JPH08308822A - X-ray diagnostic device - Google Patents

Abstract

PURPOSE: To provide an X-ray diagnostic device which automatically provides a DSA image. CONSTITUTION: An X-ray diagnostic device which contributes to an X-ray diagnosis by displaying a DSA image, which is obtained from a mask image and a contrast image picked up by an X-ray camera, on a monitor is provided with memories 132, 134 for storing the mask image and the contrast image, and a motion detection means 136 for detecting direction and quantity of the motion of the contrast image to the mask image stored in these memories. It is also provided with a DSA operation means 140 which reads out the contrast image according to the direction and quantity of the detected motion and subtracts the mask image from the contraction image so as to find the DSA image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a mask image and a contrast image to produce a DSA (digital substruction angiograph).
y) It relates to an X-ray diagnostic apparatus for obtaining an image.

[0002]

2. Description of the Related Art In X-ray diagnosis, in order to improve the diagnostic ability,
A DSA image is used in which images taken before and after the injection of the contrast agent are overlapped and subtracted, and only the site where the contrast agent is injected is raised.

In the existing X-ray diagnostic apparatus, when a DSA image is to be obtained for a wide area such as a lower limb, the procedure is as shown in FIG. First, before injecting the contrast agent, X
A mask image is photographed at several points while moving the linear camera (reference numeral 310 in FIG. 3), and then a contrast agent is injected and a contrast image is photographed at the same point (reference numeral 31 in FIG. 3).
2). Then, the mask image and the contrast image taken at the same point are subtracted to obtain a DSA image (reference numeral 314 in the figure). At this time, since there is a positional deviation between the mask image and the contrast image due to the current mechanical accuracy, in order to correct this positional deviation, the mask image or the contrast image is visually moved to cause the positional deviation. Is corrected (reference numeral 313 in the figure) to obtain a DSA image.

[0004]

In the X-ray diagnostic apparatus described above, it is necessary to visually move the mask image or the contrast image to correct the positional deviation, and this work takes time and effort. In particular, since the mask image and the contrast image are photographed at several points, a plurality of mask images and contrast images are formed. Therefore, the positional deviation is a burden on the user and is a troublesome work. Therefore, it is an object of the present invention to provide an X-ray diagnostic apparatus that can automatically obtain a DSA image without performing such work.

[0005]

In order to solve the above problems, the X-ray diagnostic apparatus according to claim 1 displays a DSA image obtained from a mask image and a contrast image captured by an X-ray camera on a monitor. By doing so, the X-ray diagnostic apparatus for X-ray diagnosis detects the memory for storing the mask image and the contrast image, and the direction and amount of movement of the contrast image with respect to the mask image stored in this memory. And a DSA calculation unit for reading a contrast image from the memory according to the detected direction and amount of the movement and subtracting the mask image and the contrast image to obtain a DSA image. Characterize.

In the X-ray diagnostic apparatus according to claim 2 of the present application, in addition to the configuration of claim 1, the DSA calculation means reads out an image of a predetermined standard image frame from the mask image stored in the memory and Of the contrast images stored in, the image of the image frame in which the standard image frame is moved according to the detected direction and amount of movement is read out, and the read mask image and the contrast image are subtracted to obtain the DSA. Characterized by seeking an image.

[0007]

According to the X-ray diagnostic apparatus of the present invention, the contrast image is read out from the memory in accordance with the detected direction and amount of movement, thereby correcting the positional deviation between the mask image and the contrast image. Therefore, it is possible to automatically obtain a DSA image without positional displacement without visually moving the mask image or the contrast image to correct the positional displacement.

According to the X-ray diagnostic apparatus of the present invention, the DSA image is obtained from the image of the mask image of the predetermined standard image frame and the image of the contrast image of the image frame obtained by moving the standard image frame. Then, in the same manner as described above, a DSA image without positional deviation can be automatically obtained.

[0009]

An embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of an X-ray diagnostic apparatus according to an embodiment of the present invention. The X-ray tube 110 is an X-ray source for irradiating the subject 100 with X-rays, and the X-ray camera unit 112.
Is an X-ray camera for picking up an X-ray image of the subject 100, and these are supported by a C arm (not shown) and are rotated so as to sandwich the subject 100.
Thereby, the X-ray image can be taken at several points while moving the X-ray camera unit 112 and the X-ray tube 110.

The X-ray camera unit 112 comprises an X-ray image intensifier and a television camera, and an X-ray image of the subject 100 is converted into an optical image by the X-ray image intensifier. Is output as a video signal by the TV camera. As the image pickup element of the television camera, one having an image pickup area larger than the displayable area on the display surface of the monitor 160 is used. A /
The D converter 120 converts this video signal into a digital value, and the X-ray image of the subject 100 is converted into a digital value video signal by these.

The motion detector 130 is a circuit for detecting the direction and amount of movement of the contrast image with respect to the mask image, and includes the mask memory 132 and the contrast memory 13.
4. It has a motion detection circuit 136. Mask memory 132
Is a memory for storing the mask image from the A / D converter 120, and the contrast memory 134 is a memory for storing the contrast image from the A / D converter 120. These memories 132 and 134 can store several points of X-ray images. The motion detection circuit 136
It is a circuit for detecting the direction and amount of movement between the mask image and the contrast image stored as digital values in these memories 132 and 134, and can be configured by using, for example, a movement detection LSI.

The DSA processing unit 140 includes the memories 132, 1
It is a circuit for reading out the mask image and the contrast image stored in 34 and calculating and obtaining the DSA image, and can be constituted by, for example, a digital signal processor. The processing block is shown in the figure.

First, the DSA processing section 140 reads out an image of an area indicated by a predetermined standard image frame in the mask image stored in the mask memory 132. FIG. 2A shows an image read at this time. Mask memory 1
The entire image pickup area 132a at the time of photographing the mask image is stored in 32, and the digital value of the mask image 142 of a portion indicated by a predetermined standard image frame 141 is sequentially read from the image pickup area 132a.

Further, the DSA processing section 140 reads out the image of the area indicated by the given image frame in the contrast image stored in the contrast memory 134. Figure 2
(B) shows an image read at this time. The contrast memory 134 stores the entire image pickup area 134a at the time of photographing a contrast image, and the digital values of the contrast image 144 of the portion indicated by the image frame 143 given therein are sequentially read out. Picture frame 14
3 is the shift amount 137 in the X direction with respect to the standard image frame 141.
It is determined by giving a shift amount 137y in the x and Y directions.

The DSA processing section 140 then reads the mask image 142 and the contrast image 1 read as described above.
44 is subtracted (reference numeral 145 in FIG. 1), and the DSA image is output as a digital-valued video signal.

The D / A converter 150 is a DSA processing unit 140.
The DSA image from the device is converted into an analog video signal, and the monitor 160 displays an image on its display surface by the analog video signal. With these, DSA
The image is displayed on the display surface of the monitor 160.

Microcomputer (microcontroller) 170
Controls the entire apparatus according to the operation of an operation panel (not shown). For example, a control signal for moving the C-arm is output, and the digital image from the A / D converter 120 is stored in the mask memory 132 when the mask image is photographed before the contrast agent is injected, and the contrast after the contrast agent is injected is stored. When capturing an image, control is performed so that the image is stored in the contrast memory 134. Further, control is performed so that the mask image and the contrast image read by the DSA processing unit 140 are captured at the same point. Further, a shift amount 137x in the X direction and a shift amount 137y in the Y direction are calculated from the direction and amount of the movement obtained by the movement detection unit 130, and DS
The control of giving to the A processing unit 140 is also performed.

In this X-ray diagnostic apparatus, the operation for obtaining a DSA image is performed as follows. First, a mask image is photographed at several points while moving the X-ray camera before injecting a contrast agent, and the obtained X-ray image (mask image) is stored in the mask memory 132. Next, a contrast agent is injected, a contrast image is photographed at the same point, and the obtained X-ray image (contrast image) is stored in the contrast memory 134. From the mask image and the contrast image thus stored in the memories 132 and 134, the DSA
The image is obtained.

When a predetermined photographing point is selected by operating the operation panel, the motion detecting unit 130 causes the memory 13 to operate.
2, 134, the mask image and the contrast image at the photographing point are read out to the motion detection circuit 136, and the motion detection circuit 136 detects the direction and amount of the motion between the mask image and the contrast image, The direction and amount of are supplied to the microcomputer 170 as data.

There is a positional deviation between the mask image and the contrast image due to a mechanical error, and it is assumed that the subject 100 is photographed in the mask image pickup area 132a as shown in FIG. 2A. Also, a contrast image pickup area 1
The position of the subject 100 photographed by 34a is out of position. When the position of the subject 100 is displaced as shown in FIG. 2B, the motion detection circuit 136 detects the direction and amount 137 of the motion. Then, the DSA processing unit 140 shifts the image frame 143 according to the shift amount 137x in the X direction and the shift amount 137y in the Y direction converted from the direction and amount of movement by the microcomputer 170, and reads the contrast image.

In FIG. 2B, the shift amount in the X direction is 1
When the shift amount 137y in the 37x and Y directions is 0, the contrast image of the portion shown by the standard image frame 141 as shown by the dotted line is read, and in this case, the mask image and the contrast image are out of alignment. . However, in the X-ray diagnostic apparatus of the present embodiment, the movement amount and the amount 137 are converted from the shift amount 137x in the X direction and the shift amount 137y in the Y direction, and the image frame 143 is shifted to obtain a mask image and a contrast image. Will match within the image frame.

In this way, the mask image and the contrast image with no positional deviation are used, and these are subtracted to obtain the DSA image. Then, a DSA image with no displacement is displayed on the display surface of the monitor 160. In this way, the motion detector 1
Based on the direction and amount of movement detected in 30, the DSA processing unit 140 reads the contrast image so that the position matches the mask image, and corrects the positional deviation.
It is possible to obtain a DSA image without positional displacement without visually performing the work of moving the mask image or the contrast image to correct the positional displacement.

A so-called stepping D in which a user such as an engineer or a doctor takes a mask image and a contrast image at several points while moving the X-ray camera.
When performing SA, the positional deviation correction is automatically performed by the above-described motion detection, so that a DSA image can be obtained without performing a manual positional deviation correction operation. In this way, misalignment is automatically corrected,
The time required for the X-ray diagnosis is shortened, and the work of visually correcting the positional deviation is not necessary, which reduces the burden on the user.

In the above embodiment, as the image pickup device of the television camera, one having an image pickup area larger than the displayable area of the monitor 160, that is, an image pickup device having a larger image frame than the output image is used. Although the case has been shown, the cutout frame may be made smaller to be enlarged and displayed.

Further, in the above embodiment, the imaged region of the subject is changed by moving the X-ray camera, but the imaged region may be changed by moving the bed on which the subject is placed. .

[0026]

According to the X-ray diagnostic apparatus of the first aspect of the present invention, the contrast image is read out from the memory in accordance with the detected direction and amount of movement, whereby the positional deviation between the mask image and the contrast image is obtained. Therefore, it is possible to automatically obtain a DSA image free from misalignment without visually performing the operation of moving the mask image or the contrast image to correct misalignment.

According to the X-ray diagnostic apparatus of the present invention, the DSA image is obtained from the image of the mask image of the predetermined standard image frame and the image of the contrast image of the image frame obtained by moving the standard image frame. Then, in the same manner as described above, a DSA image without positional deviation can be automatically obtained.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a relationship between a mask image and a contrast image.

FIG. 3 is a diagram showing a procedure for obtaining a conventional DSA image.

[Explanation of symbols]

112 X-ray camera unit, 130 Motion detector,
132 mask memory, 134 contrast memory, 136 motion detection circuit, 140 DSA processing unit 141 standard image frame, 143 image frame

Claims (2)

[Claims] 1. An X-ray diagnostic apparatus for use in X-ray diagnosis by displaying a DSA image obtained from a mask image and a contrast image captured by an X-ray camera on a monitor, wherein the mask image and the contrast image are And a motion detection unit for detecting the direction and amount of movement of the contrast image with respect to the mask image stored in the memory, and the contrast image according to the direction and amount of the detected movement. Read from the memory and subtract the mask image and the contrast image to obtain a DSA image, and an X-ray diagnostic apparatus. 2. The DSA calculation means reads out an image of a predetermined standard image frame from the mask image stored in the memory, and detects the direction of the detected movement in the contrast image stored in the memory. The image of the image frame in which the standard image frame has been moved is read according to the amount and the amount, and the read mask image and the contrast image are subtracted to obtain the DS.
The X-ray diagnostic apparatus according to claim 1, wherein the A image is obtained.