CN115272503A - Scattering correction method, computer equipment and imaging system - Google Patents
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Abstract
The application discloses a scattering correction method, computer equipment and an imaging system, wherein the method comprises the following steps: acquiring a projection image to be corrected of the target object, which is formed by rays passing through a light beam blocking array and the target object, wherein the projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array; performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction shadow image, wherein the scattering correction shadow image comprises the plurality of shadow areas; and completing the plurality of shadow areas in the input scattering correction shadow image by using a shadow completion model obtained by pre-training, and outputting a scattering correction image of the target object.
Description
Technical Field
The application relates to the technical field of imaging, in particular to a scattering correction method, computer equipment and an imaging system.
Background
Rays of Cone Beam CT (CBCT) scatter after passing through a target object (such as a phantom or a human body), and the quality of a reconstructed image is affected by the scattering of the rays, such as a decrease in image contrast, an inaccurate CT value, and the like.
In order to overcome the above problem, a Beam Stop Array (BSA) is disposed between an imaging source and a target object, a main ray (i.e., a primary emission line) emitted from the imaging source is blocked by a plurality of Beam stops (e.g., an n × n lead spot Array) in the BSA, and accordingly, signals of shadow areas corresponding to the Beam stops in a projection image are formed by scattering. Due to the low-frequency characteristic of scattering, the integral scattering distribution can be estimated by comparing a small number of scattering signal sampling points, so that scattering correction is performed.
Due to the blocking of the beam blocking part, the shadow area cannot receive the chief ray, and the chief ray of the shadow area in the projection image after the scattering correction needs to be supplemented in an interpolation mode, however, the chief ray is not slowly changed (namely, the change is slow), and the chief ray interpolation can affect the image quality.
Disclosure of Invention
The embodiment of the application provides a scattering correction method, computer equipment and an imaging system, which can be used for complementing a shadow area in a projection image after scattering correction by using a shadow complementing model obtained by pre-training without influencing the image quality.
In one aspect, the present application provides a method of scatter correction, the method comprising: acquiring a projected image to be corrected of the target object, which is formed by rays passing through a light beam blocking array and the target object, wherein the projected image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array; performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction shadow image, wherein the scattering correction shadow image comprises the plurality of shadow areas; and completing the plurality of shadow areas in the input scattering correction shadow image by using a shadow completion model obtained by pre-training, and outputting a scattering correction image of the target object.
In another aspect, the present application further provides a computer device, including: one or more processors; a memory; and one or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor to implement the steps in the scatter correction method of any one of the first aspects.
In a third aspect, the present application further provides an imaging system comprising: an imaging source for generating radiation to image a target object; a beam stop array removably/movably disposed between the imaging source and the target object, comprising a plurality of beam stops; an imager disposed opposite the imaging source for receiving radiation through the beam stop array and/or the target object; the computer apparatus of any of the second aspects, connected to the imager.
In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, the computer program being loaded by a processor to perform the steps of the scatter correction method according to any one of the first aspect.
The method includes the steps of firstly obtaining a projection image to be corrected of a target object, wherein the projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in a light beam blocking array, then carrying out scattering correction on the projection image to be corrected according to scattering sampling data of the shadow areas in the projection image to be corrected, generating a scattering correction shadow image, and finally completing the shadow areas in the input scattering correction shadow image by utilizing a shadow completion model obtained through pre-training, so that the scattering correction image of the target object is obtained. Therefore, the complete chief ray projection can be obtained by utilizing the shadow complementing model, and the influence on the image quality due to chief ray interpolation is avoided.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural view of an imaging system provided in an embodiment of the present application;
FIG. 2 is a schematic diagram of a beam stop array in an imaging system provided in an embodiment of the present application;
FIG. 3 is a schematic flow chart diagram illustrating one embodiment of a scatter correction method provided in an embodiment of the present application;
fig. 4 is a schematic structural diagram of an embodiment of a computer device provided in an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be considered as limiting the present application. Furthermore, the terms "first", "second", "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", "third" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
In this application, the word "exemplary" is used to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the application. In the following description, details are set forth for the purpose of explanation. It will be apparent to one of ordinary skill in the art that the present application may be practiced without these specific details. In other instances, well-known structures and processes are not set forth in detail in order to avoid obscuring the description of the present application with unnecessary detail. Thus, the present application is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.
It should be noted that, since the method in the embodiment of the present application is executed in a computer device, processing objects of each computer device all exist in the form of data or information, for example, time, which is substantially time information, and it is understood that, in the subsequent embodiments, if size, number, position, and the like are mentioned, corresponding data exist so as to be processed by the computer device, and details are not described herein.
As in the background art, the quality of an image is affected after the principal ray of the shadow region in scatter correction is completed by interpolation. Therefore, the embodiment of the application provides a scattering correction method, a computer device and an imaging system, which can combine a BSA scanning method and a deep learning method for a light beam blocking array to complete scattering correction of an image, and complement a shadow region in a projection image after scattering correction through a shadow complementing model obtained through pre-training, so that missing main rays in a BSA scanning process are supplemented, and the influence of main ray interpolation on the quality of a scattering correction image is avoided, which will be described in detail below.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an imaging system provided in an embodiment of the present application, and the imaging system may include an imaging source 100, a beam stop array 200, an imager 300, and a computer device 400. Wherein:
in the embodiment of the present application, the imaging source 100 may generate rays (i.e., main rays), and the imaging source 100 may be, but is not limited to, an X-ray source, a gamma-ray source, or the like. The radiation generated by the imaging source 100 may be used to image a target object P, where the target object P may be a patient, a phantom, etc., and only needs to be an object that can be imaged under the imaging system.
When the imaging source 100 scans the target object P, the rays may be scattered on the target object P, which affects the quality of the reconstructed image. To reduce the effect of scattering on reconstructed image quality, in the present embodiment, a beam stop array 200 is disposed between the imaging source 100 and the target object P. Illustratively, the beam stop array 200 may be removably/movably secured beneath the radiation emitting ports of the imaging source 100.
The beam stop array 200 may include a plurality of beam stops, which may be a regular volume such as a cylinder, sphere, etc. Here, each beam stopper may be made of a high attenuation substance (e.g., lead or tungsten), and the regions other than the plurality of beam stoppers (i.e., the regions where the non-beam stoppers are located) may be made of a radiation transmitting substance having a low attenuation characteristic (e.g., tempered glass, carbon fiber, acryl, etc.).
It should be noted that the arrangement of each beam stop may be an array of m × n, m and n are both integers greater than 0, and m may be equal to n or may not be equal to n. Of course, the beam stop elements may be arranged arbitrarily.
In the present embodiment, the imager 300 is positioned opposite the imaging source 100 such that the imager 300 receives radiation through the beam stop array 200 and/or the target object P. Here, the imager 300 may be a detector. Here, the imaging source and the imager may be Cone Beam CT (CBCT).
Illustratively, as shown in fig. 2, in the XOZ plane, the beam stop array is composed of 9*9 (81 points in total), and when the rays emitted from the imaging source 100 are received by the imager 300 only through the beam stop array 200 (without the target object P, only with air), 81 shaded areas (shaded points) are included in the projection of the imager 300. It is understood that, after the ray emitted by the image source 100 passes through the beam stop array 200 and the target object P, the projection of the imager 300 includes the projection of the target object P in addition to 81 shadow regions (shadow points); after the rays emitted from the image source 100 pass through only the target object P (removing/removing the beam block array 200), the projection of the target object P is included in the projection of the imager 300, and 81 shadow regions (shadow points) are not included.
In an embodiment of the application, a computer device 400 is connected to the imager 300 for performing the scatter correction method in the embodiments described below to generate a scatter-corrected image of the target object P.
In this embodiment, the computer device 400 may be an independent server, or may be a server network or a server cluster composed of servers, for example, the computer device described in this embodiment includes, but is not limited to, a computer, a network host, a single network server, a plurality of network server sets, or a cloud server composed of a plurality of servers. Among them, the Cloud server is constituted by a large number of computers or web servers based on Cloud Computing (Cloud Computing).
In the embodiment of the present application, the computer device 400 may be a general-purpose computer device or a special-purpose computer device. In a specific implementation, the computer device may be a desktop computer, a portable computer, a network server, a Personal Digital Assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, a communication device, an embedded device, and the like, and the embodiment does not limit the type of the computer device.
In the embodiment of the present application, the computer device 400 and the imager 300 may implement communication through any communication manner, including but not limited to mobile communication based on 2G, 3G, 4G, 5G, long Term Evolution (LTE), worldwide Interoperability for Microwave Access (WiMAX), or computer network communication based on TCP/IP Protocol Suite (TCP/IP), user Datagram Protocol (UDP), and the like.
It will be appreciated by those skilled in the art that the imaging system may also include one or more other computer devices that may process data, and is not particularly limited herein.
In the embodiment of the present application, the imaging system may further include a frame 500, which may be a fixed frame or a rotating frame, and is used to support the imaging source 100 and the imager 300, and may drive the imaging source 100 and the imager 300 to rotate. Illustratively, the rotating gantry may be a ring gantry, a C-arm gantry, a drum gantry, or the like.
In the embodiment of the present application, the imaging system further includes an array plate driving device 600 mechanically connected to the beam stop array 200 for moving the position of the beam stop array 200. Here, the array plate driving device 600 may be a motor.
The array plate driving device 600 may drive the beam stop array 200 to move outside the irradiation range of the radiation, may also move the beam stop array 200 so that the center of the radiation passes through the center of the beam stop array 200, may also drive the beam stop array 200 to move diagonally along the length direction (the Z-axis direction shown in fig. 2), the width direction (the X-axis direction shown in fig. 2), and may also drive the beam stop array 200 to rotate around its central axis (the Y-axis direction shown in fig. 1) of the target object P.
In the embodiment of the present application, the imaging system may further include a patient support device 700 for supporting and positioning the target object P. Illustratively, the patient support 101 may be a three-dimensional, four-dimensional, five-dimensional, or six-dimensional treatment couch or chair, or the like.
An embodiment of the present application provides a scattering correction method, where an execution subject of the scattering correction method is a computer device, and the method includes: acquiring a projection image to be corrected of a target object formed by rays passing through a light beam blocking array and the target object, wherein the projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array; performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction shadow image, wherein the scattering correction shadow image comprises a plurality of shadow areas; and utilizing a shadow complementing model obtained by pre-training to complement a plurality of shadow regions in the input scattering correction shadow image, and outputting the scattering correction image of the target object.
Fig. 3 is a schematic flowchart of an embodiment of a scattering correction method provided in an embodiment of the present application, and as shown in fig. 3, the scattering correction method includes the following steps S301 to S303, specifically as follows:
s301, acquiring a projection image to be corrected of the target object formed by rays passing through the beam blocking array and the target object.
In the actual scanning process, the beam blocking array is located in the irradiation range of the rays of the imaging source, the rays emitted by the imaging source penetrate through the beam blocking array and the target object to form projection on the imager, and the computer equipment can acquire a projection image to be corrected of the target object formed by the rays passing through the beam blocking array and the target object. Here, the projection image to be corrected includes a plurality of shadow areas corresponding to the plurality of beam stoppers in the beam stopper array.
S302, performing scattering correction on the projection image to be corrected according to the scattering sampling data of the shadow areas in the projection image to be corrected, and generating a scattering correction shadow image.
After the projection image to be corrected is obtained, the computer device can perform scattering correction on the projection image to be corrected according to the scattering sampling data of the shadow areas in the projection image to be corrected, so as to generate a scattering correction shadow image.
For example, the computer device may generate a corresponding scatter distribution image by using central signals of a plurality of shadow areas in the projection image to be corrected as scatter sampling data, and subtract the scatter corresponding to the scatter distribution image from the projection image to be corrected, thereby generating a scatter-corrected shadow image.
It should be noted that, since this step only performs scatter correction on the projection image to be corrected, and does not eliminate or complement the shadow region in the projection image to be corrected, the scatter-corrected shadow image after scatter correction still includes a plurality of shadow regions.
And S303, completing a plurality of shadow areas in the input scattering correction shadow image by using a shadow completion model obtained by pre-training, and outputting a scattering correction image of the target object.
The shadow complementing model is obtained by pre-training, and the input of the shadow complementing model is a scattering correction shadow image comprising a plurality of shadow areas, and the output of the shadow complementing model is a scattering correction image of the complemented shadow areas. The shadow completion model can be stored in the computer device or on a cloud server in communication connection with the computer device.
After generating the scatter-corrected shadow image including the plurality of shadow regions, the computer device may complement the plurality of shadow regions in the input scatter-corrected shadow image using a pre-trained shadow complementing model, and output a scatter-corrected image of the target object having the plurality of shadow regions complemented.
According to the embodiment of the application, on the premise that the light beam blocking array is arranged, computer equipment firstly obtains a projected image to be corrected of a target object, the projected image to be corrected comprises a plurality of shadow areas corresponding to the light beam blocking elements in the light beam blocking array, then, scattering correction is carried out on the projected image to be corrected according to scattering sampling data of the shadow areas in the projected image to be corrected, a scattering correction shadow image is generated, finally, a plurality of shadow areas in the input scattering correction shadow image are completed through a shadow completion model obtained through pre-training, and therefore the scattering correction image of the target object is obtained. Therefore, the complete chief ray projection can be obtained by utilizing the shadow complementing model, and the influence on the image quality due to chief ray interpolation is avoided.
The embodiment of the present application further provides another scattering correction method, which is applied to a computer device, and the method may include:
s401, acquiring a first scattering correction sample image and a second scattering correction sample image of different objects after scattering correction.
A computer device acquires a first scatter-corrected sample image and a second scatter-corrected sample image of different objects. Here, the first scatter correction sample image includes a plurality of shaded regions corresponding to the plurality of beam blockers in the beam blocker array, and the second scatter correction sample image does not include the plurality of shaded regions. These sample images are used to train the shadow completion model.
It should be noted that the first scatter correction sample image and the second scatter correction sample image may be a plurality of sample images that are scatter-corrected for different portions, different sizes, different placement positions, and the like of different objects. Different objects can be patients, phantoms, etc. only the object capable of being imaged under the imaging system is needed.
S402, inputting the first scattering correction sample image and the second scattering correction sample image into a neural network for training to obtain a shadow completion model.
It should be noted that, in this embodiment, the shadow completion model may adopt any Neural Network in deep learning, such as a Convolutional Neural Network (CNN), a Recurrent Neural Network (RNN), a countermeasure generated Network (GAN), and any training mode, such as a supervised training mode and an unsupervised training mode, which is not described herein in detail.
Through the steps S401 to S402, the training of the shadow completion model can be realized.
The shadow complementing model can be trained to different models according to different types of input sample images. Step S401 will be described in detail below for different cases.
In the first case: the type of the sample image is a first type, and correspondingly, the shadow completion model is a first shadow completion model.
In the first case, step S401 may specifically include the following steps:
s4011a, acquiring a first projection image of different objects formed by rays passing through the light beam blocking array and the different objects, wherein the first projection image comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array.
S4012a, generating a scattering distribution image according to the scattering sampling data of the plurality of shadow areas in the first projection image.
S4013a, performing scattering correction on the first projection image according to the scattering distribution image to generate first scattering correction sample images of different objects. The first scatter correction sample image also includes the plurality of shadow regions therein, and the type of the first scatter correction sample image is a first type.
S4014a, acquiring a second projection image of the different object formed by the ray passing through the different object and not passing through the beam blocking array.
And S4015a, performing scattering correction on the second projection image according to the scattering distribution image to generate a second scattering correction sample image of different objects. The second scatter correction sample image does not include a plurality of shaded regions therein, and the second scatter correction sample image is also of the first type.
In this way, the sample images obtained through steps S4011a to S4015a may be trained based on a neural network, and a mapping between a first scatter correction sample image of the first type and a second scatter correction sample image of the first type may be established. Illustratively, the first scatter-corrected sample image is IbsaThe second scatter-corrected sample image is IidealTraining based on GAN, building IbsaTo IidealTo be mapped between.
In the second case: the type of the sample image is a second type, and correspondingly, the shadow complementing model is a second shadow complementing model.
In the second case, step S401 may specifically include the following steps:
and S4011b, acquiring an air image formed by rays passing through the beam blocking array and air. Here, no object needs to be provided on the patient support.
S4012b, a first projection image of different objects formed by rays passing through the light beam blocking array and the different objects is obtained, wherein the first projection image comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array.
S4013b, generating a scattering distribution image according to the scattering sampling data of the plurality of shadow areas in the first projection image.
And S4014b, performing scattering correction on the first projection image according to the scattering distribution image to generate a first corrected projection image.
S4015b, calculating a line integral value of the air image and the first correction projection image to obtain first scattering correction sample images of different objects. The first scatter correction sample image also includes the plurality of shadow regions therein, and the type of the first scatter correction sample image is a second type. Illustratively, the aerial image is I0The first corrected projection image is IbsaAnd performing log transformation on the first correction projection image by using the air image to obtain an object attenuation line integral image under the condition of setting BSA (bovine serum albumin), namely a first scattering correction sample image pbsaHere, pbsa＝ln(I0/Ibsa)。
Since the first scatter-corrected sample image indicates line-integrated values (i.e., projection values of rays passing through the target object, also referred to as ray projections), the tissue structure inside the target object can be determined from the line-integrated values in various directions during image reconstruction, and the first scatter-corrected sample image in the second case is a different type of image from the first scatter-corrected sample image in the first case, which is generated through different steps.
S4016b, a second projection image of the different object formed by the ray passing through the different object and not passing through the beam stop array is obtained.
S4017b performs a scatter correction on the second projection image based on the scatter distribution image, and generates a second corrected projection image.
S4018b, calculating a line integral value of the air image and the second correction projection image to obtain a second scattering correction sample image of different objects. The second scatter correction sample image does not include a plurality of shaded regions and the type of the second scatter correction sample image is also a second type. Illustratively, the aerial image is I0The second corrected projection image is IidealAnd log-transforming the second corrected projection image with an air image to obtain an object attenuation line integral image without BSA (i.e. in an ideal state), i.e. a second scatter-corrected sample image pidealHere, pideal＝ln(I0/Iideal)。
Thus, the neural network-based intercommunication can be realizedThe sample images obtained in the steps S4011b to S4018b are trained, and a mapping between the first scatter correction sample image of the second type and the second scatter correction sample image of the second type is established. Exemplary training based on GAN, establishes pbsaTo pidealTo be mapped between.
The output result of the shadow completion model obtained by training the sample images obtained from the steps S4011b to S4018b can be directly used for image reconstruction, so that the efficiency of image reconstruction can be improved.
In the third case: the sample image is derived from a scanned image of a real target object.
In a third case, step S401 may specifically include the following steps:
s4011c, obtaining scanned images of different objects.
The scan image may be a projection image obtained by direct projection of cone beam CT, a CBCT image obtained by reconstruction of projection images of cone beam CT at different angles, a CT image obtained by a CT apparatus, an MR image obtained by an MR apparatus, a PET image obtained by a PET apparatus, or a fusion image of at least two of these images, and the like, and is not limited herein.
Since the scanned image is already scatter-corrected, no further scatter correction of the scanned image is required.
And S4012c, generating projection images of different objects at different angles according to the scanning images and using the projection images as second scatter correction sample images.
If the scanned image is a three-dimensional image, projection images of different objects at different angles, such as digital projection images, can be simulated according to the scanned image; and if the scanned image is a two-dimensional image, directly taking the scanned images of different objects at different angles as a second scatter correction sample image.
S4013c, according to a preset geometric relationship, simulating a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array in the second scattering correction sample image to obtain a first scattering correction sample image.
Here, the predetermined geometric relationship includes a geometric relationship between a plurality of beam-stops in the beam-stop array and the second scatter-corrected sample image.
In a third case, the sample image is derived from a scanned image of a real target object, and the sample image is generated more conveniently and quickly.
The shadow complementing model can be trained into different models according to requirements, and can be one model or comprise a plurality of different models. The following explanation will be made for different cases.
In the first case: the shadow complementing model is a first shadow complementing model, and the types of the input image (scatter-corrected shadow image) and the output image (scatter-corrected image) are both of a first type.
S403A, acquiring a projected image to be corrected of the target object formed by rays passing through the light beam blocking array and the target object, wherein the projected image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array.
S404A, performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a first type of scattering correction shadow image, wherein the scattering correction shadow image comprises a plurality of shadow areas.
S405A, a plurality of shadow areas in the input first type of scattering correction shadow image are supplemented by a first shadow supplementation model obtained through pre-training, and a scattering correction image of the target object is output, wherein the type of the scattering correction image is the first type.
Through steps S403A to S405A, a scatter-corrected image of the target object can be obtained.
When reconstructing the scattering correction image of the target object, it is also necessary to acquire an air image, which is an image formed by rays passing through the beam blocking array and air, and then calculate line integral values for the air image and the scattering correction image of the target object, and generate a reconstructed image of the target object using the line integral values at different angles.
In the second case: the shadow complementing model is a second shadow complementing model, and the types of the input image (the scatter-corrected shadow image) and the output image (the scatter-corrected image) are both of a second type.
And S403B, acquiring a projection image to be corrected of the target object formed by rays passing through the light beam blocking array and the target object, wherein the projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array.
S404B, acquiring an air image formed by rays passing through the beam blocking array and air.
S405B, performing scattering correction on the projection image to be corrected according to the scattering sampling data of the shadow areas in the projection image to be corrected, and generating a scattering correction projection image, wherein the scattering correction projection image comprises the shadow areas.
S406B, a line integral value is calculated according to the air image and the scattering correction projection image, and a second type scattering correction shadow image is generated.
And S407B, complementing the plurality of shadow regions in the input second type of scattering correction shadow image by using a second shadow complementing model obtained by pre-training, and outputting a scattering correction image of the target object. The type of the scatter-corrected image is of a second type.
Through steps S403B to S407B, a scatter-corrected image of the target object can be obtained. The scatter-corrected image of the target object may be used directly for image reconstruction, increasing the rate at which images are reconstructed compared to the first case.
In the third case: the shadow complementing model comprises a first shadow complementing model and a second shadow complementing model, wherein the types of an input image (a scattering correction shadow image) and an output image (a scattering correction image) of the first shadow complementing model are both of a first type, and the types of an input image (a scattering correction shadow image) and an output image (a scattering correction image) of the second shadow complementing model are both of a second type. Here, the explanation is subdivided into two cases.
Case 1:
S403C1, obtaining a user instruction for selecting a target shadow complementing model, wherein the target shadow complementing model is a first shadow complementing model or a second shadow complementing model.
S4041C1, if it is determined that the target shadow complementing model is the first shadow complementing model, the steps of the first case, that is, steps S403A to S405A, are executed.
S4042C1, if the target shadow complementing model is determined to be the second shadow complementing model, the steps of the second case, that is, step S403B to step S407B, are executed.
Through steps S403C1 to S404C1, a corresponding shadow completion model may be selected according to a user requirement to obtain a corresponding scatter correction image of the target object, and this manner may satisfy requirements of different users.
Case 2:
S403C2, acquiring a projection image to be corrected of the target object formed by the ray passing through the beam blocking array and the target object. The projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array.
S404C2, performing scattering correction on the projection image to be corrected according to the scattering sampling data of the shadow areas in the projection image to be corrected, and generating a scattering correction shadow image. The scatter-corrected shadow image includes a plurality of shadow regions
S4051C2, when the type of the scattering correction shadow image is determined to be the first type, a plurality of shadow areas in the input scattering correction shadow image are supplemented by using a first shadow supplement model obtained through pre-training, and the scattering correction image of the target object is output.
S4052C2, when the type of the scattering correction shadow image is determined to be the second type, a second shadow completion model obtained through pre-training is utilized to complete a plurality of shadow areas in the input scattering correction shadow image, and the scattering correction image of the target object is output.
Through steps S403C2 to S405C2, the corresponding shadow complementing model can be automatically selected according to the type of the scatter-corrected shadow image to complement the shadow region, and this way can adapt to different application scenarios.
An embodiment of the present application further provides a computer device, where the computer device includes: one or more processors; a memory; and one or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor for performing the steps of the scatter correction method in any of the above-described scatter correction method embodiments.
An embodiment of the present application further provides a computer device, as shown in fig. 4, which shows a schematic structural diagram of the computer device according to the embodiment of the present application, specifically:
the computer apparatus may include components such as a processor 401 of one or more processing cores, memory 402 of one or more computer-readable storage media, a power supply 403, and an input device 404. Those skilled in the art will appreciate that the computer device configuration illustrated in FIG. 4 does not constitute a limitation of computer devices, and may include more or fewer components than those illustrated, or some components may be combined, or a different arrangement of components. Wherein:
the processor 401 is a control center of the computer device, connects various parts of the entire computer device using various interfaces and lines, and performs various functions of the computer device and processes data by running or executing software programs and/or modules stored in the memory 402 and calling data stored in the memory 402, thereby monitoring the computer device as a whole.
Optionally, processor 401 may include one or more processing cores; preferably, the processor 401 may integrate an application processor, which mainly handles operating systems, user interfaces, application programs, etc., and a modem processor, which mainly handles wireless communications. It will be appreciated that the modem processor described above may not be integrated into the processor 401.
The memory 402 may be used to store software programs and modules, and the processor 401 executes various functional applications and data processing by operating the software programs and modules stored in the memory 402. The memory 402 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application program required by at least one function (such as a sound playing function, an image playing function, etc.), and the like; the storage data area may store data created according to use of the computer device, and the like. Further, the memory 402 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other volatile solid state storage device. Accordingly, the memory 402 may also include a memory controller to provide the processor 401 access to the memory 402.
The computer device further comprises a power supply 403 for supplying power to the respective components, and optionally, the power supply 403 may be logically connected to the processor 401 through a power management system, so that functions of managing charging, discharging, power consumption, and the like are implemented through the power management system. The power supply 403 may also include any component of one or more dc or ac power sources, recharging systems, power failure detection circuitry, power converters or inverters, power status indicators, and the like.
The computer device may also include an input device 404. The input device 405 may be used to receive entered numeric or character information, and to generate keyboard, mouse, joystick, optical or trackball signal inputs related to user settings and function control.
Although not shown, the computer device may further include a display device 405 and the like, and the display device 405 may be a display, which is not described in detail herein. Specifically, in this embodiment of the present application, the processor 401 in the computer device loads the executable file corresponding to the process of one or more application programs into the memory 402 according to the following instructions, and the processor 401 runs the application programs stored in the memory 402, thereby implementing various functions as follows:
acquiring a projection image to be corrected of the target object, which is formed by rays passing through a light beam blocking array and the target object, wherein the projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array; performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction shadow image, wherein the scattering correction shadow image comprises the plurality of shadow areas; and completing the plurality of shadow areas in the input scattering correction shadow image by using a shadow completion model obtained by pre-training, and outputting a scattering correction image of the target object.
It will be understood by those skilled in the art that all or part of the steps of the methods of the above embodiments may be performed by instructions or by associated hardware controlled by the instructions, which may be stored in a computer readable storage medium and loaded and executed by a processor.
To this end, an embodiment of the present application provides a computer-readable storage medium, which may include: read Only Memory (ROM), random Access Memory (RAM), magnetic or optical disks, and the like. Stored thereon, a computer program is loaded by a processor to perform the steps of any of the scatter correction methods provided by the embodiments of the present application. For example, the computer program may be loaded by a processor to perform the steps of:
acquiring a projected image to be corrected of the target object, which is formed by rays passing through a light beam blocking array and the target object, wherein the projected image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array; performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction shadow image, wherein the scattering correction shadow image comprises the plurality of shadow areas; and completing the plurality of shadow areas in the input scattering correction shadow image by using a shadow completion model obtained by pre-training, and outputting a scattering correction image of the target object.
In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and parts that are not described in detail in a certain embodiment may refer to the above detailed descriptions of other embodiments, and are not described herein again.
In specific implementation, the above structures may be implemented as independent entities, or may be combined arbitrarily, and implemented as the same or several entities, and specific implementations of the above structures may refer to the foregoing method embodiments, which are not described herein again.
The above operations can be implemented in the foregoing embodiments, and are not described in detail herein.
The foregoing describes in detail a method, an apparatus, a computer device, a system, and a storage medium for scatter correction provided in an embodiment of the present application, and a specific example is applied in the present application to explain the principle and the implementation of the present application, and the description of the foregoing embodiment is only used to help understand the method and the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
Claims (10)
1. A method of scatter correction, the method comprising:
acquiring a projection image to be corrected of the target object, which is formed by rays passing through a light beam blocking array and the target object, wherein the projection image to be corrected comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array;
performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction shadow image, wherein the scattering correction shadow image comprises the plurality of shadow areas;
and completing the plurality of shadow areas in the input scattering correction shadow image by using a shadow completion model obtained by pre-training, and outputting a scattering correction image of the target object.
2. The scatter correction method of claim 1, wherein said shadow completion model comprises: a first shadow completion model and/or a second shadow completion model;
under the condition that the shadow complementing model is a first shadow complementing model, the types of the scattering correction shadow image and the scattering correction image are both the first type;
under the condition that the shadow complementing model is a second shadow complementing model, the types of the scattering correction shadow image and the scattering correction image are both the second type;
in a case where the shadow completion model includes a first shadow completion model and a second shadow completion model, the method further includes:
acquiring a user instruction for selecting a target shadow completion model, wherein the target shadow completion model is a first shadow completion model or a second shadow completion model;
determining that the types of the scattering correction shadow image and the scattering correction image are both the first type under the condition that the target shadow complementing model is a first shadow complementing model;
and under the condition that the target shadow complementing model is determined to be a second shadow complementing model, the types of the scattering correction shadow image and the scattering correction image are both the second type.
3. The scatter correction method according to claim 2, wherein in a case where the shadow complementing model is a first shadow complementing model, the generating a scatter-corrected shadow image by performing scatter correction on the projection image to be corrected according to scatter sampling data of a plurality of shadow areas in the projection image to be corrected comprises:
and performing scattering correction on the projection image to be corrected according to the scattering sampling data of the shadow areas in the projection image to be corrected to generate a first type of scattering correction shadow image.
4. The scatter correction method of claim 2, wherein in the case where the shadow completion model is a second shadow completion model, the method further comprises:
acquiring an air image formed by rays passing through the light beam blocking array and air;
correspondingly, the performing scatter correction on the projection image to be corrected according to the scatter sampling data of the shadow areas in the projection image to be corrected to generate a scatter-corrected shadow image includes:
performing scattering correction on the projection image to be corrected according to scattering sampling data of a plurality of shadow areas in the projection image to be corrected to generate a scattering correction projection image, wherein the scattering correction projection image comprises the plurality of shadow areas;
and calculating a line integral value according to the air image and the scattering correction projection image to generate a second type of scattering correction shadow image.
5. The scatter correction method of claim 2, wherein before the acquiring a projection image of the target object to be corrected formed by the ray passing through the beam blocking array and the target object, the method further comprises:
acquiring a first scatter correction sample image and a second scatter correction sample image of different objects after scatter correction, wherein the first scatter correction sample image comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array, and the second scatter correction sample image does not comprise the plurality of shadow areas;
and inputting the first scattering correction sample image and the second scattering correction sample image into a neural network for training to obtain the shadow completion model.
6. The scatter correction method of claim 5, wherein said obtaining a first scatter-corrected sample image and a second scatter-corrected sample image of different objects in a case where the shadow-complementing model is a first shadow-complementing model comprises:
acquiring a first projection image of the different object formed by rays passing through the light beam blocking array and the different object, wherein the first projection image comprises a plurality of shadow areas corresponding to a plurality of light beam blocking parts in the light beam blocking array;
generating a scattering distribution image according to the scattering sampling data of a plurality of shadow areas in the first projection image;
performing scatter correction on the first projection image according to the scatter distribution image to generate a first scatter correction sample image of the different object, wherein the type of the first scatter correction sample image is the first type;
acquiring a second projection image of the different object formed by rays passing through the different object and not passing through the beam blocking array;
and performing scatter correction on the second projection image according to the scatter distribution image to generate a second scatter correction sample image of the different object, wherein the type of the second scatter correction sample image is the first type.
7. The scatter correction method of claim 6, wherein in the case where the shadow completion model is a second shadow completion model, the method further comprises:
acquiring an air image formed by rays passing through the light beam blocking array and air;
the scatter correcting the first projection image from the scatter distribution image to generate a first scatter corrected sample image of the different object, comprising:
performing scattering correction on the first projection image according to the scattering distribution image to generate a first corrected projection image;
obtaining a line integral value of the aerial image and the first corrected projection image to obtain a first scatter correction sample image of the different objects, wherein the type of the first scatter correction sample image is the second type;
correspondingly, the performing scatter correction on the second projection image according to the scatter distribution image to generate a second scatter-corrected sample image of the different object includes:
performing scattering correction on the second projection image according to the scattering distribution image to generate a second corrected projection image;
and calculating a line integral value of the aerial image and the second correction projection image to obtain a second scattering correction sample image of the different object, wherein the type of the second scattering correction sample image is the second type.
8. The scatter correction method of claim 5, wherein said obtaining a first scatter-corrected sample image and a second scatter-corrected sample image of different objects comprises:
acquiring scanning images of different objects;
generating projection images of the different objects at different angles according to the scanning image and using the projection images as the second scattering correction sample image;
and simulating the plurality of shadow areas corresponding to the plurality of light beam blocking parts in the light beam blocking array in the second scattering correction sample image according to a preset geometric relation to obtain the first scattering correction sample image.
9. A computer device, characterized in that the computer device comprises:
one or more processors;
a memory; and
one or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the processor to implement the steps in the scatter correction method of any of claims 1-8.
10. An imaging system, characterized in that the imaging system comprises:
an imaging source for generating radiation to image a target object;
a beam stop array removably/movably disposed between the imaging source and the target object, comprising a plurality of beam stops;
an imager disposed opposite the imaging source for receiving radiation through the beam stop array and/or the target object;
the computer device of claim 9, connected with the imager.
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