JPS6090537A - X-ray diagnostic 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 of the Invention] The present invention involves irradiating a subject into which a contrast medium has been injected with X-rays,
It relates to an X-ray diagnostic device that uses a contrast-enhanced image synthesized by the transmitted X-rays for diagnosis, and in particular, an X-ray diagnostic device that displays the concentration distribution of the infiltrated contrast agent as density contour lines. Regarding.

[Technical background of the invention and its problems]

The X
A radiographic diagnostic apparatus converts a fluoroscopic X-ray image into a digital value, performs image processing mainly on subtraction on the digital image information, and then converts it back into an analog image and displays it on a monitor.

According to the contrast image produced by such an X-ray diagnostic device, it is possible to observe the contrast with a much lower contrast agent concentration compared to the contrast image produced by conventional X-ray film.
It is now possible to observe the contrast medium infiltrating each organ as a subject moment by moment. For example, if we take a heart as an object, there are coronary arteries that supply blood to the heart muscle itself, and in order to observe the blood circulation state of these coronary arteries,
X-ray photography is performed by injecting a straight contrast agent into the coronary artery. In this cardiac diagnosis, rather than observing the hemodynamics of the coronary arteries, it is better to directly observe the resulting myocardial ischemic state or the life or death of the myocardium based on the infiltration distribution of the contrast medium. It is often important when doing so.

In response to the above requirements, conventionally, ROI (region of interest) specified point A
The concentration of is at time t! Figure 1(a) at time t2, Figure 1(b) at time tn, and Figure 1(c) at time tn as shown in Figure 2. It was made possible to observe the change in characteristics by displaying it as a graph.

However, with this display method, although it is possible to know the density change of each pixel at the ROI specified point being displayed, it is difficult to know the shape of the boundary between the lesion and normal tissue within the organ, and the shape of the lesion relative to the shape of the entire organ. It was not possible to display the positional relationship of the parts, and it was difficult to obtain good diagnostic information.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and its purpose is to be able to clearly indicate the positional relationship between a lesion in a subject into which a contrast medium has been injected and the entire subject, as well as the center position of the lesion. An object of the present invention is to provide an X-ray diagnostic device.

[Summary of the invention]

The present invention divides transmitted X-ray image information obtained by irradiating X-rays onto a subject into which a contrast agent has been injected, and after performing predetermined image processing on these pixel information, In an X-ray diagnostic apparatus that collects image information and displays it on a monitor, there is provided a means for classifying each of the above pixel information into each predetermined density level and obtaining high-purity information such as density using pixel information of the same density level. By combining the above-mentioned image information and the above-mentioned density contour line information and displaying an image, the distribution of the contrast agent concentration infiltrated into the subject is displayed as a contour line as a region of equal concentration, thereby identifying the lesion area. The positional relationship of the whole subject and the center of the lesion can be clearly shown.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Third
The figure is a block diagram schematically showing an embodiment of an X-ray diagnostic apparatus according to the present invention.

In Fig. 1, 1 is an X-ray tube that irradiates X-rays to a subject 3 placed on a top plate 2, and this X-ray tube 1 is controlled by an X-ray controller 4 equipped with an X-ray power source. has been done. These X-ray tube 1 and X-ray controller 4 constitute an X-ray generator.

The X-rays irradiated from the X-ray tube 1 pass through the subject 3, and the transmitted X-rays are detected as a plane image by the X-ray detection device 5, which consists of, for example, a Xi television, and the image information is processed by data processing. device 6. On the other hand, an electrocardiogram electrode 7 is connected to the subject 3, and an electrocardiogram signal ECG is obtained by an electrocardiograph 8. This electrocardiogram signal ECG (hereinafter abbreviated as ECG signal) is converted into a digital signal by a converter 9, and r
- applied to the evening processing device 6; In the figure, 10 is a monitor that displays image information obtained by image processing by the data processing device 6. 11 is an image file in which the above image information is filed.

Next, details of the data processing device 6 will be described with reference to FIG.

In FIG. 4, reference numeral 12 denotes a converter for converting the image information (frame) output from the X-ray detection device 5 into digital values. Reference numeral 13 denotes a bus selector that distributes time-by-time image information (frames) output from the X-ray detection device 5 to image memories to be described later in units of frames.

J4A, 14B, and 14C are image memories, respectively.
Denotal image information is stored in each. In this case, for example, the image memory 74A stores the time t before contrast medium injection.
Image information (mask image) in 6, image memory 1
4B shows time 1. after contrast agent injection. image information in,
Image memo I714C shows time t2 after contrast agent injection.
It is assumed that image information in is stored. Further, the image information (frames) stored in the image memory group 14 in 14B and 14C are as schematically shown in FIG.
kXk matrix configuration, that is, pixel information E(1,
1)~E(i,j)~E[exist],k), and each pixel information is divided into m bits of density (contrast agent density).
Has information.

Reference numeral 15 denotes a contour line level setting device for setting the density level when displaying density contour lines according to the infiltrated contrast agent concentration level in the subject image. For example, when displaying n-level contour lines, 2n=p comparisons are made. Levels D, ~D1~D are set in advance. 16 uses each density setting level DI in the contour line level setter 15 as a comparison standard, and calculates the density level (expressed in mpi, g) of each pixel information E of the image memories 141.14B and 14C with respect to this comparison standard DI. This is a level comparator that determines whether or not the concentration information (i, j) exceeds the level. 17 is in the image memory 14, 14B, 1
4C, in which kXk (7)-r trix configuration is set, that is, the partitions F(1, 1) to F(i, j) to F(k, k>). F(1,1
)~F(i,j)~F(k,k) are such that nine densities 'ゝ1 can be expressed by nbits. 18 is a frame memory that stores images to be displayed; 19 is a converter that converts the image information in the frame memory 18 into analog information for display on the monitor 10; and 20 is an ECG from the electrocardiograph 8. This is a timing setter that sets the timing when giving a signal to the level comparator 16.

Next, the operation of this embodiment configured as described above will be described.

First, X-rays are irradiated before contrast medium injection (time to), and the image information at that time is converted into pixel information Eo (1, 1) ~ EOCi,
j) It is divided into ~E' (k, k) and stored in the image memory 14k, and this is used as a mask image in subtraction processing, for example. Next, X-rays are irradiated at time t1 after contrast agent injection, and the image information at that time is converted into kXk pixel information E1 (1, 1) ~ E1 (i, j) ~ "1 (k,
k) and stored in the image memory 14B. At this time, it is assumed that 21=p comparison levels D1 to D, to D are set in the contour line level setter 15 in order to display n levels of contour line levels on the image to be displayed.

Then, the comparison level D, and the pixel information “J (1, 1) ~”
'(f, j) ~ El (k, k) are compared, and this pixel information El (1, 1) ~ ~ E1 (j, j) ~ El (k,
k) exceeds the comparison level D1, and the comparison level D2
Data (comparison level D1) indicating the above comparison level D1 is written in the corresponding sections F(1, 1) to F(i, j) to F(1<, k) of the plain memory 17 for those that do not exceed . Sequentially, the above comparison process is performed at comparison levels D2 to Di-.
D. Execute the image memory 1 by this process.
The density level of each pixel information of 4B is the comparison level D1 to D.
It is determined which of l to D corresponds to the corresponding section F(1,1) to F(i,j) to the plane memory 17.
Data indicating the comparison levels D1 to Di to Dp is written to F(k,k).

Note that during the above operation, the path selector 13 is set to be able to take in the output of the level comparator 16 in order to write the comparison level to the plain memory 17.

Next, each section F(1,1) to F of the plane memory 17
The density information stored in (i, j) to F(k, k) is sequentially read out, and the pixel information El (1, 1) to Et (i, j) stored in the image memory 14B is read out. Et
(k, k) to the frame memory 18, where the density contour data in the plain memory 17 and the pixel information in the image memory 14B are combined to generate image information in which contour lines are set in the image to be displayed. do. This image information is then converted into analog information by a D/A converter 19 and displayed as an image on the monitor 10. In this case, image information at t1 after contrast agent injection is saved in the image file 11, if necessary.

Next, at time t2 after injection of the contrast agent, X In is irradiated, and image information at that time is stored in the image memory 14C. Then, the same processing as at time tx is performed and the image is displayed on the image monitor lo on which contour lines have been set. In the above, the image information at time to in the image memory 14 is used as a mask image, and the image information at time to in the image memories 14B and 14C is
* The contour pure setting of the above embodiment may be performed by subjecting each image information of t2 to a subtraction process.

A case will be described in which a heart as shown in FIG. 6 is specifically diagnosed as a subject using the above embodiment. That is, a contrast agent is injected into the coronary artery 22 from the catheter (syringe) 21 to visualize the stenosis at part 0 in the figure. Furthermore, the contrast medium gradually infiltrates the entire myocardium 23, and density contrast begins to appear.

If there is stenosis in part 0 of the diagram, causing an abnormality in the heart, for example, the myocardium in part 0 of the diagram is damaged and there is no or very little blood circulation. . Therefore, no density contrast occurs near the 0 portion shown in the figure. If the density contour line display operation according to this embodiment is performed in such a state, the illustrated contour line will be 23°, 24.25.2
6 is displayed, so that the relative positional relationship of the illustrated part 0 to the whole heart, the range of the inactive part, etc. can be easily determined from the entire image, and important information for cardiac diagnosis can be provided.

Furthermore, in the above embodiment, a case has been described in which the phase of the cardiac cycle is not taken into consideration. In FIG. A modification may be made in which image information is selected and the contour line display operation of the above embodiment is performed on the image information having the same phase.

Furthermore, the image information from the X-ray detection device 5 is A/D converted by the converter 12, and after subtracting the scattered radiation component due to the X-rays,
It is also possible to provide a means for logarithmically converting the digital image information, and perform the contour line display operation of the above embodiment on the digital image information after the logarithmically converting the digital image information.

In addition, the present invention can be implemented with various modifications without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, the X-ray diagnostic apparatus according to the present invention divides transmitted X-ray image information obtained by irradiating X-rays onto a subject into which a contrast agent has been injected, into a plurality of pixel information, and assigns predetermined information to these pixel information. After performing image processing, in an X-ray diagnostic device that collects the image information and displays it on a monitor, the above pixel information is classified into each predetermined density level, and pixel information of the same density level is used. By combining the image information and the density contour information and displaying the image, the distribution of the contrast agent concentration that has infiltrated into the subject can be displayed in a contour line as a region of equal concentration. ,
This makes it possible to clarify the positional relationship of the lesion in the entire subject and the center of the lesion, and provides important diagnostic information in X-ray fluoroscopic examination.

[Brief explanation of the drawing]

Figures 1 (,) (b) and (c) are diagrams for explaining the operation of an X-ray diagnostic device that employs the digital radiography method, and Figure 2 is a characteristic diagram showing changes in contrast agent concentration over time. , FIG. 3 is a block diagram showing an embodiment of the X-ray diagnostic apparatus according to the present invention, FIG. 4 is a block diagram showing details of the data processing device in FIG. 3, and FIG. 5 is a block diagram showing details of the data processing device in FIG. 4. FIG. 6, which is a schematic diagram for explaining the configuration, is a diagram showing an image of a heart as a subject for explaining the operation of an embodiment of the present invention. 1... X-ray tube, 2... Top plate, 3... Subject, 4...
...X-ray controller, 5...X-ray detection lid, 6...
・Data processing device, 7... Electrocardiogram electrode, 8... Electrocardiograph, 9... φ converter, 10... Monitor, 1...
Image file, 12...A/'D converter, 13...
Bus selector, 14A, 14B, 14C...image memory, 15...contour line level setter, 16...level comparator, 12...plane memory, 18...frame memory, 19...D /A converter, 20...timing setter. Applicant's representative Patent attorney Takehiko Suzue Figure 1 (a) (b) (, c) Figure 2 Figure 3 Figure 6

Claims (1)

[Claims] Transmitted X obtained by irradiating X-rays onto a subject injected with a contrast agent
In an X-ray diagnostic apparatus that divides line image information into a plurality of pieces of pixel information, performs predetermined image processing on these pixel information, and then aggregates these image information and displays them on a monitor, each of the above pixel information is are classified into each predetermined concentration level,
An X-ray diagnostic apparatus comprising means for obtaining density contour information using pixel information of the same density level, and displaying an image by composing the image information and the density contour information.