JPH02253776A - Digital x-ray radiographic equipment - Google Patents

Abstract

PURPOSE:To arbitrarily obtain a picture, which can be observed more easily, as the picture for diagnosis by digitizing the video signal of the X-ray picture, making 9 subtraction image, executing picture adjustment and adding the subtraction image with an image including background. CONSTITUTION:When a recorder 17 is set in a reproducing state and a digital cine-mode is obtained, a mask image and the subtraction image recorded in the recorder 17 are read and the mask image is stored to a frame memory 19. Next, a switch circuit 18 is changed over to (b) side and the subtraction image is stored in a frame memory 20 and sent to an emphasis circuit 21. The density only of the subtraction image, namely, of a blood vessel image is adjusted by this emphasis circuit 21. The blood vessel image, for which the density is adjusted in such a way, is sent to an adder circuit 23 and added with the mask image read from the frame memory 19. A contrast adjuster 13 and a luminance adjuster 14 are provided and contrast and luminance can be arbitrarily adjusted by operating these adjusters by an operator.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an X-ray imaging device, and more particularly to a digital X-ray imaging device that converts an X-ray image into an electrical signal and digitally processes it.

[Conventional technology]

In the field of X-ray imaging equipment, from the conventional film-based system to the digital X-ray system, which combines an image intensifier and TV right camera to obtain an X-ray image video signal, which is then digitized for recording and display. The transition to imaging equipment is progressing. This is based on the fact that image processing such as image edge enhancement and contrast/brightness adjustment is easy with digital image processing technology, and the usefulness of this is that it is possible to easily perform image processing such as image edge enhancement and contrast/brightness adjustment. DSA(
This is particularly noticeable in digital subtraction angiography devices. By the way, moving parts such as the heart need to be observed using a series of X-ray images similar to moving images, and in this field as well, for the same reason as above, cine imaging equipment using continuous film has been replaced. A digital cine method is becoming popular, in which a digital X-ray imaging device such as a DSA device or a digital cine device is used to continuously display collected angiographic images along with a background image without any particular extraction.

[Problem to be solved by the invention]

However, in the case of conventional digital cine systems, contrast adjustment knobs and brightness adjustment knobs are provided to adjust the image displayed on the TV monitor device to make it easier to view, but depending on these knobs, the overall contrast and brightness of the image may vary. is only adjusted, so even if an attempt is made to enhance the contrast of the blood vessel image, the contrast of the background will also be enhanced at the same time, resulting in the problem that the blood vessel image will not necessarily be in a state that is easy to see. An object of the present invention is to provide a digital X-ray imaging device that is capable of adjusting the contrast and brightness of only a contrast agent image obtained by subtraction, and can arbitrarily obtain an image that is easier to see as an image for diagnosis. With the goal.

[Means to solve the problem]

In order to achieve the above object, the digital X-ray imaging apparatus according to the present invention includes means for creating a subtraction image by digitizing and processing a video signal of an X-ray image, and means for performing image adjustment of the subtraction image.
Means for adding the adjusted subtraction image to an image including the background is provided.

[For production]

The subtraction image is usually an angiographic image, and therefore, image adjustment of the subtraction image itself means that the density, etc. of only the vascular image is adjusted. After the image adjustment such as the density of only the blood vessel image is performed in this way, it is added to the image including the background, so the image adjustment such as the density of only the contrast image of the blood vessel etc. is performed in the entire image including the background. It will be possible. Therefore, when the video signal after this addition is sent to a TV monitor for observation, the density of only the blood vessel image etc. of the entire image including the background can be adjusted arbitrarily, and the overall image including the background can be adjusted as desired. It becomes possible to make only a contrast image such as a blood vessel image easily visible, regardless of the density or the like.

【Example】

Next, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, X-rays emitted from an X-ray tube 1 toward a subject 2 pass through the subject 2 and enter an image intensifier 3, where the transmitted X-ray image is converted into an optical image. This optical image is converted into a video signal by the image pickup tube 4 and the camera control unit 5, further converted into a digital signal via the A/D conversion circuit 6, and then sent to the switching circuit 7. This switching circuit 7 is initially tilted to side a, and a transmitted image of the subject 2 before the contrast agent is injected is stored in the frame memory 8 as a mask image. Next, a contrast agent is injected into the subject 2, and a video signal containing an image of the contrast agent is obtained. At this time, the switching circuit 7 is switched to the b side and stored in the frame memory 9 as a live image. Then, in the subtraction cycle NuO, the above-mentioned mask image is subtracted from this live image, and the obtained subtraction image is sent to the switching circuit 11. This switching circuit 11 is a
The subtraction image is sent to the TV monitor device 16 via the emphasis circuit 12 and the D/A conversion circuit 15. Therefore, only the blood vessel image will be displayed on this TV monitor device 16. On the other hand, the digital video signal output from the emphasis circuit 12 is sent to the recording device 17 and recorded. This video signal is
Before the contrast agent is injected, it is a mask image stored in the frame memory 8 and passed through the subtraction circuit 10, the switching circuit 11, and the emphasis circuit 12, and after the contrast agent is injected, it becomes a subtraction image, but all of these images are stored in the recording device. 17 is recorded. When this recording device 17 is put into the playback state and set to digital cine mode, the mask image and subtraction image recorded in the recording device W17 are read out and stored in the frame memory 19 via the switching circuit 18 which is first switched to the a side. A mask image is stored. Next, the switching circuit 18 is switched to the b side and the subtraction image is stored in the frame memory 20. This subtraction image is read out from the frame memory 20 and sent to the emphasis circuit 21. In this embodiment, this emphasizing circuit 21 is equipped with a density adjuster 22, so that the operator can arbitrarily set the density by operating a knob. Therefore, the emphasis circuit 21 adjusts the density of only the subtraction image, that is, the blood vessel image. The blood vessel image whose density has been adjusted in this way is sent to the addition circuit 23 and added to the mask image read out from the frame memory 19. The video signal after this addition is sent to the emphasis circuit 12 via the switching circuit 11 which has been switched to the b side. In this embodiment, the emphasizing circuit 12 includes a contrast adjuster 13 and a brightness adjuster 14, and the operator can adjust the contrast and brightness as desired by operating these knobs. Therefore, at this time, an image in which the background image appearing in the mask image is added to the blood vessel image represented in the subtraction image is displayed on the TV monitor device 16 as a moving image or as a still image. Become. If the operator adjusts the density adjuster 22, only the density of the blood vessel image can be adjusted.
Furthermore, by adjusting the contrast adjuster 13 and brightness adjuster 14, the contrast and brightness of the entire image including the blood vessel image and the background can be adjusted, so these adjustments can be made while viewing the image displayed on the TV monitor 6. By doing this, it is possible to easily adjust the image to the state that is most convenient for diagnosis. In this embodiment, the emphasis circuit 12 adjusts the contrast and brightness, and the emphasis circuit 21 adjusts only the density5, but these adjustment items are not limited, and the emphasis circuit 12.21 can be configured so that any item can be adjusted.

【Effect of the invention】

According to the digital X-ray imaging device of the present invention, only contrast images such as blood vessel images can be made easily visible without changing the contrast or brightness of the background, making it possible to make diagnostics such as determining the degree of stenosis of blood vessels will improve.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention. 1... X-ray tube, 2... Subject, 3... Image intensifier, 4... Image pickup tube, 5... Camera control unit, 6... A/D conversion circuit, 7. 1
1,]8...Switching circuit, 8.9.19.20...Frame memory, 10...Subtraction circuit, 12.21...
Emphasis circuit, 13... Contrast adjuster, 14...
Brightness adjuster, 15...D/A conversion circuit, 16...T
V monitor device, 17...recording device, 22...density adjuster, 23...addition circuit.

Claims (1)

[Claims] (1) A means for creating a subtraction image by digitizing and processing the video signal of an X-ray image, a means for adjusting the image of the subtraction image, and a means for adding the adjusted subtraction image to an image including the background. A digital X-ray imaging device comprising: