KR102216818B1 - Manufacturing method for estimating position of liver with two-dimensional of dual-energy x-ray absorptiometry - Google Patents

Abstract

The present invention relates to a method for estimating the location of the liver, and more particularly, after acquiring an image of a two-dimensional image through dual energy X-ray absorption measurement, the boundary of the liver is determined through the location of the lungs, diaphragm, ribs and vertebrae. It relates to a method of estimating and determining the liver area.
A method for estimating a liver position using a two-dimensional (2D) image of a dual energy X-ray absorption measurement method (DEXA) according to the present invention includes: a first step of obtaining a dual energy X-RAY image of the entire body; A second step of generating a bone image using a difference in attenuation degree of the dual energy X-RAY image generated in the first step; A third step of generating a tissue image from which bone components have been removed using a difference in attenuation degree of the dual energy X-RAY image generated in the first step; A fourth step of estimating the upper boundary of the liver from the tissue image of the third step; A fifth step of estimating a left boundary of the liver from the bone image of the second step; A sixth step of estimating a lower boundary of the liver from the bone image of the second step; A seventh step of estimating the right boundary of the liver from the bone image of the second step; An eighth step of calculating an outer point of the estimated liver using each boundary image of the liver estimated in steps 4 to 7; And a ninth step of determining a liver region at an outer point of the estimated liver calculated in the eighth step.

Description

Liver position estimation method using two-dimensional (2D) images of the dual-energy X-ray absorption measurement (DXA) {MANUFACTURING METHOD FOR ESTIMATING POSITION OF LIVER WITH TWO-DIMENSIONAL OF DUAL-ENERGY X-RAY ABSORPTIOMETRY}

The present invention relates to a method for estimating the location of the liver, and more particularly, after acquiring an image of a two-dimensional image through dual energy X-ray absorption measurement, the boundary of the liver is determined through the location of the lungs, diaphragm, ribs, and vertebrae. It relates to a method of estimating and determining the liver area.

The liver is an organ located in the right upper abdomen under the body's barrier and is responsible for major functions such as carbohydrate metabolism, amino acid and protein metabolism, fat metabolism, bile acid and bilirubin metabolism, vitamin and mineral metabolism, hormone metabolism, detoxification and sterilization. .

The liver is located in the upper right part of the abdomen and below the diaphragm and is surrounded by ribs and protected. The liver receives double blood supply by the hepatic artery extending from the aorta and the portal vein rising from the digestive tract, and the blood that has passed through the liver passes through the hepatic vein and returns to the heart through the inferior vena cava. The bile produced by the liver flows down the biliary tract, collects in the gallbladder (gallbladder), and is discharged into the duodenum. The liver is divided into the left and right lobes along the line connecting the inferior vena cava and the gallbladder, and is divided into 8 areas along the boundary of major structures such as blood vessels.These areas identify the location of liver cancer and are an important boundary to distinguish the extent of resection. do.

Estimation of the location of the liver for body composition analysis, such as measuring fat mass in a two-dimensional X-ray image, is currently being performed by a method of specifying only a local area using anatomical features (US13/915876, Method for measuring liver fat mass using dual-energy X. -ray absorptiometry, GENERAL ELECTRIC CO). However, if the analysis is performed using only a small portion of the liver in a general way, there is a problem that the characteristics of the entire liver region cannot be reflected. Therefore, there is a need for a study on a liver position estimation method that can automate this while including the actual liver region as much as possible using a two-dimensional X-ray image.

Korean Patent Publication 10-2013-7009616

The present invention has been conceived to solve the above problems, and an object of the present invention is to provide a method of easily estimating a liver position using X-ray.

The technical problems to be solved by the invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. I will be able to.

A method for estimating a liver position using a two-dimensional (2D) image of a dual energy X-ray absorption measurement method (DEXA) according to the present invention includes: a first step of obtaining a dual energy X-RAY image of the entire body; A third step of generating a tissue image from which bone components have been removed using a difference in attenuation degree of the dual energy X-RAY image generated in the first step; A fourth step of estimating the upper boundary of the liver from the tissue image of the third step; A fifth step of estimating a left boundary of the liver from the bone image of the second step; A sixth step of estimating a lower boundary of the liver from the bone image of the second step; A seventh step of estimating the right boundary of the liver from the bone image of the second step; An eighth step of calculating an outer point of the estimated liver using each boundary image of the liver estimated in steps 4 to 7; And a ninth step of determining a liver region at an outer point of the estimated liver calculated in the eighth step.

The dual energy X-RAY image of the first step acquires X-RAY images of low and high energy bands, respectively, but the low energy band is 40 keV to 50 keV, and the The high energy band is characterized in that 60keV to 70keV.

In the second step, the bone image is corrected using the dual energy X-ray absorption measurement method of [Equation 1] below.

[Equation 1]

In addition, in the third step, the tissue image is corrected using the dual energy X-ray absorption measurement method shown in [Equation 2] below.

[Equation 2]

By means of solving the above problems, the present invention has the effect of providing a method of easily estimating the location of the liver using X-RAY.

1 is a flow chart showing a method of estimating a liver position using a two-dimensional image of the present invention's dual energy X-ray absorption measurement method.
FIG. 2 is an image in which X-RAY images of low (a) and high (b) energy bands are stored in a first step (S100).
3 is a first step (S100) by using the low (a) and high (b) X-RAY image image of the energy band in the second step (S200) to generate an image with emphasis It is an image.
4 is an image obtained by generating an image of a tissue from which a bone component has been removed in a third step S300 by using the bone image generated in the second step S200.
5 is an image obtained by estimating the upper boundary of the liver in a fourth step S400.
6 is an image obtained by estimating the left boundary of the liver in a fifth step (S500).
7 is an image obtained by estimating the lower boundary of the liver in step S600.
8 is an image obtained by estimating the right boundary of the liver in step S700.
9 is an image obtained by calculating the outer point of the boundary area of the liver in step 8 (S800 ).
10 is an image in which a region of the liver is determined in step S900.

The terms used in the present specification will be briefly described, and the present invention will be described in detail.

The terms used in the present invention have been selected from general terms that are currently widely used while considering functions in the present invention, but this may vary depending on the intention or precedent of a technician working in the field, the emergence of new technologies, and the like. Therefore, the terms used in the present invention should be defined based on the meaning of the term and the overall contents of the present invention, not a simple name of the term.

When a part of the specification is said to "include" a certain element, it means that other elements may be further included rather than excluding other elements unless specifically stated to the contrary.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

Specific matters, including the problems to be solved, means for solving the problems, and effects of the present invention, are included in the following examples and drawings. Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

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First, in the first step (S100), a dual energy X-RAY image of the entire body is acquired. More specifically, in the first step (S100), after the X-ray irradiated by the X-ray generating apparatus passes through the measurement object, the degree of incident on the detector is stored as an image.

As shown in FIG. 2, the X-RAY image acquires an X-RAY image of a low and high energy band, respectively. It is preferable that the low energy band is 40 keV to 50 keV, and the high energy band is 60 keV to 70 keV. If the low energy band is less than 40 keV, the generated image may be too blurry to check the image, and if the low energy band exceeds 50 keV, the image difference in the high energy band is not clear. Since it may not be performed, it is preferable to perform it under the above conditions. In addition, if the high energy band is less than 60 keV, the difference in the image of the low energy band may not be clear, and if the high energy band exceeds 70 keV, the generated image is too bright. Since it may be difficult to generate a bone image and a tissue image, it is preferable to perform the above conditions.

Next, in the second step S200, a bone image is generated using the image of the image generated in the first step S100. More specifically, the bone image is an image in which a bone is emphasized by using a difference in attenuation degree between low and high energy, which is the dual energy measured in the first step S10. In FIG. 3, an image in which the bones are emphasized in the second step (S20) was generated using the X-RAY image images of the low (a) and high (b) energy bands. In addition, when a bone-enhanced image image is generated using a difference in attenuation degree between low and high energy, correction is required because there is a difference in values between the two image images. The correction for the difference in the attenuation degree of the low and high energy may be generated using the dual energy X-ray absorption measurement method of [Equation 1] below.

[Equation 1]

[Equation 1] calculates the ratio of the values of the tissue parts in the high and low energy images to make the values of the tissue parts in the high and low images to a similar level, Only bone components are left through the subtraction operation.

The reason why it is not possible to directly generate a bone image image from the low energy image and the high energy image obtained in the first step (S100) is that there is a basic level difference between the two images. Because. In other words, the energy used to measure each image is different, so even if it is the same area, the degree of attenuation is different. Therefore, an accurate emphasis image, that is, an image in which bone is emphasized, cannot be obtained by simply subtracting low energy and high energy without correction for this part. For this reason, by setting the attenuation level of other components other than the component to be emphasized in each energy image to the same level as in [Equation 1], values other than the component to be emphasized are set to 0 when subtracting the two images. Steps are needed to bring them closer together.

Next, in the third step (S300), a tissue image is generated by using the image of the image generated in the first step (S10). More specifically, the tissue image is an image in which a bone component is removed by using a difference in attenuation degree between low and high energy, which is the dual energy measured in the first step S100. In FIG. 3, bones were removed in the third step (S300) using X-RAY image images of low (a) and high (b) energy bands to create an image of a tissue. In addition, when an image image in which a tissue is emphasized is generated using a difference in attenuation degree between low and high energy, there is a difference in values between the two image images and thus correction is required. The correction for the difference in the attenuation degree of the low and high energy may be generated using the dual energy X-ray absorption measurement method of [Equation 2] below.

[Equation 2]

[Equation 2] calculates the ratio of the bone values in the high and low energy images to obtain similar levels of the bone values in the high and low energy images. After making it, only the tissue component is left through the subtraction operation. By setting the attenuation level of components other than the tissue component to be emphasized in each energy image to the same level, the step of making the values other than the component to be emphasized close to 0 when subtracting the two images is need.

Next, in the fourth step (S400), the upper boundary of the liver is estimated in the tissue image of the third step (S300). The fourth step (S400) is performed in more detail by the following steps.

In step 4-1 (S410), the tissue image is vertically corrected to become a vertical posture. As shown in Fig. 5(a), both shoulders are parallel to the floor, and the center line of the body is provided to be perpendicular to the floor or both shoulders.

Step 4-2 (S420) is binarized so that the lung portion is distinguished from the vertically corrected tissue image. As shown in Fig. 5(b), the binarization contrasts the image in black and white, and makes the tissues of the body excluding the lungs white and the lungs black to clarify the image of the lungs.

In step 4-3 (S430), the lower boundary point of the lung is detected from the binarized tissue image. As shown in FIG. 5(c), the boundary point of the lung portion detected in the binarized image detects PS2. The lower end of the lung may be estimated from the diaphragm. In the case of a system having a short measurement time, an image is measured in an inhaled state so that a more accurate location of the liver can be measured.

In step 4-4 (S440), an upper boundary of the liver is estimated by a curved line extending from the boundary point. As shown in Fig. 5(d), the curve L5 passing through the PS2 is estimated.

Next, in the fifth step (S500), the left boundary of the liver is estimated from the bone image of the second step (S200). The fifth step (S500) is carried out in more detail by the following steps.

In step 5-1 (S510), the bone image is vertically corrected to become a vertical posture. As shown in Fig. 6(a), both shoulders are parallel to the floor, and the vertebrae of the body are provided perpendicular to the floor or both shoulders.

In step 5-2 (S520), a bone part is binarized so that a bone part is distinguished from the vertically corrected bone image. As shown in Fig. 6(b), the binarization contrasts the image in black and white, and makes the tissue of the body excluding bone black and the bone black to clarify the image of the bone.

In step 5-3 (S530), points corresponding to the left outline of the rib are detected in the binarized bone image. As shown in FIG. 6(c), PS3, which is a point corresponding to the left outline of the ribs, is detected.

In step 5-4 (S540), the left boundary between the point corresponding to the outline is followed by an extended curve is estimated. As shown in Fig. 6(d), the curve L6 passing through the PS3 is estimated.

Next, in the sixth step (S600), the lower boundary of the liver is estimated from the bone image of the second step (S200). The sixth step (S600) is performed in more detail by the following steps.

In step 6-1 (S610), the bone image is vertically corrected to become a vertical posture. As shown in Fig. 7(a), both shoulders are parallel to the floor, and the vertebrae of the body are provided perpendicular to the floor or both shoulders.

In step 6-2 (S620), a bone part is binarized so that a bone part is distinguished from the vertically corrected bone image. As shown in Fig. 7(b), the binarization contrasts the image in black and white, and makes the tissue of the body excluding bone black and the bone black to clarify the image of the bone.

In step 6-3 (S630), points on the lowermost left rib are detected in the binarized bone image. As shown in Fig. 7(c), PS4, which is a point corresponding to the upper end of the lower leftmost end of the ribs, is detected.

In step 6-4 (S640), the left boundary of the liver is estimated by an extended curve following the point corresponding to the upper leftmost end of the rib. As shown in Fig. 7(d), the curve L7 passing through the PS4 is estimated.

Next, in the seventh step (S700), the right boundary of the liver is estimated in the bone image of the second step (S200). Estimating the right boundary of the liver is estimating the left boundary of the vertebrae, and the seventh step (S700) is performed in more detail by the following steps.

In step 7-1 (S710), the bone image is vertically corrected to become a vertical posture. As shown in Fig. 8(a), both shoulders are parallel to the floor, and the vertebrae of the body are provided perpendicular to the floor or both shoulders.

In step 7-2 (S720), a bone portion is binarized so that a bone portion is distinguished from the vertically corrected bone image. As shown in FIG. 8(b), the binarization contrasts the image in black and white, and makes the tissue of the body excluding bone black and the bone black to clarify the image of the bone.

In step 7-3 (S730), left boundary points of the vertebrae are detected from the binarized bone image. As shown in Fig. 8(c), PS6, which is a point corresponding to the left boundary of the vertebrae, is detected.

In step 7-4 (S740), the right boundary of the liver is estimated by a curve extending from the left boundary point of the vertebrae. As shown in Fig. 8(d), the curve L8 passing through the PS6 is estimated.

Next, in the eighth step (S800), the estimated outer point of the liver is calculated using each boundary image of the liver estimated in the fourth step (S400) to the seventh step (S700). The eighth step (S800) is more specifically implemented by the following steps. However, the following steps can be performed in any order.

Step 8-1 (S810), as shown in Figure 9 (a), estimates the point P1 where L6 estimated in the fifth step (S500) and L7 estimated in the sixth step (S700) intersect. do.

In step 8-2 (S820), as shown in FIG. 9(b), a point P2 at which L7 estimated in step 6 (S600) and L8 estimated in step 7 (S700) intersect is estimated. .

In step 8-3 (S830), as shown in FIG. 9(c), a point P3 where L5 estimated in the fourth step S400 and L8 estimated in the seventh step S700 intersect is estimated. .

In step 8-4 (S840), as shown in FIG. 9(d), the point P4 at which L5 estimated in the fourth step S400 and L6 estimated in the fifth step S500 intersect is estimated. .

Next, in the ninth step (S900), the liver region is determined at the estimated outer point of the liver calculated in the eighth step (S800). As shown in FIG. 10, R1 is estimated by connecting the points P1 to P4 with a line. It is determined that R1 is a liver region.

The method of estimating a liver position using a two-dimensional (2D) image of the dual energy X-ray absorption measurement method (DXA) according to the present invention may be implemented by a liver position estimation system. The liver position estimation system includes an image acquisition unit, a bone image generation unit, a tissue image generation unit, a boundary estimation unit, an outer point calculation unit, and a liver region determination unit.
The image acquisition unit performs the first step (S100). Specifically, a dual energy X-RAY image of the entire body is acquired.
The bone image generator performs the second step (S200). Specifically, a bone image is generated by using a difference in attenuation degree of the dual energy X-RAY image generated in the first step.
The tissue image generation unit performs the third step (S300). Specifically, a tissue image from which bone components have been removed is generated by using the difference in attenuation degree of the dual energy X-RAY image generated in the first step.
The boundary estimation unit performs the fourth step (S400) to the seventh step (S700). Specifically, the upper, left, lower, and right boundaries of the liver are estimated from the tissue image of the third step.
The outer point calculation unit performs the eighth step (S800). Specifically, the estimated outer point of the liver is calculated using each boundary image of the liver estimated in the fourth step S400 to the seventh step S700.

The inter-region determination unit performs the ninth step (S900). Specifically, the liver region is determined at the estimated outer point of the liver calculated in the eighth step (S800).

By means of solving the above problems, the present invention has the effect of providing a method of easily estimating the location of the liver using X-RAY.

As described above, it will be understood that the technical configuration of the present invention described above can be implemented in other specific forms without changing the technical spirit or essential features of the present invention by those skilled in the art.

Therefore, the embodiments described above are to be understood as illustrative and non-limiting in all respects, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and the All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

S100. A first step of obtaining a dual energy X-RAY image of the entire body;
S200. A second step of generating a bone image using a difference in attenuation degree of the dual energy X-RAY image generated in the first step;
S300. A third step of generating a tissue image from which bone components have been removed using a difference in attenuation degree of the dual energy X-RAY image generated in the first step;
S400. A fourth step of estimating the upper boundary of the liver from the tissue image of the third step;
S500. A fifth step of estimating a left boundary of the liver from the bone image of the second step;
S600. A sixth step of estimating a lower boundary of the liver from the bone image of the second step;
S700. A seventh step of estimating the right boundary of the liver from the bone image of the second step;
S800. An eighth step of calculating an outer point of the estimated liver using each boundary image of the liver estimated in steps 4 to 7;
S900. A ninth step of determining a liver region at an outer point of the estimated liver calculated in the eighth step;

Claims (5)

A first step of the image acquisition unit obtaining a dual energy X-RAY image of the entire body;
A second step of generating, by a bone image generator, a bone image using a difference in attenuation degree of the dual energy X-RAY image generated in the first step;
A third step in which the tissue image generator generates a tissue image from which bone components have been removed using a difference in attenuation degree of the dual energy X-RAY image generated in the first step;
A fourth step of estimating, by a boundary estimating unit, an upper boundary of the liver from the tissue image of the third step;
A fifth step of estimating a left boundary of the liver from the bone image of the second step by an outer point calculation unit;
A sixth step of estimating a lower boundary of the liver from the bone image of the second step by the outer point calculation unit;
A seventh step of estimating the right boundary of the liver from the bone image of the second step by the outer point calculation unit;
An eighth step of calculating, by the outer point calculation unit, an outer point of the estimated liver using each boundary image of the liver estimated in the fourth to seventh steps;
A ninth step of determining, by the liver region determining unit, the liver region at the estimated outer point of the liver calculated in the eighth step,
Estimating the upper boundary of the liver in the fourth step,
A step 4-1 of vertically correcting the tissue image so that the tissue image becomes a vertical posture, by the boundary estimating unit;
A 4-2 step of binarizing, by the boundary estimating unit, a lung portion in the vertically corrected tissue image;
Step 4-3 of the boundary estimating unit detecting the lower boundary point of the lung from the binarized tissue image; And
4-4 step of estimating, by the boundary estimating unit, the upper boundary of the liver with a curve extending from the boundary point. The method of claim 1,
The dual energy X-RAY image of the first step,
Acquire X-RAY images of low and high energy bands, respectively,
The low energy band is 40 keV to 50 keV,
The high (high) energy band is 60keV to 70keV, characterized in that the liver position estimation method using a two-dimensional image of the dual-energy X-ray absorption measurement method. The method of claim 1,
In the second step, the bone image,
Liver position estimation method using a two-dimensional image of a dual-energy X-ray absorption measurement method, characterized in that corrected using the dual-energy X-ray absorption measurement method of [Equation 1] below.
[Equation 1]

The method of claim 1,
In the third step, the tissue image,
The liver position estimation method using a two-dimensional image of the dual-energy X-ray absorption measurement method, characterized in that corrected using the dual-energy X-ray absorption measurement method of [Equation 2] below.
[Equation 2]

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