KR102478003B1 - Medical imaging device with position correction function based on imaging processing - Google Patents

Abstract

The present invention relates to a medical imaging apparatus having a position correction function based on an image processing method, which includes: an X-ray generator that repeatedly generates X-rays while varying an X-ray irradiation angle; an X-ray detection unit implemented as a location-moving type and repeatedly photographing X-rays having different radiation angles to obtain X-ray images for each photographing angle; an image separator that separates the X-ray image for each imaging angle into a low-density X-ray image and a high-density X-ray image; a location tracking unit configured to match high-density X-ray images for each photographing angle with a preset 3D standard model of a target to be photographed, and to calculate image position values for each photographing angle; and an image reconstruction unit that corrects the position of each X-ray image for each imaging angle based on the image position value for each imaging angle, and then reconstructs and outputs a digital tomography image.

Description

Medical imaging device with position correction function based on imaging processing

The present invention relates to a mobile medical imaging apparatus, and more particularly to a medical imaging apparatus having a position correction function based on an image processing method capable of minimizing the influence of the positional relationship between an X-ray generator and an X-ray detector even if it changes frequently. .

A medical imaging device such as the tomosynthesis system obtains multiple X-ray images by moving an X-ray generator around a target and changing the angle of X-ray irradiation to the target, and then synthesizes them with a computer to create a cross-sectional image of the target. It is a system that

Unlike CT, which rotates 360 degrees, tomosynthesis has the characteristic of obtaining a projection image by rotating only a limited number of angles from (-) 50 degrees to (+) 50 degrees, and synthesizing it into a single cross-sectional image.

Recently, tomosynthesis can acquire X-ray images in two ways. One is a method in which the X-ray generator and the X-ray detector move together while facing each other, taking multiple cross-sectional images consecutively and synthesizing them. A medical image may be obtained by sequentially photographing a plurality of cross-sectional images while moving the device and then synthesizing the images.

However, when the medical imaging apparatus is implemented as a mobile type, there are cases in which the positions of the X-ray generator and the X-ray detector are independently adjusted. A problem in which it is difficult to perform the operation normally occurs.

Domestic Patent Publication No. 10-2017-0021723 (published on February 28, 2017)

In order to solve the above problems, the present invention detects and corrects the positional relationship between the X-ray generator and the X-ray detector using an image processing method, thereby minimizing the influence caused by the change in the positional relationship between the X-ray generator and the X-ray detector. An object of the present invention is to provide a medical imaging device having a position correction function based on an image processing method.

The object of the present invention is not limited to the above-mentioned object, and other objects not mentioned will be clearly understood by those skilled in the art from the description below.

As a means for solving the above problems, according to an embodiment of the present invention, an X-ray generator configured to repeatedly generate X-rays while varying an X-ray irradiation angle; an X-ray detection unit implemented as a location-moving type and repeatedly photographing X-rays having different radiation angles to obtain X-ray images for each photographing angle; an image separator that separates the X-ray image for each imaging angle into a low-density X-ray image and a high-density X-ray image; a location tracking unit configured to match high-density X-ray images for each photographing angle with a preset 3D standard model of a target to be photographed, and to calculate image position values for each photographing angle; and an image reconstruction unit configured to correct the position of each X-ray image for each imaging angle based on the image position value for each imaging angle, and then reconstruct and output a single digital tomography image. provides

The position tracking unit extracts a plurality of feature points from the high-density X-ray image for each photographing angle, extracts a plurality of corresponding points from the 3D standard model of the photographing target, and then collects and analyzes the positional relationship between the feature points and the corresponding points. It is characterized in that the image position value is calculated.

The position tracking unit is characterized in that it converts the position value of the corresponding point from a 3-dimensional coordinate value to a 2-dimensional coordinate value, and analyzes the positional relationship between the feature point and the corresponding point.

In addition, the image reconstruction unit calculates and reflects a position correction value for each photographing angle so that the image position value for each photographing angle becomes a preset reference position value, and corrects the position of each X-ray image for each photographing angle.

In the present invention, a positional relationship between an X-ray generator and an X-ray detector can be detected and corrected through image matching between a 3D standard model of an object to be photographed and an X-ray image. Accordingly, it is possible to minimize the influence due to the change in the positional relationship between the X-ray generator and the X-ray detector without adding a separate hardware means such as a position sensor.

In addition, in the present invention, after a high-density X-ray image is separated from an X-ray image, image matching is performed with a 3D standard model of an object to be photographed using the image, thereby improving overall efficiency and accuracy of image matching.

1 and 2 are views illustrating the appearance of a medical imaging apparatus according to an embodiment of the present invention.
3 is a diagram showing the configuration of a medical imaging apparatus according to an embodiment of the present invention.
4 to 7 are diagrams for explaining a method for capturing a medical image according to an embodiment of the present invention.

The following merely illustrates the principles of the present invention. Therefore, those skilled in the art can invent various devices that embody the principles of the present invention and fall within the concept and scope of the present invention, even though not explicitly described or shown herein. In addition, it is to be understood that all conditional terms and embodiments listed herein are, in principle, expressly intended only for the purpose of making the concept of the present invention understood, and not limited to such specifically listed embodiments and conditions. It should be.

Further, it should be understood that all detailed descriptions reciting specific embodiments, as well as principles, aspects and embodiments of the present invention, are intended to encompass structural and functional equivalents of these matters. In addition, it should be understood that such equivalents include not only currently known equivalents but also equivalents developed in the future, that is, all devices invented to perform the same function regardless of structure.

Thus, for example, the block diagrams herein are to be understood as representing conceptual views of exemplary circuits embodying the principles of the present invention. Similarly, all flowcharts, state transition diagrams, pseudo code, etc., are meant to be tangibly represented on computer readable media and represent various processes performed by a computer or processor, whether or not the computer or processor is explicitly depicted. It should be.

1 and 2 are diagrams showing the appearance of a medical imaging apparatus according to an embodiment of the present invention. FIG. 1 is a state in which an X-ray detector is coupled to a scanning arm, and FIG. 2 is a state in which an X-ray detector is separated from a scanning arm. represent each.

As shown in FIGS. 1 and 2 , the medical imaging apparatus 100 of the present invention includes a main body 110 that can be driven, a vertical arm 120 vertically coupled to the main body 110, and the vertical arm 120 can rotate. The drive arm 130 is coupled to the drive arm 130, the X-ray generator 140 is moved along the guide hole 131 provided in the drive arm 130 to adjust the X-ray irradiation angle, and the X-ray generator 140 irradiates An X-ray detection unit 150 that repeatedly photographs X-rays passing through the patient's body and generates and outputs an X-ray image for each shooting angle, an image reconstruction unit 160 that reconstructs and outputs an X-ray image for each shooting angle into a single digital tomography image, etc. includes

In particular, as shown in FIG. 1, the medical imaging apparatus of the present invention is a position-fixed type in which the X-ray generator 140 and the X-ray detector 150 are attached to both ends of a drive arm 130 implemented in a "c" shape. In addition to being implemented, as shown in FIG. 2 , the X-ray detector 150 may be implemented as a location-moving type in which the X-ray detector 150 is separated from the driving arm 130 and placed on the bed 200 or the like.

This is to allow the patient lying on the bed 200 to take an X-ray image as it is while lying on the bed by using the medical imaging device towards the bed instead of moving to a radiation room or the like. Of course, by rotating the drive arm 130 at various angles, medical images can be captured even when the patient is standing.

However, when the X-ray detector 150 is separated from the drive arm 130 as described above, it is difficult to maintain a constant positional relationship between the X-ray generator 140 and the X-ray detector 150. Then, the relative position value of the X-ray detector 150 with respect to the X-ray generator 140 changes, so that the X-ray images for each imaging angle have different coordinate values, which makes it difficult to perform medical image reconstruction normally. will occur additionally.

Accordingly, the medical imaging apparatus of the present invention additionally includes means for detecting and correcting the position of the X-ray detector as shown in FIG. The image reconstruction operation can always be stably performed.

3 is a diagram showing the configuration of a medical imaging apparatus according to an embodiment of the present invention.

Referring to FIG. 3 , the medical imaging apparatus of the present invention further includes an image separator 170 and a position tracking unit 180 in addition to the X-ray generator 140, the X-ray detector 150, and the image reconstruction unit 160. consists of including

The image separation unit 170 is provided with any one of a bone suppression algorithm using a single energy X-ray image, a bone suppression algorithm using a dual energy X-ray image, and a bone suppression algorithm using an X-ray image using deep learning, and uses the same. Then, each X-ray image for each imaging angle is separated into a low-density X-ray image and a high-density X-ray image. Then, in the low-density X-ray image, only the image component exists in addition to the bone component, and only the bone component exists in the high-density X-ray image.

The position tracking unit 180 pre-obtains and stores a 3D standard model corresponding to each of various photographing subjects.

When the type of object to be photographed is determined, a corresponding 3D standard model is selected, and a plurality of corresponding points are extracted by image matching of high-density X-ray images for each imaging angle to the selected 3D standard model, and a positional relationship between the plurality of corresponding points is determined. It is collected and analyzed for each photographing angle to calculate image position values (ie, positional relationship between the X-ray generator and the X-ray detector) for each photographing angle.

In this case, the standard model represents the general shape of the region to be photographed, and may be obtained by collecting and averaging large-capacity high-density X-ray images.

Then, the image reconstruction unit 160 corrects the location of each X-ray image for each imaging angle based on the image position value for each imaging angle calculated by the position tracking unit 180 and then reconstructs it into a single digital tomography image, thereby eliminating errors. It is possible to acquire and provide digital tomography images.

4 to 7 are diagrams for explaining a method for capturing a medical image according to an embodiment of the present invention.

First, X-rays are radiated while varying the irradiation angle of the X-ray generator 140, and X-rays that pass through the patient through the X-ray detector 150 and reach the patient are repeatedly detected for each photographing angle, thereby obtaining an X-ray image for each photographing angle. and provided (S1).

In addition, the X-ray images for each shooting angle are separated based on the density of the object to be photographed through the image separator 170, and as shown in FIG. Obtain (S2).

And after extracting a plurality of feature points from the high-density X-ray image through the location tracking unit 180 as shown in FIG. 6, a corresponding point corresponding to each of the plurality of feature points is detected from the 3D standard model. In addition, after each corresponding point of the 3D standard model is converted from 3D coordinates to 2D coordinates, the positional relationship between feature points and corresponding points is collected and analyzed for each shooting angle, thereby calculating an image position value for each shooting angle (S3).

Then, for each photographing angle, a position correction value is calculated so that the image position value becomes a preset reference position value (S4).

Then, after position correction of each X-ray image for each imaging angle based on the position correction value for each imaging angle, a digital tomography image is reconstructed and output (S5). In this case, as shown in FIG. 7 , an effect occurs as if the X-ray detector acquires all of the X-ray images for each photographing angle at the same location, and thus, errors due to positional errors are prevented in advance.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and is common in the art to which the present invention pertains without departing from the gist of the present invention claimed in the claims. Of course, various modifications and implementations are possible by those with knowledge of, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

Claims (4)

an X-ray generator configured to repeatedly generate X-rays while varying an X-ray irradiation angle;
an X-ray detection unit implemented as a location-moving type and repeatedly photographing X-rays having different radiation angles to obtain an X-ray image for each photographing angle;
an image separator that separates the X-ray image for each imaging angle using a bone removal algorithm into a low-density X-ray image in which only image components other than bone components remain and a high-density X-ray image in which only bone components are present;
After extracting a plurality of feature points from the high-density X-ray image for each photographing angle, extracting a plurality of corresponding points from the 3D standard model of the photographing target, and then collecting and analyzing the positional relationship between the feature points and the corresponding points, the image position value for each photographing angle is obtained. a location tracking unit that calculates; and
An image reconstruction unit configured to correct the position of each X-ray image for each imaging angle based on the image position value for each imaging angle and then reconstruct and output a digital tomography image;
the location tracking unit
After acquiring and storing a plurality of three-dimensional standard models corresponding to each of a plurality of photographing subjects in advance, one of the plurality of three-dimensional standard models is selected according to the type of photographing subject,
The 3D standard model is
A medical imaging device having a position correction function based on an image processing method, characterized in that acquired by collecting and averaging large-capacity high-density X-ray images corresponding to the same imaging subject. delete The method of claim 1, wherein the location tracking unit
A medical imaging apparatus having a position correction function based on an image processing method, characterized in that the positional relationship between feature points and corresponding points is analyzed by converting the position values of corresponding points from 3-dimensional coordinate values to 2-dimensional coordinate values. The method of claim 1, wherein the image reconstruction unit
Medical having a position correction function based on an image processing method, characterized in that position correction of each X-ray image for each imaging angle is performed by calculating and reflecting a position correction value for each imaging angle so that the image location value becomes a preset reference location value for each imaging angle. video recording device.

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