JPS61113432A - Highly precise digital x-ray photographing apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention provides digital X-ray photography f! Especially regarding lE.

High-definition digital subtraction angiography equipment (hereinafter simply referred to as DSA) used for angiographic X-ray examinations
(hereinafter referred to as "equipment").

[Background technology]

Conventionally, the photographing modes of a DSA apparatus include a 500 mode of a standard television system with 525 scanning lines and a 1000 mode of a slow 5can system with 1125 scanning lines. In 500 mode, the contrast (S/N
) is good, but resolution is poor.

Ma? =,1000 mode has good resolution but poor contrast.

As described above, both the 500 mode and the 1000 mode have advantages and disadvantages, and one is selected and used depending on the subject.

However, 1. For example, in angiography X-ray examination, etc.
When you want to observe the state of a blood vessel that corresponds to the route from near the end of an arterial blood vessel to a venous blood vessel (particularly a capillary mass or a venous blood vessel), each of the single modes described above uses X-rays with high resolution and good contrast. For example, in the arterial blood vessel area, the contrast agent is still dense and the contrast resolution is high.
.

An appropriate image can be obtained in the 1000 mode, but the contrast resolution is low in the capillary masses and venous blood vessels because the contrast agent is thin, and an image with an appropriate contrast cannot be obtained in the 1000 mode.

[Purpose of the invention]

An object of the present invention is to provide a technique that allows a digital X-ray imaging apparatus to obtain high-resolution, high-definition X-ray images with good contrast.

Another object of the present invention is to select optimal imaging modes for arterial blood vessels, venous blood vessels, and other objects in digital subtraction imaging used in angiographic X-ray examinations (for arterial blood vessels, an imaging mode with high spatial resolution is used). The object of the present invention is to provide a technique in which an imaging mode with high contrast resolution (for venous blood vessels) can be selected at a predetermined point in a series of imaging images in which a contrast agent is injected.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.
It will be something like that.

[Summary of the invention]

A brief overview of typical inventions disclosed in this application is as follows.

In other words, when a contrast agent is injected through an arterial blood vessel, first,
The contrast agent flows in a concentrated state into the arterial blood vessels.

The contrast agent enters the capillaries and then into the venous blood vessels. By utilizing this time difference, it is possible to image arterial and venous blood vessels by changing the imaging mode.One problem is when to switch the imaging mode, but digital X-ray imaging devices such as DSA devices Since you can view blood vessel images in real time, press the button to switch the imaging mode when you have finished imaging the necessary arterial blood vessels.

The optimal imaging mode for arterial blood vessels, venous blood vessels, etc.
By photographing arterial blood vessels in a mode with high spatial resolution and photographing venous blood vessels in a mode with high contrast resolution, it is possible to obtain high-resolution images with good contrast.

[Structure of the invention]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Below, the configuration of the present invention will be explained using the drawings together with an embodiment in which the present invention is applied to a DSA device.

In addition, in all the times for explaining the example.

Components having the same function are given the same reference numerals, and repeated explanations thereof will be omitted. - Figures 1 to 4 are diagrams for explaining the DSA device of this embodiment, and Figure 1 is a diagram for explaining the DSA! f! This is a diagram showing the overall configuration of haze, and Figure 2 shows the 1°00 mode and 50° mode.
A timing chart when shooting by changing the 0 mode once. Figure 3 is a diagram showing the state in which images of i ooo mode and 500 mode are stored in the frame memory. Figure 4 is the timing chart shown in Figure 1. FIG. 2 is a block diagram showing a schematic configuration of a portion of the generator that creates addresses for a frame memory.

In Fig. 1, 1 is a high voltage generator, 2 is an X-ray tube,
3 is an image intensifier (hereinafter simply 1.1)
．． ), which is used to irradiate a subject with X-rays from the X-ray tube 2 and convert the X-ray image transmitted through the subject into a light image. The optical image of the output 1.1.3 is converted into an electrical signal by the television camera 4. This converted electrical signal is converted into a digital signal by an analog-to-digital (hereinafter referred to as A/D) converter S, and this converted digital signal is used for calculations such as addition or subtraction processing in the calculator 6. will be held. This calculation result is stored in the frame memory 7 and displayed on the television monitor 8 as a calculation processed image.
is an image processing section.

. . . Also, the high voltage generation device 5 device 1. The television camera 4 and the image processing unit 9 are controlled by a timing generator mio.

Reference numeral 11 denotes a computer (referred to as C, PU), which is used to control the timing generator circuit IO. Reference numeral 12 denotes an operation panel for inputting and outputting data to and from the CPU II.

Next, the photographing timing for creating the subtraction image of this embodiment is generated by the timing generator circuit IO, and is a timing signal as shown in FIG. That is, the timing signal P1 for test photography in 1000 mode, the timing signal P2 for eggplant 1 to photography in 500 mode, the timing signal P3 for mask image photography in 1000 mode, the timing signal P4 for mask image photography in 500 mode. -Do's live image (LI
VIE DIMAGE: Imaging timing signal P5 containing a contrast agent is generated in the order of the live image imaging timing signal P6 in the 500 mode.

Further, the data storage state of the frame memory 7 is the third one.
As shown in the figure, a 1000 mode mask image is stored in area M1 of the frame memory 7, and a 500 mode mask image is stored in area M2.

Area M2 uses only 1/4 of area M1. M3
is a calculation work memory area, which is shared by the 1000 mode and the 500 mode.

M4 and M5 are areas for storing subtraction images, and data in the 1000 mode is stored in area M4, which uses the entire block.

Data for the 500 mode is stored in area M5, which is one block divided into four. In this way, the frame memory 7 can be used in both the 1000 mode and the 500 mode.

The structure of the part of the timing generator circuit 1o that creates addresses in the frame memory 7 is as shown in FIG. 4. In FIG. Common address counters, C1 for horizontal memory addresses, C2
is the vertical memory address counter. C3 is an address counter for address replenishment, and in the case of 10oO mode, the address counters C1 and C2
When a horizontal or vertical memory address cannot be created, this address counter c3 is used to create it. RGS is a register that records data 0 to 3 from CPU11 and i10 from CPU11.
By command (block number select command),
0~ for each live image shot during 500 mode shooting
- This is for generating switching signals up to 3.

MPX is a multiplexer for switching from generating 1000 mode addresses to generating 500 mode addresses. The input terminal A of this multiplexer MPX is.

The input terminal B is for generating an address for the 1000 mode, and the input terminal B is for generating an address for the 500 mode. CK is a driving clock for the counters C1 to C3. Next, the operation of this embodiment will be explained using FIGS. 1 to 4.

As shown in FIG.
Appropriate photographing conditions are automatically set at tT11. A signal corresponding to the set appropriate photographing conditions is sent to the CPU 11.
The signal is sent to the timing generator circuit 10, and a control timing signal for each device is generated. This control timing signal causes the high voltage generator l to operate and generate a predetermined high voltage, which is applied to the X-ray tube 2. As a result, X-rays are generated from the X-ray tube 2 and transmitted through the subject.

1.3 is entered. The X-ray image input in 1.1.3 is converted into a light image. This converted light image is converted into an electrical signal by the television camera 4. This electrical signal is converted into a digital signal by an A/D converter 5, and an arithmetic unit 6 performs calculations such as addition or subtraction processing. This calculation result is stored in the frame memory 7. This stored image signal is read out and displayed on the television monitor 8 as a computationally processed image such as a subtraction image.

The above operations are controlled by the timing generator circuit 10. The shooting mode switching control of this control will be explained in detail below.

That is, the standard shooting mode of 5ooxsoo and too
In the case of oxtooo's high-definition shooting mode.

Horizontal synchronization signal of TV camera 4 (for example, 63.5 psec in 500 mode, 127μ5 in 1000 mode)
ec) Vertical synchronization signal (for example, 33 in 500 mode)
External synchronization control such as m5ec (132m5ec in 1000 mode) and address control of the frame memory 7 are controlled in different ways.

That is, in the middle of photographing between the 1000 mode and the 500 mode, the timing f-th generation mode of the timing generator circuit IO is switched according to an instruction from the CPU II. That is, as shown in FIG. 2, since the sensitivity of the television camera 4 is different between the 100 mode and the 500 mode, test photography is first performed in the 1000 mode using the timing signal P1. Next, a test image is taken in the 500 mode using the timing signal P2. Next, mask images are taken in the 1000 mode and 500 mode before the contrast agent is injected using the timing signals P3 and P4, and are stored in the frame memory 7. Capture and memorize. after that.

A live image injected with a contrast medium in too mode is photographed using timing signal P5, and captured into the frame memory 7.Next, a live image in 500 mode is captured and captured using timing signal P6, and captured into frame memory 7. Remember.

1 for each of the 1000 mode and 500 mode
The image is stored in a predetermined area of the frame memory 7, as shown in FIG. That is, 1000
The mode mask image is stored in area M1 consisting of 1 block, and the 500 mode mask image is stored in area M2 consisting of 1/4 block. Further, the subtraction image is stored in an area M4 that uses the entire l block in the case of the 1000 mode, and in an area M5 that is obtained by dividing the l block into four parts in the case of the 500 mode. In this way, the frame memory 7 is used in both the iooo mode and the 500 mode.

Next, creation of an address signal for reading (writing) data into the frame memory 7 will be explained.

In the timing generator circuit 10 shown in FIG. 4, in the 500 mode, the horizontal memory address is 0.
~511, and in the case of 1ooo mode, the horizontal memory address is 0~1023.

Also, the least significant bit of the vertical memory address in the 500 mode is used as the most significant bit of the horizontal memory address in the 1ooo mode. Vertical Memoriato.

500 mode and 100 mode by shifting the response in the same way
Switch 0 mode.

That is, in the case of tooo mode, address counters C1 to C5 are used to read horizontal memory addresses O to 10.
23, and vertical memory addresses 0 to 1023. For 500 mode, multiplexer MPXt-B
Switch to the side too.

The upper two bits of the vertical memory address indicated by the mode are fixed and used as the memory block number θ to 3.

These memory block numbers 0 to 3 are set to 0 by the instruction of the CPU 1l each time a live image is taken during 500 mode shooting.
to 3 and record live images in the order of 0 to 3. Therefore, four frames for the 500 mode can be stored in the area of the frame memory 7 corresponding to 1000 modes.

The actual photographing procedure is as shown in FIG. The live images in the 500 mode are each taken into the frame memory 7 using the timing signal P6 and stored, and subtraximine processing is performed between them and the mask image.
A subtraction image is displayed on the television monitor 8.

The operator changes the imaging mode to 1000 mode at a predetermined point during a series of imaging in which a contrast medium is injected and the image is taken by operating a push button provided on the operation panel 12 as necessary while viewing this image. Switch from to 500 mode.

As can be seen from the above description, according to this embodiment, by switching the imaging mode from, for example, 1000 mode to 500 mode at a predetermined point during a series of imaging in which a contrast agent is injected and imaging, high resolution and contrast can be achieved. It is possible to obtain high-definition X-ray images. For example, in angiography XR examination.

By selecting the optimal imaging mode for both the arterial vascular phase and the venous vascular phase, it is possible to obtain an excellent high-definition X-ray vascular image.

〔effect〕

As explained above, according to the novel technology disclosed in the present application, in an angiographic examination using a DSA device,
At a predetermined point during a series of images in which a contrast agent is injected,
Since the imaging mode can be switched to the optimal imaging mode depending on the subject, a high-resolution, high-definition X-ray image with good contrast can be obtained.

The present invention has been specifically explained above using examples, but
It goes without saying that the present invention is not limited to the embodiments described above, and can be modified in various ways without departing from the spirit thereof.

[Brief explanation of drawings]

FIGS. 1 to 4 are diagrams for explaining the DSA device of this embodiment. FIG. 1 shows the overall configuration of the DSA device, and FIG. 2 is a timing chart when switching between 1000 mode and 500 mode for photographing. Figure 3 is a diagram showing the state in which tooo mode and 500 mode images are stored in the frame memory, and the door Figure 4 shows the schematic configuration of the part of the timing generator shown in Figure 1 that creates the frame memory address. FIG. In the figure, 1... High voltage generator, 2... X-ray tube, 3
...1.1. ．． 4...TV camera, 5...A/
D converter. 6... Arithmetic unit, 7... Frame memory, 8... TV monitor, 9... Image processing section, O... Timing generator circuit, 11... CPU, 12... Operation panel be.

Claims (1)

[Claims] (1) Shoot with a TV camera that can switch between multiple shooting modes, convert the shot video signal to a digital signal, and calculate the digital signal to create a digital signal.
A high-definition digital X-ray imaging device capable of performing subtraction, characterized by being provided with means for switching the imaging mode at a predetermined point in the middle of a series of imaging in which a contrast medium is injected and imaging. Model digital X-ray imaging device.