Scanning Method, Device and Readable Storage Medium for Medical Images

Abstract

The present application discloses a method, device and readable storage medium for scanning medical images, relating to the field of medical imaging technology. It can dynamically control the number of samples as the current scanning angle changes, thereby making the scanning dose of the region of interest uniform, improving the consistency of image noise, and improving the quality of CT images. The method includes: obtaining the center of the region of interest; obtaining the number of samples corresponding to the scanning angle based on the positional relationship between the X-ray tube focus and the center of the region of interest; and scanning the region of interest based on the number of samples corresponding to the scanning angle.

Description

Technical Field

[0001] This application relates to the field of medical imaging technology, and particularly to a method, device, computer device and readable storage medium for scanning medical images. Background Art

[0002] With the continuous development of technology, CT (Computed Tomography) has raised traditional imaging technology to a new level. Different from only showing the outlines of bones and organs, CT scans can construct a three-dimensional model of the complete internal tissues of the human body, providing basic data for doctors' diagnoses.

[0003] In the related art, doctors assist the scanning object in positioning, making the center of the region of interest of the scanning object coincide as much as possible with the scanning center of the CT scanning system to perform CT imaging of the region of interest of the scanning object.

[0004] In the process of implementing this application, the inventors of this application found that the related art has at least the following problems:

[0005] Relying on the doctor's visual estimation of distance and the cooperation of the scanning object for adjustment will cause a certain amount of error between the center of the region of interest of the scanning object and the scanning center of the CT scanning system, resulting in uneven scanning dose in the region of interest of the scanning object, thus causing uneven CT image noise and poor quality of the generated CT images. Summary of the Invention

[0006] In view of this, this application provides a method, device, computer device and readable storage medium for scanning medical images, mainly aiming to solve the problem that the scanning dose in the region of interest of the current scanning object is uneven, thus causing uneven CT image noise and affecting the image quality of the CT image.

[0007] According to the first aspect of this application, a method for scanning medical images is provided, and the method includes:

[0008] Obtain the center of the region of interest;

[0009] Based on the positional relationship between the tube focus and the center of the region of interest, obtain the number of samples corresponding to the scanning angle;

[0010] Scan the region of interest based on the number of samples corresponding to the scanning angle.

[0011] Optionally, the obtaining the number of samples corresponding to the scanning angle based on the positional relationship between the tube focus and the center of the region of interest includes:

[0012] Obtain the angle between the line connecting the tube focus and the scanning center and the line connecting the center of the region of interest and the scanning center;

[0013] Based on the angle, obtain the number of samples corresponding to the scanning angle;

[0014] Wherein the angle and the number of samples satisfy the following relationship: the larger the angle, the more the number of samples, and the angle is an angle less than or equal to 180°.

[0015] Optionally, the obtaining the number of samples corresponding to the scanning angle based on the angle includes:

[0016] Based on the angle, obtain the projection point of the center of the region of interest on the line connecting the scanning center and the tube focus;

[0017] Based on the positional relationship between the projection point and the tube focus, obtain the number of samples corresponding to the scanning angle.

[0018] Optionally, the obtaining the number of samples corresponding to the scanning angle based on the positional relationship between the projection point and the scanning center includes:

[0019] Obtain the first distance between the scanning center and the tube focus;

[0020] Obtain the second distance between the projection point and the tube focus;

[0021] Based on the ratio of the second distance to the first distance and the initial number of samples of the corresponding angle, obtain the number of samples of the corresponding angle.

[0022] Optionally, the obtaining the second distance between the projection point and the tube focus includes:

[0023] Obtain the first sub-eccentricity degree of the region of interest in the first direction;

[0024] Obtain the second sub-eccentricity degree of the region of interest in the second direction;

[0025] Based on the first sub-eccentricity degree, the second sub-eccentricity degree, and the angle, obtain the third distance between the projection point and the scanning center;

[0026] Take the difference or sum of the first distance and the third distance as the second distance;

[0027] Wherein, the first direction is a direction perpendicular to the extension direction of the scanning center and parallel to the bed surface of the scanning bed, and the second direction is a direction perpendicular to the first direction and perpendicular to the bed surface of the scanning bed.

[0028] Optionally, obtaining the third distance between the projection point and the scanning center based on the first sub-eccentricity, the second sub-eccentricity, and the included angle includes:

[0029] Calculating the sum of the square of the first sub-eccentricity and the square of the second sub-eccentricity, and taking the square root of the sum as the distance between the center of the region of interest and the scanning center;

[0030] Calculating the arctangent value of the ratio of the second sub-eccentricity to the first sub-eccentricity, and the difference between the scanning angle and the arctangent value;

[0031] Taking the product of the cosine value of the difference and the square root as the third distance.

[0032] Optionally, obtaining the center of the region of interest includes:

[0033] Obtaining the plain film information of the region of interest;

[0034] Inputting the plain film information into a neural network model to obtain the center of the region of interest; or,

[0035] Based on the anteroposterior film and the lateral film, and the correspondence between pixels and real physical dimensions, obtaining the center of the region of interest.

[0036] Optionally, scanning the region of interest based on the number of samples corresponding to the scanning angle includes:

[0037] Before the formal scanning, based on the number of samples corresponding to the scanning angle, adjusting the number of samples at different scanning angles and then scanning the region of interest; or, [[ID=’28]]

[0038] During the formal scanning, based on the number of samples corresponding to the scanning angle, adjusting the number of samples corresponding to the scanning angle in real time and scanning the region of interest.

[0039] Optionally, scanning the region of interest based on the number of samples corresponding to the scanning angle includes:

[0040] In response to a scanning instruction, performing axial scanning or helical scanning on the region of interest based on the number of samples corresponding to the scanning angle.

[0041] According to the second aspect of the present application, a medical image scanning device is provided, and the device includes:

[0042] An acquisition module for acquiring the center of the region of interest;

[0043] A calculation module, configured to obtain the number of samples corresponding to a scanning angle based on the positional relationship between the X-ray tube focal spot and the center of the region of interest.

[0044] A scanning module, configured to scan the region of interest based on the number of samples corresponding to the scanning angle.

[0045] Optionally, the calculation module is configured to obtain the angle between the line connecting the X-ray tube focal spot and the scanning center and the line connecting the center of the region of interest and the scanning center; based on the angle, obtain the projection point of the center of the region of interest on the line connecting the scanning center and the X-ray tube focal spot; and obtain the number of samples corresponding to the scanning angle based on the positional relationship between the projection point and the X-ray tube focal spot.

[0046] Optionally, the calculation module is configured to obtain a first distance between the scanning center and the X-ray tube focal spot; obtain a second distance between the projection point and the X-ray tube focal spot; and obtain the number of samples corresponding to the corresponding angle based on the ratio of the second distance to the first distance and the initial number of samples for the corresponding angle.

[0047] Optionally, the calculation module is configured to set a first direction and a second direction, where the first direction is perpendicular to the extension direction of the scanning center and parallel to the bed surface of the scanning table, and the second direction is perpendicular to the first direction and perpendicular to the bed surface of the scanning table; based on a first sub-eccentricity degree of the center of the region of interest in the first direction and a second sub-eccentricity degree of the center of the region of interest in the second direction, obtain a third distance between the projection point and the scanning center; and use the difference or sum of the first distance and the third distance as the second distance.

[0048] Optionally, the calculation module is configured to calculate the sum of the square of the first sub-eccentricity degree and the square of the second sub-eccentricity degree, and use the square root of the sum as the distance between the center of the region of interest and the scanning center; calculate the arctangent of the ratio of the second sub-eccentricity degree to the first sub-eccentricity degree, and the difference between the scanning angle and the arctangent; and use the product of the cosine value of the difference and the square root as the third distance.

[0049] Optionally, the obtaining module is configured to obtain the plain film information of the region of interest; input the plain film information into a neural network model to obtain the center of the region of interest; or, determine a plurality of target regions indicated by the plain film information, read the corresponding sub-centers of the region of interest in each target region, and determine the center of the region of interest according to the coordinate values indicated by each sub-center.

[0050] Optionally, the device is applicable to the axial scanning mode and the spiral scanning mode.

[0051] According to the third aspect of the present application, there is provided a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the method described in any one of the above first aspects are implemented.

[0052] By means of the above technical solutions, a scanning method, device and readable storage medium for medical images provided by the present application first obtain the center of the region of interest. Further, based on the unknown relationship between the scanning center and the center of the region of interest, the number of samples corresponding to the scanning angle is obtained. Finally, based on the number of samples corresponding to the scanning angle, the region of interest is scanned. By determining the positional relationship between the center of the region of interest and the scanning center, and determining the number of samples corresponding to different scanning angles, it is realized that during the scanning process, the number of samples of the scanning system is dynamically adjusted, and the adjusted number of samples is used to scan the region of interest, so that the scanning dose of the region of interest is uniform, the consistency of image noise is improved, and the quality of CT images is improved.

[0053] The above description is only an overview of the technical solutions of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0055] Figure 1 A schematic flowchart of a scanning method for medical images provided by an embodiment of the present application is shown;

[0056] Figure 2A A schematic flowchart of a scanning method for medical images provided by an embodiment of the present application is shown;

[0057] Figure 2B A schematic structural diagram of a scanning device for medical images provided by an embodiment of the present application is shown;

[0058] Figure 2C A schematic diagram of the steps of a scanning method for medical images provided by an embodiment of the present application is shown;

[0059] Figure 2D A schematic diagram of the steps of a scanning method for medical images provided by an embodiment of the present application is shown;

[0060] Figure 2E A schematic diagram of the steps of a medical image scanning method provided in an embodiment of the present application is shown;

[0061] Figure 2F A schematic diagram of the steps of a medical image scanning method provided in an embodiment of the present application is shown;

[0062] Figure 2G A schematic diagram of the steps of a medical image scanning method provided in an embodiment of the present application is shown;

[0063] Figure 2H A schematic diagram of a medical image scanning method provided in an embodiment of the present application is shown;

[0064] Figure 3 A schematic structural diagram of a medical image scanning device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0065] The following describes exemplary embodiments of the present application in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0066] The present application provides a method for scanning medical images. Figure 1 As shown, the method includes:

[0067] 101. Get the center of the region of interest.

[0068] In an embodiment of the present application, the object to be scanned is statically placed on the scanning bed, and the CT scanning detection instrument performs a plain film scan on the object to be scanned to generate plain film information. In fact, according to the posture of the object to be scanned statically placed on the scanning bed, the generated plain film information can be anteroposterior film information or lateral film information, or both anteroposterior film information and lateral film information are obtained, that is, double plain film information. The method for obtaining the center of the region of interest can be Method 1: Obtain the plain film information of the region of interest, input the plain film information into the neural network model, and obtain the center of the region of interest; or Method 2 can also be used: Based on the anteroposterior film and the lateral film, and the correspondence between pixels and the true physical size, obtain the center of the region of interest. In Method 1, only an anteroposterior film or a lateral film can be obtained, and based on the pre-trained neural network model, the center of the region of interest can be directly obtained through the anteroposterior film or the lateral film. The choice of the anteroposterior film or the lateral film depends on the training sample information of the neural network model. For example, if the training sample is an anteroposterior film, the anteroposterior film of the region of interest is obtained. In Method 2, both an anteroposterior film and a lateral film need to be obtained. Based on the anteroposterior film, the first center position of the region of interest in one direction is obtained, and based on the lateral film, the second center position of the region of interest in the other direction is obtained. The center of the region of interest includes the first center position and the second center position. It should be noted that the plain film information in the present application can be a plain film image or raw data. The object to be scanned can be a certain part of a human or an animal, such as the forehead, nose, etc. In the actual application process, the object to be scanned generally indicates the area that it focuses on. Therefore, the present application sets a region of interest to indicate the area of key concern. For example, if a certain patient has shoulder and neck pain, the shoulder and neck part of the patient is set as the region of interest, and the CT scanning instrument scans and images the shoulder and neck of the patient.

[0069] 102. Based on the positional relationship between the tube focus and the center of the region of interest, obtain the number of samples corresponding to the scanning angle.

[0070] During the scanning process, such as axial scanning or helical scanning (also known as volume scanning), multiple scanning angle samplings are performed when the gantry rotates one week. Multiple ray emissions, that is, multiple samplings, are performed at each scanning angle, and the scanning dose is the same at each scanning angle. When the center of the region of interest does not coincide with the scanning center, the distance between the center of the region of interest and the focus of the tube will change at each scanning angle. The closer the center of the region of interest is to the focus of the tube, the greater the radiation dose received by the region of interest. Using the same scanning dose for scanning will result in uneven scanning dose in the region of interest. Therefore, in the embodiment of the present application, the number of samples at different scanning angles is adjusted based on the degree of eccentricity. The adjustment method generally follows the following rule: The greater the distance between the tube focus and the center of the region of interest at the current scanning angle, the more the number of samples at the current scanning angle.

[0071] 103. Scan the region of interest based on the number of samples corresponding to the scanning angle.

[0072] There are various ways to scan the region of interest based on the obtained number of samples. In one example, before the formal scan, adjust the number of samples at different scanning angles according to the eccentricity. During the formal scan, scan according to the number of samples corresponding to the adjusted current scanning angle. In another example, during the formal scan, the number of samples at the current angle can be adjusted in real time based on the eccentricity, enabling calculation and adjustment simultaneously. This not only makes the dose received at different positions in the region of interest more uniform, improving the quality of CT images, but also enables dynamic control of the number of samples at different scanning angles, thereby enhancing the scanning efficiency.

[0073] The method provided by the embodiments of this application first obtains the center of the region of interest; further, based on the positional relationship between the tube focus and the center of the region of interest, obtains the number of samples corresponding to the scanning angle. Finally, scans the region of interest based on the number of samples corresponding to the scanning angle. By determining the positional relationship between the center of the region of interest and the tube focus, the number of samples corresponding to different scanning angles is determined, making the scanning dose of the region of interest more uniform, improving the consistency of image noise, and enhancing the quality of CT images.

[0074] The embodiments of this application provide a method for scanning medical images, as Figure 2A shown, the method includes:

[0075] 201. Obtain the plain film information of the region of interest, and based on the plain film information, determine the center of the region of interest.

[0076] In the embodiments of this application, the method for scanning medical images is applicable to a computed tomography device (abbreviated as CT), as Figure 2B shown, the CT includes an image imaging module and a sampling number calculation module. Specifically, the plain film scanning unit in the image imaging module scans the region of interest to obtain plain film scanning data. The plain film imaging unit generates plain film data according to the scanning data and transmits the plain film data to the first calculation unit in the sampling number calculation module to determine the positional relationship between the center of the region of interest and the tube focus, and transmits the positional relationship to the second calculation unit. The second calculation unit calculates the number of samples according to the positional relationship and transmits the number of samples to the scan control unit. The scan control unit controls the rotation of the tube and the gantry to scan the region of interest and generate scanning data. Finally, the imaging unit generates a medical image of the region of interest according to the scanning data.

[0077] In the actual application process, before determining the positional relationship between the center of the region of interest and the tube focus, it is necessary to obtain the center of the region of interest. The determination method can specifically adopt the artificial intelligence method or the image processing method.

[0078] For the artificial intelligence method, the system inputs the plain film information of the region of interest into the neural network model, and the neural network model outputs the center of the region of interest, specifically, it can be the coordinates of the center of the region of interest in the rectangular coordinate system with the scanning center as the intersection point. The X direction of the rectangular coordinate system is perpendicular to the extension direction of the scanning center and parallel to the bed surface of the scanning bed, that is, the first direction, and the Y direction is perpendicular to the X direction and perpendicular to the bed surface of the scanning bed, that is, the second direction. The neural network model can be obtained based on the existing neural network architecture and the existing model training method.

[0079] For the image processing method, the plain film information is sliced into multiple target regions. Specifically, when the plain film information is the anteroposterior film information, it is sliced horizontally along the X direction. When the plain film information is the lateral film information, it is sliced horizontally along the Y direction. Among them, the X and Y directions are determined based on the structural information of the region of interest. The X direction can be understood as the width direction of the region of interest, and the Y direction can be understood as the thickness direction of the region of interest. When the scanned object lies flat on the scanning bed, the X direction is specifically perpendicular to the extension direction of the scanning center and parallel to the bed surface of the scanning bed, that is, the first direction; the Y direction is the vertical direction, specifically perpendicular to the first direction and perpendicular to the bed surface of the scanning bed, that is, the second direction. Taking the lateral view as an example, as Figures 2C to 2D shown, the white part is the region of interest. The horizontal direction of the lateral view is the Y direction. The plain film information indicated by the region of interest is sliced horizontally along the Y direction to obtain multiple target regions, for example, 7. The horizontal direction of the anteroposterior view is the X direction. The plain film information indicated by the region of interest is sliced horizontally along the X direction to obtain multiple target regions, for example, 12. Specifically, in each target region, the region of interest is identified, and the first coordinate corresponding to the right edge of the region of interest and the second coordinate corresponding to the left edge are respectively determined. The half of the sum of the first coordinate and the second coordinate is used as the coordinate of the sub-center corresponding to the region of interest in the current target region. Taking the lateral film divided into 7 target regions as an example, as Figure 2C shown, the second coordinate corresponding to the leftmost edge in the target region i = 4 is the coordinate of the position of the nose tip, and the first coordinate corresponding to the rightmost edge is the coordinate of the position of the neck depression. Further, the coordinates of the sub-center corresponding to each target region among the 7 target regions are determined, and the mean operation, median operation or weight operation is performed on the coordinates of the 7 sub-centers. The result obtained is used as the coordinate of the second center position of the region of interest, and the position indicated by this coordinate is used as the position of the center of the region of interest in the second direction. Taking the anteroposterior film as an example, as Figure 2DAs shown, the region of interest is divided into 12 target regions. Further, the coordinates of the sub - centers corresponding to each of the 12 target regions are determined, and mean operation, median operation or weighted operation is performed on the coordinates of the 12 sub - centers. The result obtained is used as the coordinates of the first central position of the region of interest, and the position indicated by the coordinates is used as the position of the center of the region of interest in the first direction.

[0080] The above steps divide the region of interest into multiple target regions, and based on the coordinates of the sub - centers of at least one region of interest, determine the central coordinates of the region of interest with an irregular shape, and then obtain the center of the region of interest.

[0081] 202. Obtain the angle between the line connecting the tube focus and the scanning center and the line connecting the center of the region of interest and the scanning center. Based on the angle, obtain the number of samples corresponding to the scanning angle, where the relationship between the angle and the number of samples is as follows: the larger the angle, the more the number of samples, and the angle is an angle less than or equal to 180°.

[0082] In the embodiments of the present application, spiral scanning rotates from 0 degrees to 360 degrees to scan the region of interest, and a scanning angle will be generated during the scanning process. In order to determine the number of samples at different scanning angles, the angle between the line connecting the tube focus and the scanning center and the line connecting the center of the region of interest and the scanning center can be determined first, and based on the angle, the number of samples corresponding to the scanning angle is obtained. The region of interest can be regarded as an axisymmetric structure based on the line connecting the center of the region of interest and the scanning center. The number of samples at the scanning angle on one side of the line connecting the center of the region of interest and the scanning center can be set mirror - symmetrically to the number of samples at the scanning angle on the other side. Therefore, the angle is an angle less than or equal to 180°. Among them, the larger the angle, the greater the distance between the tube focus and the center of the region of interest, and the more the number of samples.

[0083] The distance between the center of the region of interest and the X-ray tube focal spot. Based on the included angle, the projection point of the center of the region of interest on the line connecting the X-ray tube focal spot and the scan center can be obtained. In this application, a spatial coordinate system is set up, including three directions: X, Y, and Z. The X direction is the horizontal direction, specifically perpendicular to the extension direction of the scan center and parallel to the scan bed surface, that is, the first direction. The Y direction is the vertical direction, specifically perpendicular to the first direction and perpendicular to the scan bed surface, that is, the second direction. The Z direction is the axial direction, passing through the scan center (rotation center), that is, the extension direction of the scan center. The X, Y, and Z directions intersect at the scan center. Based on the positional relationship between the center of the region of interest and the scan center in the Y direction, that is, the second sub-eccentricity, and the positional relationship between the center of the region of interest and the scan center in the X direction, that is, the first sub-eccentricity, the distance between the scan center and the center of the region of interest is determined. Based on this distance and the included angle, the projection point of the center of the region of interest on the line connecting the X-ray tube focal spot and the scan center is obtained. Based on the positional relationship between the projection point and the X-ray tube focal spot, the number of samples corresponding to the scan angle is obtained. The specific process of calculating the number of samples is as follows:

[0084] Step 1: Obtain the first distance between the scan center and the X-ray tube focal spot.

[0085] Step 2: Based on the included angle, obtain the projection point of the center of the region of interest on the line connecting the X-ray tube focal spot and the scan center, and based on the projection point, obtain the second distance between the projection point and the X-ray tube focal spot. First, based on the lateral film information, determine the positional relationship between the center of the region of interest and the scan center in the Y direction. Specifically, as Figure 2C shown, for each of the 7 target regions, according to the above step 201, the coordinate y of the sub-center corresponding to each target region is determined i , calculate the product of the coordinate of the sub-center and the true physical size to obtain the true thickness of the current target region in the Y direction. Calculate the thickness of the region of interest in each target region. The specific calculation method can be as shown in the following formula 1:

[0086] Formula 1:

[0087] where i represents the i-th row of target regions, y right represents the first coordinate corresponding to the right edge of the region of interest, y left represents the second coordinate corresponding to the left edge of the region of interest, represents the true physical size of each pixel, fov represents the field of view angle, and pixNum represents the number of pixels indicated by the plain film information.

[0088] Furthermore, as Figure 2EAs shown, the thickness of each slice of data is calculated to determine the true thickness of the region of interest. Based on the true thickness and the height of the scanning bed, the distance y between the center of the region of interest in the Y direction and the ground is determined. body Specifically, the process of calculating the distance between the center of the region of interest and the ground can be implemented based on the following formulas 2 to 3:

[0089] Formula 2:

[0090] Where N represents the preset number of slices. In the actual application process, its value is less than or equal to the number of pixels pixNum of the plain film information indicated by the plain film.

[0091] Formula 3: y body = bedHeight + thickness / 2

[0092] Where bedHeight is the height of the scanning bed.

[0093] Next, the distance y between the scanning center and the ground in the Y direction is obtained. center Take the difference between y body and y center as the first sub-eccentricity degree y bias of the center of the region of interest in the Y direction, that is, y bias = y body - y center , indicating the degree to which the center of the region of interest deviates from the scanning center in the Y direction. y body indicates the second center position of the region of interest.

[0094] Furthermore, based on the PA film information, the positional relationship between the center of the region of interest and the scanning center in the X direction is determined. As Figure 2D shown, for each of the 12 target regions, the coordinates xi of the sub-center corresponding to each target region are determined according to the above step 201. According to the coordinates of the sub-center corresponding to each target region, the center coordinate x body of the center of the region of interest in the X direction is calculated. The specific calculation process is as shown in the following formula 4:

[0095] Formula 4:

[0096] Subsequently, according to the central coordinate of the center of the region of interest in the X direction, the second sub-eccentricity degree of the center of the region of interest in the X direction is determined. Specifically, calculate the difference between the central coordinate of the center of the region of interest in the X direction and half of the number of pixels of the flat panel information, and multiply the difference by the true physical size to obtain the second sub-eccentricity degree of the center of the region of interest in the X direction, which indicates the degree to which the center of the region of interest deviates from the scanning center in the X direction. The specific process of calculating the second sub-eccentricity degree can be implemented based on the following formula 5:

[0097] Formula 5:

[0098] where x body is the central coordinate of the center of the region of interest in the X direction, that is, the first central position.

[0099] Finally, based on the first sub-eccentricity degree, the second sub-eccentricity degree, and the included angle, the third distance is determined, that is, the distance between the projection point of the center of the region of interest on the line connecting the scanning center and the tube focus and the scanning center. In the actual application process, as Figure 2F shown, first calculate the sum of the square of the first sub-eccentricity degree and the square of the second sub-eccentricity degree, and take the square root of the sum value as the distance between the center of the region of interest and the scanning center, that is Figure 2F y' in bias . Specifically, as shown in the following formula 6:

[0100] Formula 6:

[0101] where y' bias represents the distance between the center of the region of interest and the scanning center. Then calculate the arctangent value of the ratio of the second sub-eccentricity degree to the first sub-eccentricity degree to determine the scanning angle and the difference γ between the arctangent value, that is, the included angle, as shown in the following formula 7:

[0102] Formula 7:

[0103] where represents the scanning angle. Then calculate the cosine value of the distance y' bias between the center of the region of interest and the scanning center to obtain the third distance. Finally, take the difference between the first distance and the third distance as the second distance, which can be specifically implemented based on the following formula 8:

[0104] Formula 8: D body = D center - y' bias * cosγ

[0105] The second distance mentioned in the above embodiments is based on the situation where the center of the region of interest is between the X-ray tube focus and the scanning center, that is, the projection of the center of the region of interest on the line connecting the X-ray tube focus and the scanning center is located between the X-ray tube focus and the scanning center. In other embodiments, the second distance is the sum of the first distance and the third distance. In this case, the scanning center is between the X-ray tube focus and the center of the region of interest, that is, the projection of the center of the region of interest on the line connecting the X-ray tube focus and the scanning center is located on the side of the scanning center away from the X-ray tube focus.

[0106] Step 3: Obtain the sampling number corresponding to the angle based on the ratio of the second distance to the first distance and the initial sampling number of the corresponding angle. Specifically, as Figure 2G shown, the closer the X-ray tube focus is to the region of interest, the greater the scanning dose; the farther the X-ray tube focus is from the region of interest, the smaller the scanning dose. Within the fan beam range corresponding to the X-ray tube focus, the length that the detector can detect is W. It is known that the radiation dose per unit length is the same. When the scanned object is at the scanning center, the detector receives a length of W center , and when the scanned object is at position D body , the detector receives a length of W body , and W body is greater than W center . Therefore, the closer the scanned object is to the X-ray tube focus, the greater the radiation dose. Further, according to the following formula 9, it can be inferred that the radiation dose ratio is equal to the ratio of the distance D center between the X-ray tube focus and the center of the region and the distance D body between the X-ray tube focus and the scanning center, as shown in the following formula 10:

[0107] Formula 9:

[0108] where L represents the width of the scanned object, D represents the distance between the X-ray tube focus and the CT detector, W center represents the length received by the detector when the center of the region of interest is at the scanning center, and W body represents the length received by the detector when the center of the region of interest is at D body .

[0109] Formula 10:

[0110] where represents the radiation dose ratio.

[0111] Take the ratio between the first distance and the second distance as the radiation dose ratio. Further, multiply the radiation dose ratio by the reference sampling number to obtain the sampling number view corresponding to the scanning angle, as shown in the following formula 11:

[0112] Formula 11:

[0113] Wherein, A represents the number of samples corresponding to the corresponding angle.

[0114] 203. Scan the region of interest based on the number of samples corresponding to the scanning angle.

[0115] In response to the scan instruction, based on the number of samples corresponding to the scanning angle, perform axial scanning or helical scanning on the region of interest. The scanning method provided in this application is applicable to the axial scanning mode and the helical scanning mode. The axial scanning mode is a scanning method for scanning a certain position in the region of interest when the scanning bed is fixed, and the helical scanning mode is a scanning method in which the tube and the detector rotate while the scanning bed moves at a constant speed. The CT scanning instrument scans the region of interest using the adjusted number of samples, generates CT scanning data matching the current scanning angle, realizes calculation while adjustment, and thus improves the scanning efficiency. In other exemplary embodiments, the number of samples at each scanning angle can be adjusted before scanning, and then the adjusted scanning plan can be obtained. When scanning, the adjusted scanning plan is executed, thereby reducing the computing requirements of the scanning system. Finally, based on the CT scanning data, a target CT image corresponding to the region of interest is generated, and the target CT image is sent to the display terminal for display.

[0116] In summary, as Figure 2H shown, this application can obtain plain film data through plain film scanning, calculate the positional relationship between the center of the region of interest and the tube focus, that is, the eccentricity degree deviating from the scanning center of the CT scanning system. Finally, based on the positional relationship between the center of the region of interest and the scanning center, determine the number of samples corresponding to the corresponding angle, and perform axial scanning or helical scanning according to the number of samples. By dynamically controlling the number of samples, the scanning dose of the region of interest is made uniform, and the quality of the CT image is improved.

[0117] Further, as Figure 1 a specific implementation of the method, an embodiment of this application provides a scanning device for medical images, as Figure 3 shown, the device includes: an acquisition module 301, a calculation module 302, and a scanning module 303.

[0118] The acquisition module 301 is used to acquire the center of the region of interest;

[0119] The calculation module 302 is used to obtain the number of samples corresponding to the scanning angle based on the positional relationship between the tube focus and the center of the region of interest;

[0120] The scanning module 303 is used to scan the region of interest based on the number of samples corresponding to the scanning angle.

[0121] In a specific application scenario, the calculation module 302 is configured to obtain an angle between a line connecting the tube focus and the scan center and a line connecting the center of the region of interest and the scan center; based on the angle, obtain a projection point of the center of the region of interest on the line connecting the scan center and the tube focus; and based on a positional relationship between the projection point and the scan center, obtain the number of samples corresponding to the scan angle.

[0122] In a specific application scenario, the calculation module 302 is configured to obtain a first distance between the scan center and the tube focus; obtain a second distance between the projection point and the tube focus; and based on a ratio of the second distance to the first distance and an initial number of samples for a corresponding angle, obtain the number of samples for the corresponding angle.

[0123] In a specific application scenario, the calculation module 302 is configured to obtain a first sub-eccentricity degree of the region of interest in a first direction; obtain a second sub-eccentricity degree of the region of interest in a second direction; based on the first sub-eccentricity degree, the second sub-eccentricity degree, and the angle, obtain a third distance between the projection point and the scan center, and use a difference or sum value between the first distance and the third distance as the second distance; where the first direction is a direction perpendicular to an extension direction of the scan center and parallel to a bed surface of the scan bed, and the second direction is a direction perpendicular to the first direction and perpendicular to the bed surface of the scan bed.

[0124] In a specific application scenario, the calculation module 302 is configured to calculate a sum value of the square of the first sub-eccentricity degree and the square of the second sub-eccentricity degree, and use a square root of the sum value as a distance between the center of the region of interest and the scan center; calculate an arctangent value of a ratio of the second sub-eccentricity degree to the first sub-eccentricity degree and a difference between the scan angle and the arctangent value; and use a product of a cosine value of the difference and the square root as the third distance.

[0125] In a specific application scenario, the acquisition module 301 is configured to obtain plain film information of the region of interest; input the plain film information into a neural network model to obtain the center of the region of interest; or, based on a frontal film, a lateral film, and a correspondence between pixels and real physical dimensions, obtain the center of the region of interest.

[0126] The device provided by the embodiment of the present application first obtains the center of the region of interest; based on the positional relationship between the tube focus and the center of the region of interest, obtains the number of samples corresponding to the scanning angle. Finally, based on the number of samples corresponding to the scanning angle, scans the region of interest. By determining the positional relationship between the center of the region of interest and the tube focus, determining the number of samples corresponding to different scanning angles, the scanning dose of the region of interest is made uniform, the consistency of image noise is improved, and the quality of CT images is improved.

[0127] It should be noted that for other corresponding descriptions of each functional unit involved in the medical image scanning device provided by the embodiment of the present application, reference can be made to Figure 1 and Figures 2A to 2H the corresponding descriptions therein, which will not be elaborated here.

[0128] Based on the above Figure 1 and Figures 2A to 2H In the method shown, correspondingly, the embodiment of the present application also provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the medical image scanning method as shown in Figure 1 and Figures 2A to 2H above.

[0129] Based on such an understanding, the technical solution of the present application can be embodied in the form of a software product, and the software product can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various implementation scenarios of the present application.

[0130] Based on the above Figure 1 and Figures 2A to 2H In the method shown, as well as Figure 3 In the virtual device embodiment shown, for the purpose of achieving the above object, the embodiment of the present application also provides a computer device, which can specifically be a personal computer, a server, a network device, etc. The computer device includes a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to implement the air correction method as shown in Figures 1 to 3 above.

[0131] Optionally, the computer device may further include a user interface, a network interface, a camera, a radio frequency (RF) circuit, sensors, an audio circuit, a WI-FI module, and so on. The user interface may include a display screen and an input unit such as a keyboard. Optionally, the user interface may further include a USB interface, a card reader interface, and so on. The network interface may optionally include a standard wired interface, a wireless interface (such as a Bluetooth interface, a WI-FI interface), and so on.

[0132] Those skilled in the art can understand that the drawings are only schematic diagrams of preferred implementation scenarios of a medical image scanning method, apparatus, and readable storage medium, and the modules or processes in the drawings are not necessarily essential for implementing the present application.

[0133] Those skilled in the art can understand that the modules in the apparatus in the implementation scenario can be distributed in the apparatus in the implementation scenario according to the implementation scenario description, or can be correspondingly changed and located in one or more apparatuses different from this implementation scenario. The modules in the above implementation scenario can be combined into one module, or can be further split into multiple sub-modules.

[0134] The above serial numbers of the present application are only for description and do not represent the advantages or disadvantages of the implementation scenarios.

[0135] The above discloses only several specific implementation scenarios of the present application. However, the present application is not limited thereto, and any changes that can be thought of by those skilled in the art should fall within the protection scope of the present application.

Claims

1. A scanning method for medical images, characterized in that, Including: Obtain the center of the region of interest; Based on the positional relationship between the X-ray tube focus and the center of the region of interest, obtain the angle between the line connecting the X-ray tube focus and the scan center and the line connecting the center of the region of interest and the scan center. Based on this angle, obtain the projection point of the center of the region of interest on the line connecting the scan center and the X-ray tube focus. Based on the positional relationship between the projection point and the X-ray tube focus, obtain the number of samples corresponding to the scan angle, where the relationship between the angle and the number of samples is as follows: the larger the angle, the more the number of samples, and the angle is an angle less than or equal to 180°; Scan the region of interest based on the number of samples corresponding to the scan angle.

2. The method according to claim 1, wherein The obtaining the number of samples corresponding to the scan angle based on the positional relationship between the projection point and the X-ray tube focus includes: Obtain the first distance between the scan center and the X-ray tube focus; Obtain the second distance between the projection point and the X-ray tube focus; Based on the ratio of the second distance to the first distance and the initial number of samples for the corresponding angle, obtain the number of samples for the corresponding angle.

3. The method according to claim 2, wherein The obtaining the second distance between the projection point and the X-ray tube focus includes: Obtain the first sub-eccentricity degree of the center of the region of interest in the first direction; Obtain the second sub-eccentricity degree of the center of the region of interest in the second direction; Based on the first sub-eccentricity degree, the second sub-eccentricity degree, and the angle, obtain the third distance between the projection point and the scan center; Take the difference or sum of the first distance and the third distance as the second distance; Wherein, the first direction is a direction perpendicular to the extension direction of the scan center and parallel to the bed surface of the scan bed, and the second direction is a direction perpendicular to the first direction and perpendicular to the bed surface of the scan bed.

4. The method according to claim 3, characterized in that The obtaining the third distance between the projection point and the scan center based on the first sub-eccentricity degree, the second sub-eccentricity degree, and the angle includes: Calculate the sum of the square of the first sub-eccentricity degree and the square of the second sub-eccentricity degree, and take the square root of the sum as the distance between the center of the region of interest and the scan center; Calculate the arctangent value of the ratio of the second sub-eccentricity degree to the first sub-eccentricity degree, and the difference between the scan angle and the arctangent value; Take the product of the cosine value of the difference and the square root as the third distance.

5. The method according to claim 1, characterized in that, The obtaining the center of the region of interest includes: Obtain the plain film information of the region of interest; Input the plain film information into a neural network model to obtain the center of the region of interest; or, Based on the anteroposterior film and the lateral film, as well as the corresponding relationship between pixels and real physical sizes, obtain the center of the region of interest.

6. The method according to claim 1, wherein The scanning the region of interest based on the number of samples corresponding to the scan angle includes: Before the formal scan, based on the number of samples corresponding to the scan angle, adjust the number of samples at different scan angles and then scan the region of interest; or, During formal scanning, based on the number of samples corresponding to the scanning angle, the number of samples corresponding to the scanning angle is adjusted in real time, and the region of interest is scanned.

7. A scanning device for medical images, characterized in that, It includes: An acquisition module, configured to acquire the center of the region of interest; A calculation module, configured to obtain the angle between the line connecting the tube focus and the scanning center and the line connecting the center of the region of interest and the scanning center based on the positional relationship between the tube focus and the center of the region of interest, obtain the projection point of the center of the region of interest on the line connecting the scanning center and the tube focus based on the angle, and obtain the number of samples corresponding to the scanning angle based on the positional relationship between the projection point and the tube focus, where the relationship between the angle and the number of samples is as follows: the larger the angle, the more the number of samples, and the angle is an angle less than or equal to 180°; A scanning module, configured to scan the region of interest based on the number of samples corresponding to the scanning angle.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

Images