according to the timing shown in FIG. 3(f), an added image of Life and L2 images is written in the third frame memory 13, and an added image of R1 images and R2 images is written in the first frame memory 11. It's included. Then, reading from the third frame memory 13 becomes possible at the timing shown in FIG. 3(g). By continuing this process, the required number of screens can be added.

Note that the present invention is not limited to the embodiments described above and shown in the drawings.

For example, in FIG. 1, a platform using twin focus type X-ray tubes 1 is described, but stereo focusing may be realized by combining two general X-ray tubes. Furthermore, two X-ray tubes may be combined with different high voltage generators.

In addition, various modifications can be made without departing from the gist of the present invention.

[Effects of the Invention] As described above, the present invention provides an X11 image processing device that digitally subtracts an X-ray image before contrast and an X-ray image after contrast to extract only the contrast region. In the first step, X-ray images obtained by stereography are stored alternately. Second
a storage means, a calculation means for alternately subtracting each of the X-ray images from the first and second storage means, and a means for simultaneously outputting the subtracted images from the calculation means; , which has a configuration that includes polarized glasses whose transmittance can be switched independently on the left and right sides, and a means for adjusting the transmission state of the polarized glasses in synchronization with the switching of images. It is possible to provide an X-ray image processing device that enables stereoscopic viewing by observing with polarized glasses whose transmittance alternately switches between left and right sides in synchronization with projection and image switching.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram showing the configuration of one embodiment of the present invention when two television monitors are used, and FIG. 2 is a schematic block diagram showing the configuration of an embodiment of the present invention when one television monitor is used and polarized glasses are used in combination. A schematic block diagram showing the configuration of an embodiment of
The figure is a timing diagram regarding the illumination of an X-ray image in the application of the above embodiment. 1... X-ray tube for stereo imaging, 2... High voltage generator, 3... Image inlancifier (1, 1,
), 4... Subject, 5... Optical system, 6... Television camera, 7... Image processing device, 8... Logarithmic converter,
9... A/D converter, 10... Arithmetic unit, 11
~14.16.17...Frame memory, 15...
Focus switching command device, 18.19...D/A converter, 20
゜21...TV monitor, 22...Output switch, 2
3...Polarized glasses.

Claims (2)

[Claims] (1) In an X-ray image processing device that digitally subtracts the pre-contrast X-ray image and the post-contrast X-ray image to extract only the contrast area, X-ray images obtained by stereography are alternately stored. It includes first and second storage means, calculation means for alternately subtracting the respective X-ray images from the first and second storage means, and means for simultaneously outputting the subtracted images from the calculation means. An X-ray image processing device characterized by: (2) In an X-ray image processing device that digitally subtracts the pre-contrast X-ray image and the post-contrast X-ray image to extract only the contrast area, X-ray images obtained by stereography are alternately stored. first and second storage means, arithmetic means for alternately subtracting X-ray images from the first and second storage means, means for simultaneously outputting subtracted images from the arithmetic means; What is claimed is: 1. An X-ray image processing apparatus comprising: polarized glasses whose ratios can be switched independently for left and right sides; and means for controlling the transmission state of the polarized glasses in synchronization with switching of images.