JPH04364833A - X-ray tv system - Google Patents

Abstract

PURPOSE:To enable treatment with a balloon catheter safely and accurately by determining the degree of expansion of a balloon part accurately. CONSTITUTION:An X-ray TV system which displays an image to be obtained by irradiating testee to be inspected with X rays is provided with a selection means 5 to select a pixel having a specified brightness from an image obtained by irradiating with the X rays a balloon part when a balloon catheter is introduced into a blood vessel of the testee being regarded as pixel of the balloon part and a counting means 6 to count the number of pixels selected, and the counting results for a frame time are obtained as degree of expansion of the balloon part.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Field of Industrial Application] The present invention relates to an X-ray television device that displays fluoroscopic or photographic images obtained by irradiating a subject with X-rays on a CRT display or the like, and particularly relates to an X-ray television device that displays a fluoroscopic or photographic image obtained by irradiating a subject with The present invention relates to an X-ray television device that is capable of introducing a balloon and displaying an image of this balloon section.

0003

[Prior Art] In this type of X-ray television apparatus, a balloon catheter is inserted into a blood vessel of a subject, and a contrast medium is injected to inflate the balloon within the affected area (occluded area). A treatment is being carried out in which the area is expanded for a predetermined period of time. When inflating the balloon part, since the degree of inflation of the balloon part cannot be measured, the balloon part is inflated for a predetermined period of time after the operator inserts the catheter into the body cavity. However, such a one-size-fits-all method does not allow treatment to be tailored to the occlusion state of the affected area, and in some patients, the catheter may be reinserted due to insufficient inflation of the balloon part, or the balloon part may not be fully inflated. Too much pressure was placed on the affected area, often resulting in ischemia.

[0004] In order to solve such problems, pixel data of an enlarged X-ray fluoroscopic image or an X-ray photographed image of the balloon portion is integrated, and the integrated value of the screen at each frame time is displayed on a display system. A method has been proposed in which it is determined that the balloon portion has been sufficiently inflated to the affected area when the integral value becomes approximately constant over time. For example, to explain the case where the integral value of the screen changes over time as shown in FIGS. 5 and 6, the pixel data of the contrast agent is usually lower than other pixel data, so the integral value changes over time. In FIG. 5, images 100a to 100c,
In FIG. 6, as shown in images 101a to 101c,
It can be determined that the contrast medium is injected into the balloon part and the balloon part continues to expand.

In FIG. 5, time t1, FIG.
At time t2, when the integral value becomes almost constant with respect to time, as shown in images 100d and 101d, the balloon part is sufficiently inflated and pressed against the affected area, so it is not inflated. It is determined that the contrast agent is in a suppressed state, and the contrast medium injection is stopped to stop the inflation of the balloon. However, in this method, if the rate at which the balloon part closes the screen is not large enough, changes in the screen due to slight movements of the subject will appear in the integral value graph, so the graph shows the degree of inflation of the balloon part. becomes difficult to read. Also, when the balloon part is near the heart, such as in the coronary arteries, the screen is constantly moving, so
Even when the image is sufficiently enlarged, it is difficult to judge the degree of inflation of the balloon.

[0006]

[Problems to be Solved by the Invention] As described above, in the case of the prior art, it is difficult to accurately grasp the degree of inflation of the balloon section relative to the affected area, and it is difficult to safely and accurately perform treatment using a balloon catheter. The problem was that it was difficult.

The present invention has been made to solve the above-mentioned problems of the prior art, and its purpose is to accurately grasp the degree of inflation of the balloon section and to perform treatment using a balloon catheter safely and accurately. An object of the present invention is to provide an X-ray television apparatus that can perform

[Configuration of the invention]

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an X-ray television apparatus that displays an image obtained by irradiating a subject with X-rays. a selection means for selecting pixels having a predetermined brightness from an image obtained by irradiating the balloon section with X-rays when a balloon catheter is introduced into the balloon section; and counting the number of selected pixels. and a counting means,
The present invention is characterized in that the counting result for the frame time is obtained as the degree of inflation of the balloon section.

[0010] In the above device, a display means may be provided for displaying the counting results for each frame time obtained by the counting means. Furthermore, a timer may be provided that starts operating when the rate of change over time of the number of pixels selected by the selection means becomes smaller than a predetermined value. This timer may be reset when the rate of change in the number of selected pixels over time becomes greater than a predetermined value.

[0011]

[Function] In the X-ray television apparatus of the present invention having the above-mentioned configuration, the balloon portion is preliminarily determined based on an image such as an X-ray fluoroscopic image or an X-ray photographed image of the balloon portion when the balloon catheter is inserted into a blood vessel. When pixels having a predetermined luminance close to the predicted luminance value are selected by the selection means, a change in the number of selected pixels for each screen indicates a temporal change in the size of the balloon portion. Therefore, if the number of pixels to be selected is counted by the counting means, the counting result for each frame time will be obtained as the degree of expansion of the balloon section, and when the number of pixels to be selected for the frame time is almost converging, the balloon section will reach the affected area. It becomes possible to judge that it has expanded sufficiently.

[0012] According to this method, even if a change occurs on the screen such as a change in the background of the balloon part due to movement of the subject or the balloon part, only pixels having a luminance close to the predicted luminance of the balloon part are counted. Therefore, the degree of inflation of the balloon part can be measured without being affected by changes in the background of the balloon part. Also, even if the prediction of pixels in the balloon part is inaccurate and pixels other than the balloon part are counted,
Since many pixels have higher brightness than the balloon portion in which the contrast agent is sealed, the method of counting the number of pixels has less error than the conventional method of integrating the entire screen.

[0013] Therefore, even if the subject or the balloon moves, it is possible to accurately determine the degree of inflation of the balloon without being affected by changes in the screen. The section can be inflated as much as necessary to force the occlusion apart for an appropriate amount of time. That is,
It becomes possible to perform treatment using a balloon catheter safely and accurately without reinserting the catheter and causing ischemia unnecessarily.

Furthermore, if the above-mentioned timer is provided, the time indicated by the timer is the time after the balloon part has been sufficiently inflated to the affected area. compared to when measured by a person
You can obtain more useful information for treatment without much effort.

[0015]

[Embodiments] Hereinafter, embodiments of the present invention will be explained based on the drawings. FIG. 1 is a block diagram schematically showing the configuration of an X-ray television apparatus according to an embodiment of the present invention.

This X-ray television apparatus includes an image input section 1 into which an image such as a rough X-ray fluoroscopic image is input, an image memory 2 for storing image data sent from the image input section 1, and an image memory 2 for enlarging the image. The image enlarging circuit 3 includes an image enlarging circuit 3, and a display system 4 as a display means for displaying an image on a CRT display or the like. This device also includes a selection means (selection circuit) 5 for selecting pixels having a predetermined brightness from an enlarged image of the balloon portion when a balloon catheter (not shown) is introduced into the blood vessel of the subject; a counting means (counting circuit) 6 for counting the number of pixels counted by the counting means 6; a change amount determination circuit 7 for checking temporal changes in the number of pixels counted by the counting means 6; and a timer that starts operation according to the amount of change. 8 is provided.

[0017] When performing treatment using a balloon catheter, the balloon catheter is introduced into the subject's blood vessel, and the balloon part provided on this catheter is inserted into the affected area (occluded area).
to be located. At this time, data of an X-ray fluoroscopic image or an X-ray photographed image obtained by irradiating the balloon section with X-rays is input to the image input section 1, and the image input section 1 digitally converts this data and converts this image data into an image. Store in memory 2. The image enlargement circuit 3 reads image data from the image memory 2, enlarges this image to create enlarged image data, and sends this data to the display system 4 and the sorting means 5. The display system 4 displays an enlarged image of the balloon portion as shown in FIG. 2 according to this data. 1 in the image of Figure 2
0 indicates the balloon part.

Then, the operator injects a contrast medium into the balloon part to inflate the balloon part, but the sorting means 5, the counting means 6, the change amount determining circuit 7, and the timer 8,
The operation starts according to the flowchart shown in FIG. First, the brightness Z of the balloon part is predicted in advance by a prediction means (not shown) (step 1), and the selection means 5 calculates the brightness Z from all pixels in the entire enlarged image of the balloon part or in a preset region of interest. Select pixels having similar brightness (step 2).

Here, the selection means 5 selects the predicted luminance Z
This is a comparison circuit that compares the brightness of each pixel. As a method for predicting the brightness Z of the balloon part, since a contrast medium is injected into the balloon part and the brightness of the contrast medium is usually lower than the brightness of other pixels, the minimum brightness in the screen is taken as the brightness Z of the balloon part. Based on the method and the position information of the balloon part obtained in advance during treatment of other subjects, specify the pixel in the area where the balloon part is located on the screen using a pointing device, etc., and set the brightness of this pixel as the brightness Z of the balloon part. Examples include a method to do so.

As a method for selecting pixels having a luminance close to the luminance Z, for example, the minimum luminance within the region of interest is set to the luminance Z.
In this case, if the maximum brightness in the region of interest is Z1, a method of selecting pixels having a brightness of Z + (Z1 - Z) x 0.1 or less can be used, and a more specific value is determined by the brightness Z When predicting as Z, the minimum brightness within the region of interest is Z
2.If the maximum brightness is Z3, then Z-(Z3-Z2
) x α or more, and Z + (Z3 - Z2 ) x α or less (
Here, α is a positive constant).

The counting means 6 counts the number of selected pixels for each frame (step 3), and sends data on the number of selected pixels to the display system 4 for each frame time. The display system 4 plots the number of selected pixels on a graph (step 4).
), and the counting results are displayed as a graph showing the relationship between time t and the number of pixels to be selected, as shown in FIG. Here, the display method is not limited to such a line graph, but may be displayed using any other method as long as it shows the number of pixels with respect to frame time. Further, this counting result may be displayed on the monitor displaying the image of the balloon section instead of the image of the balloon section, or may be displayed on the same screen together with the image of the balloon section. Alternatively, it may be displayed on another monitor.

[0022] The operator can know the degree of inflation of the balloon part from the graph displayed on the display system 4, and can determine whether to continue injecting the contrast medium to further inflate the balloon part.
Alternatively, the degree of inflation of the balloon portion can be controlled by appropriately determining whether to stop the injection of the contrast medium and stopping the inflation. That is, in the graph shown in FIG. 4, when the number of pixels to be selected continues to increase with respect to the frame time, the balloon section continues to expand, and when the number of pixels to be selected continues to increase with respect to the frame time ( At time t4), it can be determined that the balloon part is sufficiently inflated within the occluded area and is pushing the occluded area open, and the operator stops injecting the contrast medium at time t4 and closes the balloon part. prevent unnecessary expansion of the

According to this method, even if the subject or the balloon moves, the degree of inflation of the balloon can be accurately measured without being affected by changes in the screen such as changes in the background of the balloon. Also, since the error is smaller when counting the number of pixels than when integrating pixel values as in the conventional technology,
Even when the balloon section is located near the heart, the degree of inflation of the balloon section can be accurately determined.

Further, the counting means 6 sends data on the number of pixels to be selected to the change amount determining circuit 7, and the change amount determining circuit 7 determines whether the number of pixels with respect to the frame time is converging (step 5). In other words, find the rate of change in the number of pixels to be sorted over time, and when this rate of change becomes sufficiently small (
At time t4 in FIG. 4, it is determined that the number of pixels to be selected is converging. Examples of a method for determining whether the rate of change has become sufficiently small include a method in which it is determined that the rate of change has become sufficiently small when the rate of change has become 1/10 or less of the maximum rate of change up to that point.

The change amount determination circuit 7 first sends a reset signal to the timer 8 when the balloon section starts to expand and the rate of change in the number of pixels to be selected is sufficiently large (time t3 in FIG. 4), and the timer 8 is reset. be done. Methods for determining whether the rate of change is sufficiently large include, for example, determining that the rate of change is sufficiently large when the rate of change at a certain time is greater than the rate of change at the previous time, or determining whether the rate of change is large enough in advance. Examples include a method of determining that the rate of change is sufficiently large when it becomes larger than a set reference value.

When the rate of change in the number of selected pixels becomes sufficiently small (time t4), the change amount determining circuit 7 sends a drive signal to the timer 8, and the timer 8 starts measuring time. The time measured by the timer 8 is displayed on the display system 4. The time measured by the timer 8 is approximately equal to the time from when the balloon part is sufficiently inflated and blood no longer flows from the balloon part to the blood vessel beyond, so the operator can use this measured time to obtain more useful information for treatment. The occluded area can be expanded for an appropriate amount of time without causing unnecessary ischemia. That is, after the balloon portion is sufficiently inflated and injection of the contrast medium is stopped, the timer 8 measures a predetermined time (step 6), and the treatment is completed.

As described above, in this embodiment, the degree of inflation of the balloon can be accurately determined regardless of the movement of the subject or the balloon, and more useful information can be obtained from the timer 8. Therefore, it is possible to inflate the balloon portion as necessary depending on the occlusion state of the affected area and perform safe and accurate treatment without reinserting the balloon catheter.

Furthermore, when the balloon section is sufficiently inflated, the timer 8 automatically starts measuring time, so that when the operator measures the time since the balloon section starts to inflate, as in the prior art, In comparison, it is possible to obtain more useful information for treatment without much effort. Since the number of times the balloon catheter has to be inserted and the X-ray imaging performed again is reduced, the treatment time can be shortened and an increase in the amount of X-ray exposure can be prevented.

Although the embodiments of the present invention have been described above,
The present invention is not limited to this, and various modifications can be made.

[0030]

[Effects of the Invention] The X-ray television apparatus of the present invention has the above-described structure and function, and the degree of inflation of the balloon can be accurately grasped regardless of the movement of the subject or the balloon. It becomes possible to safely and accurately perform treatment using a balloon catheter without reinserting the catheter or causing ischemia. Also,
If a timer like the one described above is provided, the time from when the balloon part is sufficiently inflated to the affected area can be measured.
Compared to conventional techniques in which the operator measures the time since the balloon portion begins to inflate, more useful information for treatment can be obtained with less effort.

[Brief explanation of drawings]

FIG. 1 is a block diagram schematically showing the configuration of an X-ray television apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a display image of a balloon section in the same embodiment.

FIG. 3 is a flowchart showing the operation in the same embodiment.

FIG. 4 is a graph showing the relationship between time t and the number of pixels to be selected in the same example.

FIG. 5 is a graph for explaining a conventional method for measuring the degree of inflation of a balloon portion.

FIG. 6 is a graph for explaining a conventional method for measuring the degree of inflation of a balloon portion.

[Explanation of symbols]

1 Image input section 2 Image memory 3 Image enlargement circuit 4 Display system (display means) 5. Sorting means 6 Counting means 7 Change amount judgment circuit 8. Timer

Claims (4)

[Claims] Claim 1: In an X-ray television device that displays an image obtained by irradiating a subject with X-rays, an image obtained by irradiating an X-ray onto a balloon section when a balloon catheter is introduced into a blood vessel of the subject. It is equipped with a sorting means for sorting out pixels having a predetermined brightness from the image as pixels of the balloon section, and a counting means for counting the number of sorted pixels, and the counting result with respect to the frame time is used as the degree of expansion of the balloon section. An X-ray television device characterized in that it is made to be obtainable. 2. The X-ray television apparatus according to claim 1, further comprising display means for displaying the counting results for each frame time obtained by the counting means. 3. The X-ray television apparatus according to claim 1, further comprising a timer that starts operating when the rate of change over time of the number of pixels selected by the selection means becomes smaller than a predetermined value. 4. The X-ray television apparatus according to claim 3, further comprising a timer that is reset when the rate of change in the number of selected pixels over time becomes greater than a predetermined value.