JPH06165035A - X-ray diagnostic system - Google Patents

Abstract

PURPOSE:To provide the X-ray diagnostic system which can simultaneously observe the entire image of a blood vessel and the flowing state of a contrast medium with one still picture. CONSTITUTION:The partial peak hold image of time difference is prepared by subtracting a partial peak hold image Pi to be successively provided after the injection of the contrast medium and a partial peak hold image Pi+1 to be provided next to this image Pi at a subtracter 8, this partial peak hold image of time difference is fetched into an adder 9 at a fixed interval, these images are added so as to prepare an equal time line drawing, and this equal time line drawing and the peak hold image are superimposed by a superimposing device 11 so as to display a blood vessel image expressing stripe lines on a monitor 12.

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 such as a digital subtraction angiography (hereinafter referred to as "DSA") apparatus, and more particularly to an X-ray diagnostic apparatus capable of knowing the flow condition of a contrast agent.

[0002]

2. Description of the Related Art When a catheter or a guide wire is used for diagnosing cardiovascular diseases, the catheter cannot be easily guided at a portion where the blood vessel travel is complicated. Therefore, as shown in FIG. 7, a small amount of contrast medium is injected into the blood vessel. However, a plurality of X-ray fluoroscopic images 20, 21, and 22 obtained during the time when the contrast agent is flowing may be averaged to obtain a whole blood vessel image, and the blood vessel image may be observed. At this time, there arises a problem that the contrast due to the contrast agent is reduced due to the increase in the number of added frames, and the contrast agent is strongly swept into the bloodstream.
As shown at 23 in FIG. 7, there arises a problem that it becomes impossible to depict the whole blood vessel image. As a method to prevent this,
There is a peak hold process.

The peak hold processing is a method of detecting the peak contrast of the contrast agent for each pixel and drawing an image based on the pixel to obtain a high-contrast whole blood vessel image shown at 24 in FIG. . On the other hand, as a method for observing the flowing water of blood, there are TID processing and function image processing.

The TID process is a technique for displaying images obtained by subtraction one after another at a fixed interval in a moving image in order to partially emphasize the flow of the contrast agent changed within an arbitrary fixed time. Is.

In the function image processing, a time density curve is created for each pixel on a continuous image, and a parameter obtained from the curve, such as a time at which the curve reaches a maximum value from the time when a contrast agent is injected, is calculated. This is a method of creating a functional image using parameters.

[0006]

However, in the peak hold processing, it is possible to observe the whole blood vessel image in which the contrast agent has flowed with one still image, but the direction and speed of the flow of the contrast agent can be objectively measured. There is a problem that you can not grasp. On the other hand, in the TID process, the flow condition of the contrast agent cannot be grasped unless a moving image is displayed, and a change in the contrast agent flow at a certain moment (time) cannot be known from only one still image. is there. Further, there is a problem in that the contrast medium is regurgitated in a thick blood vessel, making it difficult to objectively grasp the direction of blood vessel travel. Further, in the case of the function image, it takes a long time to create a time density curve for each pixel, and a special circuit is required for parameter replacement, which is problematic in terms of manufacturing cost.

The present invention has been made in order to solve these problems, and provides an X-ray diagnostic apparatus capable of simultaneously observing the entire image of blood vessels and the flow condition of a contrast agent from a single still image. The purpose is to provide.

[0008]

The first X according to the present invention
The X-ray diagnostic apparatus injects a contrast agent into a subject, irradiates X-rays, performs peak hold processing, detects the peak contrast of the contrast agent for each pixel, and visualizes a high-contrast blood vessel image. In the apparatus, a means for subtracting a mask image from a live image to obtain a partial peak hold image after injecting a contrast agent, and a partial peak hold image and a partial peak hold image obtained next to the image are subtracted to obtain a time difference. Of the partial peak hold image of, the partial peak hold image of such a time difference is taken in at regular intervals, and the addition processing of these is performed to create an isochronous line image. And a means for simultaneously displaying the blood vessel images obtained by the peak hold processing on a monitor.

A second X-ray diagnostic apparatus according to the present invention injects a contrast agent into a subject, irradiates the object with X-rays, performs peak hold processing, detects the peak contrast of the contrast agent for each pixel, and increases the contrast. X to visualize a blood vessel image with contrast
In line diagnostic equipment,

Means for obtaining a partial peak hold image by sequentially subtracting the mask image from the live image after the injection of the contrast agent, and the partial peak hold image and the partial peak hold image obtained next to the image are subtracted to obtain the time difference. Of the partial peak hold image, means for using at least two or more colors of color data, and means for periodically changing and assigning color data to each partial peak hold image of the time difference, and based on this color data And a means for performing addition processing on each partial peak hold image of the time difference subjected to color processing.

[0011]

In the first X-ray diagnostic apparatus of the above means, for example,
The partial peak hold image is subjected to constant subtraction processing, addition processing, etc. to obtain an isochronous line image, which is then made into a white isochronous line image, and the static black color obtained by such isochronous line image and peak hold processing. The blood vessel image with a white stripe is obtained by superimposing it with the blood vessel image of. According to such a blood vessel image, it is possible to observe the whole image of the blood vessel whose contrast has been enhanced by the peak hold process in one still image, and to specify the flow speed of the contrast agent by the line spacing of the stripe lines. Can be understood.

On the other hand, in the second X-ray diagnostic apparatus, a color stripe-shaped blood vessel image is obtained by subjecting the partial peak hold image to certain subtraction processing, color processing, addition processing and the like. According to such a color stripe image, the whole image of the blood vessel is
The X-ray diagnostic apparatus can be observed in the same manner as the above X-ray diagnostic apparatus, and the speed at which the contrast agent flows can be grasped by the fringe width, and the direction in which the contrast agent flows can be appropriately grasped by the periodic change of the color of the color stripes.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the main part of the X-ray diagnostic apparatus according to the first embodiment.

The apparatus is input with a camera system 1 equipped with an image intensity firer (hereinafter referred to as "II") and a video camera, an A / D converter 2 for converting a video signal into a digital signal. A switch 3 for switching and transmitting the generated signal, a memory 4 for storing the mask image, a first subtractor 5 for subtracting the mask image from the live image, and a peak hold for performing peak hold processing and sending a partial peak hold image. Device 6, the first work memory 7 for storing the partial peak hold image, and the partial peak hold image are subtracted from each other to obtain the peak hold of the time difference (hereinafter referred to as "PTID").
A second subtractor 8 for obtaining an image, a PTID image at regular intervals, an adder 9 for adding these to obtain an isochronous image, and a second for storing a peak hold image.
A work memory 10, a superimposing device 11 for superimposing an isochronous line image and a peak hold image, and a monitor 1 for displaying a superimposing image.
It has 2 etc.

Before injecting the contrast medium into the blood vessel of the subject P, the switching circuit 3 is placed by switching to a, and when the subject P is irradiated with radiation, the camera system 1 sends the bone to the A / D converter 2. A video image signal in which the same is depicted is transmitted. Such a video signal is converted into a digital signal by the A / D converter 2 and taken into the memory 4 as a signal representing the mask image M as shown in FIG.

After injecting the contrast medium into the blood vessel of the subject P, the switching circuit 3 is switched to b, and the live images L1, L2, ... Are sequentially passed through the camera system 1 and the A / D converter 2. Li
, Li + 1 are input to the subtractor 5. The subtracter 5 subtracts the mask image M stored in the memory 4 from the sequentially obtained live images L1, L2, ..., Li to obtain a subtraction image, and sends this signal to the peak hold unit 6.

The peak hold device 6 performs peak hold processing for detecting the peak contrast of the contrast agent for each pixel and drawing a high contrast blood vessel image. As a result, high-contrast partial peak hold images P1, P2, ... Can be obtained from the subtraction image. When the partial peak hold image Pi is sent from the peak hold unit 6 to the first work memory 7, the partial peak hold image Pi + 1 obtained next is sent to the second subtractor 8.

The second subtractor 8 subtracts the partial peak hold image Pi acquired from the first work memory 7 and the partial peak hold image Pi + 1 acquired from the peak hold device 6 to obtain a PTID image. In this PTID image, since the peak hold function works on the part where the contrast agent flows away or the part where the contrast agent flows backward, only the part where the contrast agent newly flows in is extracted.

The adder 9 converts the PTID image into, for example, P
Like TID1, PTID4, and PTID7, they are taken in at regular intervals, and these peak hold images are added to obtain a black isochronous image S similar to the contour lines of the map as shown in FIG. 3 (b). . At this time, from the peak hold device 6, the peak hold image P as shown in FIG.
Are stored in the second work memory 10.

The superimposing unit 11 fetches the black-and-white inverted isochronous line image from the adder 9 and the peak hold image P displaying a static black blood vessel image from the second work memory 10, Monitor 1 by superimposing images
2 shows a blood vessel image PS with white stripes as shown in Fig. 3 (c).
Is displayed. In addition, the dense area of the stripes of the blood vessel image is
The contrast agent flows slowly, and the rough stripe indicates that the contrast agent flows quickly, so that the speed at which the contrast agent flows can be known. FIG. 4 is a block diagram showing the main part of the X-ray diagnostic apparatus according to the second embodiment. The components having the same functions as those of the device of the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

Such an apparatus comprises a camera system 1, an A / D converter 2, a switch 3, a first memory 4, a first subtractor 5 for subtracting the mask image M from the live image Li, and a peak for performing peak hold processing. The hold device 6, the work memory 7 for storing the partial peak hold images, the second subtractor 8 for performing the subtraction between the partial peak hold images, and the color images are sequentially assigned to the sequentially obtained PTID images. 2 memory 14
Adder 13, adder 13 for adding images captured from
It has a second memory 14 for temporarily storing the image sent from the device and sending it to the adder 13 again, a monitor 12 for displaying a blood vessel image, and the like.

A PTI obtained by subtracting the partial peak hold image Pi from the start of collecting the live image Li to a certain frame and the partial peak hold image Pi + 1 to the next frame
The D image is sent from the second subtractor 8 to the adder 9.

The adder 9 periodically assigns a constant color to each PTID image and outputs an image signal added to the image stored in the second memory 4. And adder 9
The image signal sent from the second memory 14 is newly stored in the second memory 14. By repeating this, the color striped blood vessel image PC can be displayed on the monitor 12 as shown in FIG. In the blood vessel image obtained here, the flow of the contrast agent is slow where the stripe width is small, and the flow of the contrast agent is fast where the stripe width is wide. Also, when two or more colors are changed cyclically to form color stripes, the contrast agent flows in the directions of red, blue, and yellow by changing the order of red, blue, yellow, and so on. I can know that.

In this embodiment, the monitor 12 displays the striped blood vessel image with colors. However, the present invention is not limited to this, and color stripes may be displayed instead of gradation stripes. good. Further, the stripes of the first embodiment may be similarly colored to show the flow of the contrast agent. Next, a specific example for carrying out the present invention will be described in the vicinity of the heart where the blood flow is fast and the portion where the blood flow is slow. FIG. 5 is a diagram showing an embodiment in the vicinity of a heart with fast blood flow.

Before the contrast agent is injected into the subject, the mask image M is obtained at the stable portion of the electrocardiographic waveform 15 of the subject, and then the contrast agent is injected and the live image is synchronized with the phase of the mask image M. Obtain Li and Li + 1. And these live images Li,
Li + 1 is subtracted to perform peak hold processing, a PTID image is created in the same manner as in the above embodiment, and this is added to obtain an isochronous image S, and a peak hold image is superimposed on the image. A blood vessel image showing a striped line is displayed on the monitor 12. This makes it possible to prevent artifacts that are likely to occur due to the movement of the heartbeat. FIG. 6 is a diagram showing an embodiment for preventing backflow of blood flow.

In this embodiment, in synchronization with the electrocardiographic waveform 15 of the subject, a mask image M and a live image L are obtained, and peak hold processing is performed for each heartbeat to obtain partial peak hold images P1, P2, P3. And a blood vessel image 1 representing a PTID image, an isochronous line image, and a striped line as in the above embodiment.
2 can be obtained. In addition, which phase of the electrocardiographic waveform is 1
Whether to set the heartbeat is set so that the backflow phase is exactly included according to the phase of the backflow generation with respect to the electrocardiographic waveform. As a result, the backflow component is removed by the peak hold processing for each heartbeat, so that the direction of blood vessel travel can be correctly observed.

[0027]

According to the X-ray diagnostic apparatus to which the present invention is applied, stripe intervals and stripe widths are displayed on the surface of a high-contrast whole blood vessel image obtained by performing peak hold processing. The speed at which the agent flows can be known, and in the case of displaying with color stripes, the direction in which the contrast agent flows can be recognized based on the periodic change in the color of the color stripes. Therefore, the whole image of the blood vessel and the flow condition of the contrast agent can be simultaneously observed with one still image, so that the examination time can be shortened and the diagnostic ability can be improved. Moreover, since the whole blood vessel image can be visualized with a small amount of contrast medium, the burden on the subject at the time of diagnosis can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of a main device of a first embodiment to which the present invention is applied.

FIG. 2 is a diagram showing a processing procedure for obtaining a PTID image in the embodiment.

FIG. 3 is an explanatory diagram of an image obtained in each calculation process.

FIG. 4 is a block diagram of a main device of a second embodiment to which the present invention is applied.

FIG. 5 is an explanatory diagram of an example when a live image is obtained by electrocardiographic synchronization.

FIG. 6 is an explanatory diagram of an example in which peak hold is performed for each heartbeat.

FIG. 7 is an explanatory diagram showing peak hold processing.

[Explanation of symbols]

 1 Camera system 2 A / D converter 3 Switching device 4 Memory, 1st memory 5 1st subtractor 6 Peak hold device 7 1st work memory 8 2nd subtractor 9 Adder 10 2nd work memory, work memory 11 Superposition Unit 12 Monitor 13 Adder 14 Second memory

Claims (2)

[Claims] 1. An X-ray diagnosis in which a contrast agent is injected into a subject, X-ray irradiation is performed, peak hold processing is performed, peak contrast of the contrast agent is detected for each pixel, and a high-contrast blood vessel image is visualized. In the apparatus, after the injection of the contrast agent, the mask image is sequentially subtracted from the live image to obtain the partial peak hold image, and the partial peak hold image and the partial peak hold image obtained next to the image are subtracted to obtain the time difference. Of the partial peak hold image of, the partial peak hold image of such a time difference is taken in at regular intervals, and the addition processing of these is performed to create an isochronous line image. An X-ray diagnostic apparatus comprising: means for superimposing a blood vessel image obtained by peak hold processing and displaying the image simultaneously on a monitor. 2. An X-ray diagnosis in which a contrast agent is injected into a subject, X-ray irradiation is performed, peak hold processing is performed, peak contrast of the contrast agent is detected for each pixel, and a high-contrast blood vessel image is visualized. In the apparatus, after the injection of the contrast agent, the mask image is sequentially subtracted from the live image to obtain the partial peak hold image, and the partial peak hold image and the partial peak hold image obtained next to the image are subtracted to obtain the time difference. Of the partial peak hold image, means for using at least two or more colors of color data, and means for periodically changing and assigning color data to each partial peak hold image of the time difference, and based on this color data An X-ray diagnostic apparatus comprising: means for performing addition processing on each partial peak hold image of the time difference subjected to color processing.