JP2847539B2 - Digital angiography imaging system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital angiographic imaging apparatus that facilitates a catheter operation for direct imaging of a target site (affected part).

[Conventional technology]

In the fluoroscopic mapping processing in the digital angiography imaging apparatus, the blood vessel running state near the target part (affected part) is known,
This is performed in order to clearly indicate the position of the catheter tip and facilitate catheter operation.

In a conventional digital angiography apparatus, there is only one kind of such fluoroscopic mapping processing means (mode).

Further, the perspective mapping processing in the conventional device is to create a mapping mask image and then subtract a real-time perspective image from this mapping mask image.

As a mapping mask image, an averaging image of a plurality of frames (about 32 frames) for about one second immediately after injection of a small amount of a contrast agent, usually called a flash, is used. You can see the position of the catheter passing through and how it moves.

[Problems to be solved by the invention]

In the conventional digital angiography apparatus described above, there is only one type of condition for generating a mapping mask image and a means for generating a perspective mapping image using the mapping mask image generated under this condition. There was a problem that it was not given and was inconvenient to use.

In the perspective mapping processing in the above-described conventional apparatus,
If there is no movement of the subject, only the position and movement of the contrasted blood vessel and catheter will be displayed, and the bone and soft tissue of that part will not be displayed. However, there is a problem that it is difficult to grasp the spatial position of the target part in the subject. Further, when the subject moves, an artefact of the bone or soft tissue appears, which makes it difficult to see the position and movement of the catheter.

An object of the present invention is to prepare a plurality of types of conditions for generating a mapping mask image, and allow a diagnostician to select a condition for generating a predetermined mapping mask image, and to select a mapping mask image generated under the selected condition. Can be used to generate a perspective mapping image, so that it is easy to use, and a perspective mapping image based on a mapping mask image generated under one of the conditions for generating a plurality of types of mapping mask images is defined as a contrasted blood vessel. It is an object of the present invention to provide a digital angiography apparatus capable of displaying not only the position and movement of a catheter but also the bones and soft tissues of that part, so that even an inexperienced diagnostician can grasp the spatial position of a target site in a subject. .

[Means for solving the problem]

The above object is provided with a perspective mapping processing device that generates a perspective mapping image by adding an image after injection of a contrast agent (mapping mask image) and a real-time perspective image or subtracting (subtracting) the mapping mask image from the real-time perspective image (subtraction). A digital angiography apparatus that displays a perspective mapping image generated by the perspective mapping processing apparatus, wherein the perspective mapping processing apparatus includes a mapping mask image generation condition storage unit that stores conditions for generating a plurality of types of mapping mask images; Selecting means for selecting a predetermined mapping mask image generation condition from the mapping mask image generation condition storage means, generating a mapping mask image under the mapping mask image generation condition selected by the selecting means, and using the mapping mask image. To produce the perspective mapping image It is achieved by. Further, one of the conditions for generating the plurality of types of mapping mask images is to use an averaging image for a plurality of frames immediately after the injection of the contrast agent, and the mapping mask image generated under these conditions is used. From the image obtained by appropriately weighting the real-time perspective image or subtracting the image obtained by appropriately weighting the mapping mask image,
This is achieved by subtracting the real-time perspective image to generate a perspective mapping image.

Furthermore, one of the conditions for generating the plurality of types of mapping mask images may be a plurality of frames from a plurality of frames after the plurality of frames immediately after the injection of the contrast agent from an averaging image of a plurality of frames immediately after the injection of the contrast agent. A subtraction of the averaging image of the minute is used. This is achieved by subtracting a real-time perspective image from a mapping mask image generated under this condition to generate a perspective mapping image.

[Action]

A plurality of conditions for generating a mapping mask image are provided, and among these conditions, a condition for generating a predetermined mapping mask image can be selected. This allows the diagnostician to select a condition for generating a predetermined mapping mask image, generate a mapping mask image based on the selected condition, and generate a perspective mapping image using the mapping mask image, thereby improving usability. Also, one of the conditions for generating the mapping mask image is as follows.
The seed is to use an averaged image for a plurality of frames immediately after the injection of the contrast agent. From the mapping mask image generated under this condition, the real-time fluoroscopic image is appropriately multiplied by, for example, 1/2 times (density of each pixel of the real-time fluoroscopic image). Multiply by 1/2)
Is subtracted, or a real-time perspective image is subtracted from an image obtained by appropriately weighting the mapping mask image to generate a perspective mapping image. As a result, backgrounds such as bones and soft tissues remain without disappearing. For this reason, it is easy to grasp the spatial positional relationship between the target part and the bone or soft tissue, and the artifact is less noticeable even when the subject moves.

Further, one type of condition for generating the mapping mask image is to subtract an averaged image for a plurality of frames immediately after the injection of the contrast agent from an averaged image for a plurality of frames immediately after the injection of the contrast agent. That is. Thus, the mapping mask image becomes only the contrasted blood vessel image. The mapping image displayed by subtracting the fluoroscopic image from the mapping mask image looks like a normal fluoroscopic image with a blood vessel image in the vicinity of the target portion superimposed. In addition, since the catheter appears to progress in the blood vessel image, a mapping image that does not have a sense of incongruity with a conventional fluoroscopic image can be displayed.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a digital X-ray television apparatus according to the present invention. In FIG. 1, reference numeral 1 denotes an X-ray tube as a radiation source, and 2 denotes an X-ray tube 1 with a subject 3 interposed therebetween. II, 4 are radiation detectors that are opposed to each other and convert a transmission X-ray image into a visible light image, and 4 are TV cameras that convert the optical image output from II2 into electrical signals, and 5 are digital signals that convert the output signals of the TV camera into digital signals. A / D converter for conversion. 6 is A / D
A log converter for log-converting the signal from the converter 5, 7 (71
7n) is a frame memory which is a storage device for storing a signal from a log converter 6 or an arithmetic unit or a central processing unit to be described later as projection data, and 8 is an arithmetic unit (ALU) for reading projection data from the frame memory 7 and performing arithmetic processing. ), 9
Is a D / A converter for converting a digital signal obtained by arithmetic processing by the arithmetic unit 8 into an analog signal, and 10 is a monitor television which is a display device for displaying an image based on the analog signal from the D / A converter 9 It is.

11 is an X-ray controller, 12 is a high-pressure generator controlled by the X-ray controller 11 to operate the X-ray tube 1, 13 is a console, 14
Is provided with a plurality of conditions for generating a mapping mask image and a plurality of perspective mapping processing means for generating a perspective mapping image with the mapping mask image generated under this condition, and among these, a condition for generating a predetermined mapping mask image and a perspective mapping processing means are provided. A selectable perspective mapping processing device 15 is a central processing unit (CPU) that controls each part of the device.

Here, the perspective mapping processing device 14 includes a condition for generating the following two types of mapping mask images (1) and (2) and a perspective mapping processing means for generating a perspective mapping image using the mapping mask image generated under these conditions. It has.

(1) As a mapping mask image, an averaged image of a plurality of frames, for example, one second, for example, 32 frames is used immediately after the injection of the contrast agent, and a real-time fluoroscopic image is appropriately obtained from the mapping mask image. / 2 times (the density of each pixel of the real-time perspective image is multiplied by 1/2) is subtracted from the image obtained by weighting, or from the image obtained by appropriately weighting the mapping mask image, Perspective mapping processing means for subtracting the real-time perspective image.

(2) As a mapping mask image, a plurality of frames in one second immediately after the injection of the contrast agent, for example, a plurality of frames in one second, for example, in this case, an averaged image of 32 frames. Here, a perspective mapping processing means for subtracting an averaged image of 32 frames and subtracting a real-time perspective image from this mapping mask image. Next, the operation of the present invention will be described.

X-rays emitted from the X-ray tube 1 pass through the subject 3
It is converted to an optical image in II2. This optical image is photographed by the television camera 4, the output signal of the television camera 4 is A / D converted by the A / D converter 5, and then log-converted by the log converter 6. The log-converted signal is calculated directly or by the calculator 8 and recorded in the frame memory 7 (71 to 7n), for example, the frame memory 71. The image signal recorded in the frame memory 71 is D / A converted by the D / A converter 9 and then is
Displayed as an image at 10.

The X-rays are generated from an X-ray tube 1 to which a high voltage generated by a high voltage generator 12 is applied by a signal from an X-ray controller 11.

 The operation of these units is controlled by the central processing unit 15.

Further, the operator or the diagnostician inputs necessary commands from the console 13.

 The above operation is not particularly different from the conventional device.

In the present invention, the perspective mapping processing device 14 includes a condition for generating a plurality of types of mapping mask images and a perspective mapping processing means for generating a perspective mapping image with the mapping mask images generated under the conditions, and a predetermined mapping Conditions for generating a mask image and perspective mapping processing means can be selected.

The execution of the perspective mapping processing means is performed directly by the perspective mapping processing device 14 or by the central processing unit 15.
The selection of the conditions for generating the mapping mask image and the perspective mapping processing means is performed by the console 13. As a result, the perspective mapping is executed by the condition for generating an arbitrary mapping mask image selected by the diagnostician and the perspective mapping processing means.

Next, the conditions for generating a mapping mask image and the perspective mapping processing means provided in the perspective mapping processing device 14 will be described with reference to the flowcharts of FIGS. FIG. 2 is a flowchart for explaining the condition (1) for generating a mapping mask image and the perspective mapping processing means. Hereinafter, the processing contents will be described.

The frame memory 72 for creating a mapping mask image is cleared (step 201).

Counter for adding 32 frames (not shown)
Is set (step 202).

The output video signal of the TV camera 4 that has been A / D converted and log-converted is added for 32 frames, and then divided by 32 to create an averaged image. This is used as a mapping mask image. During this time, the image is stored in the frame memory 72 (step
203-206).

From the mapping mask image recorded in the frame memory 72, the video signal (real-time perspective image) input in real time is appropriately reduced by a factor of 1/2 (here, the density of each pixel of the real-time perspective image is reduced by half). The image obtained by weighting the image is subtracted, stored in the frame memory 71, and displayed on the monitor television 10 (step 207).

Is repeated until the end of fluoroscopy (steps 208 to 2).
07-208).

FIG. 3 is a flowchart for explaining the condition (2) for generating a mapping mask image and the perspective mapping processing means. Hereinafter, the processing contents will be described.

The frame memory 72 for creating a mapping mask image is cleared (step 301).

Counter for adding 32 frames (not shown)
Is set (step 302).

The A / D converted and log converted output video signal of the television camera 4 is added for 32 frames and then divided by 32 to create an average image. This is the fluoroscopic average image when the contrast agent is injected. During this time, the image is recorded in the frame memory 72 (steps 303 to 306).

The frame memory 73 for creating a mapping mask image is cleared (step 307).

Counter for adding 32 frames (not shown)
Is set (step 308).

The A / D converted and log converted output video signal of the television camera 4 is added for 32 frames and then divided by 32 to create an average image. This is the fluoroscopic average image after the injection of the contrast agent. During this time, the image is recorded in the frame memory 73 (steps 309 to 312).

The image from the image is subtracted to create a mapping mask image consisting only of the blood vessel image filled with the contrast agent, and is recorded in the frame memory 72 (step 31).
3).

The video signal (real-time perspective image) input in real time is subtracted from the mapping mask image recorded in the frame memory 72, recorded in the frame memory 71, and displayed on the monitor television 10 (step). 314).

Is repeated until the end of fluoroscopy (steps 315 to 3
14-315).

〔The invention's effect〕

According to the present invention, in a fluoroscopic mapping process that is effective when performing a catheter operation required in an angiographic examination,
Since the diagnostician can select the conditions for generating a predetermined mapping mask image and the perspective mapping processing means, there is an effect that the usability is good. In particular, one of the conditions for generating a mapping mask image and the perspective mapping processing means
This is a method in which the seed remains intact, such as bones and soft tissues. For this reason, it is easy to grasp the spatial positional relationship between the target part and the bone or soft tissue, and the artifact is less noticeable even when the subject moves. As a result, the efficiency of catheter operation is improved, and the risk to the subject (the risk of X-ray exposure due to re-imaging) is reduced. In addition, since the amount of the contrast agent used in the flash performed during the operation of the catheter can be reduced, the risk to the patient is further reduced. This has effects such as being effective as a transdermal agent.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a system configuration according to an embodiment of the present invention, and FIGS. 2 and 3 are views for explaining a perspective mapping processing means provided in the perspective mapping processing apparatus in FIG. It is a flow chart. 1 ... X-ray tube, 2 ... II, 3 ... Subject, 4 ... TV camera, 5 ... A / D converter, 6 ... Log converter, 7 (7
1 to 7n) ... frame memory, 8 ... arithmetic unit (ALU),
9 D / A converter, 10 Monitor TV, 11 X-ray controller, 12 High voltage generator, 13 Console, 14 Transparent mapping processing unit, 15 Central processing unit (CPU).

Claims (3)

(57) [Claims] 1. A perspective mapping processing apparatus for generating a perspective mapping image by adding an image after injection of a contrast agent (mapping mask image) and a real-time perspective image or subtracting (subtracting) the mapping mask image from the real-time perspective image. In a digital angiography apparatus for displaying a perspective mapping image generated by the perspective mapping processing apparatus, the perspective mapping processing apparatus stores a condition for generating a plurality of types of mapping mask images. And selecting means for selecting a predetermined mapping mask image generation condition from the mapping mask image generation condition storage means. A mapping mask image is generated under the mapping mask image generation condition selected by the selecting means, and the mapping mask image is generated. To generate the perspective mapping image Digital angiography apparatus characterized by. 2. One of the conditions for generating a plurality of types of mapping mask images is to use an averaging image for a plurality of frames immediately after injection of a contrast agent. And subtracting an image obtained by appropriately weighting the real-time perspective image or subtracting the real-time perspective image from an image obtained by appropriately weighting the mapping mask image to generate a perspective mapping image. The digital angiographic imaging apparatus according to claim 1. 3. A method according to claim 1, wherein one of the conditions for generating the plurality of types of mapping mask images is a plurality of frames from a plurality of frames immediately after the injection of the contrast agent, based on an averaged image of the plurality of frames immediately after the injection of the contrast agent. 2. The digital angiographic imaging apparatus according to claim 1, wherein a subtraction of the averaging image of the minute is used, and a fluoroscopic mapping image is generated by subtracting a real-time fluoroscopic image from a mapping mask image generated under this condition.