A hardening correction method, system and storage medium

Abstract

The present invention provides a hardening correction method, system, and storage medium. The method includes: determining initial hardening correction parameters; determining a first image based on a first phantom; and automatically updating the initial hardening correction parameters based on the initial hardening correction parameters and the first image.

Description

Technical Field

[0001] This specification relates to the field of imaging, and in particular to a hardening correction method, system, and storage medium. Background Art

[0002] With the continuous advancement of science and technology, X-ray imaging has been widely used. Taking electronic computed tomography (CT) technology as an example, CT imaging equipment is usually hardened and calibrated before leaving the factory to reduce hardening artifacts during the imaging process. However, as the use time increases and the state of the internal structure of the equipment changes, the imaging equipment may experience slight miscalibration that is difficult for doctors to judge. In addition, if the imaging equipment is frequently re-hardened and calibrated, it will take up a lot of equipment usage time and increase equipment maintenance costs. Therefore, it is necessary to provide a hardening correction solution to achieve adaptive hardening correction. Summary of the Invention

[0003] One or more embodiments of the present disclosure provide a hardening correction method, comprising: determining initial hardening correction parameters; determining a first image based on a first phantom; and automatically updating the initial hardening correction parameters based on the initial hardening correction parameters and the first image.

[0004] One or more embodiments of the present disclosure provide a hardening correction method. The method includes: acquiring a second image based on a second phantom, wherein the imaging range of the second phantom covers the range of a detector; simulating an imaging process based on the second image; determining a first attenuation parameter corresponding to a multi-energy radiation beam and a second attenuation parameter corresponding to a mono-energetic radiation beam based on the simulated imaging process; and determining initial hardening correction parameters based on the first attenuation parameter and the second attenuation parameter.

[0005] One or more embodiments of the present disclosure provide a hardening correction method, which includes removing interference of scattered rays on a first image and / or a second image.

[0006] One or more embodiments of the present disclosure provide a hardening correction method, which includes: determining an artifact level of a first image; and automatically updating an initial hardening correction parameter based on the artifact level.

[0007] One or more embodiments of the present disclosure provide a hardening correction method, which includes: adjusting the energy spectrum and / or filtering parameters of a multi-energy radiation beam in response to the artifact level being greater than a first threshold and not greater than a second threshold.

[0008] One or more embodiments of the present disclosure provide a hardening correction method, which includes: in response to the artifact level being greater than a second threshold, re-determining a hardening correction parameter.

[0009] One or more embodiments of the present specification provide a hardening correction system, comprising: an initial parameter determination module for determining initial hardening correction parameters; an image determination module for determining a first image based on a first model; and a parameter update module for automatically updating the initial hardening correction parameters based on the initial hardening correction parameters and the first image.

[0010] One or more embodiments of the present disclosure provide a hardening correction device, which includes at least one storage medium storing computer instructions and at least one processor executing the computer instructions to implement a hardening correction method.

[0011] One or more embodiments of the present specification provide a computer-readable storage medium, wherein the storage medium stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes a hardening correction method.

[0012] Some embodiments of the present specification determine whether and how to update the initial hardening correction parameters based on the artifact level of the phantom image, thereby achieving automatic adaptive adjustment of the hardening correction parameters, thereby avoiding the impact of slight decorrection that is difficult to detect manually as the imaging device is used on the imaging effect, and avoiding the impact of frequent manual updates on device maintenance; the imaging parameters of the imaging device are simulated by the phantom image, and the first attenuation parameters and second attenuation parameters (corresponding to multi-energy radiation beams and mono-energy radiation beams, respectively) under filters of different sizes and / or different positions and / or phantoms of different sizes are simulated and calculated based on the simulated imaging parameters, so that the hardening correction parameters can be accurately determined; by setting the first threshold and the second threshold, the decorrection of the imaging device is specifically divided into slight decorrection and severe decorrection based on the artifact level of the first image, and different measures are taken for slight decorrection and severe decorrection, respectively, so as to improve the efficiency of adjusting the hardening correction parameters while ensuring the accuracy of the hardening correction parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0014] Figure 1 is a schematic diagram of an application scenario of a hardening correction system according to some embodiments of this specification;

[0015] Figure 2 is an exemplary module diagram of a hardening correction system according to some embodiments of this specification;

[0016] Figure 3 is an exemplary flow chart of a hardening correction method according to some embodiments of this specification;

[0017] Figure 4 is an exemplary flow chart for determining initial hardening correction parameters according to some embodiments of the present specification;

[0018] Figure 5 is an exemplary flow chart of automatically updating hardening correction parameters according to some embodiments of the present specification;

[0019] Figure 6 is a schematic diagram of collecting imaging data according to some embodiments of this specification;

[0020] Figure 7A is a schematic diagram of capturing a second image according to some embodiments of this specification;

[0021] Figure 7B is a schematic diagram of capturing a second image according to some further embodiments of this specification;

[0022] Figure 8A and Figure 8B is a schematic diagram of capturing a second image from multiple angles according to some embodiments of this specification;

[0023] Figure 9 is a schematic diagram of a first image according to some embodiments of this specification. DETAILED DESCRIPTION

[0024] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0025] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0026] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0027] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0028] Figure 1 It is a schematic diagram of an application scenario of a hardening correction system according to some embodiments of this specification.

[0029] In some embodiments, as Figure 1 As shown, the hardening correction system 100 may include an imaging device 110, a processing device 120, a terminal device 130, a network 140, and a storage device 150. The components of the hardening correction system 100 may be connected in one or more ways. For example, Figure 1 As shown, the imaging device 110 can be connected to the processing device 120 via the network 140. For another example, the imaging device 110 can be directly connected to the processing device 120 (as shown by the dashed double-headed arrow connecting the imaging device 110 and the processing device 120). As a further example, the storage device 150 can be connected to the processing device 120 directly or via the network 140. As a further example, the terminal device 130 can be connected to the processing device 120 directly (as shown by the dashed double-headed arrow connecting the terminal device 130 and the processing device 120) and / or via the network 140.

[0030] The imaging device 110 can collect imaging data of a scanned object. In some embodiments, the scanned object may include, but is not limited to, a human body, an organ, an organism, a lesion, a tumor, an object, a phantom, etc. In some embodiments, the imaging device 110 may include an X-ray imaging device. In some embodiments, the imaging device 110 may include a computed tomography (CT) device, a cone beam computed tomography (CBCT) device, a multi-slice computed tomography (MSCT) device, etc., or any combination thereof.

[0031] In some embodiments, the imaging device 110 may include a radiation source and a detector. In some embodiments, the radiation source may provide a radiation beam (e.g., X-rays). In some embodiments, the detector may receive the radiation beam that passes through the scanned object and convert it into a corresponding signal. In some embodiments, the detector may be composed of a plurality of detection elements. For example, the detector may include 320,000 (1,000 columns × 320 rows) detection elements. In some embodiments, each detection element may receive a radiation beam that passes through a position on the scanned object. In some embodiments, the detector may include, but is not limited to, a gas detector, a scintillator detector, a semiconductor detector, and the like.

[0032] In some embodiments, the imaging device 110 may further include a filter for absorbing low-energy particles in the radiation beam, which may correspondingly reduce the radiation dose received by the scanned object. In some embodiments, the filter may include inherent filter and additional filter. The inherent filter may be a non-detachable filter in the imaging device (for example, a filter inside the radiation source). In some embodiments, the inherent filter may include but is not limited to the tube wall of the X-ray tube, the insulating oil layer, the window on the X-ray tube sleeve, a non-detachable filter plate, etc. The additional filter may be a detachable filter in the imaging device. In some embodiments, the additional filter may include but is not limited to an aluminum plate, a composite plate of copper and aluminum, etc. Figure 6 is a schematic diagram of collecting imaging data according to some embodiments of this specification. Figure 6 As shown, additional filtering can be located at the outlet of the radiation source to pre-absorb low-energy particles in the radiation beam generated by the radiation source.

[0033] The processing device 120 can process data and / or information obtained from the imaging device 110, the terminal device 130, and / or the storage device 150. For example, the processing device 120 can obtain imaging data from the imaging device 110 and determine a corresponding image based on the imaging data. For another example, the processing device 120 can determine initial hardening correction parameters based on the phantom image. For another example, the processing device 120 can automatically update the initial hardening correction parameters based on the phantom image. In some embodiments, the processing device 120 can include a central processing unit (CPU), a digital signal processor (DSP), a system on a chip (SoC), a microcontroller unit (MCU), and / or any combination thereof. In some embodiments, the processing device 120 can include a computer, a user console, a single server, a server group, and / or the like. The server group can be centralized or distributed. In some embodiments, the processing device 120 can be local or remote. For example, the processing device 120 can access information and / or data stored in the imaging device 110, the terminal device 130, and / or the storage device 150 via the network 140. For another example, processing device 120 can directly connect to imaging device 110, terminal device 130, and / or storage device 150 to access stored information and / or data. In some embodiments, processing device 120 can be implemented on a cloud platform. By way of example only, a cloud platform can include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud, a multi-cloud, or any combination thereof. In some embodiments, processing device 120 or a portion of processing device 120 can be integrated into imaging device 110.

[0034] The terminal device 130 can display images to the user and / or receive user input. The terminal device 130 can include a mobile device 131, a tablet computer 132, a notebook computer 133, etc. or any combination thereof. In some embodiments, the terminal device 130 can be part of the processing device 120.

[0035] The network 140 may comprise any suitable network that facilitates the exchange of information and / or data for the hardening correction system 100. In some embodiments, one or more components of the hardening correction system 100 (e.g., the imaging device 110, the processing device 120, the terminal device 130, the storage device 150) may communicate information and / or data with one or more other components of the hardening correction system 100 via the network 140. In some embodiments, the network 140 may be and / or include a public network, a private network, a wide area network (WAN), a wired network, a wireless network, a cellular network, a frame relay network, a virtual private network, a satellite network, a telephone network, a router, a hub, a switch, or the like, or any combination thereof. In some embodiments, the network 140 may comprise one or more network access points. For example, the network 140 may comprise wired and / or wireless network access points, such as base stations and / or Internet exchange points, through which one or more components of the hardening correction system 100 may connect to the network 140 to exchange data and / or information.

[0036] The storage device 150 can store data, instructions, and / or any other information. In some embodiments, the storage device 150 can store data acquired from the imaging device 110, the terminal device 130, and / or the processing device 120. In some embodiments, the storage device 150 can include mass storage, removable storage, volatile read-write memory, read-only memory (ROM), or the like, or any combination thereof. In some embodiments, the storage device 150 can be executed on a cloud platform. In some embodiments, the storage device 150 can be connected to the network 140 to communicate with one or more other components of the hardening correction system 100 (e.g., the imaging device 110, the processing device 120, the terminal device 130). One or more components of the hardening correction system 100 can access the data or instructions stored in the storage device 150 via the network 140. In some embodiments, the storage device 150 can be directly connected to or communicate with one or more other components of the hardening correction system 100 (e.g., the imaging device 110, the processing device 120, the storage device 150, the terminal device 130). In some embodiments, the storage device 150 can be part of the processing device 120.

[0037] It should be noted that the above description is provided for illustrative purposes only and is not intended to limit the scope of this specification. For those of ordinary skill in the art, under the guidance of the contents of this specification, various changes and modifications can be made. The features, structures, methods and other features of the exemplary embodiments described in this specification can be combined in various ways to obtain additional and / or alternative exemplary embodiments. However, these changes and modifications will not deviate from the scope of this specification.

[0038] Figure 2is an exemplary module diagram of a hardening correction system according to some embodiments of this specification. Figure 2 As shown, the hardening correction system 200 may include an initial parameter determination module 210 , an image determination module 220 and a parameter update module 230 .

[0039] Initial parameter determination module 210 can be used to determine initial hardening correction parameters. In some embodiments, initial parameter determination module 210 can perform one or more of the following operations: acquiring a second image based on a second phantom; simulating an imaging process based on the second image; determining a first attenuation parameter corresponding to the multi-energy radiation beam and a second attenuation parameter corresponding to the mono-energetic radiation beam based on the simulated imaging process; and determining the initial hardening correction parameters based on the first attenuation parameter and the second attenuation parameter. A detailed description of initial parameter determination module 210 can be found in the description of step 310 and is not repeated here.

[0040] The image determination module 220 may be used to determine the first image based on the first phantom. Detailed description of the image determination module 220 may be found in the related description of step 310 and will not be repeated here.

[0041] The parameter update module 230 can be configured to automatically update the initial hardening correction parameters based on the initial hardening correction parameters and the first image. In some embodiments, the parameter update module 230 can perform one or more of the following operations: determining an artifact level of the first image; and automatically updating the initial hardening correction parameters based on the artifact level.

[0042] In some embodiments, in response to the artifact level being greater than a first threshold and not greater than a second threshold, parameter update module 230 may adjust the energy spectrum and / or filtering parameters of the multi-energy radiation beam. In some embodiments, in response to the artifact level being greater than the second threshold, parameter update module 230 may re-determine the hardening correction parameters. A detailed description of parameter update module 230 can be found in the description of step 330 and is not repeated here.

[0043] Figure 3 is an exemplary flow chart of a hardening correction method according to some embodiments of the present specification. In some embodiments, process 300 can be executed by the hardening correction system 100 (e.g., the processing device 120) or the hardening correction system 200. For example, process 300 can be stored in a storage device (e.g., the storage device 150, the storage unit of the system) in the form of a program or instruction, and when the processing device 120 or the hardening correction system 200 executes the instruction, process 300 can be implemented. The operational diagram of process 300 presented below is illustrative. In some embodiments, the process can be completed using one or more additional operations not described and / or one or more operations not discussed. In addition, Figure 3The order in which the operations of flow 300 are illustrated and described below is not intended to be limiting.

[0044] Step 310 : Determine initial hardening correction parameters. Specifically, step 310 may be performed by the initial parameter determination module 210 .

[0045] Hardening correction parameters can be data used to correct for the hardening effects of imaging devices. For example, in actual use of imaging devices, the radiation beam emitted by the radiation source (e.g., X-rays) is typically a multi-energy radiation beam with a continuous energy spectrum. Radiation beams of different energies within the energy spectrum experience different attenuations when passing through the same material. As a result, after passing through the scanned object, the low-energy radiation beam component in the energy spectrum gradually decreases, while the high-energy radiation beam component gradually increases, leading to hardening artifacts. Accordingly, hardening correction parameters can be used to mitigate or reduce potential hardening artifacts.

[0046] In some embodiments, the initial hardening correction parameters may be data initially used to correct the hardening effect of the imaging device. In some embodiments, the initial hardening correction parameters may include but are not limited to an initial hardening correction function, an initial hardening correction model, etc., or any combination thereof.

[0047] In some embodiments, the initial parameter determination module 210 may determine the initial hardening correction parameters before the imaging device leaves the factory and / or before the imaging device is used for the first time. Figure 4 The related descriptions will not be repeated here.

[0048] Step 320 : Determine a first image based on the first phantom. Specifically, step 320 may be performed by the image determination module 220 .

[0049] The first phantom may be a phantom used to update initial hardening correction parameters.

[0050] In some embodiments, the first mold body can be a mold body made of a uniform material. In some embodiments, the material of the first mold body can include but is not limited to water, organic glass, resin, etc. or any combination thereof. For example, the first mold body can be a water mold.

[0051] In some embodiments, the first mold body may be a mold body with uneven thickness. For example, the first mold body may be a wedge-shaped body. For another example, Figure 6 As shown, the first mold body can be a cylinder.

[0052] The first image may be a scanned image of the first phantom. In some embodiments, the format of the first image may include, but is not limited to, Joint Photographic Experts Group (JPEG) format, Tagged Image File Format (TIFF) format, Graphics Interchange Format (GIF) format, Kodak Flash PiX (FPX) format, Digital Imaging and Communications in Medicine (DICOM) format, etc.

[0053] In some embodiments, the image determination module 220 may determine the first image based on the imaging data of the first phantom acquired by the imaging device. Figure 6 As shown, the positions of the detector and the radiation source can remain relatively unchanged and can rotate synchronously around the rotation axis (for example, point O in the figure). Filtering can absorb low-energy particles (such as photons) in the radiation beam to reduce the radiation dose received by the scanned object. Specifically, the radiation source can generate a radiation beam; the radiation beam penetrates the filtration to remove low-energy particles; the radiation beam passes through the first phantom and the energy is attenuated; the attenuated radiation enters the detector and interacts with the working medium (such as gas, scintillating crystal, semiconductor, etc.) in the multiple detection elements in the detector, losing energy and generating ionization and / or excitation, and the detector converts the ionization or excitation effect into corresponding imaging data (or imaging signals).

[0054] In some embodiments, during the imaging data acquisition process of the first phantom, the initial hardening correction parameters can be used to mitigate or reduce the hardening effect of the imaging device. Accordingly, the first image can reflect the hardening correction effect of the initial hardening correction parameters.

[0055] In some embodiments, the image determination module 220 may reconstruct the first image based on the imaging data of the first phantom according to a reconstruction algorithm. In some embodiments, the reconstruction algorithm may include but is not limited to an analytical reconstruction algorithm, an iterative reconstruction algorithm, and the like.

[0056] In some embodiments, when determining the first image, scattering correction can also be performed to remove interference of scattered rays (for example, Compton scattered rays produced by the Compton effect between photons in X-rays and atoms in the first model, and Rayleigh scattered rays produced by the electron pair effect between photons in X-rays and atoms in the first model) on the first image.

[0057] In some embodiments, scatter correction can be performed by preventing the detector from receiving scattered radiation signals. Specifically, at least one hardware tool can be placed between the radiation source and the detector to reduce the amount of scattered radiation reaching the detector. This, in turn, reduces scatter interference in the imaging data collected by the imaging device. In some embodiments, such hardware tools may include, but are not limited to, X-ray collimators and anti-scatter grids.

[0058] In some embodiments, a scattered signal corresponding to the scattered ray can be estimated, and then a scattering distribution map can be obtained based on the scattered signal. The scattered signal in the first image can be removed using the scattering distribution map. For example, a Monte Carlo method can be used to correct for interference of the scattered ray on the first image.

[0059] Step 330 : Automatically update the initial hardening correction parameters based on the initial hardening correction parameters and the first image. Specifically, step 330 may be performed by the parameter updating module 230 .

[0060] In some embodiments, the parameter update module 230 can determine the artifact level of the first image and automatically update the initial hardening correction parameters based on the artifact level of the first image. As previously described, the first image can reflect the hardening correction effect of the initial hardening correction parameters. Accordingly, the hardening correction effect of the initial hardening correction parameters can be evaluated based on the artifact level of the first image, and then updated and / or adjusted accordingly. A detailed description of updating the initial hardening correction parameters can be found in Figure 5 The related descriptions will not be repeated here.

[0061] In some embodiments of the present specification, the hardening correction effect of the current hardening correction parameters can be evaluated based on the model image, and automatically updated based on the evaluation results, so that automatic adaptive adjustment of the hardening correction parameters can be achieved, thereby avoiding the impact of slight miscorrection that is difficult to detect manually during the use of the imaging device on the imaging effect, and avoiding the impact of frequent manual updates on equipment maintenance.

[0062] It should be noted that the above description of process 300 is provided for illustrative purposes only and is not intended to limit the scope of this specification. A person of ordinary skill in the art may make various changes and modifications based on the description of this specification. However, such changes and modifications do not depart from the scope of this specification. In some embodiments, process 300 may include one or more additional operations, or may omit one or more of the above operations.

[0063] Figure 4is an exemplary flow chart for determining initial hardening correction parameters according to some embodiments of the present specification. In some embodiments, process 400 can be executed by the hardening correction system 100 (e.g., the processing device 120) or the hardening correction system 200. For example, process 400 can be stored in a storage device (e.g., the storage device 150, the storage unit of the system) in the form of a program or instructions, and when the processing device 120 or the hardening correction system 200 executes the instructions, process 400 can be implemented. The operational diagram of process 400 presented below is illustrative. In some embodiments, the process can be completed using one or more additional operations not described and / or one or more operations not discussed. In addition, Figure 4 In some embodiments, the process 400 may be executed by the initial parameter determination module 210 .

[0064] Step 410: Acquire a second image based on the second phantom.

[0065] The second phantom may be used to obtain initial hardening correction parameters. Similar to the first phantom, the second phantom may be a phantom made of a uniform material (e.g., a water phantom). In some embodiments, the second phantom may be the same as or different from the first phantom. In some embodiments, the second phantom and the first phantom may be the same phantom or different phantoms.

[0066] The format or type of the second image is similar to that of the first image and will not be described in detail here.

[0067] In some embodiments, the initial parameter determination module 210 may acquire the second image using an imaging device. In some embodiments, the initial parameter determination module 210 may determine the second image based on imaging data of the second phantom acquired by the imaging device.

[0068] In some embodiments, the imaging range of the second phantom can cover the detector range. In some embodiments, the size of the second phantom must meet certain requirements so that its imaging range can cover the detector range. For example, Figure 7A FIG. 1 is a schematic diagram of capturing a second image according to some embodiments of this specification. Figure 7A As shown, the second phantom cd is placed at the isocenter of the imaging device (e.g., the intersection of the rotation axis O and the central axis of the radiation beam). The area between the dashed lines L1 and L2 can represent the imaging range of the second phantom cd. It can be seen that the imaging range of the second phantom cd can completely cover the detector range ab.

[0069] In some embodiments, the imaging range of the second phantom (e.g., the imaging range when the second phantom is at the isocenter position) may cover a portion of the detector range. In this case, the second phantom may be placed at a position offset from the isocenter to achieve coverage of the detector range by the adjusted imaging range. For example, Figure 7B FIG is a schematic diagram of capturing a second image according to some other embodiments of this specification. Figure 7B As shown, the area between the dotted lines L3 and L4 can represent the imaging range when the second phantom ef is placed at the isocenter position (i.e., the position P1 shown by the dotted line). At this time, the imaging range of the second phantom ef only covers a part e'f' of the detector range. The area between the dotted lines L5 and L6 can represent the imaging range of the second phantom ef when the second phantom ef is moved upward to the position P2. At this time, the imaging range of the second phantom ef can cover the detector range ab.

[0070] In some embodiments, the imaging range of the second phantom (e.g., the imaging range when the second phantom is at the isocenter) can cover a portion of the detector range. In this case, the second phantom can be placed at a position offset from the isocenter, and the imaging range of the second phantom at multiple angles can cover the detector range. For example, Figure 8A and Figure 8B FIG is a schematic diagram of capturing a second image from multiple scanning angles according to some embodiments of this specification. Figure 8A and 8B As shown, the area between the dotted line L7 and the dotted line L8 and the area between the dotted line L9 and the dotted line L10 are the imaging ranges of the second phantom cd at two different angles, respectively. The imaging range between the dotted line L7 and the dotted line L8 can cover a part am of the detector, and the imaging range between the dotted line L9 and L10 can cover another part mb of the detector, thereby achieving coverage of the full range ab of the detector.

[0071] In some embodiments of the present disclosure, the imaging range of the second phantom covers the range of the detector, so that the imaging parameters simulated based on the second image can reflect the functions of all components in the detector.

[0072] In some embodiments, when determining the second image, scatter correction may be performed to remove the interference of scattered rays on the second image. For more information on scatter correction, see Figure 3 Part, no longer detailed here.

[0073] Step 420 , simulating an imaging process based on the second image.

[0074] In some embodiments, variables involved in the imaging process (also referred to as "imaging parameters") may include the energy spectrum of the multi-energy radiation beam, filter position, filter size, phantom size, etc., or any combination thereof.

[0075] The energy spectrum of a polyenergetic radiation beam can be a description of the energies and corresponding weights of the particles contained in the radiation beam. In some embodiments, the energy spectrum of a polyenergetic radiation beam can be represented by a distribution curve of the weights of the particles in the radiation beam as a function of the particle energy. For example, the abscissa and ordinate of the curve can represent the energy and corresponding weight of the particles in the radiation beam, respectively.

[0076] The filter size may include the length, width, thickness, etc. of the filter or any combination thereof. Filters of different sizes have different filtering effects on the radiation beam. For ease of description, the filtration described herein refers to additional filtration.

[0077] The filter position may include the distance between the filter and the radiation source and / or detector. It is understood that energy loss occurs in the radiation beam's path from the radiation source to the scanned object, and accordingly, the filtering effect varies depending on the distance between the filter and the radiation source and / or detector.

[0078] The size of the phantom may include the length, width, thickness, etc. of the phantom or any combination thereof. The size of the phantom may affect the imaging range, attenuation degree, etc. of the phantom.

[0079] In some embodiments, the initial parameter determination module 210 can simulate the imaging process through simulation. Through simulation, the energy spectrum, filter position, filter size, phantom size, and their corresponding parameters or coefficients of the multi-energy radiation beam are dynamically adjusted so that the simulated image is consistent or substantially consistent with the actual captured second image. In some embodiments, the initial parameter determination module 210 can simulate the imaging process based on methods such as Monte Carlo, which is not limited in this specification.

[0080] Step 430 : determining a first attenuation parameter corresponding to the multi-energetic radiation beam and a second attenuation parameter corresponding to the mono-energetic radiation beam based on the simulated imaging process.

[0081] In some embodiments, based on the simulated imaging process, a first attenuation parameter of the polyenergetic radiation beam after passing through a filter of a preset size and position and a phantom of a preset size can be simulated and calculated. In other words, the first attenuation parameter of the polyenergetic radiation beam can be simulated and calculated using the filter and the phantom as quantities.

[0082] In some embodiments, based on the simulated imaging process, a first attenuation parameter of a multi-energy radiation beam after passing through a filter of a predetermined size and position and phantoms of different sizes (e.g., different thicknesses) can be simulated and calculated. In other words, using the filter as a quantitative variable and the phantom as a variable, the first attenuation parameter corresponding to phantoms of different sizes can be simulated and calculated.

[0083] In some embodiments, based on the simulated imaging process, the first attenuation parameter of the multi-energy radiation beam after passing through a phantom of a predetermined size and / or filtered at different locations can be simulated and calculated. In other words, the phantom is used as a quantitative variable and the filtered state as a variable, and the corresponding first attenuation parameter for each filter state of different sizes and / or locations is simulated and calculated.

[0084] In some embodiments, based on the simulated imaging process, the first attenuation parameter of the multi-energetic radiation beam after passing through filters of varying sizes and / or locations, as well as phantoms of varying sizes (e.g., varying thicknesses), can be simulated and calculated. In other words, the filters and the phantom are both considered variables, and the corresponding first attenuation parameters for filters of varying sizes and / or locations, as well as for phantoms of varying sizes, are simulated and calculated.

[0085] The second attenuation parameter can be a constant. In some embodiments, the corresponding second attenuation parameter can be set based on the equivalent monoenergetic radiation beam intensity of the polyenergetic radiation beam. In some embodiments, the second attenuation parameter for the corresponding monoenergetic radiation beam can be calculated based on the first attenuation parameter and the energy spectrum of the polyenergetic radiation beam.

[0086] In step 440 , an initial hardening correction parameter is determined based on the first attenuation parameter and the second attenuation parameter.

[0087] As previously described, the initial hardening correction parameters can be used to correct for the hardening effect of an imaging device, which is caused by the different attenuation of beams of different energies within a multi-energy radiation beam. Accordingly, in the embodiments of this specification, the initial hardening correction parameters are intended to ensure that the imaging effect achieved by the multi-energy radiation beam is substantially the same as or similar to that achieved by a mono-energetic radiation beam. Accordingly, the initial hardening correction parameters can be determined based on the mapping relationship between the first attenuation parameter and the second attenuation parameter.

[0088] In some embodiments, the initial hardening correction parameters may include a mapping function, a mapping model, the like, or any combination thereof.

[0089] In some embodiments, the mapping function may include the number of terms in the function and the variable parameters corresponding to each term. In some embodiments, the initial parameter determination module 210 may determine the mapping function by polynomial fitting, dual-energy correction, single-energy correction, and iterative correction.

[0090] In some embodiments, the mapping model may include a feedforward neural network model, a deep neural network model, a convolutional neural network model, etc., or any combination thereof.

[0091] In some embodiments of the present specification, by simulating the imaging process and calculating the first attenuation parameter and the second attenuation parameter corresponding to the multi-energy radiation beam and the mono-energy radiation beam in different situations based on the simulated imaging process, and then determining the initial hardening correction parameter based on the mapping relationship between the two, the hardening correction parameter can be accurately determined to achieve an accurate hardening correction effect.

[0092] Figure 5 is an exemplary flowchart of automatically updating hardening correction parameters according to some embodiments of the present specification. In some embodiments, process 500 can be executed by the hardening correction system 100 (e.g., the processing device 120) or the hardening correction system 200. For example, process 500 can be stored in a storage device (e.g., the storage device 150, the storage unit of the system) in the form of a program or instructions, and when the processing device 120 or the hardening correction system 200 executes the instructions, process 500 can be implemented. The operational diagram of process 500 presented below is illustrative. In some embodiments, the process can be completed using one or more additional operations not described and / or one or more operations not discussed. In addition, Figure 4 The order of the operations of process 500 shown in FIG. 5 and described below is not limiting. In some embodiments, process 500 may be performed by parameter update module 230 .

[0093] Step 510: Determine the artifact level of the first image.

[0094] As mentioned above, the artifact degree of the first image can reflect the hardening correction effect of the initial hardening correction parameters. In some embodiments, the artifact degree can be reflected in the form of a numerical value, a vector, a matrix, a distribution graph, etc.

[0095] In some embodiments, the parameter updating module 230 may determine the artifact level of the first image based on the uniformity of the first image region. In some embodiments, the uniformity may reflect the difference between different locations of the phantom region in the first image (e.g., the difference between a region near the center and a region near the edge).

[0096] In some embodiments, the parameter updating module 230 may segment the motif region from the first image based on a segmentation model. In some embodiments, the segmentation model may include but is not limited to a threshold method, a region growing method, an edge detection method, a genetic algorithm, a wavelet analysis, a wavelet transform, an active contour model, or the like, or any combination thereof. In some embodiments, the segmentation model may include but is not limited to a Fully Convolutional Networks (FCN) model, a Visual Geometry Group Network (VGG Net) model, an Efficient Neural Network (ENet) model, a Full-Resolution Residual Networks (FRRN) model, a Mask Region-based Convolutional Neural Network (Mask R-CNN) model, a Multi-Dimensional Recurrent Neural Networks (MDRNNs) model, or the like, or any combination thereof.

[0097] In some embodiments, the parameter updating module 230 may determine the absolute value of the difference between the average pixel value of the area near the center of the phantom area and the average pixel value of the area near the edge of the phantom area to evaluate the artifact degree of the first image. Figure 9 is a schematic diagram of a first image according to some embodiments of this specification. Figure 9 As shown, an area within a preset range (e.g., 1 cm) from the phantom region boundary can be divided into an edge region; an area within a preset range from the center of the phantom region can be divided into a center region; and the absolute difference between the average pixel value of the center region and the average pixel value of the edge region can be calculated. In some embodiments, the area of ​​the center region and the edge region can be the same to ensure more accurate evaluation results.

[0098] Because the first phantom is made of uniform material, the pixel values ​​of the image region corresponding to the first phantom in the first image should be uniform and consistent under ideal conditions, without the influence of the hardening effect (for example, the hardening correction parameters can completely eliminate the influence of the hardening effect on the scanned image). However, when the hardening correction parameters are miscalibrated, the first image is affected by the hardening effect, resulting in inconsistent pixel values ​​in the image region corresponding to the uniform material of the first phantom. Therefore, the larger the absolute value of the aforementioned difference, the lower the uniformity of the first image, indicating a higher degree of artifacts in the first image.

[0099] In step 520 , the initial hardening correction parameters are automatically updated based on the artifact level.

[0100] In some embodiments, the parameter updating module 230 may automatically update the initial hardening correction parameters based on the artifact level and at least one of the first threshold or the second threshold.

[0101] The first threshold may be a threshold used to determine whether the hardening correction parameter is out of calibration. In some embodiments, when the artifact level is greater than the first threshold, it indicates that the hardening correction parameter is out of calibration; when the artifact level is less than or equal to the first threshold, it indicates that the hardening correction parameter is not out of calibration.

[0102] The second threshold may be a threshold used to determine the degree of decalibration of the hardening correction parameter. In some embodiments, when the artifact level is greater than the second threshold, it indicates that the hardening correction parameter is severely decalibrated; when the artifact level is less than or equal to the second threshold, it indicates that the hardening correction parameter is slightly decalibrated.

[0103] In some embodiments, the first threshold and / or the second threshold may be a system default value or may be set by a user.

[0104] In some embodiments, in response to the artifact level being greater than a first threshold and less than a second threshold, parameter update module 230 may adjust the energy spectrum and / or filtering parameters of the polyenergetic radiation beam. When the artifact level is greater than the first threshold and less than the second threshold, this indicates that the initial hardening correction parameters are slightly miscalibrated. In this case, fine-tuning the initial hardening correction parameters (or the hardening correction effect achieved by the initial hardening correction parameters) can be achieved by adjusting imaging parameters (e.g., the energy spectrum of the polyenergetic radiation beam, filter locations, filter sizes, phantom size, etc.).

[0105] In some embodiments, the parameter update module 230 can automatically adjust imaging parameters based on the first image. In some embodiments, the parameter update module 230 can utilize an imaging parameter adjustment model to automatically adjust imaging parameters based on the first image and historical images captured by the imaging device. Specifically, the parameter update module 230 can utilize the imaging parameter adjustment model to extract image features (e.g., image average grayscale value, image contrast, etc.) of the first image and the historical images, respectively, and automatically adjust the imaging parameters based on the features of the first image and the features of the historical images.

[0106] In some embodiments, the imaging parameter adjustment model may be a machine learning model. In some embodiments, the imaging parameter adjustment model may be trained based on a large number of identified training samples. Specifically, the identified training samples are input into the imaging parameter adjustment model, and the parameters of the imaging parameter adjustment model are updated through training. In some embodiments, the training samples may be historical images captured by an imaging device at at least two time points. In some embodiments, the identifications may be imaging parameters corresponding to the historical images at at least two time points annotated by a user.

[0107] In some embodiments, the parameter updating module 230 may determine the imaging parameters to be adjusted based on the artifact level of the first image. In some embodiments, the parameter updating module 230 may determine the imaging parameters to be adjusted based on a user instruction (eg, user input).

[0108] For example, after the imaging device has been used for a period of time, the X-ray tube ages and the energy spectrum of the emitted multi-energy radiation beam may change. The parameter update module 230 can appropriately increase the weight of low-energy photons in the energy spectrum of the multi-energy radiation beam and appropriately decrease the weight of high-energy photons based on the degree of artifacts in the first image.

[0109] For another example, after the imaging device has been used for a period of time, the filter fixing device may become slightly loose due to mechanical vibration, resulting in a slight change in the filter position. The parameter updating module 230 may instruct the corresponding motion component to adjust the filter position accordingly.

[0110] For another example, after the imaging device has been used for a period of time, the insulating oil layer of the X-ray tube may be partially oxidized, resulting in a decrease in the aluminum equivalent corresponding to the inherent filtration and a decrease in the thickness of the corresponding filter size. The parameter update module 230 can instruct the corresponding motion component to replace the filter or adjust the filter thickness.

[0111] In some embodiments, in response to the artifact level exceeding a second threshold, parameter update module 230 may re-determine the hardening correction parameters. When the artifact level exceeds the second threshold, it indicates that the initial hardening correction parameters are significantly out of calibration. In this case, the hardening correction parameters may be re-determined. The process for re-determining the hardening correction parameters is similar to the process for determining the initial hardening correction parameters and is not further described here.

[0112] In some embodiments, in response to the artifact level being less than or equal to a first threshold, the parameter updating module 230 may continue to use the initial hardening correction parameters. When the artifact level is less than the first threshold, it indicates that the degree of misalignment of the initial hardening correction parameters is within an allowable error range, and there is no need to adjust the initial hardening correction parameters.

[0113] In some embodiments of this specification, a first threshold can be used to quickly and automatically identify minor decalibration of an imaging device that is difficult for the user to determine. By automatically adjusting imaging parameters, the effects of minor decalibration can be quickly and accurately eliminated. A second threshold can be used to quickly and automatically identify severe decalibration of an imaging device. Resetting the calibration parameters in this situation can avoid equipment maintenance issues caused by frequent calibration. Furthermore, by setting the first and second thresholds, imaging device decalibration can be specifically categorized as minor decalibration and severe decalibration. Different measures can be taken for each, ensuring the accuracy of the hardening correction parameters while improving the efficiency of adjusting the hardening correction parameters.

[0114] In some embodiments, the parameter update module 230 can also automatically update the initial hardening correction parameters based on the artifact degree based on the correspondence between the preset artifact degree and different processing methods (such as not adjusting the imaging parameters, adjusting the imaging parameters and determining the hardening correction parameters).

[0115] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: (1) Based on the degree of artifacts in the phantom image, it is determined whether the initial hardening correction parameters need to be updated and how to update them, so that the hardening correction parameters can be automatically and adaptively adjusted, thereby avoiding the impact of slight decorrection that is difficult to detect manually during the use of the imaging device on the imaging effect, and also avoiding the impact of frequent manual updates on equipment maintenance. (2) By simulating the imaging parameters of the imaging device through the phantom image, and based on the simulated imaging parameters, the first attenuation parameter and the second attenuation parameter (corresponding to multi-energy radiation beams and mono-energy radiation beams, respectively) under filters of different sizes and / or different positions and / or phantoms of different sizes can be simulated and calculated, so that the hardening correction parameters can be accurately determined. (3) By setting the first threshold and the second threshold, the decorrection of the imaging device is specifically divided into slight decorrection and severe decorrection based on the degree of artifacts in the first image, and different measures are taken for slight decorrection and severe decorrection respectively, so that the efficiency of adjusting the hardening correction parameters can be improved while ensuring the accuracy of the hardening correction parameters.

[0116] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0117] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0118] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0119] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0120] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0121] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0122] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A hardening correction method, characterized in that: The method comprises: determining initial hardening correction parameters; Determining a first image based on the first phantom; determining a degree of artifacts in the first image; In response to the artifact level being greater than a first threshold and not greater than a second threshold, indicating that the decorrection level of the initial hardening correction parameter is relatively slight, adjusting the energy spectrum and / or filtering parameters of the multi-energetic radiation beam; In response to the artifact level being greater than a second threshold, indicating that the decorrection level of the initial hardening correction parameter is relatively serious, the hardening correction parameter is re-determined.

2. The method according to claim 1, wherein Determining the initial hardening correction parameters includes: Based on the second phantom, acquiring a second image; simulating an imaging process based on the second image; Determining a first attenuation parameter corresponding to the multi-energetic radiation beam and a second attenuation parameter corresponding to the mono-energetic radiation beam based on the simulated imaging process; The initial hardening correction parameter is determined based on the first attenuation parameter and the second attenuation parameter.

3. The method according to claim 2, wherein The imaging range of the second phantom covers the detector range.

4. The method according to claim 2, wherein The method further comprises: The interference of scattered rays on the first image and / or the second image is removed.

5. A hardening correction system, characterized in that: The system comprises: An initial parameter determination module, used to determine initial hardening correction parameters; an image determination module, configured to determine a first image based on the first phantom; Parameter update module for determining a degree of artifacts in the first image; In response to the artifact level being greater than a first threshold and not greater than a second threshold, indicating that the decorrection level of the initial hardening correction parameter is relatively slight, adjusting the energy spectrum and / or filtering parameters of the multi-energetic radiation beam; In response to the artifact level being greater than a second threshold, indicating that the decorrection level of the initial hardening correction parameter is relatively serious, the hardening correction parameter is re-determined.

6. A hardening correction device, characterized in that: The device comprises: at least one storage medium storing computer instructions; At least one processor executes the computer instructions to implement the hardening correction method according to any one of claims 1 to 4. 7 . A computer-readable storage medium storing computer instructions, wherein when a computer reads the computer instructions, the computer executes the hardening correction method according to claim 1 .

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