Method, device and system for determining exposure parameters of CT scanning system

Abstract

The method, device and system for determining exposure parameters of a CT scanning system provided by the embodiments of the present disclosure include: determining the spatial contour data of a target object; obtaining the mass and centroid of the target object, and determining the mass distribution function of each scanning area included in the target object and the centroid distribution function of each scanning area included in the target object according to the spatial contour data; determining the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial contour data; determining the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object; determining the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function. This makes the modulated exposure parameters more accurate and realizes precise automatic exposure dose control.

Description

Technical Field

[0001] The present invention relates to the field of scanning technology and related technical fields, and in particular to a method, device and system for determining exposure parameters of a CT scanning system. Background Art

[0002] CT is a device that emits X-rays to the scanned part through an X-ray generating component (usually a tube), then receives the attenuated rays through the scanned part through a detector, and finally obtains a three-dimensional image through an image reconstruction algorithm. At present, CT scanning technology has fully entered the era of spiral scanning. In spiral CT scanning, the X-ray tube rotates continuously around the frame for exposure, while the examination bed moves synchronously at a uniform speed, and the detector continuously collects data. The attenuation of X-rays by an object is related to its own attenuation coefficient and the path length of the X-rays through the object. Obviously, different patients, different parts of the body, and the same part at different angles have different attenuations of X-rays. Therefore, in CT scanning, it is necessary to automatically modulate the exposure parameters according to the actual attenuation characteristics of the patient's scanned part to achieve automatic exposure dose control, that is, to minimize the radiation dose borne by the patient while ensuring image quality.

[0003] However, in the prior art, it is impossible to accurately and individually modulate the exposure parameters related to the patient's scanned part by scanning the positioning image or the size of the body surface structure alone, which will affect the quality of the reconstructed image or bring unnecessary excessive radiation dose to the patient. Summary of the invention

[0004] The embodiments described herein provide a method, device, and system for determining exposure parameters of a CT scanning system, which solve the problems existing in the prior art.

[0005] In a first aspect, according to the present disclosure, a method for determining exposure parameters of a CT scanning system is provided, which is applied to a CT scanning system and includes:

[0006] Determine spatial contour data of the target object;

[0007] Acquire the mass and the center of mass of the target object, and determine the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the center of mass;

[0008] Determining theoretical attenuation thicknesses of each scanning area included in the target object at different scanning angles according to the spatial profile data;

[0009] Determining the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object;

[0010] The exposure parameters of the CT scanning system in each scanning area are determined according to the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function.

[0011] In some embodiments of the present disclosure, determining the spatial contour data of the target object includes:

[0012] Acquire a depth image and an RGB two-dimensional plane image of the target object, wherein the depth image includes depth information corresponding to pixel points included in the outer contour of the target object, and the RGB two-dimensional plane image includes the target object information and background information;

[0013] The spatial contour data of the target object is determined according to the depth image of the target object and the RGB two-dimensional plane image.

[0014] In some embodiments of the present disclosure, determining the mass distribution function of each scanning area included in the target object and the centroid distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the centroid includes:

[0015] Determining the volume of each scanning area included in the target object according to the spatial contour data;

[0016] Determining a mass distribution function of each scanning area included in the target object according to the mass of the target object and the volume of each scanning area included in the target object;

[0017] The centroid distribution function of each scanning area included in the target object is determined according to the centroid of the target object, the volume of each scanning area included in the target object, and the mass distribution function of each scanning area included in the target object.

[0018] In some embodiments of the present disclosure, the CT scanning system includes a first sensor, a second sensor, a third sensor and a fourth sensor, wherein the first sensor, the second sensor, the third sensor and the fourth sensor are respectively arranged at symmetrical fulcrum positions of the scanning bed;

[0019] The obtaining the mass and center of mass of the target object comprises:

[0020] Acquire initial measurement information of the first sensor, the second sensor, the third sensor, and the fourth sensor, target measurement information, the center of mass of the scanning bed, first distance information of the center of mass of the scanning bed relative to the first line segment, length information of the first line segment, second distance information of the center of mass of the scanning bed relative to the second line segment, third distance information between the center of mass of the scanning bed and a plane formed by the first sensor, the second sensor, the third sensor, and the fourth sensor, length information of the second line segment, and height information of the third line segment when the scanning bed is tilted to a target angle, wherein the first line segment is a line between the second sensor and the fourth sensor, the second line segment is a line between the third sensor and the fourth sensor, and the third line segment is a line between the first sensor and the third sensor;

[0021] Determining the quality of the target object according to the target measurement information and the initial measurement information;

[0022] The center of mass of the target object is determined according to the center of mass of the scanning bed, the initial measurement information, the mass of the target object, first distance information of the center of mass of the scanning bed relative to a first line segment, length information of the first line segment, second distance information of the center of mass of the scanning bed relative to a second line segment, length information of the second line segment, and height information of the third line segment when the scanning bed is tilted to a target angle.

[0023] In some embodiments of the present disclosure, the distance between the center of mass of the target object and the X-axis is satisfy:

[0024] ,

[0025] The distance of the target object's center of mass relative to the Z axis satisfy:

[0026]

[0027] The distance of the target object's center of mass relative to the Y axis satisfy:

[0028] ,

[0029] in, is the mass of the target object, is the initial measurement information, is the first distance information of the centroid of the scanning bed relative to the first line segment, is the second distance information of the center of mass of the scanning bed relative to the second line segment, is the third distance information between the center of mass of the scanning bed and the plane formed by the first sensor, the second sensor, the third sensor and the fourth sensor, is the length information of the first line segment, is the length information of the second line segment, is the height information of the third line segment when the scanning bed is tilted to the target angle, is the measurement value of the first sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the second sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the third sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the fourth sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the first sensor when the target object lies on the scanning bed when the scanning bed is tilted to the target angle, is the measurement value of the third sensor when the target object lies on the scanning bed when the scanning bed is tilted to the target angle, The target angle for tilting the scanning bed.

[0030] In some embodiments of the present disclosure, determining the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial profile data includes:

[0031] Determine, according to the spatial contour data, coordinate information of pixel points included in the outer contour of the target object;

[0032] According to the coordinate information of any two pixel points included in the outer contour of the target object, determine the path information of the X-ray passing through the any two pixel points and the angle information between the X-ray and the long axis of the cross section of the scanning area;

[0033] The theoretical attenuation thickness of each scanning area included in the target object at different scanning angles is determined according to the path information of the X-ray passing through any two pixel points and the angle information between the X-ray and the long axis of the scanning area cross section.

[0034] In some embodiments of the present disclosure, determining the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function includes:

[0035] Determining the actual attenuation thickness of each scanning area included in the target object according to the mass distribution function, the center of mass distribution function and the theoretical attenuation thickness;

[0036] The exposure parameters of the CT scanning system in each scanning area are determined according to the actual attenuation thickness and the attenuation distribution function, wherein the exposure parameters include exposure time, tube voltage and tube current.

[0037] In a second aspect, according to the content of the present disclosure, a device for determining exposure parameters of a CT scanning system is provided, which is applied to a CT scanning system, and includes:

[0038] A spatial contour data determination module, used to determine the spatial contour data of the target object;

[0039] A mass and centroid distribution function determination module, used to obtain the mass and centroid of the target object, and determine the mass distribution function of each scanning area included in the target object and the centroid distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the centroid;

[0040] A theoretical attenuation thickness determination module, used to determine the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial profile data;

[0041] An attenuation distribution function determination module, used to determine the attenuation distribution function of each scanning area included in the target object according to the projection data corresponding to the positioning scanning image of the target object;

[0042] The exposure parameter determination module is used to determine the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function.

[0043] In a third aspect, according to the content of the present disclosure, a CT scanning system is provided, comprising the exposure parameter determination device of the CT scanning system according to the second aspect, and further comprising: a scanning bed, a scanning frame, an identification component, a sensor module and a lifting structure, wherein the sensor module comprises a first sensor, a second sensor, a third sensor and a fourth sensor, wherein the first sensor, the second sensor, the third sensor and the fourth sensor are arranged at four symmetrical fulcrum positions on a side of the scanning bed away from the identification module, and the lifting structure is used to drive the first fulcrum and the third fulcrum of the scanning bed to rise and fall;

[0044] The recognition component is arranged opposite to a side of the scanning bed where the target object is placed, and the recognition range of the recognition component covers the target object.

[0045] In some embodiments of the present disclosure, a driving structure is further included, wherein the driving structure is used to drive the scanning bed to move to the scanning frame position.

[0046] The method, device and system for determining exposure parameters of a CT scanning system provided by the embodiments of the present disclosure first determine the spatial contour data of a target object; then obtain the mass and center of mass of the target object, and determine the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object according to the spatial contour data, the mass and the center of mass; and determine the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial contour data; and determine the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object; finally, determine the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function. In the present application, the exposure parameters of the CT scanning system in each scanning area are determined by the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function of each scanning area included in the target object. Not only the attenuation distribution function of different scanning areas of the target object is considered, but also the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles is modulated by the mass distribution function and the centroid distribution function of each scanning area of ​​the target object, so as to ensure the accuracy of the actual attenuation thickness of each scanning area included in the target object at different scanning angles, more accurately obtain the actual body size of the target object, make the modulated exposure parameters more accurate, and realize precise automatic exposure dose control.

[0047] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly described below. It should be noted that the drawings described below only relate to some embodiments of the present disclosure, but are not intended to limit the present disclosure, wherein:

[0049] Figure 1 is a flow chart of a method for determining exposure parameters of a CT scanning system provided by an embodiment of the present disclosure;

[0050] Figure 2 is a schematic diagram of an identification component in a CT scanning system provided by an embodiment of the present disclosure;

[0051] Figure 3 is a schematic diagram of a sensor module in a CT scanning system provided in an embodiment of the present disclosure;

[0052] Figure 4is a schematic diagram of a scanning structure in a CT scanning system provided in an embodiment of the present disclosure;

[0053] Figure 5 is a structural schematic diagram of a device for determining exposure parameters of a CT scanning system provided by an embodiment of the present disclosure;

[0054] Figure 6 is a structural schematic diagram of a CT scanning system provided by an embodiment of the present disclosure;

[0055] Figure 7 is a partial structural schematic diagram of a CT scanning system provided by an embodiment of the present disclosure;

[0056] Figure 8 It is a structural diagram of a computer device provided in an embodiment of the present disclosure.

[0057] In the drawings, reference numerals with the same last two digits correspond to the same elements. It should be noted that the elements in the drawings are schematic and not drawn to scale. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without creative work also fall within the scope of protection of the present disclosure.

[0059] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by a person skilled in the art to which the subject matter of the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the specification and the relevant art, and will not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, a statement that two or more parts are "connected" or "coupled" together shall mean that the parts are joined together directly or through one or more intermediate components.

[0060] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0061] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0062] Furthermore, in all embodiments of the present disclosure, terms such as “first” and “second” are used only to distinguish one component (or a part of a component) from another component (or another part of a component).

[0063] In the description of the present application, unless otherwise specified, “plurality” means more than two (including two), and similarly, “plurality groups” means more than two (including two).

[0064] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0065] Based on the problems existing in the prior art, the present disclosure provides a method for determining exposure parameters of a CT scanning system. Figure 1 is a flow chart of a method for determining exposure parameters of a CT scanning system provided by an embodiment of the present disclosure, such as Figure 1 As shown, the method for determining exposure parameters of a CT scanning system includes:

[0066] S110: Determine spatial contour data of the target object.

[0067] In a specific implementation, determining the spatial contour data of the target object includes: acquiring a depth image and an RGB two-dimensional plane image of the target object, wherein the depth image includes depth information corresponding to the target object, and the RGB two-dimensional plane image includes target object information and background information; determining the spatial contour data of the target object based on the depth information and the RGB two-dimensional plane image of the target object.

[0068] Specifically, in the field of depth recognition, the relative distance between the object and the camera at each pixel in the scene, i.e., the depth information, is mainly identified through technologies such as structured light, time of flight, or binocular stereo vision, and a depth image with the depth information of the object in the scene is output, and then the spatial contour data is determined based on the depth image with depth information. Among them, structured light technology has high accuracy and strong practicality, but is affected by strong outdoor light environments and reflective surfaces; time of flight technology is good at long-distance measurement and complex lighting environments, and the cost is relatively high; binocular stereo vision method has low cost and is applicable both indoors and outdoors, but its performance is limited in scenes lacking texture or with large lighting changes; therefore, considering the application scenarios in CT imaging examination rooms, it is mainly preferred to use structured light technology to obtain depth images containing all parts of the patient.

[0069] Structured light technology projects a structured light source (such as gratings, stripes, etc.) into the scene, then uses a camera to capture the scene image after being illuminated by the projected light source, and calculates the depth information of each point in the scene by analyzing the deformation of the light source in the scene.

[0070] The specific recognition principle is as follows Figure 2 As shown, 101 is a depth camera, 102 is a structured light source, 103 is an imaging plane, and 104 is a target object. The surface structured light source is simplified to a combination of several line structured light sources. During the recognition process, the line structured light source gradually scans the target object, and the camera records the scanning process. Assuming that the structured light source scans a point P on the outer contour of the target object, the following geometric relationship can be obtained according to the triangle sine formula:

[0071] ,

[0072] Further,

[0073] ,

[0074] Among them, baseline is the distance between the camera focus and the structured light source, α is the angle between the direction of the structured light source and the X-axis, and β is the angle between the line connecting point P and the camera focus and the X-axis, which is determined by the ratio of the coordinates of the corresponding pixel point projected by point P in the image to the focal length.

[0075] From the above formula, we can get the distance between point P and the camera focus: , then the spatial coordinates of point P can be expressed as , so the depth of point P satisfies:

[0076] ,

[0077] in, and are the corresponding points in the target point cloud and the original point cloud respectively, R is the rotation transformation matrix, and T is the translation transformation matrix.

[0078] Optionally, the registration is performed based on the ICP (Iterative Closest Point) algorithm, the objective function is constructed by the least squares method, the overall distance between point pairs is iteratively minimized, and finally the transformation matrix is ​​obtained.

[0079] Then point cloud filtering is performed to filter out the hash points and isolated points in the point cloud data.

[0080] Optionally, point cloud filtering can be accomplished by bilateral filtering, Gaussian filtering, conditional filtering, and the like.

[0081] Finally, the three-dimensional point cloud data belonging to the human body is extracted from the point cloud data through the target recognition algorithm.

[0082] Optionally, a traditional algorithm based on edge, region, or attribute may be used, or an algorithm based on deep learning may be used. Since the point cloud data in this method contains complex information such as geometry, texture, and color, preferably, accurate recognition is achieved through a method based on a deep learning model.

[0083] The deep learning model is trained based on historical data. First, a depth camera is used to synchronously collect three-dimensional point cloud data samples of several human bodies lying supine, prone, and sideways on the scanning bed. Expert calibration technology is used to finely annotate the collected point cloud data to accurately define the human body area and form a labeled point cloud data set. The point cloud data set is then divided into training set, test set, and validation set in a ratio of 8:1:1 to ensure the comprehensiveness and effectiveness of model training and evaluation. The training set is used to iteratively train the deep learning model. During the training process, the model parameters are continuously optimized to improve its recognition accuracy of human point cloud data. Subsequently, the test set is used to evaluate the recognition performance of the model, and the validation set is used to further verify its recognition accuracy and robustness to ensure the stability and reliability of the model in practical applications. Finally, a set of efficient point cloud data human recognition algorithms is formed.

[0084] Optionally, the aforementioned deep learning model may use Point Transformer, RandLANet, etc. to fully utilize their powerful feature extraction and processing capabilities.

[0085] The Poisson reconstruction algorithm can be used to reconstruct the three-dimensional human body surface based on point cloud data. The surface of the object is estimated by implicitly fitting the indicator function of the object, thereby extracting and reconstructing the patient's spatial contour.

[0086] It should be noted that in the above embodiment, the spatial contour data of the target object is a set of three-dimensional coordinate points in the system coordinate system; based on the set of three-dimensional coordinate points, information such as the height of the target object, the width of the human body distributed along the height direction, the thickness and volume of various parts of the human body, etc. can be obtained.

[0087] S120, obtaining the mass and the center of mass of the target object, and determining the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the center of mass.

[0088] In a specific embodiment, obtaining the mass and center of mass of the target object includes: obtaining initial measurement information of the first sensor, the second sensor, the third sensor, and the fourth sensor, target measurement information, the center of mass of the scanning bed, first distance information of the center of mass of the scanning bed relative to the first line segment, length information of the first line segment, second distance information of the center of mass of the scanning bed relative to the second line segment, third distance information of the center of mass of the scanning bed relative to a plane formed by the first sensor, the second sensor, the third sensor, and the fourth sensor, length information of the second line segment, and height information of the third line segment when the scanning bed is tilted to a target angle, wherein the first line segment is a line between the second sensor and the fourth sensor, the second line segment is a line between the third sensor and the fourth sensor, and the third line segment is a line between the first sensor and the third sensor; determining the mass of the target object according to the target measurement information and the initial measurement information; determining the center of mass of the target object according to the center of mass of the scanning bed, the initial measurement information, the mass of the target object, first distance information of the center of mass of the scanning bed relative to the first line segment, length information of the first line segment, second distance information of the center of mass of the scanning bed relative to the second line segment, length information of the second line segment, and height information of the third line segment when the scanning bed is tilted to the target angle.

[0089] Specific, combined Figure 3 The CT scanning system includes a first sensor, a second sensor, a third sensor and a fourth sensor. The first sensor, the second sensor, the third sensor and the fourth sensor are respectively arranged at the symmetrical fulcrum positions of the scanning bed, wherein the first sensor is arranged at the first fulcrum Position, the second sensor is set at the second fulcrum Position, the third sensor is set at the third fulcrum Position, the fourth sensor is set at the fourth fulcrum At the position, 202 is the target object and 203 is the centroid of the target object.

[0090] Among them, the first sensor, the second sensor, the third sensor and the fourth sensor are pressure sensors.

[0091] When the scanning bed is in a horizontal position and the scanning bed is empty, initial measurement information of the first sensor, the second sensor, the third sensor and the fourth sensor is obtained; when the scanning bed is in a horizontal position and the target object is lying on the scanning bed, target measurement information of the first sensor, the second sensor, the third sensor and the fourth sensor is obtained; the sum of the target measurement information of the first sensor, the second sensor, the third sensor and the fourth sensor is subtracted from the sum of the initial measurement information of the first sensor, the second sensor, the third sensor and the fourth sensor to obtain the mass of the target object.

[0092] The quality of the target object meets:

[0093] ,

[0094] in, is the target measurement information of the i-th sensor (i.e., the measurement value of the i-th sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed), is the initial measurement information of the ith sensor (ie, the measurement value of the ith sensor when the scanning bed is in a horizontal position and the scanning bed is empty).

[0095] In addition, since the shape and material of the scanning bed are fixed, the center of mass of the scanning bed can be determined.

[0096] Combination Figure 3 , the distance of the target object's center of mass relative to the X axis satisfy:

[0097] ,

[0098] in, is the quality of the target object, is the initial quality information, is the first distance information of the center of mass of the scanning bed relative to the first line segment, is the measurement value of the first sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the third sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the length information of the second line segment.

[0099] The distance of the target object's center of mass relative to the Z axis satisfy:

[0100] ,

[0101] in, is the quality of the target object, is the initial quality information, is the second distance information of the center of mass of the scanning bed relative to the second line segment, is the measurement value of the second sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the fourth sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the length information of the first line segment.

[0102] Get the distance of the target object's center of mass relative to the X axis The distance relative to the Z axis Afterwards, the supporting points corresponding to the first sensor and the third sensor are synchronously raised by the lifting structure, so that the scanning bed moves around the second supporting point. and the fourth fulcrum The line between them rotates to a certain angle. At this time, the distance between the center of mass of the target object and the Y axis is satisfy:

[0103] ,

[0104] in, is the quality of the target object, is the initial quality information, is the third distance information between the center of mass of the scanning bed and the plane formed by the first sensor, the second sensor, the third sensor and the fourth sensor, is the measurement value of the first sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the third sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the first sensor when the target object lies on the scanning bed when the scanning bed is tilted to the target angle, is the measurement value of the third sensor when the target object lies on the scanning bed when the scanning bed is tilted to the target angle, It is the height information of the third line segment when the scanning bed is tilted to the target angle. is the length information of the first line segment, The target angle for the table tilt.

[0105] Through the above formula, the mass and center of mass of the target object can be obtained.

[0106] After obtaining the mass and centroid of the target object, the volume of each scanning area included in the target object is determined according to the spatial profile data; the mass distribution function of each scanning area included in the target object is determined according to the mass of the target object and the volume of each scanning area included in the target object. The centroid distribution function of each scanning area included in the target object is determined according to the mass, centroid of the target object and the volume of each scanning area included in the target object.

[0107] Specifically, after obtaining the mass and center of mass of the target object, the volume of different scanning areas of the target object can be determined based on the spatial contour data of the target object. Then, by combining the formulas of density, mass and volume, when the density of the target object remains unchanged and the volumes of different scanning areas of the target object are known, the mass corresponding to the different scanning areas of the target object can be obtained. Therefore, the mass distribution function of each scanning area of ​​the target object can be determined.

[0108] Furthermore, the centroid distribution function of each scanning area included in the target object is determined according to the centroid of the target object, the volume of each scanning area included in the target object, and the mass distribution function of each scanning area included in the target object.

[0109] S130 , determining theoretical attenuation thicknesses of each scanning area included in the target object at different scanning angles according to the spatial profile data.

[0110] After the spatial contour data of the target object is determined in step S110, the coordinate information of the pixel points included in the outer contour of the target object can be obtained; then, based on the coordinate information of any two pixel points included in the outer contour of the target object, the path information of the X-ray passing through any two pixel points and the angle information between the X-ray and the long axis of the cross-section of the scanning area are determined; finally, based on the path information of the X-ray passing through any two pixel points and the angle information between the X-ray and the long axis of the cross-section of the scanning area, the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles is determined.

[0111] Specific, combined Figure 4 When the target object lies flat on the scanning bed, and the axis of the target object's body or the area to be scanned basically coincides with the scanning center, the horizontal line passing through the axis in each section of the area to be scanned of the target object is defined as the long axis.

[0112] Assume that during spiral scanning, the rays emitted by the tube pass through two points A and B on a certain cross-sectional surface of the scanning area. Figure 4 In the figure, 301 is a tube, 302 is a collimator, 303 is a detector, 304 is a scanned part section, and 305 is a section long axis. Based on the spatial contour data of the target object determined in step S110, the coordinates of pixel point A and pixel point B in the spatial contour of the target object can be known, wherein the coordinates of pixel point A are (x1, y1), and the coordinates of pixel point B are (x2, y2). Therefore, the path information of the X-ray of the CT scanning system passing through pixel point A and pixel point B satisfies:

[0113] ,

[0114] The angle information between the X-ray and the long axis of the scanning area section satisfies:

[0115] ,

[0116] After determining the path information of the X-ray passing through any two pixel points and the angle information between the X-ray and the long axis of the scanning area section, it can be calculated that the theoretical attenuation thickness of all sections of the area to be scanned in the Z-axis direction of the CT scanning system at different angles satisfies: .

[0117] S140 , determining the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object.

[0118] Before performing CT scanning on the target object, it is necessary to obtain a positioning scan image of the target object. Based on the positioning scan image of the target object, the positioning projection data of the target object can be determined. Based on the positioning projection data, the attenuation distribution function of each scanning area included in the target object can be determined. .

[0119] Specifically, the process of obtaining the positioning scanning image of the target object includes: after the target object is positioned on the scanning bed, the tube rotates to the top of the target object, and the detector rotates to the bottom of the target object accordingly, and the tube and the detector remain in a fixed position. At this time, the scanning bed moves horizontally into the scanning frame steadily, so as to obtain the positioning scanning image of the target object, and then calculate the attenuation distribution function of the target object according to the positioning projection data of the positioning scanning image of the target object. .

[0120] S150, determining exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function.

[0121] Specifically, the actual attenuation thickness of each scanning area included in the target object is determined according to the mass distribution function, the center of mass distribution function and the theoretical attenuation thickness; the exposure parameters of the CT scanning system in each scanning area are determined according to the actual attenuation thickness and the attenuation distribution function, wherein the exposure parameters include exposure time, tube voltage and tube current.

[0122] According to the Lambert-Beer law, It can be seen that the attenuation of X-rays by an object is related to its attenuation coefficient and thickness. Therefore, it is necessary to modulate the exposure parameters according to the attenuation distribution function of each scanning area of ​​the target object and the structural size of the target object in the scanning area.

[0123] Among them, the formula middle, is the intensity of X-rays after passing through matter, is the original intensity of the X-rays, is the attenuation coefficient, ‌ represents the absorption and scattering ability of the material to X-rays, and d is the thickness of the object.

[0124] Since the original intensity of X-rays determines the radiation dose received by the target object, and the original intensity of X-rays is related to the exposure parameters of the tube, the exposure parameters of the CT scanning system in each scanning area are determined by the thickness of the object and the attenuation of the object to X-rays. However, in the prior art, it is impossible to accurately modulate the exposure parameters related to the patient's scanning part by scanning the positioning image or the size of the body surface structure alone. In the present application, the exposure parameters of the CT scanning system in each scanning area are determined by the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function of each scanning area included in the target object, which not only considers the attenuation distribution function of different scanning areas of the target object, but also modulates the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles through the mass distribution function and the centroid distribution function of each scanning area of ​​the target object, so as to ensure the accuracy of the actual attenuation thickness of each scanning area included in the target object at different scanning angles, more accurately obtain the actual body size of the target object, make the modulated exposure parameters more accurate, and realize precise automatic exposure dose control.

[0125] The exposure parameters include tube voltage, exposure time and tube current automatic modulation curve. If the tube voltage and exposure time of the tube remain unchanged, the tube current changes in real time according to the theoretical attenuation thickness, mass distribution function, center of mass distribution function and attenuation distribution function of the scanning area.

[0126] The method for determining exposure parameters of a CT scanning system provided by an embodiment of the present disclosure first determines spatial contour data of a target object; then obtains the mass and center of mass of the target object, and determines the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object according to the spatial contour data, the mass and the center of mass; and determines the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial contour data; and determines the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object; finally, determines the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function. In the present application, the exposure parameters of the CT scanning system in each scanning area are determined by the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function of each scanning area included in the target object. Not only the attenuation distribution function of different scanning areas of the target object is considered, but also the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles is modulated by the mass distribution function and the centroid distribution function of each scanning area of ​​the target object, so as to ensure the accuracy of the actual attenuation thickness of each scanning area included in the target object at different scanning angles, more accurately obtain the actual body size of the target object, make the modulated exposure parameters more accurate, and realize precise automatic exposure dose control.

[0127] On the basis of the above-mentioned embodiments, the embodiments of the present disclosure further provide a device for determining exposure parameters of a CT scanning system. The device for determining exposure parameters of a CT scanning system is applied to a CT scanning system. Figure 5 is a schematic diagram of the structure of a device for determining exposure parameters of a CT scanning system provided by an embodiment of the present disclosure, such as Figure 5 As shown, the exposure parameter determination device of the CT scanning system includes:

[0128] A space contour data determination module 210 is used to determine the space contour data of the target object;

[0129] The mass and centroid distribution function determination module 220 is used to obtain the mass and centroid of the target object, and determine the mass distribution function of each scanning area included in the target object and the centroid distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the centroid;

[0130] Theoretical attenuation thickness determination module 230 is used to determine the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial profile data;

[0131] An attenuation distribution function determination module 240 is used to determine the attenuation distribution function of each scanning area included in the target object according to the projection data corresponding to the positioning scanning image of the target object;

[0132] The exposure parameter determination module 250 is used to determine the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function.

[0133] The exposure parameter determination device of the CT scanning system provided by the embodiment of the present disclosure first determines the spatial contour data of the target object; then obtains the mass and the center of mass of the target object, and determines the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object according to the spatial contour data, the mass and the center of mass; and determines the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial contour data; and determines the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object; finally, determines the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function. In the present application, the exposure parameters of the CT scanning system in each scanning area are determined by the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function of each scanning area included in the target object. Not only the attenuation distribution function of different scanning areas of the target object is considered, but also the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles is modulated by the mass distribution function and the centroid distribution function of each scanning area of ​​the target object, so as to ensure the accuracy of the actual attenuation thickness of each scanning area included in the target object at different scanning angles, more accurately obtain the actual body size of the target object, make the modulated exposure parameters more accurate, and realize precise automatic exposure dose control.

[0134] Based on the above embodiments, the present disclosure also provides a CT scanning system, which includes the exposure parameter determination device for a CT scanning system described in any one of the above embodiments, and further includes: a scanning bed, a scanning frame, an identification component, a sensor module and a lifting structure, combined with Figure 3 and Figure 6 The sensor module includes a first sensor, a second sensor, a third sensor and a fourth sensor, the first sensor, the second sensor, the third sensor and the fourth sensor are arranged at four symmetrical fulcrum positions on a side of the scanning bed away from the recognition component, and the lifting structure is used to drive the first fulcrum and the third fulcrum of the scanning bed to lift;

[0135] The recognition component is arranged relative to a side of the scanning bed where the target object is placed, and a recognition range of the recognition component covers the target object.

[0136] In addition, the CT scanning system also includes a driving structure, which is used to drive the scanning bed to move to the scanning frame position.

[0137] Combination Figure 6 Before the scanning process starts, the physician guides the target object to lie still on the scanning bed, and then the operating technician completes the positioning of the target object by finely adjusting the target object's body position and the scanning bed position according to clinical needs. After this process is completed, the operator enters the scanning protocol parameters on the console terminal to ensure that the scanning process meets clinical specifications and diagnostic requirements; after the scanning protocol is set, the main control module of the CT scanning system sends a control instruction to control the recognition component and the sensor module to work, and the CT scanning system exposure parameter determination device of the CT scanning system first determines the contour data of the target object according to the depth image and RGB two-dimensional plane image obtained by the recognition component, and then determines the mass of the target object according to the initial measurement information collected by the sensor module when the target object is not lying still on the scanning bed and the target measurement information collected by the sensor module when the target object is lying still on the scanning bed, and determines the center of mass of the target object according to the first distance information of the center of mass of the scanning bed relative to the first line segment, the length information of the first line segment, the second distance information of the center of mass of the scanning bed relative to the second line segment, the length information of the second line segment, and the height information of the third line segment when the scanning bed is tilted to the target angle. Then, based on the spatial profile data, mass and center of mass, the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object are determined, providing key data support for subsequent scanning parameter optimization.

[0138] After the data preparation stage is completed, the main control module of the CT scanning system accurately controls the position of the tube and the detector according to the preset logic, so that the tube is accurately positioned directly above the target object, and the detector is correspondingly aligned directly below the target object, ensuring that both remain statically stable during the scanning process; then, the scanning bed, driven by the main control module, advances horizontally into the scanning frame until the area to be scanned completely enters the scanning field of view; at this time, the tube starts laying out according to the control instructions, and the image reconstruction module receives the positioning projection data in real time, and determines the attenuation distribution function of each scanning area included in the target object based on the positioning projection data.

[0139] Figure 6 In the figure, 201 is a scanning bed, 402 is a sensor module, 403 is a slider, 404 is an identification component, 405 is an effective field of view of the identification component, 406 is a patient, 407 is an auxiliary moving roller, and 408 is a scanning frame.

[0140] In order to further optimize the scanning effect and image quality, the exposure parameter determination module in the exposure parameter determination device of the CT scanning system makes full use of the spatial contour data, attenuation distribution function, mass distribution function and center of mass distribution function of the target object to correct the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles to obtain the target attenuation thickness, so as to more accurately obtain the actual body size of the target object, make the modulated exposure parameters more accurate, and realize precise automatic exposure dose control, so as to ensure that the scanning process meets the clinical requirements of reducing radiation dose and maximizes image quality.

[0141] The scanning process officially begins. The scanning bed, driven by the slider, uniformly delivers the target object into the scanning frame. When the preset scanning area enters the scanning field of view, the tube begins to accurately lay out the line according to the personalized exposure parameters generated above. After the X-rays penetrate the human tissue, they are captured by the high-precision detector and converted into electrical signals. At the same time, the tube and the detector realize synchronous rotation under the drive of the scanning frame, completing the spiral scanning process with automatic exposure dose control. Figure 7 As shown, 301 is the tube, 302 is the collimator blade, 304 is the scanning part section, 201 is the scanning bed, and 303 is the detector. During this process, the image reconstruction module receives the projection data in real time and quickly converts it into high-quality CT image data.

[0142] The present application also provides a computer device. Figure 8 , Figure 8 This is a basic structural block diagram of the computer device in this embodiment.

[0143] The computer device includes a memory 510 and a processor 520 that are connected to each other through a system bus. It should be noted that the figure only shows a computer device with components 510-520, but it should be understood that it is not required to implement all the components shown, and more or fewer components can be implemented instead. Among them, those skilled in the art can understand that the computer device here is a device that can automatically perform numerical calculations and / or information processing according to pre-set or stored instructions, and its hardware includes but is not limited to microprocessors, application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field-programmable gate arrays (Field-Programmable Gate Array, FPGA), digital processors (Digital Signal Processor, DSP), embedded devices, etc.

[0144] Computer devices can be computing devices such as desktop computers, notebooks, PDAs, and cloud servers. Computer devices can interact with users through keyboards, mice, remote controls, touch pads, or voice control devices.

[0145] The memory 510 includes at least one type of readable storage medium, and the readable storage medium includes a non-volatile memory or a volatile memory, such as a flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD or DX memory, etc.), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, etc., and the RAM may include a static RAM or a dynamic RAM. In some embodiments, the memory 510 may be an internal storage unit of a computer device, such as a hard disk or a memory of the computer device. In other embodiments, the memory 510 may also be an external storage device of a computer device, such as a plug-in hard disk, a smart memory card (SMC), a secure digital (SD) card, or a flash card (Flash Card), etc., equipped on the computer device. Of course, the memory 510 may also include both an internal storage unit of the computer device and an external storage device thereof. In this embodiment, the memory 510 is generally used to store an operating system and various application software installed on the computer device, such as the program code of the above method, etc. In addition, the memory 510 may also be used to temporarily store various data that have been output or are to be output.

[0146] The processor 520 is generally used to perform the overall operation of the computer device. In this embodiment, the memory 510 is used to store program codes or instructions, the program code includes computer operation instructions, and the processor 520 is used to execute the program codes or instructions stored in the memory 510 or process data, such as running the program code of the above method.

[0147] In this article, the bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus system can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0148] Another embodiment of the present application also provides a computer-readable medium, which may be a computer-readable signal medium or a computer-readable medium. A processor in a computer reads a computer-readable program code stored in the computer-readable medium, so that the processor can execute the functional actions specified in each step or a combination of steps in the above method; and generate a device for implementing the functional actions specified in each block or a combination of blocks in the block diagram.

[0149] Computer-readable media include but are not limited to electronic, magnetic, optical, electromagnetic, infrared memory or semiconductor systems, devices or apparatuses, or any appropriate combination of the foregoing, the memory is used to store program codes or instructions, the program codes include computer operating instructions, and the processor is used to execute the program codes or instructions of the above methods stored in the memory.

[0150] For the definitions of memory and processor, please refer to the description of the aforementioned computer device embodiment and will not be repeated here.

[0151] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic, for example, the division of modules or units is only a logical function division, and there may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0152] Each functional unit or module in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0153] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc., and other media that can store program codes.

[0154] Unless the context clearly indicates otherwise, the singular form of the words used herein and in the appended claims includes the plural and vice versa. Thus, when referring to the singular, the plural form of the corresponding term is generally included. Similarly, the words "comprise" and "include" are to be interpreted as inclusive rather than exclusive. Likewise, the terms "include" and "or" should be interpreted as inclusive unless such interpretation is expressly prohibited herein. Where the term "example" is used herein, particularly when it is located after a group of terms, the "example" is merely exemplary and illustrative and should not be considered exclusive or comprehensive.

[0155] Further aspects and scopes of adaptability become apparent from the description provided herein. It should be understood that various aspects of the present application can be implemented individually or in combination with one or more other aspects. It should also be understood that the description and specific embodiments herein are intended for purposes of illustration only and are not intended to limit the scope of the present application.

[0156] Several embodiments of the present disclosure are described in detail above, but it is obvious that those skilled in the art can make various modifications and variations to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. The protection scope of the present disclosure is defined by the attached claims.

Claims

1. A method for determining exposure parameters of a CT scanning system, applied to a CT scanning system, characterized in that: include: Determine spatial contour data of the target object; Acquire the mass and the center of mass of the target object, and determine the mass distribution function of each scanning area included in the target object and the center of mass distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the center of mass; Determining theoretical attenuation thicknesses of each scanning area included in the target object at different scanning angles according to the spatial profile data; Determining the attenuation distribution function of each scanning area included in the target object according to the positioning projection data corresponding to the positioning scanning image of the target object; The exposure parameters of the CT scanning system in each scanning area are determined according to the mass distribution function, the centroid distribution function, the theoretical attenuation thickness and the attenuation distribution function.

2. The method according to claim 1, characterized in that The step of determining the spatial contour data of the target object comprises: Acquire a depth image and an RGB two-dimensional plane image of the target object, wherein the depth image includes depth information corresponding to pixel points included in the outer contour of the target object, and the RGB two-dimensional plane image includes the target object and background information; The spatial contour data of the target object is determined according to the depth image of the target object and the RGB two-dimensional plane image.

3. The method according to claim 1, characterized in that Determining the mass distribution function of each scanning area included in the target object and the centroid distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the centroid includes: Determining the volume of each scanning area included in the target object according to the spatial contour data; Determining a mass distribution function of each scanning area included in the target object according to the mass of the target object and the volume of each scanning area included in the target object; The centroid distribution function of each scanning area included in the target object is determined according to the centroid of the target object, the volume of each scanning area included in the target object, and the mass distribution function of each scanning area included in the target object.

4. The method according to claim 1, characterized in that: The CT scanning system comprises a first sensor, a second sensor, a third sensor and a fourth sensor, wherein the first sensor, the second sensor, the third sensor and the fourth sensor are respectively arranged at symmetrical fulcrum positions of the scanning bed; The obtaining of the mass and the center of mass of the target object comprises: Acquire initial measurement information of the first sensor, the second sensor, the third sensor, and the fourth sensor, target measurement information, the center of mass of the scanning bed, first distance information of the center of mass of the scanning bed relative to the first line segment, length information of the first line segment, second distance information of the center of mass of the scanning bed relative to the second line segment, third distance information between the center of mass of the scanning bed and a plane formed by the first sensor, the second sensor, the third sensor, and the fourth sensor, length information of the second line segment, and height information of the third line segment when the scanning bed is tilted to a target angle, wherein the first line segment is a line between the second sensor and the fourth sensor, the second line segment is a line between the third sensor and the fourth sensor, and the third line segment is a line between the first sensor and the third sensor; Determining the quality of the target object according to the target measurement information and the initial measurement information; The center of mass of the target object is determined according to the center of mass of the scanning bed, the initial measurement information, the mass of the target object, first distance information of the center of mass of the scanning bed relative to a first line segment, length information of the first line segment, second distance information of the center of mass of the scanning bed relative to a second line segment, length information of the second line segment, and height information of the third line segment when the scanning bed is tilted to a target angle.

5. The method according to claim 4, characterized in that The distance of the target object's center of mass relative to the X axis satisfy: The distance of the target object's center of mass relative to the Z axis satisfy: The distance of the target object's center of mass relative to the Y axis satisfy: in, is the mass of the target object, is the initial measurement information, is the first distance information of the centroid of the scanning bed relative to the first line segment, is the second distance information of the center of mass of the scanning bed relative to the second line segment, is the third distance information between the center of mass of the scanning bed and the plane formed by the first sensor, the second sensor, the third sensor and the fourth sensor, is the length information of the first line segment, is the length information of the second line segment, is the height information of the third line segment when the scanning bed is tilted to the target angle, is the measurement value of the first sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the second sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the third sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the fourth sensor when the target object lies on the scanning bed in the horizontal position of the scanning bed, is the measurement value of the first sensor when the target object lies on the scanning bed when the scanning bed is tilted to the target angle, is the measurement value of the third sensor when the target object lies on the scanning bed when the scanning bed is tilted to the target angle, The target angle for tilting the scanning bed.

6. The method according to claim 1, characterized in that Determining the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial profile data includes: Determine, according to the spatial contour data, coordinate information of pixel points included in the outer contour of the target object; According to the coordinate information of any two pixel points included in the outer contour of the target object, determine the path information of the X-ray passing through the any two pixel points and the angle information between the X-ray and the long axis of the cross section of the scanning area; The theoretical attenuation thickness of each scanning area included in the target object at different scanning angles is determined according to the path information of the X-ray passing through any two pixel points and the angle information between the X-ray and the long axis of the scanning area cross section.

7. The method according to claim 1, characterized in that Determining the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function includes: Determining the actual attenuation thickness of each scanning area included in the target object according to the mass distribution function, the center of mass distribution function and the theoretical attenuation thickness; The exposure parameters of the CT scanning system in each scanning area are determined according to the actual attenuation thickness and the attenuation distribution function, wherein the exposure parameters include exposure time, tube voltage and tube current.

8. A device for determining exposure parameters of a CT scanning system, applied to a CT scanning system, characterized in that: include: A spatial contour data determination module, used to determine the spatial contour data of the target object; A mass and centroid distribution function determination module, used to obtain the mass and centroid of the target object, and determine the mass distribution function of each scanning area included in the target object and the centroid distribution function of each scanning area included in the target object according to the spatial profile data, the mass and the centroid; A theoretical attenuation thickness determination module, used to determine the theoretical attenuation thickness of each scanning area included in the target object at different scanning angles according to the spatial profile data; An attenuation distribution function determination module, used to determine the attenuation distribution function of each scanning area included in the target object according to the projection data corresponding to the positioning scanning image of the target object; The exposure parameter determination module is used to determine the exposure parameters of the CT scanning system in each scanning area according to the mass distribution function, the center of mass distribution function, the theoretical attenuation thickness and the attenuation distribution function.

9. A CT scanning system, characterized in that: The device comprises the exposure parameter determination device of the CT scanning system according to claim 8, and further comprises: a scanning bed, a scanning frame, an identification component, a sensor module and a lifting structure, wherein the sensor module comprises a first sensor, a second sensor, a third sensor and a fourth sensor, wherein the first sensor, the second sensor, the third sensor and the fourth sensor are arranged at four symmetrical fulcrum positions on a side of the scanning bed away from the identification module, and the lifting structure is used to drive the first fulcrum and the third fulcrum of the scanning bed to rise and fall; The recognition component is arranged opposite to a side of the scanning bed where the target object is placed, and the recognition range of the recognition component covers the target object.

10. The CT scanning system according to claim 9, characterized in that: It also includes a driving structure, which is used to drive the scanning bed to move to the scanning frame position.

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