JPH08130752A - Radiographic processing method and device therefor - Google Patents

Abstract

PURPOSE: To improve diagnosis accuracy and to facilitate a catheter operation by performing an image processing for enabling roadmapping at the time of stereo radioscopy in a radiation device, reducing noise and removing after- images. CONSTITUTION: Video signals outputted from a TV camera 420 are inputted to the A/D conversion part 510 of an image processing part and converted to digital signals, the digital signals are inputted to a pre-processing part 520 and the noise and the after-images are removed. Images for which the noise is reduced and the after-images of the previous images are removed by the pre-processing part 520 in such a manner are outputted to a masking image preparation part 530, a contrast image preparation part 540, a landmark part 560 and a scanning converter part 570. Thus, the noise is reduced, the after- images are effectively removed and roadmapping images capable of the stereo radioscopy are obtained. Thus, the tip direction of a catheter is three- dimensionally displayed by clear images with less noise of the images.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation image processing method and apparatus therefor, and more particularly to a radiation image processing method and apparatus therefor capable of stereoscopic fluoroscopy or stereo imaging.

[0002]

2. Description of the Related Art In recent years, with the technical improvement of TV cameras and TV monitors, imaging has been performed in various fields. Also in the field of X-ray diagnostic equipment, instead of capturing an X-ray image of the subject on an X-ray film, an X-ray is detected by an image intensifier.
An X-ray TV system has been developed which converts a line image into an optical image and displays a perspective image on a TV monitor. Here, a stereo X-ray tube having left and right two focal points is used as the X-ray tube,
A stereo X-ray TV system capable of stereoscopically seeing a subject is realized by alternately irradiating X-rays from left and right focal points and capturing left and right perspective images.

In such an X-ray TV system,
The left and right perspective images of X-rays emitted from the left and right focal points are detected by one image intensifier and one TV camera, but the left and right images are separated strictly by the left and right eyes. Need to observe. However, the TV camera has image components of one field and one frame before in the image signal of each field or each frame based on the afterimage characteristic of the shooting surface. It is not possible to observe them separately with the eyes, and the left and right perspective images are displayed in a crossed manner on the display screen, making the images difficult to see. The afterimage on the image pickup surface of the TV camera is usually about 10%.

In order to eliminate this afterimage, the image signal input for each frame and the output signal of the preceding frame are multiplied by a predetermined coefficient (negative coefficient) and then added to obtain the output signal of each frame. The recursive filter to be obtained is effective. However, with this method, although afterimages can be erased, noise cannot be reduced.

Further, in order to advance a catheter into a complicated blood vessel, it is necessary to three-dimensionally grasp the directions of the blood vessel and the catheter. However, since the X-ray image is a projected image from one side, the operator changes the direction of the X-ray and repeats fluoroscopy, and advances the catheter with a three-dimensional grasp. In this method, displaying blood vessels and displaying the direction of the tip of the catheter in three dimensions are very effective not only for the operability of the catheter but also for safety and reduction of exposure. Therefore,
A road map that superimposes a blood vessel image on a fluoroscopic image and displays the direction in which the catheter is advanced is very effective. However, the conventional radiographic image processing method and apparatus for performing stereoscopic fluoroscopy or stereoscopic imaging has a problem that a roadmap image cannot be obtained.

[0006]

As described above, the conventional radiographic image processing method and apparatus for performing stereoscopic fluoroscopy or stereoscopic imaging cannot reduce noise, and in addition, a roadmap image can be obtained. There was a problem of not having.

The present invention has been made based on the above circumstances, and a radiation image processing method and a method thereof, in which noise is reduced, afterimages are effectively removed, and a roadmap image is obtained even in stereoscopic fluoroscopy. The purpose is to provide a device.

[0008]

The present invention has taken the following means in order to solve the above problems. The radiographic image processing method of the present invention includes a first radiation image processing method that is arranged at a predetermined interval.
And a radiation image processing method for performing stereoscopic fluoroscopy of the subject by alternately irradiating the subject with radiation from the first and second focal points of the radiation generating means having two focal points. A first step of alternately exposing X-rays from the first and second focal points to create first and second mask images corresponding to those first and second perspective images;
After injecting a blood vessel contrast agent into the subject, X-rays are alternately emitted from the first and second focal points to obtain first and second contrast images corresponding to the third and fourth fluoroscopic images. A second step of creating, a first blood vessel image is created by taking a difference between the first mask image and the first contrast image, and a first blood vessel image is taken by taking a difference between the second mask image and the second contrast image. A third step of creating a two-vessel image, a fifth perspective image by X-ray exposure from the first focus and the first blood vessel image are superimposed to create a first roadmap image, and the second focus is created. 6th by X-ray exposure from
A fourth step of creating a second roadmap image by superimposing the fluoroscopic image and the second blood vessel image.

In order to reduce noise and remove afterimages, in the first step, the second step, and the fourth step, (1) the perspective image obtained at this time is multiplied by a predetermined first coefficient of 1 or less. The seventh perspective image and the eighth perspective image obtained by multiplying the perspective image obtained by the previous exposure from the same focus point by the second coefficient obtained by subtracting the first coefficient from 1 are added, Obtaining the first to sixth perspective images with reduced noise, (2) From the perspective image obtained by adding the seventh perspective image and the eighth perspective image, the previous X-ray exposure The first to sixth perspective images in which the afterimage of the image obtained by the previous exposure is removed by subtracting the ninth image obtained by multiplying the image obtained by the emission by a predetermined third coefficient It is desirable to further include:

Further, the radiographic image processing apparatus of the present invention has two focal points, a first focal point and a second focal point, which are arranged at a predetermined interval, and the first focal point and the second focal point for performing stereoscopic fluoroscopy of an object. It corresponds to radiation generating means for alternately irradiating the subject with radiation from a second focus and two types of first and second perspective images obtained by X-ray exposure from the first and second focus. Mask image creating means for creating first and second mask images, and two types of third and third obtained by X-ray irradiation from the first and second focal points after injecting a blood vessel contrast agent into the subject. A contrast image creating unit that creates first and second contrast images corresponding to the fourth perspective image, and a difference between the first mask image and the first contrast image is taken to create a first blood vessel image, and the first blood vessel image is created. With 2 mask images The blood vessel image creating means for creating a second blood vessel image by taking the difference from the second contrast image, and the fifth perspective image by X-ray exposure from the first focus and the first blood vessel image are superimposed. Roadmap image creating means for creating a first roadmap image and superimposing a sixth perspective image by X-ray irradiation from the second focus and the second blood vessel image to create a second roadmap image. It is characterized by having.

For noise reduction and afterimage removal, (1)
The first perspective coefficient is subtracted from 1 for the seventh perspective image obtained by multiplying the perspective image obtained at this time by a predetermined first coefficient of 1 or less, and for the perspective image obtained by irradiation from the same focus one time before. Noise reduction means for obtaining the first to sixth perspective images with reduced noise by adding and the eighth perspective image multiplied by the second coefficient, and (2) the seventh perspective image and the eighth perspective image. The 9th image obtained by multiplying the image obtained by the previous X-ray exposure by a predetermined third coefficient is subtracted from the perspective image obtained by adding It is desirable to further include afterimage removing means for obtaining the first to sixth perspective images from which the afterimage of the image obtained by the exposure is removed.

[0012]

As a result of taking the above-mentioned means, the following effects occur. As described above, according to the present invention, the image processing that enables the road map during stereoscopic fluoroscopy in the radiation apparatus is performed, and noise reduction, and since it is possible to remove the afterimage, noise is reduced, Effectively removes afterimages,
In addition, it is possible to obtain a roadmap image that allows stereo see-through. Therefore, since there is little noise in the image and the tip direction of the catheter can be stereoscopically displayed with a clear image, the accuracy of diagnosis can be improved and the catheter operation can be facilitated. It can contribute to improvement and reduction of exposure.

[0013]

Embodiments of the present invention will be described with reference to the drawings.
Hereinafter, a stereo X-ray device using X-rays as a radiation generation source will be described, but the present invention can be applied to any radiation generation device, not limited to X-rays, as long as the same fluoroscopic image can be obtained.

FIG. 1 is a schematic block diagram of a stereo X-ray apparatus according to an embodiment of the present invention. The stereo X-ray apparatus of the present invention includes a see-through switch 100, a display changeover switch 110, a blood vessel image extraction switch 120, an X-ray controller 200, an X-ray high voltage generator 210, a stereo X-ray tube 220, and Image intensifier 400
An optical system 410, a TV camera 420, an image processing unit 500, a TV monitor 600, and a polarization filter 610.
And polarizing glasses 620.

An operator such as a doctor turns on / off the see-through by using the see-through switch 100. Further, the display switching switch 110 switches between displaying and non-displaying the roadmap image. Further, the blood vessel image extraction switch 120 ends the fluoroscopy, and the contrast image is created subsequent to the creation of the mask image.

The X-ray controller 200 outputs a control signal for controlling the X-ray high-voltage generator 210 based on the fluoroscopic signal from the fluoroscopic switch 100 and the signal (for example, a timing signal) from the image processing section 500.

The X-ray high-voltage generator 210 is a stereo X-ray tube 22 based on a control signal from the X-ray controller 200.
A high voltage (high-voltage pulse) is applied to the left and right focal points of 0 at a predetermined timing.

The stereo X-ray tube 220 has left and right focal points L and R separated by a predetermined distance (usually 35 to 65 mm), and the left and right focal points L according to a high voltage pulse from the X-ray high voltage generator 210. , R are alternately irradiated at predetermined timing to the subject 300 with pulsed X-rays of predetermined energy.

The image intensifier 400 is arranged to face the stereo X-ray tube 220 with the subject 300 interposed therebetween. The X-ray image transmitted through the subject 300 is converted into an optical image by the image intensifier 400, and is incident on the TV camera 420 via an optical system 410 integrated with the image intensifier 400.

The TV camera 420 employs a non-interlaced system and outputs an image signal of one frame for each cycle. The image processing unit 500 inputs the image signal output from the TV camera 420, performs preprocessing (removal of noise and afterimage) described later in detail, and creates a roadmap image, and outputs a predetermined signal.

The TV monitor 600 receives the signal output from the image processing unit 500 and displays left and right perspective images based on pulse X-rays alternately emitted from the left and right focal points L and R of the stereo X-ray tube 220. Display alternately. TV monitor 60
In front of the 0 screen, a polarization filter 610 is provided for changing the polarization planes in association with this alternating display in order to perform stereoscopic viewing, and polarizing the left and right perspective images so that the vibrations of the light are orthogonal to each other. ing. The operator wears polarizing glasses 620 in which filters having the same polarization planes as the left and right polarization perspective images are placed on the left and right so that the left and right polarization perspective images can be observed only by the left and right eyes, and the TV monitor 600 is displayed. Observe the display image of.

The operation of the stereo X-ray apparatus constructed as above will be described. The X-ray high-voltage generator 210 is provided with fixed time intervals (a) and (b) from the left and right focal points L and R of the stereo X-ray tube 220, as shown in FIGS. 2 (a) and 2 (b).
The pulse X-ray is applied to the object 300
Irradiate. Since the left and right focal points L and R are separated by a predetermined distance, the perspective images of L and R obtained by the X-rays emitted from the focal points L and R are as shown in FIGS. 3 (a) and 3 (b). , The projection angles are different, and there is a predetermined parallax between them.
Occurs. Therefore, the subject can be stereoscopically viewed by separating them into both eyes and observing them separately.

The exposure timing of the pulsed X-ray and the operation cycle of the TV camera 420 are linked to each other, and the TV camera 42
The pulsed X-rays are emitted in synchronization with the 0 frame synchronization pulse. Therefore, as shown in FIG. 2B, when the pulse X-ray is emitted from the left focus L, the left perspective image is T
Output from the V camera 420, pulse X from right focus R
When the line is exposed, the perspective image on the right is the TV camera 420.
Output from However, since the TV camera 420 has the afterimage characteristic, the right and left perspective image signals have about the components of the right perspective image or the left perspective image of the previous frame as indicated by the diagonal lines in FIG. 2B. About 10% is included. This T
When the output of the V camera 420 is supplied to the image processing unit 500, the afterimage is erased by a preprocessing device (not shown), which will be described in detail later, and as shown in FIG. The left and right perspective images are alternately output from the image processing unit 500 in conjunction with the alternating exposure of the pulse X-rays, and the TV
It is displayed alternately on the monitor 600.

A specific configuration and operation of the image processing section 500 will be described with reference to FIGS. FIG. 4 is a diagram showing a configuration example of the image processing unit 500. Image processing unit 500
Is an analog / digital converter (hereinafter referred to as “A / D converter”) 510 that converts a video signal output from the TV camera 420 into a digital signal, a pre-processing unit 520 that removes noise and an afterimage, and a mask. A mask image creating unit 530 that creates an image, a contrast image creating unit 540 that creates a contrast image, a difference unit 550 that obtains the difference between the mask image and the contrast image, and a land that performs a superimposing process on the blood vessel image and the perspective image. Mark part 560,
Up scan the image that has been subjected to edging processing,
For example, the scan speed is converted by the scan converter unit 570 that converts the scan speed from one frame into four frames and switches the image after up-scanning to the TV monitor 600 by alternately switching between left and right at high speed. Digital-to-analog converter (hereinafter, "D / A converter") that converts a digital signal to an analog signal
580).

The image processing unit 50 configured as described above.
The operation of 0 will be specifically described. The video signal output from the TV camera 420 is input to the A / D converter 510 and converted into a digital signal by the A / D converter 510.

This digital signal is input to the preprocessing unit 520, and the noise and afterimage as described above are removed. A method of removing the noise and the residual image will be described with reference to FIG. FIG. 5 is a diagram showing a specific configuration example of the preprocessing unit 520.

The operation when the image on the right side is input will be described below. Note that parenthesized writing indicates the operation when the image on the left side is input. The digital signal R of the image on the right side (or the digital signal L of the image on the left side) output from the A / D converter 510 is input to the first multiplier 521, and the first multiplier 521 has a predetermined coefficient (this embodiment). In the example, the signal K · R (or K · L) obtained by multiplying the input signal by K is output.

The second multiplier 522 applies predetermined coefficients (in the present embodiment) to the image signals R _M and L _M stored in the first and second memories (ie, the right-hand processed image and the left-hand processed image immediately before). Then, a signal R _M (1
-K) (or L _M (1-K)) is output. In this case, K is a constant of 1 or less.

The adder 523 adds the outputs of the first multiplier 521 and the second multiplier 522, and as a result, K · R + R _M (1-K) (or K · L + L _M (1-
K)) is output. By the operation as described above, the image on the same focus side due to the previous exposure and the image obtained this time are superimposed, so that noise can be reduced.

Next, the noise-reduced addition signal KR + _RM (1-K) (or KL +) from the adder 523 is added.
L _M (1−K) is input to the subtractor 525. The subtractor 525 outputs a predetermined signal from the addition signal K · R + R _M (1-K) (or K · L + L _M (1-K)) to the image signal L _M (or R _M ) obtained by the previous exposure. coefficient (in this embodiment and a) by subtracting the signal from the third multiplier 524 multiplied by a result _{K · R + R M (1} -K) -aL M ( _{or, K · L + L M (} 1- K) -aR _M) to output. By this operation, the afterimage caused by the image obtained by the previous exposure can be removed. In this case, a is, for example, 0.1
Therefore, when 10% of the image is the afterimage,
Afterimages can be effectively removed.

The output of the subtractor 525 is the first selector 5
If the image being currently input is an image on the right side via 26, it is input to the first memory 527a, and if it is an image on the left side, the second image is input.
It is input to the memory 527b and temporarily stored in each memory.

The images temporarily stored in the first and second memories are called at predetermined timings and input to the second selector 528a and the third selector 528b.

The second selector 528a is the A / D converter 51.
An image obtained by exposure twice before the image signal input from 0 (that is, an image obtained by exposure once before at the same focal point)
Is output to the second multiplier 522, the mask image creation unit 530, and the like. In addition, the third selector 528b is the A / D converter 5
The image obtained by the exposure one time before the image signal input from 10 (that is, the image on the different focus side) is given to the third multiplier 52.
4 is output.

As described above, the image in which the noise is reduced by the main preprocessing unit 520 and the afterimage of the previous image is removed is the mask image creating unit 530, the contrast image creating unit 540, and the landmark unit 560. To the scan converter unit 570.

The mask image creating section 530 creates a mask image for creating a road map image. FIG. 6 is a diagram showing a specific configuration example of the mask image creation unit 530. The mask image is created before the injection of the blood vessel contrast agent.
In FIG. 6, the image before the blood vessel contrast agent injection input from the pre-processing circuit 520 is the third memory 53 if the image currently input via the fourth selector 531 is the right image.
2 and the image on the left side is input to the fourth memory 533 and temporarily stored as a mask image.
Then, the mask images temporarily stored in the third and fourth memories 532 and 533 are called at a predetermined timing and output to the difference unit 550 via the fifth selector 534. In this case, the third and fourth memories 5
The images of 32 and 533 are designed to be stored once, but the images are acquired a predetermined number of times, the acquired images are added, and the added image is divided by the number of additions, and the average is calculated. A mask image may be created. In that case, a mask image with further reduced noise can be obtained.

The contrast image creating section 540 creates a contrast image for creating a road map image. FIG. 7 is a diagram illustrating a specific configuration example of the contrast image creation unit 540.

The contrast image is created after the injection of the vascular contrast agent. In FIG. 7, the image after the injection of the blood vessel contrast agent is input from the preprocessing unit 520 to the comparator 541. Comparator 5
An image obtained by the previous exposure (that is, an image on the same focus side by the previous exposure) is input to 41, and the result is output. In this case, the comparator 541 performs peak hold processing in which the maximum values of each pixel are collected from the continuous image to form one image. Then, the image output from the comparator 541 is input to the fifth memory 543 via the sixth selector 542 if the image is the right image, and is input to the sixth memory 544 if the image is the left image. Then, each is temporarily stored as a mask image. And the fifth and sixth
The mask images temporarily stored in the memories 543 and 544 are called at a predetermined timing and output to the difference unit 550 via the seventh selector 545.

The difference section 550 takes the difference between the mask image and the contrast image created as described above, and extracts the blood vessel image. FIG. 8 is a diagram showing a specific configuration example of the difference unit 550.

In FIG. 8, the mask image is input to the first logarithmic converter 551 for logarithmic conversion, and the contrast image is input to the second logarithmic converter 552 for logarithmic conversion. Then, the logarithmically converted mask image and contrast image are input to the subtractor 553, and the subtractor 553 subtracts the mask image from the contrast image to obtain a blood vessel image.

The landmark section 560 performs a superimposing process on the blood vessel image and the fluoroscopic image. FIG. 9 shows the landmark portion 56.
It is a figure which shows the specific structural example of 0. After the acquisition of the contrast images, the blood vessel image output from the difference unit 550 is input to the multiplier 561, which multiplies the blood vessel image by a predetermined coefficient (for example, 1 / b) to adder 5.
62. In addition to the output of the multiplier 561, the adder 562 inputs the fluoroscopic image from the preprocessing unit 520, adds the blood vessel image and the fluoroscopic image, and obtains a roadmap image obtained by superimposing the blood vessel image on the fluoroscopic image. Scan converter section 5
Output to 70.

The scan converter unit 570 temporarily stores the roadmap image and the perspective image input from the preprocessing unit 510 in a memory, reads the roadmap image stored in the memory at a predetermined timing, and outputs the D / D image. Output to the A converter 580. Specifically, as shown in FIG. 10A, in the scan converter unit 570, for example, an image R on the right side and an image L on the left side alternate R1 → L1 → R2.
When inputting → L2 → R3 ..., The scan converter unit 570 changes and outputs the scan speed at a timing delayed by one cycle. In the example of FIG. 10, the scan converter unit 570 is converted to scan at a speed four times higher, and when R2 is input, R1 and L1 one cycle before are alternately output twice each. That is,
As shown in FIG. 10B, while inputting R2, R1 → L1
→ Output R2 → L2. Further, the scan converter unit 570 outputs the signal from the landmark unit 560 when the road map is displayed by the display changeover switch 110, and the pre-processing unit 520 when the road map is not displayed.
Output the signal from.

The subsequent operation is as described above.
As described above, noise is reduced, afterimages are effectively removed, and a roadmap image can be obtained even in the case of stereoscopic fluoroscopy.

The X-ray fluoroscopic timing and roadmap procedure in the case of stereoscopic fluoroscopy constructed as described above will be briefly described with reference to FIG. FIG. 11 is a timing chart showing the X-ray fluoroscopic timing and the roadmap procedure.

First, when the first fluoroscopy is turned on, the mask image creating section 530 creates a mask image. The creation method is as described above. In creating the mask image, image collection of the subject is performed until the operator operates the blood vessel image extraction switch 120 (in this case, it is turned on). A mask image is created after the blood vessel image extraction switch 120 is turned on. Here, the X-rays are alternately emitted from the left and right focal points, as shown in FIG. In this case, for example, after the blood vessel image extraction switch 120 is turned on, for example, the right side mask image is created when the right side X-ray pulse is turned on,
The left mask image is created when the left X-ray pulse is on. When the mask image creation is completed, the mode shifts to the contrast image creation mode.

In the contrast image creation mode,
When the blood vessel contrast agent is injected at time t ₀ , the contrast image creation unit 540 creates a contrast image. In this case, the shaded portion in the figure shows the change in the concentration of the blood vessel contrast agent, and shows that the concentration of the blood vessel contrast agent gradually increases from time t ₀ and gradually decreases with time. As shown in FIG. 11D, the contrast image creating unit 540 starts creating a contrast image at the same timing as the X-ray exposure timing after the injection of the blood vessel contrast agent. That is, the contrast image creation unit 540 creates the left contrast image at the timing of time t ₁ .
Creation of the right contrast image is started at the timing of time t ₂ .

Then, at the time point t when the first fluoroscopy is completed.
Finish creating the contrast image at ₃ . At time t ₄ ,
When the second fluoroscopy is started, a blood vessel image is obtained by the difference unit 550 from the mask image and the contrast image created by the first fluoroscopy, and the fluoroscopic image obtained by the second fluoroscopy is superimposed on this. A stereo roadmap image can be obtained.

In this case, it is needless to say that all the perspective images are noise-reduced and afterimages are removed as described above. As described in detail above, according to the present invention, it is possible to reduce noise, effectively remove afterimages, and obtain a roadmap image that is stereoscopically transparent. Therefore, since there is little noise in the image and the tip direction of the catheter can be stereoscopically displayed with a clear image, the accuracy of diagnosis can be improved and the catheter operation can be facilitated. It can contribute to improvement and reduction of exposure. The present invention is not limited to the above embodiments, and it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0048]

According to the present invention, the following effects can be obtained. As described above, according to the present invention, the image processing that enables the road map during stereoscopic fluoroscopy in the radiation apparatus is performed, and noise reduction, and since it is possible to remove the afterimage, noise is reduced, Effectively removes afterimages,
In addition, it is possible to obtain a roadmap image that allows stereo see-through. Therefore, since there is little noise in the image and the tip direction of the catheter can be stereoscopically displayed with a clear image, the accuracy of diagnosis can be improved and the catheter operation can be facilitated. It can contribute to improvement and reduction of exposure.

[Brief description of drawings]

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

FIG. 2 is a diagram for explaining the operation of the stereo X-ray device.

FIG. 3 is a diagram for explaining the operation of the stereo X-ray device.

FIG. 4 is a diagram showing a configuration example of an image processing unit.

FIG. 5 is a diagram showing a specific configuration example of a preprocessing unit.

FIG. 6 is a diagram showing a specific configuration example of a mask image creation unit.

FIG. 7 is a diagram showing a specific configuration example of a contrast image creation unit.

FIG. 8 is a diagram showing a specific configuration example of a difference unit.

FIG. 9 is a diagram showing a specific configuration example of a landmark portion.

FIG. 10 is a diagram showing the operation of the scan converter unit.

FIG. 11 is a timing chart showing X-ray fluoroscopic timing and a roadmap procedure.

[Explanation of symbols]

100 ... Fluoroscopic switch, 110 ... Display change switch, 120 ... Blood vessel image extraction switch, 200 ... X-ray controller, 210 ... X-ray high voltage generator, 220 ... Stereo X
Line tube, 300 ... Subject, 400 ... Image intensifier, 410 ... Optical system, 420 ... TV camera, 500
Image processing unit 510 ... Analog-to-digital converter (A
/ D converter), 520 ... Pre-processing unit, 530 ... Mask image creating unit, 540 ... Contrast image creating unit, 550 ... Difference unit, 560 ... Landmark unit, 570 ... Scan converter unit, 580 ... Digital / analog converter (D / A
Converter), 600 ... TV monitor, 610 ... Polarizing filter, 620 ... Polarizing glasses.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location A61B 6/02 351 C 7638-2J G06T 1/00 H04N 7/18 L

Claims (6)

[Claims] 1. A subject is irradiated with radiation alternately from the first and second focal points of a radiation generating means having two focal points, a first focal point and a second focal point, which are arranged at a predetermined interval. In a radiographic image processing method for performing stereoscopic fluoroscopy of the subject, first and second masks corresponding to the first and second fluoroscopic images by alternately exposing X-rays from the first and second focal points. First step of creating an image, and after injecting a blood vessel contrast agent into the subject, alternately irradiating X-rays from the first and second focal points to correspond to those third and fourth perspective images A second step of creating first and second contrast images, a first blood vessel image is created by taking a difference between the first mask image and the first contrast image, and the second mask image and the second mask image are created. Take the difference from the contrast image A third step of creating a second blood vessel image; a fifth roadmap image by X-ray irradiation from the first focus and the first blood vessel image are superimposed to create a first roadmap image; A radiation image processing method, comprising: a fourth step of creating a second roadmap image by superimposing a sixth fluoroscopic image by X-ray irradiation from a focus and the second blood vessel image. 2. The first step, the second step,
And in the fourth step, the perspective image obtained by multiplying the perspective image obtained at this time by a predetermined first coefficient of 1 or less and the perspective image obtained by exposure from the same focal point one time before are set to 1 Second obtained by subtracting the first coefficient from
The radiographic image processing method according to claim 1, further comprising the step of adding the eighth perspective image multiplied by a coefficient and to obtain the first to sixth perspective images with reduced noise. 3. The first step, the second step,
And in the fourth step, a predetermined third coefficient is added to the image obtained by the previous X-ray exposure from the perspective image obtained by adding the seventh perspective image and the eighth perspective image. The method further comprises the step of subtracting the ninth image obtained by multiplication to obtain the first to sixth perspective images from which the afterimage of the image obtained by the previous exposure is removed. Item 2. The radiation image processing method according to Item 2. 4. Having two focal points, a first focal point and a second focal point, which are arranged at a predetermined interval, and alternately irradiating radiation from the first focal point and the second focal point in order to perform stereoscopic fluoroscopy of a subject. Radiation generating means for irradiating the subject, and first and second mask images corresponding to two types of first and second perspective images obtained by X-ray irradiation from the first and second focal points are created. And a first corresponding to two types of third and fourth fluoroscopic images obtained by X-ray irradiation from the first and second focal points after injecting a blood vessel contrast agent into the subject. And a contrast image creating unit for creating a second contrast image, a first blood vessel image is created by taking a difference between the first mask image and the first contrast image, and the second mask image and the second contrast image. And the difference A blood vessel image creating means for creating a second blood vessel image, and a fifth road image by superimposing a fifth perspective image by X-ray irradiation from the first focus and the first blood vessel image, Radiation, comprising: a roadmap image creating means for creating a second roadmap image by superimposing the sixth perspective image by X-ray irradiation from the second focus and the second blood vessel image. Image processing device. 5. The first to the seventh fluoroscopic image obtained by multiplying the fluoroscopic image obtained at this time by a predetermined first coefficient of 1 or less and the fluoroscopic image obtained by irradiation from the same focal point one time before. It is characterized by further comprising noise reduction means for obtaining the first to sixth perspective images with reduced noise by adding and to the eighth perspective image multiplied by the second coefficient obtained by subtracting the first coefficient. The radiation image processing apparatus according to claim 4. 6. A fluoroscopic image obtained by adding the seventh fluoroscopic image and the eighth fluoroscopic image is multiplied by an image obtained by the previous X-ray exposure by a predetermined third coefficient. It is characterized by further comprising afterimage removing means for subtracting the obtained ninth image to obtain the first to sixth perspective images from which the afterimage of the image obtained by the previous exposure is removed. Item 5. The radiation image processing device according to item 5.