KR102418483B1 - Method and device for calculating risk of vascular disease in ct image using low voltage - Google Patents

Abstract

The present invention relates to a method for calculating the risk of vascular disease, the method comprising: obtaining a CT image of a blood vessel using a tube voltage value set by a user; unit value), counting the sorted pixels in the order of the highest HU value, determining the pixel equal to the total number of pixels up to a preset threshold, and HU corresponding to the determined number of pixels and setting the value to the new HU threshold.

Description

Calculation method and apparatus for vascular disease risk in CT image using low voltage

The present invention relates to a method and apparatus for calculating the risk of vascular disease in a CT image using a low voltage. More specifically, it relates to a method for accurately calculating a Coronary Artery Calcium Score (CACS) at a voltage lower than a reference voltage, an apparatus for performing the same, and a CT scanner.

The CAC score, which can be confirmed by computed tomography (CT), is the most reliable non-invasive predictor of cardiovascular disease and coronary artery disease.

In general, the CAC score obtained through CT scan was defined as the Agatston Score calculated as ∑ (area x concentration factor x section thickness/3 of each selected site). It is determined based on the CT image obtained when tube voltage is applied.

Recently, as various studies to gradually lower radiation exposure in radiology examinations are in progress, the method of calculating the CAC score also tried to calculate the CAC score at a voltage lower than the existing optimized standard (120 kV), but at a lower voltage, the actual CAC It is calculated as an exaggerated score rather than a score, so there is a problem in that people who do not need treatment are treated.

The description underlying the invention has been prepared to facilitate understanding of the invention. It should not be construed as an admission that the matters described in the background technology of the invention exist as prior art.

Accordingly, there is a need for a method capable of accurately calculating the CAC score at a voltage value lower than the most optimal voltage value for calculating the CAC score.

As a result, the inventors of the present invention found that even with a CT image taken at a tube voltage lower than 120 kV, a threshold value for calculating the CAC score can be obtained in the same way as the CAC score calculated under the reference tube voltage (120 kV tube voltage). An attempt was made to develop a risk calculation method and device.

In this case, the inventors of the present invention constructed a method and apparatus to obtain a threshold value for calculating a CAC score by comparing/matching a histogram of a reference CT image and a CT image taken at a lower tube voltage.

In particular, the inventors of the present invention took a CT image using a tube voltage of 100 kV in order to reduce the radiation dose proportional to the size of the tube voltage, and based on this, a method and apparatus for obtaining the patient's coronary calcium score. reached

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, there is provided a method for calculating the risk of vascular disease according to an embodiment of the present invention. The method includes: acquiring a CT image of a blood vessel using a tube voltage value set by a user; The HU values are counted in ascending order, determining pixels equal to the total number of pixels up to a preset threshold, and setting a HU value corresponding to the determined number of pixels as a new HU threshold. do.

According to a feature of the present invention, the tube voltage value set by the user may have a lower value than the reference tube voltage value set to obtain the reference CT image.

According to another feature of the present invention, the histogram of the reference CT image is divided into at least four sections based on four preset threshold values, and the setting of the new HU threshold value includes the tube voltage set by the user. It may be a step of setting the first to fourth HU threshold values according to

According to another feature of the present invention, the setting of the new HU threshold value may include setting the lowest HU value in the extracted pixel as the first HU threshold value and based on the first HU threshold value. The method may further include sequentially setting the second to fourth HU threshold values.

According to another feature of the present invention, the tube voltage value set by the user may be a tube voltage value of less than 120 kV.

According to another feature of the present invention, the setting of the new HU threshold may further include displaying pixels classified according to the new HU threshold in the histogram of the acquired CT image.

In order to solve the above problems, there is provided a method for calculating the risk of vascular disease according to another embodiment of the present invention. The method includes obtaining a CT image by performing computed tomography with a tube voltage value of 100 kV for the coronary artery, and the coronary calcium score based on the first to fourth HU threshold values in the histogram of the obtained CT image. is configured to include the step of calculating

According to a feature of the present invention, the first HU threshold is 141HU or more and 145HU or less, the second HU threshold is 218HU or more and 222HU or less, and the third HU threshold is 318HU or more and 322HU or less, the fourth HU The threshold value may have a value of 437HU or more and 441HU or less.

According to another feature of the present invention, each of the first to fourth HU threshold values may correspond to 130HU, 200HU, 300HU, and 400HU threshold values set in a histogram of a CT image taken with a tube voltage value of 120 kV.

In order to solve the above problems, there is provided an apparatus for calculating a risk of vascular disease according to another embodiment of the present invention. The apparatus includes a receiver configured to receive a CT image of a blood vessel, and a processor operatively connected to the receiver, wherein the processor acquires a CT image of the blood vessel using a tube voltage value set by a user, and obtains In the histogram of the CT image, pixels are arranged according to the HU value (Hounsfield Unit Value) for each pixel, the sorted pixels are counted in the order of the highest HU value, and the pixel equal to the total number of pixels up to a preset threshold is determined. and set a HU value corresponding to the determined number of pixels as a new HU threshold value.

In order to solve the above problems, there is provided an apparatus for calculating a risk of vascular disease according to another embodiment of the present invention. The apparatus includes a receiver configured to receive a CT image of a blood vessel, and a processor operatively connected to the receiver, wherein the processor performs computed tomography with a tube voltage value of 100 kV for a coronary artery to obtain a CT image. and calculate the coronary calcium score based on the first to fourth HU threshold values in the histogram of the acquired CT image.

Specific details of other embodiments are included in the detailed description and drawings.

The present invention can calculate an accurate CAC score using the HU threshold applicable under the tube voltage condition of 100 kV. In particular, since the tube voltage is lower than 120 kV, radiation exposure by CT scan can be minimized.

Furthermore, even if a CT image is taken using a tube voltage lower than 120 kV, such as 70 or 80 kV, rather than 100 kV, the appropriate HU threshold value according to the imaging conditions is simplified through comparison/matching with the CT image taken using the reference tube voltage. can be obtained

In addition, the present invention intuitively calculates a threshold value for CAC score calculation through a histogram pixel-HU value matching of a reference CT image and a photographed CT image without using a complicated algorithm or a method of calculating the kV photon energy attenuation ratio. can be obtained In particular, since the CT scanner and the processor of the device do not need to perform complex calculations, overload of the device can be prevented and the CAC score can be calculated quickly.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present invention.

1 is a schematic diagram for explaining the principle of a method for calculating the risk of vascular disease according to an embodiment of the present invention.
2A is a schematic diagram exemplarily showing the configuration of a vascular disease risk calculation system according to an embodiment of the present invention.
2B is a block diagram illustrating the configuration of an apparatus for calculating a risk of vascular disease according to an embodiment of the present invention.
3 is an exemplary diagram of an interface screen output to the risk calculation device using a MATLAB program according to an embodiment of the present invention.
4A to 4D are schematic diagrams exemplarily illustrating a histogram matching process according to an embodiment of the present invention.
5 is a flowchart of a method for calculating a vascular disease risk according to an embodiment of the present invention.
6 is a flowchart of a method of calculating a CAC score of a CT image taken at a tube voltage value of 100 kV according to an embodiment of the present invention.
7 is a graph comparing a CAC score of a CT image taken under a low voltage condition with a reference CAC score according to an embodiment of the present invention.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. In connection with the description of the drawings, like reference numerals may be used for like components.

In this document, expressions such as "have," "may have," "includes," or "may include" refer to the presence of a corresponding characteristic (eg, a numerical value, function, operation, or component such as a part). and does not exclude the presence of additional features.

In this document, expressions such as “A or B,” “at least one of A or/and B,” or “one or more of A or/and B” may include all possible combinations of the items listed together. . For example, "A or B," "at least one of A and B," or "at least one of A or B" means (1) includes at least one A, (2) includes at least one B; Or (3) it may refer to all cases including both at least one A and at least one B.

As used herein, expressions such as "first," "second," "first," or "second," may modify various elements, regardless of order and/or importance, and refer to one element. It is used only to distinguish it from other components, and does not limit the components. For example, the first user equipment and the second user equipment may represent different user equipment regardless of order or importance. For example, without departing from the scope of the rights described in this document, the first component may be named as the second component, and similarly, the second component may also be renamed as the first component.

A component (eg, a first component) is "coupled with/to (operatively or communicatively)" to another component (eg, a second component); When referring to "connected to", it will be understood that the certain element may be directly connected to the other element or may be connected through another element (eg, a third element). On the other hand, when it is said that a component (eg, a first component) is "directly connected" or "directly connected" to another component (eg, a second component), the component and the It may be understood that other components (eg, a third component) do not exist between other components.

The expression "configured to (or configured to)" as used in this document, depending on the context, for example, "suitable for," "having the capacity to ," "designed to," "adapted to," "made to," or "capable of." The term “configured (or configured to)” may not necessarily mean only “specifically designed to” in hardware. Instead, in some circumstances, the expression “a device configured to” may mean that the device is “capable of” with other devices or parts. For example, the phrase "a processor configured (or configured to perform) A, B, and C" refers to a dedicated processor (eg, an embedded processor) for performing the corresponding operations, or by executing one or more software programs stored in a memory device. , may mean a generic-purpose processor (eg, a CPU or an application processor) capable of performing corresponding operations.

Terms used in this document are only used to describe specific embodiments, and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meanings as commonly understood by one of ordinary skill in the art described in this document. Among terms used in this document, terms defined in a general dictionary may be interpreted with the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in this document, ideal or excessively formal meanings is not interpreted as In some cases, even terms defined in this document cannot be construed to exclude embodiments of this document.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, and as those skilled in the art will fully understand, technically various interlocking and driving are possible, and each embodiment may be implemented independently of each other, It may be possible to implement together in a related relationship.

For clarity of interpretation of the present specification, terms used herein will be defined below.

1 is a schematic diagram for explaining the principle of a method for calculating the risk of vascular disease according to an embodiment of the present invention.

Referring to FIG. 1 , in the method for calculating the risk of vascular disease according to an embodiment of the present invention, a computed tomography (CT) image is acquired with a tube voltage value of 100 kV, and the CAC score is adjusted based on the existing optimal standard value. The amount of exposure can be reduced and an accurate diagnosis can be performed.

Specifically, in one embodiment of the present invention, the reference value for calculating the CAC score at 100 kV is derived by comparing the result of CT scanning with the 120 kV tube voltage value, which is the existing optimal standard, by deriving the reference value calculated under the 120 kV condition. The same diagnostic result can be obtained.

2A is a schematic diagram exemplarily showing the configuration of a vascular disease risk calculation system according to an embodiment of the present invention, and FIG. 2B is a block diagram showing the configuration of an apparatus for calculating vascular disease risk according to an embodiment of the present invention.

Referring to FIG. 2A , the vascular disease risk calculation system 1000 includes an imaging apparatus 100 for capturing a medical image of an object 10 and an apparatus 200 for calculating a CAC score based on the medical image. may include

The imaging apparatus 100 includes a cylindrical bore 110 into which the object 10 is carried, and the object 10 in order to obtain a medical image of a target portion of the object 10 such as a person or an animal. It may include a transfer device 130 that is seated and carried into the bore 110 . Here, the target site includes various organs of the object 10 such as the brain, liver, and varicose veins, and in an embodiment of the present invention, the target site may be a blood vessel of the heart.

Also, the imaging apparatus 100 may obtain a cross-sectional medical image in which the object 10 is horizontally cut by irradiating X-rays capable of projecting the object 10 toward the object. However, according to embodiments, the medical image of the object 10 obtainable by the imaging apparatus 100 may include a two-dimensional image, a three-dimensional volume image, a still image of one cut, a video composed of a plurality of cuts, and various cross-sectional images. It may include a plurality of images having

Referring to FIG. 2B , the vascular disease risk calculation device 200 (hereinafter referred to as “risk calculation device”) includes a receiving unit 210, an input unit 220, an output unit 230, a storage unit 240, and a processor ( 250) may be included.

The receiver 210 may be connected to the imaging apparatus 100 to receive a medical image of a target portion of the object 10 from the imaging apparatus 100 . According to an embodiment, the receiver 210 may receive a CT image of a blood vessel, and the CT image may be an image taken using a tube voltage value of 120 kV or less.

The input unit 220 may receive various setting information from the user. The input unit 220 may receive a shooting condition of the image capturing apparatus 100 from a user and may receive operation information of the image capturing apparatus 100 . For example, a medical practitioner may input a tube voltage value for taking a CT image using the input unit 220 , and may move the transfer device 130 to fit a target portion of the object 10 . For another example, the medical practitioner may select a portion suspected of having a disease in the CT image output to the output unit 230 .

The output unit 230 may output an image photographed by the image photographing apparatus 100 . According to an embodiment, the output unit 230 may output a CT image of a blood vessel of the object 10 . The output unit 230 may display a portion in the CT image of the blood vessel in which the Hounsfield unit (HU) value is equal to or greater than a preset value.

3 is an exemplary diagram of an interface screen output to the risk calculation device using a MATLAB program according to an embodiment of the present invention.

Referring to FIG. 3 , the output unit 230 may output a CT image captured by the image capturing apparatus 100 . In this case, the output unit 230 may display a portion having a HU value of 130HU or more in a CT image of a blood vessel in a chromatic color. Accordingly, the medical personnel can check the CT image according to the tube voltage values of 100kV and 120kV, see the area of 130HU or more displayed in chromatic colors, and diagnose whether a disease occurs.

If the medical person checks that a disease has occurred in the corresponding area using the input unit 220, the processor 250 may check and adjust the HU threshold value according to the imaging condition, where the HU threshold value is used for diagnosing a disease. It means the reference value for For example, if the HU value of the region/pixel selected by the medical practitioner is lower than the HU threshold value according to the imaging condition, the processor 250 may lower the HU threshold value to the HU value of the region/pixel selected by the medical practitioner.

It will be described again with reference to FIG. 2B.

The output unit 230 may receive a user's touch input, and in this case, the input unit 220 and the output unit 230 may be formed of one physical component. Accordingly, the output unit 230 may include various sensing means capable of recognizing various inputs generated in an image display area.

The storage unit 240 may store various data used in the image capturing apparatus 100 and the risk calculating apparatus 200 . For example, in order to obtain the HU threshold value of the CT image taken at a tube voltage value lower than 120 kV, the storage unit 240 may store a CT image taken at a tube voltage value of 120 kV as a control, the average value of the CAC score, and the HU threshold value. , the number of pixels according to the HU value, etc. may be stored.

Also, the storage unit 240 may match and store the HU threshold value for disease diagnosis with the low voltage value. That is, if the HU threshold value is initially set in the CT image taken with the low voltage value, the CAC score can be calculated based on the stored HU threshold value when shooting with the same low voltage value again.

In various embodiments, the storage unit 240 may include a volatile or nonvolatile recording medium capable of storing various data, commands, and information. For example, the storage unit 240 may include a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (eg, SD or XD memory, etc.), RAM, SRAM, ROM, EEPROM, PROM, network storage. It may include a storage medium of at least one type of storage, cloud, and block chain database.

Also, the storage unit 240 may record instructions for operation with the risk calculating device 200 . In various embodiments, an application (not shown) for calculating the risk of vascular disease according to the tube voltage value may be recorded in the storage unit 240 .

The processor 250 is operatively connected to the receiving unit 210 , the input unit 220 , the output unit 230 , and the storage unit 240 to control the overall operation of the risk calculation device 200 , and the storage unit By driving an application or program stored in 240 , various commands for setting a HU threshold value, which is a criterion for diagnosing a disease, may be performed according to a tube voltage value input by a medical practitioner.

Meanwhile, the processor 250 may correspond to a computing device such as a central processing unit (CPU) or an application processor (AP). In addition, the processor 250 may be implemented in the form of an integrated chip (IC), such as a system on chip (SoC) in which various computing devices are integrated.

According to an embodiment, the processor 250 may set a new HU threshold value for diagnosing a disease based on a CT image taken at a tube voltage value of less than 120 kV. Specifically, in the case of a CT image taken at a low voltage value, since it has a larger number of pixels than necessary, the processor 250 may obtain a new HU threshold value through a process of reducing the number of pixels in the CT image, and the HU threshold value At least four values may be set to divide the HU value into four sections.

More specifically, the processor 250 may acquire a CT image of a blood vessel using a tube voltage value set by a user, and may align pixels according to each HU value in a histogram of the acquired CT image. The processor 250 may count the sorted pixels in the order of increasing the HU value, and determine a pixel equal to the total number of pixels up to a preset threshold. That is, the processor 250 may adjust the number of pixels for histogram matching with the optimal standard value, and accordingly, the preset threshold is 130HU, which is the minimum HU value that is the standard for diagnosing diseases in the CT image taken with the 120kV tube voltage value. can be

4A to 4D are schematic diagrams exemplarily illustrating a histogram matching process according to an embodiment of the present invention.

Referring to FIGS. 4A and 4B , each graph is an arrangement of pixels according to HU values in a histogram of a CT image taken with 120 kV and 80 kV tube voltage values. In the 120kV imaging condition, the total number of pixels may be 260,104, and in the 80kV imaging condition, the total number of pixels may be 280,737.

Before the processor 250 sets a new HU threshold, values corresponding to the graph A may be previously stored as reference values in the storage unit 240 .

The processor 250 may sequentially count up to 260 and 104 from the highest HU value in the CT image taken at the tube voltage value of 80 kV. Referring to the graph of FIG. 4B , the processor 250 counts inversely from the number of pixels having a value of approximately 1000HU, but may end counting at 260 and 104 th. Accordingly, after counting 260,104 pixels, the processor 250 excludes the remaining 20,633 pixels from the data for calculating the CAC score, and sets the HU value of the 260,104th pixel as the minimum HU threshold that is the standard for diagnosing the disease. can For example, if the HU value of the 260,104th pixel is 151HU, the minimum HU threshold value for calculating the CAC score in the CT image taken at the 80kV tube voltage value may be 151HU.

That is, the processor 250 may set a new first HU threshold value for the HU value of the last pixel as the pixels are counted in the reverse order. can be matched with

Looking at the graph of FIG. 4C , it can be confirmed that the number of pixels having the same HU value is different according to the histogram matching, and the processor 250 sets the remaining HU threshold values sequentially based on the newly set minimum HU value. can

Looking at the graph of FIG. 4D , according to the histogram matching of the processor 250, the reference HU threshold values (130HU, 200HU, 300HU, 400HU) shown in circles in FIG. 4A are changed and set as shown in red circles in FIG. 4D. can be

It will be described again with reference to FIG. 2B.

According to an embodiment, the processor 250 may calculate a CAC score for diagnosing a coronary artery disease (eg, coronary atherosclerosis) based on a CT image taken at a tube voltage value of 100 kV among tube voltage values of less than 120 kV. Specifically, the processor 250 acquires a CT image of the coronary artery photographed with a tube voltage value of 100 kV from the imaging apparatus 100, and based on the first to fourth HU threshold values in the histogram of the CT image, the coronary artery Calcium score can be calculated.

Specifically, the first HU threshold is 141HU or more and 145HU or less, the second HU threshold is 218HU or more and 222HU or less, the third HU threshold is 318HU or more and 322HU or less, and the fourth HU threshold is 437HU or more and 441HU or less , which may correspond to the 130HU, 200HU, 300HU, and 400HU threshold values set in the histogram of the CT image taken with the tube voltage value of 120 kV.

So far, the apparatus 200 for calculating the risk of vascular disease according to an embodiment of the present invention has been described. According to the present invention, even if the risk calculation device 200 takes a CT image using a tube voltage lower than 120 kV, such as 70 kV, 80 kV, etc., through comparison/matching with the CT image taken using the reference tube voltage, the An appropriate HU threshold can be obtained simply.

Hereinafter, a method of setting the HU threshold value for calculating the CAC score in the CT image using the low voltage by the above-described risk calculation device 200 will be described.

5 is a flowchart of a method for calculating a vascular disease risk according to an embodiment of the present invention.

Referring to FIG. 5 , the risk calculation apparatus 200 obtains a CT image of a blood vessel using a tube voltage value set by a user ( S110 ). The risk calculation apparatus 200 may transmit the tube voltage value to the image photographing apparatus 100 and receive a CT image according to the specified tube voltage value from the image photographing apparatus 100 .

After step S110, the risk calculation apparatus 200 aligns pixels according to each HU value in the histogram of the acquired CT image (S120). In other words, the risk calculating device 200 may count the number of pixels having the same HU value. For example, as the HU value increases as a result of the alignment by the risk calculation device 200, the number of pixels corresponding thereto may be small.

After the step S120, the risk calculating device 200 counts the sorted pixels in the order of the HU value, and determines the pixels equal to the total number of pixels up to a preset threshold (S130). Specifically, in the case of a CT image taken at a low voltage value, it is common to have a larger number of pixels than necessary. Accordingly, the risk calculation apparatus 200 may adjust the number of pixels to match the histogram with the optimal standard value. Here, the preset threshold may be 130HU, which is the minimum HU value serving as a criterion for diagnosing a disease in a CT image taken with a 120kV tube voltage value.

After step S130, the risk calculation device 200 sets the HU value corresponding to the determined number of pixels as a new HU threshold value (S140). The new HU threshold set through the number of pixels is the first reference value for calculating the CAC score. .

Thereafter, the risk calculation device 200 may sequentially set the remaining HU threshold values based on the set minimum HU value, and finally obtain a new HU threshold value for dividing the histogram into four sections.

So far, the method for calculating the risk of vascular disease according to an embodiment of the present invention has been described. According to the present invention, the threshold value for calculating the CAC score is intuitively determined through the histogram pixel-HU value matching of the reference CT image and the photographed CT image without using a complicated algorithm or a method of calculating the kV photon energy attenuation ratio. can be obtained

6 is a flowchart of a method of calculating a CAC score of a CT image taken at a tube voltage value of 100 kV according to an embodiment of the present invention.

Referring to FIG. 6 , the risk calculation apparatus 200 obtains a CT image of the coronary artery photographed with a tube voltage value of 100 kV from the imaging apparatus 100 ( S210 ). To this end, the risk calculation apparatus 200 may transmit information for controlling components in the image capturing apparatus 100 .

After step S210, the risk calculating device 200 calculates a coronary calcium score based on the first to fourth HU threshold values in the histogram of the CT image (S220). Specifically, the first HU threshold is 141HU or more and 145HU or less, the second HU threshold is 218HU or more and 222HU or less, the third HU threshold is 318HU or more and 322HU or less, and the fourth HU threshold is 437HU or more and 441HU or less can have a value of

The risk calculation device 200 may calculate a score according to the new HU threshold using the Agatston score calculation method used to calculate the coronary calcium score under the condition of 120 kV. For example, the risk calculation device 200 has a value of 1, 221HU or more and 320HU or less in the case of a value of 143HU or more and 220HU or less, 2 if it has a value of 321HU or more and 439HU or less If it has a value of 3, 440HU or more 4 , and the coronary calcium score can be calculated according to a formula such as “∑ (area x concentration factor x section thickness/3) of each selected site”.

7 is a graph comparing a CAC score of a CT image taken under a low voltage condition with a reference CAC score according to an embodiment of the present invention.

Meanwhile, prior to explaining FIG. 7, a patient group for comparing CAC scores in different CT images according to voltage conditions was recruited based on patients with no significant differences in age and mean values of body mass index (BMI). .

Referring to (a) of FIG. 7 , the CAC score was calculated using the vascular disease risk calculation method according to an embodiment of the present invention after taking pictures at a low voltage of less than 120 kV and a reference value of 120 kV for the same blood vessel. , it can be seen that the values are almost the same.

In addition, referring to (b), when the present method is applied to calculate the CAC score for the CT image taken under the low voltage condition, it can be confirmed that the difference from the CAC value calculated at 120 kV does not significantly deviate from the confidence interval. have.

So far, a method for calculating the risk of vascular disease in a CT image using a low voltage according to an embodiment of the present invention has been described. According to the present invention, an accurate CAC score can be calculated using the applicable HU threshold value under the tube voltage condition of 100 kV. In particular, since the tube voltage condition is lower than 120 kV, radiation exposure by CT scan can be minimized.

Although one embodiment of the present invention has been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

1000: vascular disease risk calculation system
10: object
100: video recording device
110: bore
130: transfer device
200: vascular disease risk calculation device
210: receiver
220: input unit
230: output unit
240: storage
250: processor

Claims (11)

acquiring a CT image of a blood vessel using a tube voltage value set by a user;
aligning pixels according to a HU value (Hounsfield Unit Value) for each pixel in the histogram of the acquired CT image;
counting the sorted pixels in order of increasing the HU value, and determining a pixel equal to the total number of pixels up to a preset threshold; and
setting a HU value corresponding to the determined number of pixels as a new HU threshold value; A vascular disease risk calculation method comprising a. According to claim 1,
The tube voltage value set by the user is,
A method for calculating the risk of vascular disease, which has a lower value than a reference tube voltage set for obtaining a reference CT image. 3. The method of claim 2,
The histogram of the reference CT image is,
It is divided into at least four sections based on four preset threshold values,
The step of setting the new HU threshold value is,
The step of setting first to fourth HU threshold values according to the tube voltage set by the user, the vascular disease risk calculation method. 4. The method of claim 3,
The step of setting the new HU threshold value is,
setting the lowest HU value in the aligned pixel as the first HU threshold value, and
The method further comprising: sequentially setting the second to fourth HU threshold values based on the first HU threshold value. 3. The method of claim 2,
The tube voltage value set by the user is,
A method of calculating the risk of vascular disease, which is a tube voltage value of less than 120 kV. According to claim 1,
The step of setting the new HU threshold value is,
Displaying the pixels divided according to the new HU threshold in the histogram of the acquired CT image, vascular disease risk calculation method further comprising. acquiring a CT image by performing computed tomography with a tube voltage value of 100 kV for the coronary artery; and
In the histogram of the acquired CT image, pixels are arranged in the order of the highest HU value for each pixel, and the sorted pixels are extracted up to a pixel equal to the total number of pixels up to a preset threshold, and the extracted pixels are first to fourth calculating a coronary calcium score according to the HU threshold; includes,
The preset threshold is,
A method of calculating the risk of vascular disease, which corresponds to the minimum HU value, which is a criterion for diagnosing diseases in a CT image taken with a tube voltage of 120 kV. 8. The method of claim 7,
The first HU threshold value is 141HU or more and 145HU or less,
The second HU threshold is 218HU or more and 222HU or less,
The third HU threshold is 318HU or more and 322HU or less,
The fourth HU threshold value, having a value of 437HU or more and 441HU or less, vascular disease risk calculation method. 9. The method of claim 8,
Each of the first to fourth HU threshold values is,
A method of calculating the risk of vascular disease, which corresponds to the 130HU, 200HU, 300HU and 400HU threshold values set in the histogram of the CT image taken with the tube voltage value of 120kV. a receiver configured to receive a CT image of blood vessels; and
a processor operatively connected to the receiver; including,
The processor is
A CT image of the blood vessel is acquired using the tube voltage value set by the user, and pixels are aligned according to the Hounsfield Unit Value (HU) for each pixel in the histogram of the acquired CT image, and the aligned pixels are selected for the high HU value. Counting sequentially, determining pixels equal to the total number of pixels up to a preset threshold, and setting a HU value corresponding to the determined number of pixels as a new HU threshold, vascular disease risk calculation device. a receiver configured to receive a CT image of blood vessels; and
a processor operatively connected to the receiver; including,
The processor is
Computed tomography is performed on the coronary artery with a tube voltage value of 100 kV to obtain a CT image, and the pixels are arranged in the order of the highest HU value for each pixel in the histogram of the acquired CT image, and the aligned pixels are set to a preset threshold. By extracting pixels equal to the total number of pixels up to and calculating the coronary calcium score according to the first to fourth HU threshold values for the extracted pixels, the preset threshold is a CT image taken with a tube voltage value of 120 kV A device for calculating the risk of vascular disease, which corresponds to the minimum HU value that is a criterion for diagnosing a disease.

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