WO2023115879A1 - 一种数据校正方法和*** - Google Patents

一种数据校正方法和*** Download PDF

Info

Publication number
WO2023115879A1
WO2023115879A1 PCT/CN2022/102081 CN2022102081W WO2023115879A1 WO 2023115879 A1 WO2023115879 A1 WO 2023115879A1 CN 2022102081 W CN2022102081 W CN 2022102081W WO 2023115879 A1 WO2023115879 A1 WO 2023115879A1
Authority
WO
WIPO (PCT)
Prior art keywords
detector
data
correction
pixel unit
response
Prior art date
Application number
PCT/CN2022/102081
Other languages
English (en)
French (fr)
Inventor
徐探
许文挺
杨维
Original Assignee
武汉联影生命科学仪器有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 武汉联影生命科学仪器有限公司 filed Critical 武汉联影生命科学仪器有限公司
Publication of WO2023115879A1 publication Critical patent/WO2023115879A1/zh

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/032—Transmission computed tomography [CT]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/037—Emission tomography
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/42—Arrangements for detecting radiation specially adapted for radiation diagnosis
    • A61B6/4266—Arrangements for detecting radiation specially adapted for radiation diagnosis characterised by using a plurality of detector units
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/44—Constructional features of apparatus for radiation diagnosis
    • A61B6/4411—Constructional features of apparatus for radiation diagnosis the apparatus being modular
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5205—Devices using data or image processing specially adapted for radiation diagnosis involving processing of raw data to produce diagnostic data
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/52—Devices using data or image processing specially adapted for radiation diagnosis
    • A61B6/5211—Devices using data or image processing specially adapted for radiation diagnosis involving processing of medical diagnostic data
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/58—Testing, adjusting or calibrating thereof
    • A61B6/582—Calibration
    • A61B6/583—Calibration using calibration phantoms

Definitions

  • This description relates to the field of medical imaging calculations, in particular to a data correction method and system.
  • photon counting detectors are gradually widely used in medical imaging.
  • photon-counting detectors suffer from non-uniform response across pixels, which can lead to artifacts in the reconstructed image.
  • the response data of the detector pixel unit is corrected by using the Flat Field Correction method to improve the response uniformity of the detector pixel unit, thereby eliminating artifacts in the reconstructed image.
  • flat-field correction is less effective in improving the response uniformity of the detector.
  • the medical scanning device includes a radiation emitting device and a detector, and the detector includes a plurality of detector pixel units.
  • the method includes: obtaining the spatial position of the pixel unit of the detector; calculating cosine correction data according to the spatial position of the pixel unit of the detector and the spatial position of the focal point of the ray emitting device; determining the corrected position of the detector Response data; use the cosine correction data to correct the response data to be corrected to obtain target data; determine the correction coefficient corresponding to the detector pixel unit according to the target data; the processor treats according to the correction coefficient The response data of the detection object is corrected.
  • the determining the correction coefficient corresponding to the detector pixel unit according to the target data includes: calculating the detection coefficient for each row of detector pixel units in the preset direction. The average value of the target data corresponding to the detector pixel unit is used as the correction data of the detector pixel unit; and the correction coefficient is determined according to the correction data of all the detector pixel units.
  • the response data to be corrected includes data of the detector responding to homogeneous flat plates of different thicknesses.
  • the determining the correction coefficient according to the correction data of all the detector pixel units includes: establishing a linear relationship between the correction data and the target data; For the correction data of all the detector pixel units, the linear relationship between the correction data and the target data is solved to determine the correction coefficient.
  • the acquiring the spatial position of the pixel unit of the detector includes: acquiring a projection image of the test phantom on the detector; determining the response center point of the detector according to the projection image ; Determine the three-dimensional coordinates of the detector pixel units according to the response center point, the distance between the detector pixel units and the distance between the focus of the ray emitting device and the response center point.
  • the calculating the cosine correction data according to the three-dimensional coordinates of the detector pixel unit and the focal point space position of the ray emitting device includes: for each detector pixel unit, according to the detection The three-dimensional coordinates of the pixel unit of the detector and the coordinates of the focus, calculate the cosine of the angle between the first connection line and the second connection line, and obtain the cosine correction data, wherein the first connection line refers to the detector The connection line between the pixel unit and the focal point of the ray emitting device, the second connection line is the connection line between the focus point of the ray emitting device and the vertical point on the detector, the second connection line The line is perpendicular to the detector.
  • the vertical point is the response center point.
  • the determination of the response data to be corrected of the detector includes: acquiring phantom data and air data through the detector, wherein the phantom data is the ray emitting device and the The response data of the detector when the test phantom is set between the detectors, the air data is the response data of the detector when the test phantom is not set between the ray emitting device and the detector; The response data to be corrected is determined according to the air data and the phantom data.
  • the form is a homogeneous flat plate of at least two thicknesses.
  • One of the embodiments of this specification provides a data correction system, the system includes: an acquisition module, configured to acquire the spatial position of the pixel unit of the detector, according to the spatial position of the pixel unit of the detector and the ray emitting device The focus space position, calculate the cosine correction data; the determination module is used to determine the response data to be corrected of the detector, and use the cosine correction data to correct the response data to be corrected to obtain the target data; the correction module uses The correction coefficient corresponding to the pixel unit of the detector is determined according to the target data, and the response data of the object to be detected is corrected according to the correction coefficient.
  • the correction module is further configured to: for each row of detector pixel units of the detector in a preset direction, calculate the mean value of the target data corresponding to the detector pixel units, and convert the The average value is used as the correction data of the pixel unit of the detector; and the correction coefficient is determined according to the correction data of all the pixel units of the detector.
  • the response data to be corrected includes data of the detector responding to homogeneous flat plates of different thicknesses.
  • the correction module is further configured to: establish a linear relationship between correction data and target data; The linear relationship between the correction data and the target data is solved to determine the correction coefficient.
  • the acquiring module is further configured to: acquire the projection image of the test phantom on the detector; determine the response center point of the detector according to the projection image; determine the response center point of the detector according to the response center point , the distance between the detector pixel units and the distance between the focus of the ray emitting device and the response center point determine the three-dimensional coordinates of the detector pixel units.
  • the acquisition module is further configured to: for each detector pixel unit, calculate the first connection line and the second connection line according to the three-dimensional coordinates of the detector pixel unit and the focus coordinates The cosine of the included angle to obtain the cosine correction data, wherein the first connection refers to the connection between the pixel unit of the detector and the focal point of the ray emitting device, and the second connection is a connecting line between the focus of the ray emitting device and a vertical point on the detector, and the second connecting line is perpendicular to the detector.
  • the vertical point is the response center point.
  • the determination module is also used to: obtain phantom data and air data through the detector, wherein the phantom data is a test model set between the ray emitting device and the detector.
  • the response data of the detector when the phantom is in the body, and the air data is the response data of the detector when the test phantom is not set between the ray emitting device and the detector; according to the air data and the The phantom data is used to determine the response data to be corrected.
  • the form is a homogeneous flat plate of at least two thicknesses.
  • the system further includes a distribution determination module, configured to: determine a plurality of homogeneous flat panel combinations, the homogeneous flat panel combinations include at least two homogeneous flat panels with different thicknesses, and the at least two different thicknesses
  • the homogeneous flat plate is composed of at least two base substances; the detector is obtained to respond to the null calibration data of each combination of the homogeneous flat panels; data, determining the decomposition coefficients corresponding to the different thicknesses of homogeneous plates of each material; and determining the distribution of the base substance in the detection object based on the response data of the detection object and the decomposition coefficient.
  • the system further includes an energy determination module, configured to: determine the effective attenuation coefficient of the homogeneous slab based on the correction data corresponding to the homogeneous slab of different thickness; The attenuation factor determines the effective energy of the radiation emission device or the detector.
  • One of the embodiments of this specification provides a data correction device, including a processor, where the processor is configured to execute a data correction method.
  • One of the embodiments of this specification provides a computer-readable storage medium, the storage medium stores computer instructions, and after the computer reads the computer instructions in the storage medium, the computer executes the data correction method.
  • One of the embodiments of this specification provides a data correction method or system, which obtains the spatial position of the detector pixel unit; calculates the cosine correction data according to the spatial position of the detector pixel unit and the focal point coordinates of the ray emitting device; determines the detector’s Response data to be corrected; use cosine correction data to correct the response data to be corrected to obtain the target data; determine the correction coefficient corresponding to the pixel unit of the detector according to the target data; correct the response data of the object to be detected according to the correction coefficient, and the detector can be obtained
  • the correction coefficient for correcting the inhomogeneity of the pixel unit, through which the response data of the object to be detected can be corrected more accurately, so that the effect of correcting the inhomogeneity of the detector pixel unit can be improved, and thus the The reconstructed image of the object to be detected has lower noise and fewer artifacts.
  • Fig. 1 is a schematic diagram of an application scenario of a data correction system according to some embodiments of this specification
  • Fig. 2 is a block diagram of a data correction system according to some embodiments of the present specification
  • Fig. 3 is an exemplary flowchart of a data correction method according to some embodiments of the present specification
  • Fig. 4 is a schematic diagram of a three-dimensional Cartesian coordinate system where the three-dimensional coordinates of detector pixel units are located according to some embodiments of the present specification;
  • Fig. 5 is an exemplary flow chart of determining a correction coefficient according to the mean value of the target data corresponding to each row of detector pixel units according to some embodiments of the present specification
  • Fig. 6 is an exemplary flow chart of analyzing the distribution of the base substance composition of the object to be detected according to some embodiments of the present specification
  • Fig. 7 is an exemplary flowchart of determining effective energy according to some embodiments of the present specification.
  • Fig. 8 is an exemplary flow chart of determining correction coefficients according to correction data of all detector pixel units according to some embodiments of the present specification
  • Fig. 9 is a schematic diagram of an application environment of a data correction method according to some embodiments of this specification.
  • Fig. 10 is a schematic structural diagram of a radiation emitting device according to some embodiments of the present specification.
  • Fig. 11 is a schematic flowchart of the steps of a data correction method according to some embodiments of the present specification.
  • Fig. 12 is a schematic diagram of a cosine correction matrix according to some embodiments of the present specification.
  • Fig. 13 is a schematic flow chart of obtaining the three-dimensional coordinates of a pixel unit of a detector according to some embodiments of the present specification
  • Fig. 14 is a schematic flowchart of acquiring the response data to be corrected of the detector according to some embodiments of the present specification
  • Fig. 15 is a schematic diagram of the response data to be corrected corresponding to the 10mm thick polymethyl methacrylate plate shown before and after correction according to some embodiments of the specification;
  • Fig. 16 is a schematic diagram of the response data to be corrected corresponding to the 100mm thick polymethyl methacrylate plate shown before and after correction according to some embodiments of the specification;
  • Fig. 17 is a sinogram before correcting the water film response data according to some embodiments of the present specification.
  • Fig. 18 is a sine diagram after correcting the water film response data according to some embodiments of the present specification.
  • Fig. 19 is an internal structure diagram of a computer device according to some embodiments of the present specification.
  • system means for distinguishing different components, elements, parts, parts or assemblies of different levels.
  • the words may be replaced by other expressions if other words can achieve the same purpose.
  • Fig. 1 is a schematic diagram of an application scenario 100 of a data correction system according to some embodiments of the present specification.
  • an application scenario 100 may include a processor 110 , a network 120 , a user terminal 130 , a storage device 140 and a medical scanning device 150 .
  • the application scenario 100 can quickly and accurately correct the response data of the object to be detected by implementing the method and/or process disclosed in this specification.
  • the processor 110 may be configured to process data and/or information from at least one component of the application scenario 100 or an external data source (eg, a cloud data center). Processor 110 may access data and/or information from user terminal 130 , storage device 140 , medical scanning device 150 via network 120 . Processor 110 may be directly connected to user terminal 130, storage device 140, and medical scanning device 150 to access information and/or data. For example, the processor 110 may obtain the spatial location of the detector pixel unit. The processor 110 may process the acquired data and/or information.
  • an external data source eg, a cloud data center
  • the processor 110 may calculate the cosine correction data according to the acquired spatial position of the detector pixel unit and the focus spatial position of the ray emitting device, and use the cosine correction data to correct the acquired response data to be corrected to obtain the target data, and according to The target data determines the correction coefficient corresponding to the pixel unit of the detector, and then corrects the response data of the object to be detected according to the correction coefficient.
  • processor 110 may be a single server or a group of servers. Processor 110 may be local or remote.
  • Network 120 may include any suitable network that provides information and/or data exchange capable of facilitating application scenario 100 .
  • one or more components of the application scenario 100 (for example, the processor 110 , the user terminal 130 , the storage device 140 and the medical scanning device 150 ) can exchange information and/or data through the network 120 .
  • the network 120 may be any one or more of a wired network or a wireless network.
  • network 120 may include one or more network access points.
  • network 120 may include wired or wireless network access points, such as base stations and/or network switching points, through which one or more components of application scenario 100 may connect to network 120 to exchange data and/or or information.
  • the user terminal 130 refers to one or more terminals or software used by the user. In some embodiments, the user terminal 130 refers to a terminal or software used by medical personnel (eg, nurses, doctors, etc.). In some embodiments, the user terminal 130 may include, but is not limited to, a smart phone, a tablet computer, a laptop computer, a desktop computer, and the like. In some embodiments, the user terminal 130 can interact with other components in the application scenario 100 through the network 120 . For example, the user terminal 130 may send one or more control instructions to the processor 110 to control the processor 110 to correct the response data of the object to be detected.
  • Storage device 140 may be used to store data, instructions and/or any other information.
  • the storage device 140 may store data and/or information obtained from the processor 110, the user terminal 130, the storage device 140, the medical scanning device 150, and the like.
  • the storage device 140 may store the acquired spatial position of the detector pixel unit.
  • storage device 140 may include mass storage, removable storage, etc., or any combination thereof.
  • the medical scanning device 150 may be a device for acquiring a user's medical image.
  • the medical scanning device 150 can scan the measured object, obtain scanning data and generate a medical image of the user.
  • the measured object can be the whole or a part of the detection object.
  • the detection objects may include organisms such as human body and animals.
  • the analyte may include an organ, a tissue, a lesion, a tumor or any combination thereof.
  • the measured object may be head, chest, abdomen, heart, liver, upper limbs, lower limbs, etc., or any combination of the above-mentioned parts.
  • medical scanning device 150 may be a device or a group of devices.
  • the medical scanning device 150 may be a medical imaging system, for example, a PET (Positron Emission Tomography) device, a SPECT (Single Photon Emission Computed Tomography) device, a CT (Computed Tomography) device, an MRI (Magnetic Resonance Imaging ) equipment, etc.
  • the medical imaging system can be used alone or in combination.
  • the medical scanning device 150 may include a cavity 151, a bed frame 152, an operation control computer device and an image generator.
  • the cavity 151 can house components used to generate and detect radioactive rays.
  • the cavity 151 can accommodate the radiation emitting device 154 and the detector 153 .
  • the radiation emitting device 154 may emit radioactive radiation.
  • the radioactive rays can be emitted to the object placed in the cavity 151 and received by the detector 153 through the object.
  • the radioactive rays may include one or a combination of particle rays, photon rays, and the like.
  • Particulate rays may include one or a combination of neutrons, protons, electrons, mu media, heavy ions, and the like.
  • the photon rays may include one or a combination of X-rays, ⁇ -rays, ⁇ -rays, ⁇ -rays, ultraviolet rays, lasers, etc.
  • the photon rays may be X-rays
  • the corresponding medical scanning device 150 may be one or more of a CT system, a digital radiography system (DR), and a multimodal medical imaging system.
  • the multimodal medical imaging system may include one or more of a CTPET system, a SPECTMRI system, and the like.
  • the radiation emitting device 154 may be an X-ray tube. The X-ray tube can emit X-rays, which pass through the object placed inside the cavity 151 and are received by the detector 153 .
  • the detector 153 may include a plurality of detector pixel units.
  • a plurality of detector pixel units on the detector 153 can be arranged in a preset manner, for example, a plurality of detector pixel units are arranged in m rows and n columns, where the row can be the row of the detector 153 direction, the column may be the channel direction of the detector 153 .
  • the detector 153 may be a circular detector, a square detector, or an arc detector, among others.
  • the rotation angle of the arc detector can be between 0 degrees and 360 degrees. In some embodiments, the rotation angle of the arc detector may be fixed. In some embodiments, the rotation angle of the arc detector can be adjusted as needed.
  • detector 153 may be a one-dimensional detector, a two-dimensional detector, or a three-dimensional detector.
  • the bed frame 152 may support a test object (eg, a patient to be tested, a homogeneous plate, etc.).
  • a test object eg, a patient to be tested, a homogeneous plate, etc.
  • Operational control computer equipment may be associated with the cavity 151 , the radiation emitting device 154 , the detector 153 , the high voltage generator, the bed frame 152 and/or the image generator.
  • the above devices may be connected directly or indirectly.
  • the operation control computer device can control the rotation of cavity 151 to a certain position. The position can be a default value of the system, or can be set by a user (such as a doctor, a nurse, etc.).
  • the operating control computer device may control the high voltage generator.
  • an operator control computer device may control the magnitude of the voltage or current produced by the high voltage generator.
  • Image Generator can generate images.
  • the image generator can perform operations such as image preprocessing, image reconstruction, and/or region-of-interest extraction to generate the user's medical image.
  • the image generator may be associated with detector 153, operational control computer equipment and/or external data sources (not shown).
  • the image generator may receive data from the detector 153 or an external data source and generate a medical image of the user based on the received data.
  • the external data source may be one or more of hard disk, floppy disk, random access memory (RAM), dynamic random access memory (DRAM), etc.
  • the application scenario 100 is provided for illustrative purposes only, and is not intended to limit the scope of this description.
  • the application scenario 100 may also include a database.
  • these changes and modifications do not depart from the scope of this specification.
  • FIG. 2 is an exemplary block diagram of a data correction system 200 according to some embodiments of the present specification.
  • the data correction system 200 may include an acquisition module 210 , a determination module 220 , and a correction module 230 .
  • the obtaining module 210 may be used to obtain the spatial position of the detector pixel unit, and calculate cosine correction data according to the spatial position of the detector pixel unit and the focal point spatial position of the ray emitting device. In some embodiments, the obtaining module 210 may be used to obtain the three-dimensional coordinates of the detector pixel unit, and calculate cosine correction data according to the spatial position of the detector pixel unit and the focal point coordinates of the ray emitting device.
  • the acquisition module 210 can also be used to: acquire the projection image of the test phantom on the detector; determine the response center point of the detector according to the projection image; The distance between the focal point of the ray emitting device and the center point of the response determines the three-dimensional coordinates of the pixel unit of the detector.
  • the obtaining module 210 is further configured to: for each detector pixel unit, calculate the cosine of the angle between the first connecting line and the second connecting line according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates, Obtain the cosine correction data, wherein, the first connecting line refers to the connecting line between the pixel unit of the detector and the focal point of the ray emitting device, and the second connecting line refers to the connecting line between the focal point of the ray emitting device and the vertical point on the detector. line, the second line is perpendicular to the detector.
  • the determination module 220 may be used to determine the response data to be corrected of the detector, and use the cosine correction data to correct the response data to be corrected to obtain target data.
  • the determining module 220 is also used to: obtain phantom data and air data through the detector, wherein the phantom data is the response data of the detector when a test phantom is set between the radiation emitting device and the detector, and the air The data is the response data of the detector when no test phantom is set between the ray emitting device and the detector; the response data to be corrected is determined according to the air data and the phantom data.
  • the correction module 230 can be configured to determine a correction coefficient corresponding to the pixel unit of the detector according to the target data, and correct the response data of the object to be detected according to the correction coefficient.
  • the correction module 230 can also be used to: for each row of detector pixel units in the preset direction, calculate the mean value of the target data corresponding to the detector pixel unit, and use the mean value as the detector pixel unit The correction data; according to the correction data of all detector pixel units, the correction coefficient is determined.
  • the response data to be corrected includes detector response data for homogeneous slabs of different thicknesses.
  • the correction module 230 is also used to: establish a linear relationship between the correction data and the target data; Solve the relationship and determine the correction coefficient.
  • the data correction system 200 may also include a distribution determination module 240 .
  • the distribution determination module 240 can be used to: determine a plurality of homogeneous flat plate combinations, the homogeneous flat plate combination includes at least two homogeneous flat plates of different thicknesses, and the at least two homogeneous flat plates of different thicknesses are composed of at least two base materials;
  • the sensor responds to the null calibration data of each homogeneous flat panel combination; based on the detector’s response to the null calibration data of each homogeneous flat panel combination, determine the decomposition coefficient of each material’s homogeneous flat panel corresponding to different thicknesses; based on the object to be detected
  • the response data and the decomposition coefficient are used to determine the distribution of the base substance in the object to be detected.
  • the data correction system 200 may also include an energy determination module 250 .
  • the energy determination module 250 can be used to determine the effective attenuation coefficient of the homogeneous plate based on the correction data corresponding to the homogeneous plate with different thicknesses; determine the effective energy of the ray emitting device or the detector based on the effective attenuation coefficient of the homogeneous plate.
  • the acquisition module 210, the determination module 220, the correction module 230, the distribution determination module 240, and the energy determination module 250 disclosed in FIG. functions of one or more modules.
  • each module may share one storage module, or each module may have its own storage module. Such deformations are within the protection scope of this specification.
  • Fig. 3 is an exemplary flowchart of a data correction method 300 according to some embodiments of the present specification.
  • the process 300 includes the following steps.
  • the process 300 is applied to medical scanning equipment, and the medical scanning equipment includes a ray emitting device and a detector.
  • the process 300 may be executed by the processor 110 or the data correction system 200 .
  • the data correction method provided in the embodiment of the present application can be applied in the application environment shown in FIG. 9 , where the application environment includes a terminal 910 and a medical scanning device 920 .
  • the terminal 910 can communicate with the medical scanning device 920 through the network.
  • the terminal 910 may be, but not limited to, various personal computers, notebook computers and tablet computers.
  • the medical scanning device 920 may be, but not limited to, a CT (Computed Tomography, computerized tomography) device and a PET (Positron Emission Computed Tomography, positron emission computed tomography)-CT device.
  • CT Computerized Tomography
  • PET Positron Emission Computed Tomography, positron emission computed tomography
  • the structure of the medical scanning device 920 is shown in FIG. 10 , and the medical scanning device 920 includes a radiation emitting device 1010 and a detector 1020 .
  • the ray emitting device 1010 may be an X-ray emitting device, such as an X-ray tube.
  • the detector 1020 is composed of a whole piece of semiconductor crystal material and a plurality of detector pixel units, each detector pixel unit may include an Application Specific Integrated Circuit (ASIC), and the ASIC may be composed of a charge-sensitive preamplifier, a pulse Integer, comparator and digital counter form.
  • the ray emitting device 1010 is used for emitting rays through the focal point 1030 of the ray emitting device, and the rays pass through the object to be scanned in the medical scanning device 920 to form a projection of the object to be scanned on the detector 1020 .
  • the embodiment of the present disclosure does not limit the types and structures of the radiation emitting device 1010 and the detector 1020 , as long as their functions can be realized.
  • Step 310 acquiring the spatial position of the pixel unit of the detector.
  • step 310 may be performed by the acquisition module 210 .
  • the spatial position of the detector pixel unit can represent the position information of the detector pixel unit in three-dimensional space.
  • the spatial position of the detector pixel unit can be expressed in various forms.
  • the spatial position of the detector pixel unit can be expressed as a relative positional relationship with a reference object (eg, the center of the detector).
  • the spatial position of the pixel unit of the detector may be represented by three-dimensional coordinates.
  • the spatial position of the detector pixel unit may be a three-dimensional Cartesian coordinate of the detector pixel unit on a certain three-dimensional Cartesian coordinate system.
  • the spatial position of the detector pixel unit may be the cylindrical coordinates of the detector pixel unit on a certain cylindrical coordinate system.
  • the acquisition module 210 may acquire the three-dimensional coordinates of the detector pixel unit in any feasible way.
  • the three-dimensional coordinates of the detector pixel unit are directly obtained from the user terminal 130, the storage device 140, the medical scanning device 150 or an external data source.
  • a data correction method is provided.
  • the method 1100 is applied to the terminal 910 in FIG. 9 as an example for illustration, including step 1110, obtaining the three-dimensional coordinates of the detector pixel unit.
  • the acquisition module 210 can also determine the three-dimensional coordinates of the detector pixel unit through the test phantom. For example, the acquisition module 210 can acquire the projection image of the test phantom on the detector, determine the response center point of the detector according to the projection image, and determine the response center point of the detector according to the distance between the response center point, the distance between the pixel units of the detector and the focus and The three-dimensional coordinates of the detector pixel unit are determined in response to the distance between the center points.
  • the test phantom may be an object scanned by the medical scanning device 150 to obtain the three-dimensional coordinates of the detector pixel units.
  • the medical scanning device 150 may obtain the three-dimensional coordinates of the detector pixel units. For example, homogeneous plates, steel balls, etc.
  • the three-dimensional coordinates of the detector pixel unit may refer to the three-dimensional coordinates of the detector pixel unit on the detector determined with the rotation center as the coordinate origin; the focus coordinates of the ray emitting device are the three-dimensional coordinates of the focus determined with the rotation center as the coordinate origin.
  • the rotation center refers to the center when the ray emitting device and the detector rotate around the detection object, and the rotation center is a virtual point. Specifically, when the medical scanning device is a CT device, the center of rotation may refer to a point on an aperture centerline of the CT device.
  • Fig. 4 is a schematic diagram of the three-dimensional Cartesian coordinate system where the three-dimensional coordinates of the detector pixel unit according to some embodiments of this specification are located.
  • the rotation center of the ray emitting device may be The origin, the theoretical center projection line of the ray emitting device as the Y axis, the row direction of the detector as the X axis and the channel direction of the detector as the Z axis, establish a three-dimensional Cartesian coordinate system, and the three-dimensional coordinates of the pixel unit of the detector may be the coordinates of the detector pixel unit on the three-dimensional Cartesian coordinate system.
  • the theoretical center projection line of the ray emitting device may refer to a projection line vertically projected from the focal point of the ray emitting device to the detector.
  • FIG. 13 it relates to a possible implementation of obtaining the three-dimensional coordinates of the detector pixel unit, and the steps include:
  • Step 1310 acquiring the projection image of the test phantom on the detector.
  • the ray emitting device and the detector rotate around the test phantom, and through the rotation of the ray emitting device and the detector, projection images of the test phantom on the detector at different angles can be obtained.
  • the projection image may be transmitted to the terminal after being obtained by the detector, and stored in the terminal's memory, and the terminal may directly acquire it in the memory when needed.
  • the test phantom can be a homogeneous flat plate or a steel ball phantom. This embodiment does not limit the type and structure of the test phantom, as long as its function can be realized.
  • Step 1320 according to the projection image, determine the response center point of the detector.
  • the terminal can determine the response center point of the detector according to the projection images. Specifically, the terminal analyzes each acquired projection image, determines the centroid of the projection image, connects the centroids of all the projection images, and finds the center point of all the connected images, which is the response center point of the detector.
  • Step 1330 Determine the three-dimensional coordinates of the detector pixel units according to the response center point, the distance between the detector pixel units, and the distance between the focus of the ray emitting device and the response center point.
  • the distance between the detector pixel units can be pre-stored in the memory of the terminal by the staff, and the terminal can directly acquire it in the memory when needed. After obtaining the response center point of the detector, the terminal can determine the three-dimensional coordinates of the detector pixel unit according to the response center point, the distance between the detector pixel units, and the distance between the focus of the ray emitting device and the response center point.
  • the three-dimensional coordinates of the detector pixel unit are determined by the center of rotation when the ray emitting device and the detector rotate around the detection object as the coordinate origin, and the response center point, the center of rotation, and the focus of the ray emitting device are on the same straight line , then according to the focus coordinates of the ray emitting device and the distance between the focus of the ray emitting device and the response center point, the three-dimensional coordinates of the response center point can be obtained; according to the three-dimensional coordinates of the response center point, the response center point and its nearest detector pixel According to the distance between the units, the three-dimensional coordinates of the detector pixel unit can be obtained, and the three-dimensional coordinates of other detector pixel units can be determined according to the distance between the detector pixel units.
  • the method for determining the three-dimensional coordinates of the pixel unit of the detector provided in this embodiment is simple, easy to understand, and easy to implement.
  • the distance between the detector pixel units is the distance between two adjacent detector pixel units.
  • the obtaining module 210 may obtain the distance between the detector pixel units in any feasible manner. For example, the distance between the detector pixel units is obtained directly from the user terminal 130, the storage device 140, the medical scanning device 150 or an external data source.
  • the acquiring module 210 can acquire the distance between the focus of the ray emitting device and the center of rotation, and determine the three-dimensional coordinates (0,-y tube ,0) of the focus of the ray emitting device, where y tube is the ray emitting The distance between the focal point of the device and the center of rotation.
  • the obtaining module 210 may obtain the distance between the focus of the ray emitting device and the center of the response and the distance between the focus of the ray emitting device and the center of the response in any feasible manner.
  • the distance between the focus of the ray emitting device and the center of the response and the distance between the focus of the ray emitting device and the center of the response are obtained directly from the user terminal 130, the storage device 140, the medical scanning device 150 or an external data source.
  • the acquisition module 210 may determine the three-dimensional coordinates of each detector pixel unit according to the three-dimensional coordinates of the response center point and the distance between the detector pixel units. For example, the acquisition module 210 may first determine the three-dimensional coordinates of multiple detector pixel units adjacent to the response center point (that is, the first adjacent detectors), and then determine the multiple detector pixel units adjacent to each first adjacent detector. The three-dimensional coordinates of the detector pixel unit (that is, the second adjacent detector), and so on, until the three-dimensional coordinates of all detector phase pixel units are determined.
  • the three-dimensional coordinates of the detector pixel unit adjacent to the left side of the response center point are (x space , y center , 0), where x space is the distance between the detector pixel units; the three-dimensional coordinates of the adjacent detector pixel units on the right side of the response center point are (-x space ,y center ,0).
  • the three-dimensional coordinates of the detector pixel units can be quickly and accurately determined according to the response center point, the distance between the detector pixel units and the distance between the focus of the ray emitting device and the response center point.
  • Step 320 calculating cosine correction data according to the spatial position of the pixel unit of the detector and the spatial position of the focal point of the ray emitting device.
  • step 320 may be performed by the acquisition module 210 .
  • the spatial position of the focal point of the radiation emitting device can be used to characterize the spatial position of the focal point of the radiation emitting device.
  • the spatial position of the focal point of the ray emitting device may be expressed in any form.
  • the spatial position of the focal point of the ray emitting device may be expressed as a relative positional relationship with a reference object (eg, the center of the detector).
  • the spatial position of the pixel unit of the detector may be represented by three-dimensional coordinates (ie, focus coordinates).
  • the cosine correction data can be used to characterize the included angle between the line connecting the pixel unit of the detector and the focal point of the ray emitting device and the theoretical central projection line of the ray emitting device.
  • step 1110 may further include calculating cosine correction data according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates of the ray emitting device.
  • the detector includes multiple detector pixel units, and the terminal can obtain the three-dimensional coordinates of each detector pixel unit and the focus coordinates of the ray emitting device, and according to the three-dimensional coordinates of each detector pixel unit and the focus coordinates of the ray emitting device , to calculate the cosine correction data between the three-dimensional coordinates of each detector pixel unit and the focal point coordinates of the ray emitting device.
  • One cosine correction data can be calculated for each detector pixel unit, and multiple cosine correction data can be obtained for multiple detector pixel units on the detector. This embodiment does not limit the specific process of calculating the cosine correction data, as long as the function can be realized.
  • a plurality of detector pixel units on the detector can be arranged in a preset manner, for example, a plurality of detector pixel units are arranged in m rows and n columns, wherein the rows are arranged in the order of The row direction is defined, and the column is defined by the channel direction of the detector.
  • the row direction of the detectors may be the Z-axis direction in the three-dimensional coordinate system where the detector pixel units are located
  • the channel direction of the detectors may be the X-axis direction in the three-dimensional coordinate system where the detector pixel units are located.
  • the element s i, j in row i and column j in the first matrix S represents the included angle cos ⁇ i,j corresponding to the detector pixel unit in row i and column j in the detector.
  • the matrix of the cosine correction data is shown in Figure 12.
  • Channel refers to the channel direction of the detector
  • Slice refers to the row direction of the detector.
  • the acquisition module 210 can calculate the angle corresponding to the detector pixel unit through the three-dimensional coordinates of the detector pixel unit and the focal point coordinates of the ray emitting device, and then each The included angles corresponding to the detector pixel units are combined according to the arrangement of the detector pixel units on the detector to determine the cosine correction data.
  • the cosine of the angle between the first connection line and the second connection line is calculated to obtain cosine correction data;
  • the first connection line refers to the detection
  • the second connecting line is the connecting line between the focal point of the radiation emitting device and the vertical point on the detector, and the second connecting line is perpendicular to the detector.
  • the acquisition module 210 can calculate the length of the first connection line according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates, and then combine the length of the second connection line to determine the cosine of the included angle of the detector pixel unit, thereby determining the detector pixel unit corresponding angle. It can be understood that the ratio of the length of the second connection line to the length of the first connection line is the cosine of the angle between the pixel units of the detector.
  • Both the first connection and the second connection are virtual connections and do not actually exist.
  • the vertical point is also a virtual point, and the vertical point is the intersection point of the second connecting line and the detector.
  • the terminal when calculating the cosine correction data, the terminal first determines the first connection (the connection between the detector pixel unit and the focal point of the ray emitting device) and the second connection (the The angle between the line between the focus and the vertical point on the detector), calculate the cosine value of the angle, that is, the distance between the focus of the ray emitting device and the pixel unit of the detector and the focus of the ray emitting device and the detection
  • the cosine correction data of the detector pixel unit can be obtained by the ratio of the distance between the vertical points on the detector.
  • the cosine correction data of all detector pixel units in the detector can be obtained by using the same method.
  • the three-dimensional coordinates of the detector pixel unit can be expressed as (xi ,j ,y i,j ,zi ,j ), the three-dimensional coordinates of the focus of the ray emitting device can be expressed as (0,-y tube ,0), then the ray
  • the distance l i,j between the focal point of the emitting device and the pixel unit of the detector can be expressed as
  • the distance between the focal point of the ray emitting device and the vertical point on the detector can be expressed as k i,j
  • the method for determining and calculating the cosine correction data provided in this embodiment is simple and quick, and can improve the efficiency of determining the correction coefficient.
  • the vertical point is the above-mentioned response center point.
  • the second connecting line can be determined directly according to the response center point and the focus of the ray emitting device without re-determining the vertical point, which can improve the efficiency of calculating cosine correction data.
  • the cosine of the angle between the first line and the second line is calculated according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates, and the cosine correction data can be obtained quickly and accurately , so as to quickly determine the angle between the line connecting the detector pixel unit and the focal point of the ray emitting device and the theoretical center projection line of the ray emitting device, which facilitates subsequent determination of the correction coefficient of the detector pixel unit.
  • Step 330 determining the response data of the detector to be corrected.
  • step 330 may be performed by the determination module 220 .
  • the response data to be corrected may be data related to the response data of each detector pixel unit in the detector after scanning by the radiation emitting device.
  • the response data to be corrected may refer to the response data of each detector pixel unit in the detector after the radiation emitted by the radiation emitting device is emitted to the detector through the test phantom.
  • the type, structure, material, etc. of the test phantom are known.
  • the determination module 220 may control the medical scanning device 150 to perform at least one scan to obtain the response data to be corrected.
  • FIG. 14 it relates to a possible implementation of obtaining the response data to be corrected of the detector, and the steps include:
  • Step 1410 acquire phantom data and air data
  • the phantom data is the response data of the detector when a test phantom is set between the radiation emitting device and the detector
  • the air data is that no test phantom is set between the radiation emitting device and the detector Time detector response data.
  • the test phantom can be a homogeneous flat plate of different thickness, for example: polymethyl methacrylate plate or aluminum plate.
  • a test phantom is set between the ray emitting device and the detector. The radiation emitted by the ray emitting device passes through the test phantom and then is transmitted to the detector. The response data of each detector pixel unit in the detector is recorded as phantom data. The response data of the detector when no test phantom is set between the ray emitting device and the detector, that is, the radiation emitted by the ray emitting device is transmitted to the detector through the air, and the response of each detector pixel unit in the detector Data are recorded as air data.
  • the phantom may comprise homogenous flat plates of different thicknesses of the same material, homogeneous flat plates of the same thickness of different materials, homogeneous flat plates of different thicknesses of different materials, or any combination thereof.
  • the phantom may comprise scans of 10 mm thick, 8 mm thick and 6 mm thick polymethyl methacrylate plates.
  • the phantom may include a 10 mm thick polymethyl methacrylate plate after scanning and a 10 mm thick aluminum plate.
  • the mold body may include a polymethyl methacrylate plate with a thickness of 10 mm, a polymethyl methacrylate plate with a thickness of 6 mm, and an aluminum plate with a thickness of 8 mm.
  • Step 1420 according to the air data and phantom data, determine the response data to be corrected.
  • the terminal After obtaining the air data and the phantom data, the terminal calculates the ratio of the air data and the phantom data, and calculates the logarithm of the ratio to obtain the response data to be corrected.
  • the response data M i,j to be corrected can be expressed as
  • the influence of the air on the radiation emitted by the ray emitting device is considered, so that the determined response data to be corrected is closer to the actual application scene, and the correction coefficient determined according to the response data to be corrected It will be more accurate and can improve the correction effect of the non-uniformity of the detector's response.
  • the test phantom is a homogeneous flat plate
  • the influence of the difference in the length of rays passing through the homogeneous flat plate from different directions on the finally determined correction coefficient can be eliminated, so that the determined correction coefficient is more correct.
  • the test phantom is a polymethyl methacrylate plate with a thickness of 10 mm, as shown in FIG. 15 before the response data to be corrected is corrected.
  • the test model is a polymethyl methacrylate plate with a thickness of 100mm, and the response data to be corrected is shown in Figure 16 after correction.
  • the abscissa in Fig. 15 and Fig. 16 is the pixel unit of the detector, and the ordinate is the target data after correction of the response data to be corrected, A represents the target data after correction, and B represents the response data to be corrected before correction. It can be seen from Figure 15 and Figure 16 that the fluctuation of the corrected target data is reduced, and the uniformity is greatly improved.
  • the sine diagram before correcting the response data of the actual water film is shown in Figure 17, using the data correction method provided by this application to correct the actual water film
  • the corrected sinogram of the response data is shown in Figure 18. Comparing Figure 17 and Figure 18, it can be found that the uniformity of the corrected sinogram is improved, and the streak artifacts are weakened.
  • the response data to be corrected corresponding to each homogeneous slab can be represented by a fourth matrix, wherein an element in the fourth matrix can represent a null correction value of a detector pixel unit corresponding to the homogeneous slab .
  • the element in row i, column j in the fourth matrix That is, it represents the data corresponding to the detector pixel unit in the i-th row and j-th column in the detector.
  • Step 340 the processor uses the cosine correction data to correct the response data to be corrected to obtain target data.
  • step 340 may be performed by the determining module 220 .
  • the target data may be the response data to be corrected after eliminating the difference in length of rays in different directions passing through the homogeneous plate.
  • the determination module 220 may use the cosine correction data to correct the response data to be corrected to obtain the target data.
  • the processor can use the included angle corresponding to each detector pixel unit to correct it, so as to obtain the target data corresponding to each homogeneous plate.
  • a data correction method as shown in FIG. 11 further includes step 1120, determining the response data to be corrected of the detector, and using the cosine correction data to correct the response data to be corrected to obtain target data.
  • the terminal uses the calculated cosine correction data to correct the response data to be corrected, and obtains the corrected data, that is, the target data.
  • the method for determining the response data to be corrected of the detector is not limited, as long as the function can be realized.
  • the determination module 220 uses the cosine correction data to correct the response data to be corrected, which can eliminate the influence of the length difference of rays passing through the homogeneous plate in different directions on the final determined correction coefficient, so that the determined correction coefficient more correct.
  • Step 350 determine the correction coefficient corresponding to the pixel unit of the detector according to the target data.
  • step 350 may be performed by the correction module 230 .
  • the correction coefficient may be a parameter used to correct the response data of the detector pixel unit to reduce artifacts.
  • the correction module 230 can determine the correction coefficient according to the mean value of the target data corresponding to each row of detector pixel units. For determining the correction coefficient according to the mean value of the target data corresponding to each row of detector pixel units, refer to FIG. 5 and its related descriptions will not be repeated here.
  • Step 360 correcting the response data of the object to be detected according to the correction coefficient.
  • step 360 may be performed by the correction module 230 .
  • the calibration module 230 may first determine the response data of the object to be detected.
  • the object to be detected may be placed between the ray emitting device and the detector, and the medical scanning device 150 scans the object to be detected to obtain scan data of the object to be detected.
  • the scanning data of the object to be detected can be represented by a fifth matrix D i,j , wherein an element in the fifth matrix can represent the response data of a detector pixel unit in response to the object to be detected.
  • the element d i,j in row i and column j in the fifth matrix D i,j represents the response data of the detector pixel unit in row i and column j in the detector responding to the object to be detected.
  • the correction module 230 can determine the null calibration data of the object to be detected based on the air data and the scan data of the object to be detected The processor can correct the empty data of the object to be detected through the correction coefficient Perform corrections to obtain corrected data.
  • a data correction method as shown in FIG. 11 may further include step 1130, determining a correction coefficient corresponding to the detector pixel unit according to the target data, and correcting the response data of the object to be detected according to the correction coefficient.
  • the response data of the object to be detected refers to the response data of each detector pixel unit in the detector after the radiation emitted by the ray emitting device is emitted to the detector through the object to be detected.
  • the terminal After obtaining the target data, the terminal determines a correction coefficient when correcting the response data of the detector pixel unit according to the target data, and uses the correction coefficient to correct the response data of the detection object.
  • This embodiment does not limit the specific method for determining the correction coefficient, as long as its function can be realized.
  • the data correction method obtains the spatial position of the detector pixel unit, and calculates the cosine correction data according to the spatial position of the detector pixel unit and the focal point spatial position of the ray emitting device; determines the to-be-corrected response data of the detector, The cosine correction data is used to correct the response data to be corrected to obtain target data; the correction coefficient corresponding to the pixel unit of the detector is determined according to the target data, and the response data of the target to be detected is corrected according to the correction coefficient.
  • the data correction method provided in this embodiment can obtain the correction coefficient for correcting the inhomogeneity of the detector pixel unit by correcting the target data of the response data to be corrected according to the determined cosine correction data, through which the correction coefficient for the treatment
  • the response data of the detected object is corrected more accurately, so that the effect of correcting the inhomogeneity of the detector pixel unit can be improved, and the reconstructed image of the detected object can have lower noise and fewer artifacts.
  • Fig. 5 is an exemplary flow chart of determining a correction coefficient according to an average value of target data corresponding to each row of detector pixel units according to some embodiments of the present specification. As shown in FIG. 5 , the process 500 includes the following steps. In some embodiments, the process 500 may be executed by the processor 110 .
  • Step 510 for each row of detector pixel units in the detector in a preset direction, the processor calculates the mean value of the target data corresponding to the detector pixel units, and uses the mean value as the correction data of the detector pixel unit.
  • Correction data may refer to data used to determine a correction coefficient.
  • the preset direction of the detectors may refer to the row direction of the detectors or the channel direction of the detectors. If the preset direction is the row direction, the terminal calculates the mean value of the target data corresponding to all detector pixel units in the row for each row of detector pixel units in the row direction, and uses the mean value as the row of detector pixels Calibration data for the unit. Specifically, the correction data corresponding to the i-th row of detector pixel units It can be expressed as
  • the processor may calculate the mean value of the target data corresponding to the row of detector pixel units, so as to determine the correction data of each detector pixel unit in the row of detector pixel units .
  • the processor can calculate n The mean value of the target data corresponding to the detector pixel units, and use the mean value as the correction data of n detector pixel units.
  • Step 520 determining correction coefficients according to the correction data of all detector pixel units.
  • the correction coefficient refers to a coefficient corresponding to the corrected data that can be obtained after correcting the response data of the detector pixel unit. Specifically, after obtaining the correction data of all detector pixel units in the detector, the terminal determines the correction coefficient. The determination of the correction coefficient can be determined according to the variation relationship of the inhomogeneity of the detector pixel unit.
  • the method for determining the correction coefficient provided in this embodiment is simple and easy to understand, quick to calculate, and easy to implement.
  • the target data of the detector pixel unit is linearly mapped to the correction data, which can be obtained in, is the mean value of the target data corresponding to the i-th row of detector pixel units, g i,j is the first correction coefficient corresponding to the i-th row and j-th column of the detector pixel unit, b i,j is the i-th row and j-th column The second correction coefficient corresponding to the detector pixel unit.
  • the processor may solve the linear relationship between the correction data and the target data based on the correction data corresponding to all detector pixel units of the homogeneous flat plate with different thicknesses, and determine the correction coefficient.
  • FIG. 8 is an exemplary flow chart of determining correction coefficients according to the correction data of all detector pixel units according to some embodiments of the present specification. As shown in FIG.
  • the processor may according to The detector pixel unit is responsive to correction data for at least two homogeneous slabs of different thicknesses (e.g., 810 for homogeneous slab a, 820 for homogeneous slab b, and 820 for homogeneous slab n Correction data 830 etc.), solve the above linear relationship 840, and obtain the first correction coefficient 850 and the second correction coefficient 860 corresponding to the detector pixel unit.
  • the detector pixel unit is responsive to correction data for at least two homogeneous slabs of different thicknesses (e.g., 810 for homogeneous slab a, 820 for homogeneous slab b, and 820 for homogeneous slab n Correction data 830 etc.), solve the above linear relationship 840, and obtain the first correction coefficient 850 and the second correction coefficient 860 corresponding to the detector pixel unit.
  • the processor may correct the null calibration data of the detector pixel unit in response to the object to be detected based on the above linear relationship, so as to obtain corrected data.
  • the corrected data is:
  • the calibration coefficient corresponding to each detector pixel unit can be quickly determined.
  • the processor calculates the mean value of the target data corresponding to the detector pixel unit, and determines the correction coefficient based on the mean value, which can further reduce the cost of Due to the volatility of the data for determining the correction coefficient, after the determined correction coefficient is applied to the correction of the response data of the object to be detected, it is more helpful to improve the uniformity of the reconstructed image.
  • the data correction method can also be used to analyze the distribution of the base substance composition of the object to be detected.
  • Fig. 6 is an exemplary flow chart of analyzing the distribution of the base material composition of the object to be detected according to some embodiments of the present specification. As shown in Fig. 6, the process 600 may include the following steps.
  • Step 610 determining a plurality of homogeneous plate combinations.
  • a combination of homogeneous slabs may include at least two homogeneous slabs of different thicknesses.
  • the homogeneous plate assembly 1 may include a homogeneous plate a with a thickness t p and a homogeneous plate b with a thickness t a .
  • Two different homogeneous plates can be composed of two different base substances.
  • the homogeneous flat plate a is a polymethyl methacrylate homogeneous flat plate
  • the homogeneous flat plate b is a homogeneous aluminum plate.
  • Step 620 acquiring null calibration data of detectors responding to each combination of homogeneous flat plates.
  • the ray emitting device can scan the homogeneous flat panel combination, and the distribution determination module 240 acquires the null calibration data of each homogeneous flat panel in response to the homogeneous flat panel combination.
  • the empty calibration data of the tablet please refer to FIG. 3 and its related descriptions, which will not be repeated here.
  • Step 630 based on the null calibration data of the detectors in response to each combination of homogeneous plates, determine the decomposition coefficients corresponding to different thicknesses of the homogeneous plates of each material.
  • the distribution determination module 240 can determine the null calibration data of the homogeneous plate combination and the relationship between the thickness of each homogeneous plate in the homogeneous plate combination and the decomposition coefficient corresponding to each matrix material, based on the detection The detector determines the decomposition coefficient corresponding to each base substance in response to the null calibration data of each homogeneous flat plate combination and the thickness of each homogeneous flat plate.
  • the data correction method provided in the embodiment of the present application can be used to analyze the distribution of the basic substance composition of the object to be detected.
  • the test phantom uses a homogeneous polymethyl methacrylate flat plate with a thickness of t p and a homogeneous aluminum plate with a thickness of t a as the base material.
  • L) for the ray emitting device the thickness of the test model is represented by the following formula:
  • B H is the target data corrected by the data correction method provided by the application for the data collected by the high-energy chamber of the ray emission device
  • BL is the target data corrected by the data correction method provided by the application for the data collected by the low-energy chamber of the ray emission device data.
  • m 0 , m 1 , m 3 represent the decomposition coefficient of a polymethyl methacrylate homogeneous flat plate with a thickness of t p
  • n 0 , n 1 , n 3 represent the decomposition coefficient of a homogeneous aluminum plate with a thickness of t a .
  • the decomposition coefficient in the above formula can be determined by the above formula and the corrected target data corresponding to the two homogeneous plates. Based on the above formula, the decomposition coefficient and the target data of the object to be detected, the distribution of the two basic substances in the object to be detected can be obtained.
  • the energy of the rays corresponding to the high energy bin H and the low energy bin L are different, for example, the high energy bin H can emit For 80keV-140keV rays, the low-energy chamber L can emit rays below 30keV.
  • B H is the data collected by the detector after scanning the homogeneous flat plate combination 1 in response to the high-energy chamber of the ray emitting device, and the target data corrected by the data correction method provided by this application;
  • BL is the target data corrected by the detector in response to the ray emitting device The data collected after the low-energy chamber scans the homogeneous plate combination 1.
  • the processor can solve the above formula based on the empty calibration data of at least 9 kinds of homogeneous plate combinations to determine m 0 , m 1 , m 2 , m 3 , m 4 , m 5 , m 6 , m 7 , m 8 , n 0 , n 1 , n 2 , n 3 , n 4 , n 5 , n 6 , n 7 and n 8 .
  • Step 640 based on the response data and decomposition coefficient of the object to be detected, determine the distribution of the base substance in the object to be detected.
  • the distribution determination module 240 can substitute the response data and decomposition coefficient of the object to be detected into the blank calibration data of the homogeneous flat plate combination and the thickness of each homogeneous flat plate in the homogeneous flat plate combination corresponds to each base material The relationship between the decomposition coefficients to determine the distribution of the base substance in the object to be detected.
  • the response data of the object to be detected may include null calibration data after the detector responds to the object to be detected scanned by the high-energy chamber of the radiation emitting device and blank calibration data after the detector responds to the object to be detected scanned by the low-energy chamber of the radiation emitting device.
  • the object to be detected is composed of polymethyl methacrylate homogeneous flat plate and homogeneous aluminum plate, then the polymethyl methacrylate in the object to be detected is
  • the thickness t x1 of the flat plate and the thickness t x2 of the homogeneous aluminum plate are respectively:
  • B H,i is the empty calibration data after the detector responds to the object to be detected scanned by the high-energy chamber of the radiation emitting device
  • B L,i is the empty calibration data after the detector responds to the low-energy chamber of the radiation emitting device to scan the object to be detected.
  • the processor obtains null calibration data of the detector in response to each homogeneous panel combination, and based on the null calibration data of the detector in response to each homogeneous panel combination, The decomposition coefficients corresponding to different thicknesses of homogeneous flat plates of each material can be accurately determined, and then based on the response data and decomposition coefficients of the object to be detected, the distribution of the base substance in the object to be detected can be accurately determined.
  • Fig. 7 is an exemplary flow chart of determining effective energy according to some embodiments of the present specification. As shown in FIG. 7 , the process 700 may include the following steps.
  • an effective attenuation coefficient of the homogeneous slab is determined based on the calibration data corresponding to the homogeneous slabs of different thicknesses.
  • the effective attenuation coefficient can characterize the corresponding relationship between the thickness of the homogeneous flat plate and the calibration data.
  • the energy determination module 250 can determine a linear curve for characterizing the correspondence between the thickness of the homogeneous slab and the calibration data based on the calibration data of homogeneous slabs of different thicknesses through linear fitting, and The slope of the linear curve serves as the effective attenuation coefficient for the homogeneous plate.
  • Step 720 Determine the effective energy of the ray emitting device or the detector based on the effective attenuation coefficient of the homogeneous plate.
  • the effective energy may refer to the radiation energy that can be responded by the detector after the radiation emitted by the radiation emitting device passes through the homogeneous flat plate.
  • the energy determining module 250 may determine the effective energy of the radiation emitting device or the detector based on the effective attenuation coefficient of the homogeneous flat plate.
  • the energy determining module 250 may determine the effective energy of the ray emitting device or the detector based on the ray energy emitted by the ray emitting device and the effective attenuation coefficient of the homogeneous plate.
  • the energy determining module 250 may use the product of the ray energy emitted by the ray emitting device and the effective attenuation coefficient as the effective energy.
  • the effective attenuation coefficient of the homogeneous slab can be accurately determined based on the calibration data corresponding to the homogeneous slab with different thicknesses, and based on the effective attenuation coefficient of the homogeneous slab, the ray emitting device or detector can be quickly determined
  • the effective energy can provide a reference for the parameter setting of medical scanning equipment.
  • a computer device is provided.
  • the computer device may be a terminal, and its internal structure may be as shown in FIG. 19 .
  • the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Wherein, the processor of the computer device is used to provide calculation and control capabilities.
  • the memory of the computer device includes a non-volatile storage medium and an internal memory.
  • the non-volatile storage medium stores an operating system and computer programs.
  • the internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium.
  • the communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, mobile cellular network, NFC (Near Field Communication) or other technologies.
  • the computer program implements a data correction method when executed by a processor.
  • the display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covered on the display screen, or a button, a trackball or a touch pad provided on the casing of the computer device , and can also be an external keyboard, touchpad, or mouse.
  • Figure 19 is only a block diagram of a part of the structure related to the solution of this application, and does not constitute a limitation on the computer equipment on which the solution of this application is applied.
  • the specific computer equipment can be More or fewer components than shown in the figures may be included, or some components may be combined, or have a different arrangement of components.
  • a computer device including a memory and a processor, a computer program is stored in the memory, and the processor implements the following steps when executing the computer program:
  • the correction coefficient corresponding to the pixel unit of the detector is determined according to the target data, and the response data of the object to be detected is corrected according to the correction coefficient.
  • the processor executes the computer program, the following steps are also implemented: For each row of detector pixel units in the preset direction of the detector, calculate the mean value of the target data corresponding to the detector pixel unit, and use the mean value as the detected The correction data of the detector pixel unit; according to the correction data of all the detector pixel units, the correction coefficient is determined.
  • the processor when the processor executes the computer program, the following steps are also implemented: acquiring the projection image of the test phantom on the detector; determining the response center point of the detector according to the projection image; The distance between and the distance between the focal point of the ray emitting device and the response center point determine the three-dimensional coordinates of the detector pixel unit.
  • the processor executes the computer program, the following steps are also implemented: for each detector pixel unit, according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates, calculate the distance between the first connection line and the second connection line Included angle cosine, to obtain cosine correction data;
  • the first connection refers to the connection between the pixel unit of the detector and the focus of the ray emitting device, and the second connection is between the focus of the ray emitting device and the vertical point on the detector
  • the connection line, the second connection line is perpendicular to the detector.
  • the vertical point is the response center point.
  • the following steps are also implemented when the processor executes the computer program: acquiring phantom data and air data, the phantom data being the response data of the detector when a test phantom is set between the ray emitting device and the detector, and the air data It is the response data of the detector when no test phantom is set between the ray emitting device and the detector; according to the air data and phantom data, the response data to be corrected is determined.
  • a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the following steps are implemented:
  • the correction coefficient corresponding to the pixel unit of the detector is determined according to the target data, and the response data of the object to be detected is corrected according to the correction coefficient.
  • the following steps are also implemented: For each row of detector pixel units in the preset direction of the detector, calculate the mean value of the target data corresponding to the detector pixel unit, and use the mean value as Correction data of the detector pixel units; determining correction coefficients according to the correction data of all detector pixel units.
  • the following steps are also implemented: acquiring the projection image of the test phantom on the detector; determining the response center point of the detector according to the projection image; The distance between the units and the distance between the focal point of the ray emitting device and the response center point determine the three-dimensional coordinates of the pixel unit of the detector.
  • the following steps are also implemented: for each detector pixel unit, according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates, calculate the distance between the first connection line and the second connection line The cosine of the included angle to obtain the cosine correction data; the first connection is the connection between the pixel unit of the detector and the focus of the ray emitting device, and the second connection is the connection between the focus of the ray emitting device and the vertical point on the detector The connecting line between them, the second connecting line is perpendicular to the detector.
  • the second connection line is a connection line between the focal point of the ray emitting device and the response center point.
  • the following steps are also implemented: acquiring phantom data and air data, the phantom data being the response data of the detector when a test phantom is set between the ray emitting device and the detector, and the air
  • the data is the response data of the detector when no test phantom is set between the ray emitting device and the detector; the response data to be corrected is determined according to the air data and the phantom data.
  • a computer program product comprising a computer program, which, when executed by a processor, implements the following steps:
  • the correction coefficient corresponding to the pixel unit of the detector is determined according to the target data, and the response data of the object to be detected is corrected according to the correction coefficient.
  • the following steps are also implemented: For each row of detector pixel units in the preset direction of the detector, calculate the mean value of the target data corresponding to the detector pixel unit, and use the mean value as Correction data of the detector pixel units; determining correction coefficients according to the correction data of all detector pixel units.
  • the following steps are also implemented: acquiring the projection image of the test phantom on the detector; determining the response center point of the detector according to the projection image; The distance between the units and the distance between the focal point of the ray emitting device and the response center point determine the three-dimensional coordinates of the pixel unit of the detector.
  • the following steps are also implemented: for each detector pixel unit, according to the three-dimensional coordinates of the detector pixel unit and the focal point coordinates, calculate the distance between the first connection line and the second connection line The cosine of the included angle to obtain the cosine correction data; the first connection is the connection between the pixel unit of the detector and the focus of the ray emitting device, and the second connection is the connection between the focus of the ray emitting device and the vertical point on the detector The connecting line between them, the second connecting line is perpendicular to the detector.
  • the vertical point is the response center point.
  • the following steps are also implemented: acquiring phantom data and air data, the phantom data being the response data of the detector when a test phantom is set between the ray emitting device and the detector, and the air
  • the data is the response data of the detector when no test phantom is set between the ray emitting device and the detector; the response data to be corrected is determined according to the air data and the phantom data.
  • numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of the embodiments use the modifiers "about”, “approximately” or “substantially” in some examples. grooming. Unless otherwise stated, “about”, “approximately” or “substantially” indicates that the stated figure allows for a variation of ⁇ 20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximations that can vary depending upon the desired characteristics of individual embodiments. In some embodiments, numerical parameters should take into account the specified significant digits and adopt the general digit reservation method. Although the numerical ranges and parameters used in some embodiments of this specification to confirm the breadth of the range are approximations, in specific embodiments, such numerical values are set as precisely as practicable.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Medical Informatics (AREA)
  • Optics & Photonics (AREA)
  • Biomedical Technology (AREA)
  • Biophysics (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Veterinary Medicine (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Public Health (AREA)
  • Pathology (AREA)
  • Radiology & Medical Imaging (AREA)
  • Physics & Mathematics (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Pulmonology (AREA)
  • Theoretical Computer Science (AREA)
  • Apparatus For Radiation Diagnosis (AREA)

Abstract

本说明书实施例提供一种数据校正方法和***，该方法应用于医学扫描设备，所述医学扫描设备包括射线发射装置和探测器，所述探测器包括多个探测器像素单元，所述方法包括：获取所述探测器像素单元的空间位置；根据所述探测器像素单元的空间位置和所述射线发射装置的焦点空间位置，计算余弦校正数据；确定所述探测器的待校正响应数据；使用所述余弦校正数据对所述待校正响应数据进行校正，得到目标数据；根据所述目标数据确定所述探测器像素单元对应的校正系数；根据所述校正系数对待检测对象的响应数据进行校正。

Description

一种数据校正方法和***
优先权声明
本申请要求2021年12月23提交的中国专利申请号202111594782.2的优先权，其内容全部通过引用并入本文。
技术领域
本说明书涉及医学成像计算领域，特别涉及一种数据校正方法和***。
背景技术
随着科学技术的发展，光子计数探测器逐渐在医学成像中广泛应用。但是，光子计数探测器存在像素间响应不均匀的问题，这样会导致重建的图像中出现伪影。传统技术中，通过采用平场校正(Flat Field Correction)的方法对探测器像素单元的响应数据进行校正，以提高探测器像素单元的响应均匀性，从而消除重建图像中的伪影。然而，平场校正对探测器的响应均匀性提高效果较差。
因此，需要提供一种数据校正方法和***，用于降低重建图像中的伪影。
发明内容
本说明书实施例之一提供一种数据校正方法，应用于医学扫描设备，所述医学扫描设备包括射线发射装置和探测器，所述探测器包括多个探测器像素单元。所述方法包括：获取所述探测器像素单元的空间位置；根据所述探测器像素单元的空间位置和所述射线发射装置的焦点空间位置，计算余弦校正数据；确定所述探测器的待校正响应数据；使用所述余弦校正数据对所述待校正响应数据进行校正，得到目标数据；根据所述目标数据确定所述探测器像素单元对应的校正系数；所述处理器根据所述校正系数对待检测对象的响应数据进行校正。
在一些实施例中，所述根据所述目标数据确定所述探测器像素单元对应的校正系数，包括：对于所述探测器在预设方向上的每一排探测器像素单元，计算所述探测器像素单元对应的目标数据的均值，将所述均值作为所述探测器像素单元的校正数据；根据所有所述探测器像素单元的校正数据，确定所述校正系数。
在一些实施例中，所述待校正响应数据包括所述探测器响应于不同厚度的均质平板的数据。
在一些实施例中，所述根据所有所述探测器像素单元的校正数据，确定所述校正系数，包括：建立校正数据与目标数据的线性关系；基于对应于所述不同厚度的均质平板的所有所述探测器像素单元的校正数据，对所述校正数据与目标数据的线性关系求解，确定所述校正系数。
在一些实施例中，所述获取所述探测器像素单元的空间位置，包括：获取测试模体在所述探测器上的投影图像；根据所述投影图像，确定所述探测器的响应中心点；根据所述响应中心点、所述探测器像素单元之间的距离和所述射线发射装置的焦点与所述响应中心点之间的距离，确定所述探测器像素单元的三维坐标。
在一些实施例中，所述根据所述探测器像素单元的三维坐标和所述射线发射装置的焦点空间位置，计算余弦校正数据，包括：针对每一个所述探测器像素单元，根据所述探测器像素单元的三维坐标和所述焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到所述余弦校正数据，其中，所述第一连线是指所述探测器像素单元和所述射线发射装置的焦点之间的连线，所述第二连线为所述射线发射装置的焦点与所述探测器上的垂直点之间的连线，所述第二连线垂直于所述探测器。
在一些实施例中，所述垂直点为所述响应中心点。
在一些实施例中，所述确定所述探测器的待校正响应数据，包括：通过所述探测器获取模体数据和空气数据，其中，所述模体数据为所述射线发射装置和所述探测器之间设置测试模体时所述探测器的响应数据，所述空气数据为所述射线发射装置和所述探测器之间未设置所述测试模体时所述探测器的响应数据；根据所述空气数据和所述模体数据，确定所述待校正响应数据。
在一些实施例中，所述模体为至少两种厚度的均质平板。
本说明书实施例之一提供一种数据校正***，所述***包括：获取模块，用于获取所述探测器像素单元的空间位置，根据所述探测器像素单元的空间位置和所述射线发射装置的焦点空间位置，计算余弦校正数据；确定模块，用于确定所述探测器的待校正响应数据，使用所述余弦校正数据对所述待校正响应数据进行校正，得到目标数据；校正模块，用于根据所述目标数据确定所述探测器像素单元对应的校正系数，根据所述校正系数对待检测对象的响应数据进行校正。
在一些实施例中，所述校正模块还用于：对于所述探测器在预设方向上的每一排探测器像素单元，计算所述探测器像素单元对应的目标数据的均值，将所述均值作为所述探测器像素单元的校正数据；根据所有所述探测器像素单元的校正数据，确定所述校正系数。
在一些实施例中，所述待校正响应数据包括所述探测器响应于不同厚度的均质平板的数据。
在一些实施例中，所述校正模块还用于：建立校正数据与目标数据的线性关系；基于对应于所述不同厚度的均质平板的所有所述探测器像素单元的校正数据，对所述校正数据与目标数据的线性关系求解，确定所述校正系数。
在一些实施例中，所述获取模块还用于：获取测试模体在所述探测器上的投影图像；根据所述投影图像，确定所述探测器的响应中心点；根据所述响应中心点、所述探测器像素单元之间的距离和所述射线发射装置的焦点与所述响应中心点之间的距离，确定所述探测器像素单元的三维坐标。
在一些实施例中，所述获取模块还用于：针对每一个所述探测器像素单元，根据所述探测器像素单元的三维坐标和所述焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到所述余弦校正数据，其中，所述第一连线是指所述探测器像素单元和所述射线发射装置的焦点之间的连线，所述第二连线为所述射线发射装置的焦点与所述探测器上的垂直点之间的连线，所述第二连线垂直于所述探测器。
在一些实施例中，所述垂直点为所述响应中心点。
在一些实施例中，所述确定模块还用于：通过所述探测器获取模体数据和空气数据，其中，所述模体数据为所述射线发射装置和所述探测器之间设置测试模体时所述探测器的响应数据，所述空气数据为所述射线发射装置和所述探测器之间未设置所述测试模体时所述探测器的响应数据；根据所述空气数据和所述模体数据，确定所述待校正响应数据。
在一些实施例中，所述模体为至少两种厚度的均质平板。
在一些实施例中，所述***还包括分布确定模块，用于：确定多个均质平板组合，所述均质平板组合包括至少两个不同厚度的均质平板，所述至少两个不同厚度的均质平板由至少两种基物质组成；获取所述探测器响应于每个所述均质平板组合的空校数据；基于所述探测器响应于每个所述均质平板组合的空校数据，确定每种材料的均质平板对应所述不同厚度的分解系数；基于所述待检测对象的响应数据及所述分解系数，确定所述待检测对象中所述基物质的分布。
在一些实施例中，所述***还包括能量确定模块，用于：基于响应于不同厚度的均质平板的校正数据，确定所述均质平板的有效衰减系数；基于所述均质平板的有效衰减系数确定所述射线发射装置或所述探测器的有效能量。
本说明书实施例之一提供一种数据校正装置，包括处理器，所述处理器用于执行数据校正方法。
本说明书实施例之一提供一种计算机可读存储介质，所述存储介质存储计算机指令，当计算机读取存储介质中的计算机指令后，计算机执行数据校正方法。
本说明书实施例之一提供一种数据校正方法或***，获取通过探测器像素单元的空间位置；根据探测器像素单元的空间位置和射线发射装置的焦点坐标，计算余弦校正数据；确定探测器的待校正响应数据；使用余弦校正数据对待校正响应数据进行校正，得到目标数据；根据目标数据确定探测器像素单元对应的校正系数；根据校正系数对待检测对象的响应数据进行校正，可以得到对探测器像素单元的不均匀性进行校正的校正系数，通过该校正系数可以实现对待检测对象的响应数据进行更加准确的校正，从而能够提高对探测器像素单元的不均匀性进行校正的效果，进而能够使得待检测对象的重建图像具备更低的噪声和更少的伪影。
附图说明
本说明书将以示例性实施例的方式进一步说明，这些示例性实施例将通过附图进行详细描述。这些实施例并非限制性的，在这些实施例中，相同的编号表示相同的结构，其中：
图1是根据本说明书一些实施例所示的数据校正***的应用场景示意图；
图2是根据本说明书一些实施例所示的数据校正***的模块示意图；
图3是根据本说明书一些实施例所示的数据校正方法的示例性流程图；
图4是根据本说明书一些实施例所示的探测器像素单元的三维坐标所在的三维笛卡尔坐标系的示意图；
图5是根据本说明书一些实施例所示的根据每一排探测器像素单元对应的目标数据的均值，确定校正系数的示例性流程图；
图6是根据本说明书一些实施例所示的分析待检测对象的基物质组成的分布的示例性流程图；
图7是根据本说明书一些实施例所示的确定有效能量的示例性流程图；
图8是根据本说明书一些实施例所示的根据所有探测器像素单元的校正数据确定校正系数的示例 性流程图；
图9是根据本说明书一些实施例所示的数据校正方法的应用环境示意图；
图10是根据本说明书一些实施例所示的射线发射装置的结构示意图；
图11是根据本说明书一些实施例所示的数据校正方法的步骤的流程示意图；
图12是根据本说明书一些实施例所示的余弦校正矩阵的示意图；
图13是根据本说明书一些实施例所示的获取探测器像素单元的三维坐标的流程示意图；
图14是根据本说明书一些实施例所示的获取探测器的待校正响应数据的流程示意图；
图15是根据本说明书一些实施例所示的10mm厚的聚甲基丙烯酸甲酯板对应的待校正响应数据校正前后的示意图；
图16是根据本说明书一些实施例所示的100mm厚的聚甲基丙烯酸甲酯板对应的待校正响应数据校正前后的示意图；
图17是根据本说明书一些实施例所示的对水膜响应数据进行校正前的正弦图；
图18是根据本说明书一些实施例所示的对水膜响应数据进行校正后的正弦图；
图19是根据本说明书一些实施例所示的计算机设备的内部结构图。
具体实施方式
为了更清楚地说明本说明书实施例的技术方案，下面将对实施例描述中所需要使用的附图作简单的介绍。显而易见地，下面描述中的附图仅仅是本说明书的一些示例或实施例，对于本领域的普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图将本说明书应用于其它类似情景。除非从语言环境中显而易见或另做说明，图中相同标号代表相同结构或操作。
应当理解，本文使用的“***”、“装置”、“单元”和/或“模块”是用于区分不同级别的不同组件、元件、部件、部分或装配的一种方法。然而，如果其他词语可实现相同的目的，则可通过其他表达来替换所述词语。
如本说明书和权利要求书中所示，除非上下文明确提示例外情形，“一”、“一个”、“一种”和/或“该”等词并非特指单数，也可包括复数。一般说来，术语“包括”与“包含”仅提示包括已明确标识的步骤和元素，而这些步骤和元素不构成一个排它性的罗列，方法或者设备也可能包含其它的步骤或元素。
本说明书中使用了流程图用来说明根据本说明书的实施例的***所执行的操作。应当理解的是，前面或后面操作不一定按照顺序来精确地执行。相反，可以按照倒序或同时处理各个步骤。同时，也可以将其他操作添加到这些过程中，或从这些过程移除某一步或数步操作。
图1是根据本说明书一些实施例所示的数据校正***的应用场景100示意图。
如图1所示，在一些实施例中，应用场景100可以包括处理器110、网络120、用户终端130、存储设备140及医学扫描设备150。应用场景100可以通过实施本说明书中披露的方法和/或过程快速且准确地对待检测对象的响应数据进行校正。
处理器110可以用于处理来自应用场景100的至少一个组件或外部数据源(例如，云数据中心)的数据和/或信息。处理器110可以通过网络120从用户终端130、存储设备140、医学扫描设备150访问数据和/或信息。处理器110可以直接连接用户终端130、存储设备140及医学扫描设备150以访问信息和/或数据。例如，处理器110可以获取探测器像素单元的空间位置。处理器110可以对获取的数据和/或信息进行处理。例如，处理器110可以根据获取的探测器像素单元的空间位置和射线发射装置的焦点空间位置，计算余弦校正数据，使用余弦校正数据对获取的待校正响应数据进行校正，得到目标数据，并根据目标数据确定探测器像素单元对应的校正系数，再根据校正系数对待检测对象的响应数据进行校正。在一些实施例中，处理器110可以是单个服务器或服务器组。处理器110可以是本地的、远程的。
网络120可以包括提供能够促进应用场景100的信息和/或数据交换的任何合适的网络。在一些实施例中，应用场景100的一个或多个组件(例如，处理器110、用户终端130、存储设备140及医学扫描设备150)之间可以通过网络120交换信息和/或数据。
在一些实施例中，网络120可以是有线网络或无线网络中的任意一种或多种。在一些实施例中，网络120可以包括一个或以上网络接入点。例如，网络120可以包括有线或无线网络接入点，例如，基站和/或网络交换点，通过这些网络接入点，应用场景100的一个或多个组件可连接到网络120以交换数据和/或信息。
用户终端130指用户所使用的一个或多个终端或软件。在一些实施例中，用户终端130是指医护人员(例如，护工、医生等)使用的终端或软件。在一些实施例中，用户终端130可以包含但不限于智能电话、平板电脑、膝上型计算机、台式计算机等。在一些实施例中，用户终端130可以通过网络120与应用场景100中的其他组件交互。例如，用户终端130可以向处理器110发送一个或多个控制指令以控制处 理器110对待检测对象的响应数据进行校正。
存储设备140可以用于存储数据、指令和/或任何其他信息。在一些实施例中，存储设备140可以存储从处理器110、用户终端130、存储设备140及医学扫描设备150等获得的数据和/或信息。例如，存储设备140可以存储获取的探测器像素单元的空间位置。在一些实施例中，存储设备140可包括大容量存储器、可移除存储器等或其任意组合。
医学扫描设备150可以是用于获取用户的医学图像的设备。在一些实施例中，医学扫描设备150可以对被测物进行扫描，得到扫描数据并生成用户的医学图像。被测物可以是检测对象的整体或其中的一部分。检测对象可以包括人体、动物等生物体。作为示例，被测物可以包括器官、组织、病变部位、肿瘤部位或者上述部位的任意组合。具体例如，被测物可以是头部、胸部、腹部、心脏、肝脏、上肢、下肢等，或者上述部位的任意组合。在一些实施例中，医学扫描设备150可以是一个设备或一个设备组。具体地，医学扫描设备150可以是一个医学成像***，例如，一个PET(Positron Emission Tomography)设备、一个SPECT(Single Photon Emission Computed Tomography)设备、一个CT(Computed Tomography)设备、一个MRI(Magnetic Resonance Imaging)设备等。进一步地，医学成像***可以是单独使用，也可以结合使用。例如，一个PETCT设备、一个PETMRI设备或一个SPECTMRI设备等。
在一些实施例中，医学扫描设备150可以包括腔体151、床架152、操作控制计算机设备和图像生成器。腔体151内部可以收容用来产生和检测放射性射线的组件。在一些实施例中，腔体151可以收容射线发射装置154和探测器153。射线发射装置154可以发射放射性射线。放射性射线可以发射到置于腔体151中的物体处，并透过物体被探测器153接收。放射性射线可以包括微粒射线、光子射线等中的一种或其组合。微粒射线可以包括中子、质子、电子、μ介质、重离子等中的一种或其组合。光子射线可以包括X射线、γ射线、α射线、β射线、紫外线、激光等中的一种或其组合。作为示例，光子射线可能是X射线，其相应的医学扫描设备150则可以是一个CT***、一个数字式射线成像***(DR)、一个多模态医学成像***等其中的一种或多种。进一步地，在一些实施例中，多模态医学成像***可以包括CTPET***、SPECTMRI***等中的一种或多种。作为示例，射线发射装置154可以是一个X射线管。X射线管可以发射X射线，该射线透过置于腔体151内部的物体，并被探测器153接收。
探测器153可以包括多个探测器像素单元。在一些实施例中，探测器153上的多个探测器像素单元可以按照预设方式进行排列，例如，多个探测器像素单元按照m行n列排列，其中，行可以为探测器153的排方向，列可以为探测器153的通道方向。在一些实施例中，探测器153可以是圆形探测器、方形探测器、或弧形探测器等。弧形探测器的旋转角度可以是在0度到360度之间。在一些实施例中，弧形探测器的旋转角度可以是固定不变的。在一些实施例中，弧形探测器的旋转角度可以根据需要调整。例如，可以根据所需要的图像的分辨率、图像的大小、探测器的灵敏度、探测器的稳定性或其中的一种或者几种的组合，进行调整。在一些实施例中，探测器153可以是一维探测器、二维探测器、或三维探测器。
床架152可以支撑检测对象(例如，待检测的病人、均质平板等)。
操作控制计算机设备可以与腔体151、射线发射装置154、探测器153、高压发生器、床架152和/或图像生成器相关联。上述设备之间可以通过直接或者间接的方式相连接。在一些实施例中，操作控制计算机设备可以控制腔体151旋转至某一位置。该位置可以是***默认值，也可以由用户(例如医生、护士等)设定。在一些实施例中，操作控制计算机设备可以控制高压发生器。例如，操作控制计算机设备可以控制高压发生器产生的电压或电流的强度。
图像生成器可以生成图像。在一些实施例中，图像生成器可以进行图像预处理、图像重建、和/或感兴趣区域提取等操作，以生成用户的医学图像。图像生成器可以和探测器153、操作控制计算机设备和/或外部数据源(图中未体现)相关联。在一些实施例中，图像生成器可以从探测器153或者外部数据源接收数据，并基于所接收的数据生成用户的医学图像。外部数据源可以是硬盘、软盘、随机存储器(random access memory,RAM)、动态随机存储器(dynamic random access memory,DRAM)等中的一种或多种。
应当注意应用场景100仅仅是为了说明的目的而提供的，并不意图限制本说明书的范围。对于本领域的普通技术人员来说，可以根据本说明书的描述，做出多种修改或变化。例如，应用场景100还可以包括数据库。然而，这些变化和修改不会背离本说明书的范围。
图2是根据本说明书一些实施例所示的数据校正***200的示例性框图。
如图2所示，数据校正***200可以包括获取模块210及确定模块220、校正模块230。
获取模块210可以用于获取探测器像素单元的空间位置，根据探测器像素单元的空间位置和射线发射装置的焦点空间位置，计算余弦校正数据。在一些实施例中，获取模块210可以用于获取探测器像素单元的三维坐标，根据探测器像素单元的空间位置和射线发射装置的焦点坐标，计算余弦校正数据。在一些实施例中，获取模块210还可以用于：获取测试模体在探测器上的投影图像；根据投影图像，确定探测器的响应中心点；根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间 的距离，确定探测器像素单元的三维坐标。在一些实施例中，获取模块210还用于：针对每一个探测器像素单元，根据探测器像素单元的三维坐标和焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到余弦校正数据，其中，第一连线是指探测器像素单元和射线发射装置的焦点之间的连线，第二连线为射线发射装置的焦点与探测器上的垂直点之间的连线，第二连线垂直于探测器。
确定模块220可以用于确定探测器的待校正响应数据，使用余弦校正数据对待校正响应数据进行校正，得到目标数据。在一些实施例中，确定模块220还用于：通过探测器获取模体数据和空气数据，其中，模体数据为射线发射装置和探测器之间设置测试模体时探测器的响应数据，空气数据为射线发射装置和探测器之间未设置测试模体时探测器的响应数据；根据空气数据和模体数据，确定待校正响应数据。
校正模块230可以用于根据目标数据确定探测器像素单元对应的校正系数，根据校正系数对待检测对象的响应数据进行校正。在一些实施例中，校正模块230还可以用于：对于探测器在预设方向上的每一排探测器像素单元，计算探测器像素单元对应的目标数据的均值，将均值作为探测器像素单元的校正数据；根据所有探测器像素单元的校正数据，确定校正系数。
在一些实施例中，待校正响应数据包括探测器响应于不同厚度的均质平板的数据。在一些实施例中，校正模块230还用于：建立校正数据与目标数据的线性关系；基于对应于不同厚度的均质平板的所有探测器像素单元的校正数据，对校正数据与目标数据的线性关系求解，确定校正系数。
在一些实施例中，数据校正***200还可以包括分布确定模块240。分布确定模块240可以用于：确定多个均质平板组合，均质平板组合包括至少两个不同厚度的均质平板，至少两个不同厚度的均质平板由至少两种基物质组成；获取探测器响应于每个均质平板组合的空校数据；基于探测器响应于每个均质平板组合的空校数据，确定每种材料的均质平板对应不同厚度的分解系数；基于待检测对象的响应数据及分解系数，确定待检测对象中基物质的分布。
在一些实施例中，数据校正***200还可以包括能量确定模块250。能量确定模块250可以用于基于响应于不同厚度的均质平板的校正数据，确定均质平板的有效衰减系数；基于均质平板的有效衰减系数确定射线发射装置或探测器的有效能量。
关于获取模块210、确定模块220、校正模块230、分布确定模块240及能量确定模块250的更多描述可以参见图3及其相关描述，此处不再赘述。
需要注意的是，以上对于数据校正***200及其模块的描述，仅为描述方便，并不能把本说明书限制在所举实施例范围之内。可以理解，对于本领域的技术人员来说，在了解该***的原理后，可能在不背离这一原理的情况下，对各个模块进行任意组合，或者构成子***与其他模块连接。在一些实施例中，图1中披露的获取模块210、确定模块220、校正模块230、分布确定模块240及能量确定模块250可以是一个***中的不同模块，也可以是一个模块实现上述的两个或两个以上模块的功能。例如，各个模块可以共用一个存储模块，各个模块也可以分别具有各自的存储模块。诸如此类的变形，均在本说明书的保护范围之内。
图3是根据本说明书一些实施例所示的数据校正方法300的示例性流程图。如图3所示，流程300包括下述步骤。在一些实施例中，流程300应用于医学扫描设备，医学扫描设备包括射线发射装置和探测器，关于医学扫描设备的更多描述可以参见图1及其相关描述，此处不再赘述。在一些实施例中，流程300可以由处理器110或数据校正***200执行。
本申请实施例提供的数据校正方法，可以应用于如图9所示的应用环境中，该应用环境包括终端910和医学扫描设备920。其中，终端910可以通过网络与医学扫描设备920进行通信。终端910可以但不限于是各种个人计算机、笔记本电脑机和平板电脑。医学扫描设备920可以但不限于是CT(Computed Tomography，即电子计算机断层扫描)设备和PET(Positron Emission Computed Tomography，正电子发射型计算机断层显像)-CT设备。医学扫描设备920的结构如图10所示，医学扫描设备920包括射线发射装置1010和探测器1020。射线发射装置1010可以是X射线发射装置，例如X射线球管。探测器1020由整块的半导体晶体材料和多个探测器像素单元组成，每一个探测器像素单元可以包括专用集成电路(Application Specific Integrated Circuit，ASIC)，ASIC可以由电荷敏感型前置放大器、脉冲整型器、比较器和数字计数器构成。射线发射装置1010用于通过射线发射装置的焦点1030发射射线，该射线经过医学扫描设备920中的待扫描对象可以在探测器1020上形成待扫描对象的投影。本公开实施例对射线发射装置1010和探测器1020的种类和结构等不作限制，只要能够实现其功能即可。
步骤310，获取探测器像素单元的空间位置。在一些实施例中，步骤310可以由获取模块210执行。
探测器像素单元的空间位置可以表征探测器像素单元在三维空间中的位置信息。探测器像素单元的空间位置可以有多种表达形式。例如，探测器像素单元的空间位置可以表示为与参照物(例如，探测器的中心)的相对位置关系。又例如，探测器像素单元的空间位置可以通过三维坐标进行表示。示例地，探 测器像素单元的空间位置可以为探测器像素单元在某个三维笛卡尔坐标系上的三维笛卡尔坐标。又例如，探测器像素单元的空间位置可以为探测器像素单元在某个圆柱坐标系上的圆柱坐标。在一些实施例中，获取模块210可以通过任意可行的方式获取探测器像素单元的三维坐标。例如，直接从用户终端130、存储设备140、医学扫描设备150或外部数据源获取探测器像素单元的三维坐标。
在一些实施例中，如图11所示，提供了一种数据校正方法，以该方法1100应用于图9中的终端910为例进行说明，包括步骤1110、获取探测器像素单元的三维坐标。
在一些实施例中，获取模块210还可以通过测试模体确定探测器像素单元的三维坐标。例如，获取模块210可以获取测试模体在探测器上的投影图像，根据投影图像，确定探测器的响应中心点，根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间的距离，确定探测器像素单元的三维坐标。
测试模体可以为被医学扫描设备150扫描以获取探测器像素单元的三维坐标的物体。例如，均质平板、钢珠等。
探测器像素单元的三维坐标可以是指以旋转中心为坐标原点确定的探测器上探测器像素单元的三维坐标；射线发射装置的焦点坐标是以该旋转中心为坐标原点确定的焦点的三维坐标。旋转中心是指射线发射装置和探测器绕检测对象做圆周旋转时的中心，旋转中心是虚拟的点。具体地，在医学扫描设备为CT设备时，旋转中心可以是指CT设备的孔径中心线上的点。
图4是根据本说明书一些实施例所示的探测器像素单元的三维坐标所在的三维笛卡尔坐标系的示意图，如图4所示，在一些实施例中，可以以射线发射装置的旋转中心为原点、以射线发射装置的理论中心投影线为Y轴、以探测器的排方向为X轴及以探测器的通道方向为Z轴，建立一个三维笛卡尔坐标系，探测器像素单元的三维坐标可以为探测器像素单元在该三维笛卡尔坐标系上的坐标。其中，射线发射装置的理论中心投影线可以指射线发射装置的焦点垂直投影至探测器的投影线。
在一个实施例中，如图13所示，涉及获取探测器像素单元的三维坐标的一种可能的实现方式，步骤包括：
步骤1310、获取测试模体在探测器上的投影图像。
射线发射装置和探测器是绕测试模体旋转的，在通过射线发射装置和探测器的旋转，可以得到不同角度下的测试模体在探测器上的投影图像。具体地，投影图像可以是在探测器获得后传输至终端，并存储在终端的存储器中的，终端在需要时直接在存储器中获取即可。测试模体可以是均质平板，也可以是钢珠模体。本实施例对测试模体的种类和结构等不作限制，只要能够实现其功能即可。
步骤1320、根据投影图像，确定探测器的响应中心点。
终端在获取到测试模体在探测器上的多个投影图像后，根据投影图像可以确定探测器的响应中心点。具体地，终端对获取到的每个投影图像进行分析，确定投影图像的质心，将所有投影图像的质心连接，并求解所有质心连接后的图像的中心点，即为探测器的响应中心点。
步骤1330、根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间的距离，确定探测器像素单元的三维坐标。
探测器像素单元之间的距离可以由工作人员预先存储在终端的存储器中的，终端在需要时直接在存储器中获取即可。终端在得到探测器的响应中心点后，根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点和响应中心点之间的距离，可以确定探测器像素单元的三维坐标。
具体地，探测器像素单元的三维坐标是射线发射装置和探测器绕检测对象旋转时的旋转中心为坐标原点确定的，响应中心点、旋转中心和射线发射装置的焦点是在同一条直线上的，则根据射线发射装置的焦点坐标和射线发射装置的焦点和响应中心点之间的距离，可以得到响应中心点的三维坐标；根据响应中心点的三维坐标、响应中心点与其最近的探测器像素单元之间的距离，可以得到该探测器像素单元的三维坐标，根据探测器像素单元之间的距离，可以确定其他探测器像素单元的三维坐标。
本实施例提供的确定探测器像素单元的三维坐标的方法简单易懂，且容易实现。
探测器像素单元之间的距离即相邻两个探测器像素单元之间的距离。在一些实施例中，获取模块210可以通过任意可行的方式获取探测器像素单元之间的距离。例如，直接从用户终端130、存储设备140、医学扫描设备150或外部数据源获取探测器像素单元之间的距离。
在一些实施例中，获取模块210可以获取射线发射装置的焦点与旋转中心之间的距离，确定射线发射装置的焦点的三维坐标(0,-y tube,0)，其中，y tube为射线发射装置的焦点与旋转中心之间的距离。
在一些实施例中，获取模块210可以再根据射线发射装置的焦点的三维坐标确定探测器的响应中心点的三维坐标(0,y center,0)，其中，y center为响应中心点与旋转中心之间的距离。可以理解的，y center＝y total-y tube，其中，y total为射线发射装置的焦点与响应中心点之间的距离。
在一些实施例中，获取模块210可以通过任意可行的方式获取射线发射装置的焦点与响应中心点 之间的距离及射线发射装置的焦点与响应中心点之间的距离。例如，直接从用户终端130、存储设备140、医学扫描设备150或外部数据源获取射线发射装置的焦点与响应中心点之间的距离及射线发射装置的焦点与响应中心点之间的距离。
在一些实施例中，获取响应中心点的三维坐标后，获取模块210可以根据响应中心点的三维坐标及探测器像素单元之间的距离确定每个探测器像素单元的三维坐标。例如，获取模块210可以先确定与响应中心点相邻的多个探测器像素单元(即第一相邻探测器)的三维坐标，再确定每个第一相邻探测器相邻的多个探测器像素单元(即第二相邻探测器)的三维坐标，如此循环，直到所有的探测器相像素单元的三维坐标均被确定。仅作为示例地，响应中心点的左侧为X轴正方向时，响应中心点的左侧相邻的探测器像素单元的三维坐标即为(x space,y center,0)，其中，x space为探测器像素单元之间的距离；响应中心点的右侧相邻的探测器像素单元的三维坐标即为(-x space,y center,0)。
在一些实施例中，通过根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间的距离，可以快速且准确地确定探测器像素单元的三维坐标。
步骤320，根据探测器像素单元的空间位置和射线发射装置的焦点空间位置，计算余弦校正数据。在一些实施例中，步骤320可以由获取模块210执行。
射线发射装置的焦点空间位置可以用于表征射线发射装置的焦点的空间位置。射线发射装置的焦点空间位置可以通过任意形式进行表示。例如，射线发射装置的焦点空间位置可以表示为与参照物(例如，探测器的中心)的相对位置关系。又例如，探测器像素单元的空间位置可以通过三维坐标(即焦点坐标)进行表示。
余弦校正数据可以用于表征探测器像素单元与射线发射装置的焦点之间的连线，与射线发射装置的理论中心投影线之间的夹角。
在一些实施例中，如图11所示，步骤1110还可以包括根据探测器像素单元的三维坐标和射线发射装置的焦点坐标，计算余弦校正数据。
探测器上包括多个探测器像素单元，终端可以获取每一个探测器像素单元的三维坐标，以及射线发射装置的焦点坐标，并根据每一个探测器像素单元的三维坐标和射线发射装置的焦点坐标，计算得到每一个探测器像素单元的三维坐标和射线发射装置的焦点坐标之间的余弦校正数据。对于每一个探测器像素单元都可以计算得到一个余弦校正数据，则对于探测器上的多个探测器像素单元可以得到多个余弦校正数据。本实施例对计算余弦校正数据的具体过程不作限制，只要能够实现其功能即可。
在一个可选的实施例中，探测器上的多个探测器像素单元可以按照预设方式进行排列，例如，多个探测器像素单元按照m行n列排列，其中，行是以探测器的排方向进行定义的，列是以探测器的通道方向进行定义的。如图4所示，探测器的排方向可以是探测器像素单元所在的三维坐标系中的Z轴方向，探测器的通道方向可以是探测器像素单元所在的三维坐标系中的X方向。具体地，对于多个余弦校正数据可以使用矩阵的形式表示为S i,j，i＝1，2…m，j＝1，2…n，矩阵的行和列与探测器像素单元的行和列相对应，例如，第一矩阵S中的第i行第j列元素s i,j即表征探测器中的第i行第j列探测器像素单元对应的夹角cosθ i,j。余弦校正数据的矩阵如图12所示，图12中Channel是指探测器的通道方向，Slice是指探测器的排方向。
在一些实施例中，对于每个探测器像素单元，获取模块210可以通过该探测器像素单元的三维坐标和射线发射装置的焦点坐标，计算该探测器像素单元对应的夹角，再将每个探测器像素单元对应的夹角按照探测器上的探测器像素单元的排列方式进行组合，确定余弦校正数据。
在一些实施例中，针对每一个探测器像素单元，根据三维坐标和焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到余弦校正数据；第一连线是指探测器像素单元和射线发射装置的焦点之间的连线，第二连线为射线发射装置的焦点与探测器上的垂直点之间的连线，第二连线垂直于探测器。获取模块210可以根据探测器像素单元的三维坐标和焦点坐标计算第一连线的长度，再结合第二连线的长度，确定该探测器像素单元的夹角余弦，从而确定该探测器像素单元对应的夹角。可以理解的，第二连线的长度与第一连线长度的比值即为该探测器像素单元夹角余弦。
第一连线和第二连线均是虚拟连线，并不是实际存在的。垂直点也是虚拟的点，垂直点为第二连线与探测器的交点。对于某一个探测器像素单元，终端在计算余弦校正数据时，先确定第一连线(该探测器像素单元和射线发射装置的焦点之间的连线)与第二连线(射线发射装置的焦点与探测器上的垂直点之间的连线)的夹角，计算该夹角的余弦值，即射线发射装置的焦点与该探测器像素单元之间的距离与射线发射装置的焦点与探测器上的垂直点之间的距离的比值，就可以得到该探测器像素单元的余弦校正数据。使用同样的方法可以得到探测器中所有探测器像素单元的余弦校正数据。
探测器像素单元的三维坐标可以表示为(x i,j,y i,j,z i,j)，射线发射装置的焦点的三维坐标可以表示 为(0,-y tube,0)，则射线发射装置的焦点与探测器像素单元之间的距离l i,j可以表示为
Figure PCTCN2022102081-appb-000001
Figure PCTCN2022102081-appb-000002
射线发射装置的焦点与探测器上的垂直点之间的距离可以表示为k i,j，则余弦校正数据可以表示为cosθ i,j＝k ij/l i,j。
本实施例提供的确定计算余弦校正数据的方法简单快捷，可以提高确定校正系数的效率。
在一些实施例中，该垂直点即为上述的响应中心点。在确定响应中心点后，就可以直接根据响应中心点和射线发射装置的焦点确定第二连线，无需重新确定垂直点，能够提高计算余弦校正数据的效率。
在一些实施例中，根据所述探测器像素单元的三维坐标和所述焦点坐标，计算第一连线和第二连线之间的夹角余弦，可以快速且准确地得到所述余弦校正数据，从而快速确定探测器像素单元与射线发射装置的焦点之间的连线，与射线发射装置的理论中心投影线之间的夹角，便于后续确定探测器像素单元的校正系数。
步骤330，确定探测器的待校正响应数据。在一些实施例中，步骤330可以由确定模块220执行。
待校正响应数据可以为与射线发射装置扫描后，探测器中每一个探测器像素单元的响应数据相关的数据。例如，待校正响应数据可以指射线发射装置发射的射线通过测试模体发射到探测器后，探测器中每一个探测器像素单元的响应数据。该测试模体的种类、结构和材料等是已知的。需要获取待校正响应数据时，确定模块220可以控制医学扫描设备150执行至少一次扫描，以获取待校正响应数据。
在一个实施例中，如图14所示，涉及获取探测器的待校正响应数据的一种可能的实现方式，步骤包括：
步骤1410、获取模体数据和空气数据，模体数据为射线发射装置和探测器之间设置测试模体时探测器的响应数据，空气数据为射线发射装置和探测器之间未设置测试模体时探测器的响应数据。
测试模体可以是不同厚度的均质平板，例如：聚甲基丙烯酸甲酯板或铝板。在射线发射装置和探测器之间设置测试模体，射线发射装置发射的射线通过测试模体后传输至探测器，探测器中的每个探测器像素单元的响应数据记为模体数据。在射线发射装置和探测器之间未设置测试模体时探测器的响应数据，也就是说，射线发射装置发射的射线通过空气传输至探测器，探测器中的每个探测器像素单元的响应数据记为空气数据。不同厚度的测试模体的模体数据可以表示为
Figure PCTCN2022102081-appb-000003
i＝1，2…m，j＝1，2…n，其中，t表示测试模体的厚度。空气数据可以表示为
Figure PCTCN2022102081-appb-000004
i＝1，2…m，j＝1，2…n。
在一些实施例中，模体可以包括同一材料的不同厚度的均质平板、不同材料的同一厚度的均质平板、不同材料的不一厚度的均质平板或其任意组合。例如，模体可以包括10mm厚、8mm厚及6mm厚的聚甲基丙烯酸甲酯板扫描。又例如，模体可以包括10mm厚的聚甲基丙烯酸甲酯板扫描后及10mm厚的铝板。又例如，模体可以包括10mm厚的聚甲基丙烯酸甲酯板、6mm厚的聚甲基丙烯酸甲酯板及8mm厚的铝板。
步骤1420、根据空气数据和模体数据，确定待校正响应数据。
终端在得到空气数据和模体数据后，计算空气数据和模体数据的比值，并对该比值求对数，可以得到待校正响应数据。具体地，待校正响应数据M i,j可以表示为
Figure PCTCN2022102081-appb-000005
在本实施例中，在确定待校正响应数据时考虑到了空气对射线发射装置发射的射线的影响，使得确定的待校正响应数据更加接近实际应用场景，则根据该待校正响应数据确定的校正系数会更加准确，可以提高对探测器的响应非均匀性的校正效果。并且，在测试模体为均质平板时，可以消除由不同方向的射线穿过均质平板的长度差异对最终确定的校正系数的影响，从而使得确定的校正系数更加正确。
在一个具体的实施例中，在测试模体为10mm厚的聚甲基丙烯酸甲酯板，在对待校正响应数据进行校正前的如图15所示。在测试模体为100mm厚的聚甲基丙烯酸甲酯板，在对待校正响应数据进行校正后的如图16所示。图15和图16中的横坐标为探测器像素单元，纵坐标为对待校正响应数据进行校正后的目标数据，A表示校正后的目标数据，B表示校正前的待校正响应数据。从图15和图16中可以看出，校正后的目标数据的波动降低，均匀性得到较大的提升。
在一个具体的实施例中，在待检测对象为实际水膜时，对实际水膜的响应数据进行校正前的正弦图如图17所示，使用本申请提供的数据校正方法对实际水膜的响应数据进行校正后的正弦图如图18所示。对图17和图18进行对比中可以发现校正后正弦图均匀性提升，条状伪影减弱。
在一些实施例中，每个均质平板对应的待校正响应数据可以用第四矩阵表示，其中，第四矩阵中的一个元素可以表征一个探测器像素单元对应于该均质平板的空校值。例如，第四矩阵中第i行第j列元素
Figure PCTCN2022102081-appb-000006
即表征探测器中的第i行第j列探测器像素单元对应的数据。
步骤340，处理器使用余弦校正数据对待校正响应数据进行校正，得到目标数据。在一些实施例中，步骤340可以由确定模块220执行。
目标数据可以为待校正响应数据消除了不同方向的射线穿过均质平板的长度差异后的数据。在一些实施例中，确定模块220可以使用余弦校正数据对待校正响应数据进行校正，得到目标数据。对于每个均质平板对应的空校数据，处理器可以使用每个探测器像素单元对应的夹角对其进行校正，以获取每个均质平板对应的目标数据。
在一些实施例中，如图11所示的一种数据校正方法，还包括步骤1120、确定探测器的待校正响应数据，使用余弦校正数据对待校正响应数据进行校正，得到目标数据。终端获取探测器的待校正数据响应数据后，使用计算得到的余弦校正数据对待校正响应数据进行校正，得到校正后的数据，即目标数据。本实施例对确定探测器的待校正响应数据的方法不作限制，只要能够实现其功能即可。
具体地，探测器的待校正响应数据可以用矩阵来表示，可以表示为M i,j，i＝1，2…m，j＝1，2…n，终端可以将余弦校正数据(矩阵形式的)与待校正响应数据相乘(矩阵中对应位置的元素相乘)，得到目标数据，则目标数据B i,j可以表示为：
Figure PCTCN2022102081-appb-000007
其中，
Figure PCTCN2022102081-appb-000008
为哈达玛积(Hadamard product)，即两个矩阵的对应位置的元素相乘的运算。
在一些实施例中，确定模块220使用余弦校正数据对待校正响应数据进行校正，可以消除由不同方向的射线穿过均质平板的长度差异对最终确定的校正系数的影响，从而使得确定的校正系数更加正确。
步骤350，根据目标数据确定探测器像素单元对应的校正系数。在一些实施例中，步骤350可以由校正模块230执行。
校正系数可以为用于对探测器像素单元的响应数据进行校正，以减少伪影的参数。
在一些实施例中，校正模块230可以根据每一排探测器像素单元对应的目标数据的均值，确定校正系数，关于根据每一排探测器像素单元对应的目标数据的均值，确定校正系数可以参见图5及其相关描述，此处不再赘述。
步骤360，根据校正系数对待检测对象的响应数据进行校正。在一些实施例中，步骤360可以由校正模块230执行。
在一些实施例中，校正模块230可以先确定待检测对象的响应数据。可以将待检测对象放置在射线发射装置和探测器之间，医学扫描设备150对待检测对象扫描，以获取待检测对象的扫描数据。待检测对象的扫描数据可以用一个第五矩阵D i,j表示，其中，第五矩阵中的一个元素可以表征一个探测器像素单元响应于待检测对象的响应数据。例如，第五矩阵D i,j中第i行第j列元素d i,j即表征探测器中的第i行第j列探测器像素单元响应于待检测对象的响应数据。
在一些实施例中，校正模块230可以基于空气数据和待检测对象的扫描数据确定待检测对象的空校数据
Figure PCTCN2022102081-appb-000009
处理器可以通过校正系数对待检测对象的空校数据
Figure PCTCN2022102081-appb-000010
进行校正，获得校正后的数据。
如图11所示的一种数据校正方法，还可以包括步骤1130、根据目标数据确定探测器像素单元对应的校正系数，根据校正系数对待检测对象的响应数据进行校正。
待检测对象的响应数据是指射线发射装置发射的射线通过待检测对象发射到探测器后，探测器中每一个探测器像素单元的响应数据。终端在得到目标数据后，根据目标数据确定对探测器像素单元的响应数据进行校正时的校正系数，使用该校正系数可以对检测对象的响应数据进行校正。本实施例对确定校正系数的具体方法不作限制，只要能够实现其功能即可。
在一些实施例中，数据校正方法通过获取探测器像素单元的空间位置，根据探测器像素单元的空间位置和射线发射装置的焦点空间位置，计算余弦校正数据；确定探测器的待校正响应数据，使用余弦校正数据对待校正响应数据进行校正，得到目标数据；根据目标数据确定探测器像素单元对应的校正系数，根据校正系数对待检测对象的响应数据进行校正。本实施例提供的数据校正方法通过根据确定的余弦校正数据对待校正响应数据进行校正后的目标数据，可以得到对探测器像素单元的不均匀性进行校正的校正系数，通过该校正系数可以实现对待检测对象的响应数据进行更加准确的校正，从而能够提高对探测器像素单元的不均匀性进行校正的效果，进而能够使得待检测对象的重建图像具备更低的噪声和更少的伪影。
应当注意的是，上述有关流程300的描述仅仅是为了示例和说明，而不限定本说明书的适用范围。对于本领域技术人员来说，在本说明书的指导下可以对流程300进行各种修正和改变。然而，这些修正和改变仍在本说明书的范围之内。
图5是根据本说明书一些实施例所示的根据每一排探测器像素单元对应的目标数据的均值，确定校正系数的示例性流程图。如图5所示，流程500包括下述步骤。在一些实施例中，流程500可以由处理器110执行。
步骤510，对于探测器在预设方向上的每一排探测器像素单元，处理器计算探测器像素单元对应的目标数据的均值，将均值作为探测器像素单元的校正数据。
校正数据可以指用于确定校正系数的数据。
探测器的预设方向可以是指探测器的排方向，也可以是指探测器的通道方向。若预设方向为排方向，则终端对于探测器在排方向上的每一排探测器像素单元，计算该排所有探测器像素单元对应的目标数据的均值，将该均值作为该排探测器像素单元的校正数据。具体地，第i排探测器像素单元对应的校正数据
Figure PCTCN2022102081-appb-000011
可以表示为
Figure PCTCN2022102081-appb-000012
在一些实施例中，对于每一排探测器像素单元，处理器可以计算该排探测器像素单元对应的目标数据的均值，从而确定该排探测器像素单元中每个探测器像素单元的校正数据。例如，对于第a排探测器像素单元，其包括n个探测器像素单元(即，第一探测器像素单元、第二探测器像素单元及第n探测器像素单元等)，处理器可以计算n个探测器像素单元对应的目标数据的均值，并将该均值作为n个探测器像素单元的校正数据。
步骤520，根据所有探测器像素单元的校正数据，确定校正系数。
校正系数是指对探测器像素单元的响应数据进行校正后可以得到校正数据对应的系数。具体地，终端在得到探测器中所有探测器像素单元的校正数据后，确定校正系数。校正系数的确定可以根据探测器像素单元的不均匀性的变化关系进行确定。
本实施例提供的确定校正系数的方法简单易懂，计算快捷，容易实现。
在一个可选的实施例中，假设，探测器像素单元的不均匀性是线性变化的，则将探测器像素单元的目标数据线性映射至校正数据，可以得到
Figure PCTCN2022102081-appb-000013
其中，
Figure PCTCN2022102081-appb-000014
为第i排探测器像素单元对应的目标数据的均值，g i,j为第i行第j列的探测器像素单元对应的第一校正系数，b i,j为第i行第j列的探测器像素单元对应的第二校正系数。
在一些实施例中，处理器可以基于对应于不同厚度的均质平板的所有探测器像素单元的校正数据，对校正数据与目标数据的线性关系求解，确定校正系数。例如，图8是根据本说明书一些实施例所示的根据所有探测器像素单元的校正数据确定校正系数的示例性流程图，如图8所示，对于每个探测器像素单元，处理器可以根据该探测器像素单元响应于至少两个不同厚度的均质平板的校正数据(例如，响应于均质平板a的校正数据810、响应于均质平板b的校正数据820及响应于均质平板n的校正数据830等)，对上述线性关系840进行求解，得到该探测器像素单元对应的第一校正系数850和第二校正系数860。
在一些实施例中，处理器可以基于上述线性关系，对探测器像素单元响应于待检测对象的空校数据进行校正，以获得校正后的数据。例如，对于第i行第j列探测器像素单元，其校正后的数据为：
Figure PCTCN2022102081-appb-000015
在一些实施例中，通过建立校正数据与目标数据的线性关系，可以快速确定每个探测器像素单元对应的校正系数。
在一些实施例中，对于所述探测器在预设方向上的每一排探测器像素单元，处理器计算探测器像素单元对应的目标数据的均值，基于该均值确定校正系数，可以进一步降低用于确定校正系数的数据的波动性，使得确定的校正系数应用于待检测对象的响应数据的校正后，更有助于提升重建图像的均匀性。
在一些实施例中，数据校正方法还可以用于分析待检测对象的基物质组成的分布。图6是根据本说明书一些实施例所示的分析待检测对象的基物质组成的分布的示例性流程图。如图6所示，流程600可以包括以下步骤。
步骤610，确定多个均质平板组合。
均质平板组合可以包括至少两个不同厚度的均质平板。例如，均质平板组合1可以包括厚度为t p的均质平板a及厚度为t a的均质平板b。两个不同的均质平板可以由两种不同的基物质组成。例如，均质平板a为聚甲基丙烯酸甲酯均质平板，均质平板b为均质铝板。
步骤620，获取探测器响应于每个均质平板组合的空校数据。
对于每个均质平板组合，射线发射装置可以对该均质平板组合进行扫描，分布确定模块240获取探测器响应于该均质平板组合的每个均质平板的空校数据，关于获取均质平板的空校数据的更多描述可以参见图3及其相关描述，此处不再赘述。
步骤630，基于探测器响应于每个均质平板组合的空校数据，确定每种材料的均质平板对应不同厚度的分解系数。
在一些实施例中，分布确定模块240可以确定均质平板组合的空校数据及该均质平板组合中每块均质平板的厚度与每种基物质对应的分解系数之间的关系，基于探测器响应于每个均质平板组合的空校数据及每块均质平板的厚度，确定每种基物质对应的分解系数。
在一个实施例中，本申请实施例提供的数据校正方法可以用于分析待检测对象的基物质组成的分布。具体地，假设，测试模体使用厚度为t p的聚甲基丙烯酸甲酯均质平板和厚度为t a的均质铝板作为基物质，对于具有两个能量仓的(高能仓H和低能仓L)的射线发射装置，测试模体的厚度用以下公式表示：
Figure PCTCN2022102081-appb-000016
Figure PCTCN2022102081-appb-000017
其中，B H为射线发射装置高能仓采集的数据通过本申请提供的数据校正方法校正后的目标数据，B L为射线发射装置低能仓采集的数据通过本申请提供的数据校正方法校正后的目标数据。m 0，m 1，m 3…表示厚度为t p的聚甲基丙烯酸甲酯均质平板的分解系数，n 0，n 1，n 3…表示厚度为t a的均质铝板的分解系数。通过上述公式和两种均质平板对应的校正后的目标数据可以确定上述公式中的分解系数。基于上述公式、分解系数和待检测对象的目标数据可以得到待检测对象中两种基物质的分布情况。
以均质平板组合1为例，对于具有两个能量仓的(高能仓H和低能仓L)的射线发射装置，高能仓H和低能仓L对应的射线能量不同，例如，高能仓H可以发射80keV-140keV的射线，低能仓L可以发射30keV以下的射线。其中，B H为探测器响应于射线发射装置高能仓对均质平板组合1扫描后采集的数据，通过本申请提供的数据校正方法校正后的目标数据；B L为探测器响应于射线发射装置低能仓对均质平板组合1扫描后采集的数据。
可以理解的，处理器可以基于至少9种均质平板组合的空校数据，对上述公式进行求解，以确定m 0、m 1、m 2、m 3、m 4、m 5、m 6、m 7、m 8、n 0、n 1、n 2、n 3、n 4、n 5、n 6、n 7及n 8。
步骤640，基于待检测对象的响应数据及分解系数，确定待检测对象中基物质的分布。
在一些实施例中，分布确定模块240可以将待检测对象的响应数据及分解系数代入均质平板组合的空校数据及该均质平板组合中每块均质平板的厚度与每种基物质对应的分解系数之间的关系，以确定待检测对象中基物质的分布。其中，待检测对象的响应数据可以包括探测器响应于射线发射装置高能仓对待检测对象扫描后的空校数据及探测器响应于射线发射装置低能仓对待检测对象扫描后的空校数据。关于获取待检测对象的空校数据的更多描述可以参见图3及其相关描述，此处不再赘述。
仍以上述聚甲基丙烯酸甲酯均质平板及均质铝板为例，待检测对象由聚甲基丙烯酸甲酯均质平板及均质铝板组成，则待检测对象中聚甲基丙烯酸甲酯均质平板的厚度t x1和均质铝板的厚度t x2分别为：
Figure PCTCN2022102081-appb-000018
Figure PCTCN2022102081-appb-000019
其中，B H,i为探测器响应于射线发射装置高能仓对待检测对象扫描后的空校数据，B L,i为探测器响应于射线发射装置低能仓对待检测对象扫描后的空校数据。
在一些实施例中，通过确定多个均质平板组合，处理器获取探测器响应于每个均质平板组合的空校数据，并基于探测器响应于每个均质平板组合的空校数据，可以准确确定每种材料的均质平板对应不同厚度的分解系数，再基于待检测对象的响应数据及分解系数，可以准确确定待检测对象中基物质的分布。
在一些实施例中，数据校正方法还可以用于确定有效能量。图7是根据本说明书一些实施例所示的确定有效能量的示例性流程图。如图7所示，流程700可以包括以下步骤。
步骤710，基于响应于不同厚度的均质平板的校正数据，确定均质平板的有效衰减系数。
有效衰减系数可以表征均质平板的厚度与校正数据之间的对应关系。在一些实施例中，能量确定模块250可以通过线性拟合，基于不同厚度的均质平板的校正数据，确定用于表征均质平板的厚度与校正数据之间的对应关系的线性曲线，并将该线性曲线的斜率作为该均质平板的有效衰减系数。
步骤720，基于均质平板的有效衰减系数确定射线发射装置或探测器的有效能量。
有效能量可以指射线发射装置发射的射线穿过均质平板后能够被探测器响应的射线能量。在一些实施例中，能量确定模块250可以基于均质平板的有效衰减系数确定射线发射装置或探测器的有效能量。例如，能量确定模块250可以基于射线发射装置发射的射线能量及均质平板的有效衰减系数确定射线发射装置或探测器的有效能量。仅作为示例地，能量确定模块250可以将射线发射装置发射的射线能量与有效衰减系数的乘积作为有效能量。
在一些实施例中，通过基于响应于不同厚度的均质平板的校正数据，可以准确确定均质平板的有效衰减系数，再基于均质平板的有效衰减系数，可以快速确定射线发射装置或探测器的有效能量，为医学扫描设备的参数设置提供参考。
在一个实施例中，提供了一种计算机设备，该计算机设备可以是终端，其内部结构图可以如图19所示。该计算机设备包括通过***总线连接的处理器、存储器、通信接口、显示屏和输入装置。其中，该计算机设备的处理器用于提供计算和控制能力。该计算机设备的存储器包括非易失性存储介质、内存储器。该非易失性存储介质存储有操作***和计算机程序。该内存储器为非易失性存储介质中的操作***和计算机程序的运行提供环境。该计算机设备的通信接口用于与外部的终端进行有线或无线方式的通信，无线方式可通过WIFI、移动蜂窝网络、NFC(近场通信)或其他技术实现。该计算机程序被处理器执行时以实现一种数据校正方法。该计算机设备的显示屏可以是液晶显示屏或者电子墨水显示屏，该计算机设备的输入 装置可以是显示屏上覆盖的触摸层，也可以是计算机设备外壳上设置的按键、轨迹球或触控板，还可以是外接的键盘、触控板或鼠标等。
本领域技术人员可以理解，图19中示出的结构，仅仅是与本申请方案相关的部分结构的框图，并不构成对本申请方案所应用于其上的计算机设备的限定，具体的计算机设备可以包括比图中所示更多或更少的部件，或者组合某些部件，或者具有不同的部件布置。
在一个实施例中，提供了一种计算机设备，包括存储器和处理器，存储器中存储有计算机程序，该处理器执行计算机程序时实现以下步骤：
获取探测器像素单元的三维坐标，根据探测器像素单元的三维坐标和射线发射装置的焦点坐标，计算余弦校正数据；
确定探测器的待校正响应数据，使用余弦校正数据对待校正响应数据进行校正，得到目标数据；
根据目标数据确定探测器像素单元对应的校正系数，根据校正系数对待检测对象的响应数据进行校正。
在一个实施例中，处理器执行计算机程序时还实现以下步骤：对于探测器在预设方向上的每一排探测器像素单元，计算探测器像素单元对应的目标数据的均值，将均值作为探测器像素单元的校正数据；根据所有探测器像素单元的校正数据，确定校正系数。
在一个实施例中，处理器执行计算机程序时还实现以下步骤：获取测试模体在探测器上的投影图像；根据投影图像，确定探测器的响应中心点；根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间的距离，确定探测器像素单元的三维坐标。
在一个实施例中，处理器执行计算机程序时还实现以下步骤：针对每一个探测器像素单元，根据探测器像素单元的三维坐标和焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到余弦校正数据；第一连线是指探测器像素单元和射线发射装置的焦点之间的连线，第二连线为射线发射装置的焦点与探测器上的垂直点之间的连线，第二连线垂直于探测器。
在一个实施例中，垂直点为响应中心点。
在一个实施例中，处理器执行计算机程序时还实现以下步骤：获取模体数据和空气数据，模体数据为射线发射装置和探测器之间设置测试模体时探测器的响应数据，空气数据为射线发射装置和探测器之间未设置测试模体时探测器的响应数据；根据空气数据和模体数据，确定待校正响应数据。
在一个实施例中，提供了一种计算机可读存储介质，其上存储有计算机程序，计算机程序被处理器执行时实现以下步骤：
获取探测器像素单元的三维坐标，根据探测器像素单元的三维坐标和射线发射装置的焦点坐标，计算余弦校正数据；
确定探测器的待校正响应数据，使用余弦校正数据对待校正响应数据进行校正，得到目标数据；
根据目标数据确定探测器像素单元对应的校正系数，根据校正系数对待检测对象的响应数据进行校正。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：对于探测器在预设方向上的每一排探测器像素单元，计算探测器像素单元对应的目标数据的均值，将均值作为探测器像素单元的校正数据；根据所有探测器像素单元的校正数据，确定校正系数。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：获取测试模体在探测器上的投影图像；根据投影图像，确定探测器的响应中心点；根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间的距离，确定探测器像素单元的三维坐标。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：针对每一个探测器像素单元，根据探测器像素单元的三维坐标和焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到余弦校正数据；第一连线是指探测器像素单元和射线发射装置的焦点之间的连线，第二连线为射线发射装置的焦点与探测器上的垂直点之间的连线，第二连线垂直于探测器。
在一个实施例中，第二连线为射线发射装置的焦点与响应中心点之间的连线。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：获取模体数据和空气数据，模体数据为射线发射装置和探测器之间设置测试模体时探测器的响应数据，空气数据为射线发射装置和探测器之间未设置测试模体时探测器的响应数据；根据空气数据和模体数据，确定待校正响应数据。
在一个实施例中，提供了一种计算机程序产品，包括计算机程序，该计算机程序被处理器执行时实现以下步骤：
获取探测器像素单元的三维坐标，根据探测器像素单元的三维坐标和射线发射装置的焦点坐标，计算余弦校正数据；
确定探测器的待校正响应数据，使用余弦校正数据对待校正响应数据进行校正，得到目标数据；
根据目标数据确定探测器像素单元对应的校正系数，根据校正系数对待检测对象的响应数据进行校正。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：对于探测器在预设方向上的每一 排探测器像素单元，计算探测器像素单元对应的目标数据的均值，将均值作为探测器像素单元的校正数据；根据所有探测器像素单元的校正数据，确定校正系数。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：获取测试模体在探测器上的投影图像；根据投影图像，确定探测器的响应中心点；根据响应中心点、探测器像素单元之间的距离和射线发射装置的焦点与响应中心点之间的距离，确定探测器像素单元的三维坐标。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：针对每一个探测器像素单元，根据探测器像素单元的三维坐标和焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到余弦校正数据；第一连线是指探测器像素单元和射线发射装置的焦点之间的连线，第二连线为射线发射装置的焦点与探测器上的垂直点之间的连线，第二连线垂直于探测器。
在一个实施例中，垂直点为响应中心点。
在一个实施例中，计算机程序被处理器执行时还实现以下步骤：获取模体数据和空气数据，模体数据为射线发射装置和探测器之间设置测试模体时探测器的响应数据，空气数据为射线发射装置和探测器之间未设置测试模体时探测器的响应数据；根据空气数据和模体数据，确定待校正响应数据。
上文已对基本概念做了描述，显然，对于本领域技术人员来说，上述详细披露仅仅作为示例，而并不构成对本说明书的限定。虽然此处并没有明确说明，本领域技术人员可能会对本说明书进行各种修改、改进和修正。该类修改、改进和修正在本说明书中被建议，所以该类修改、改进、修正仍属于本说明书示范实施例的精神和范围。
同时，本说明书使用了特定词语来描述本说明书的实施例。如“一个实施例”、“一实施例”、和/或“一些实施例”意指与本说明书至少一个实施例相关的某一特征、结构或特点。因此，应强调并注意的是，本说明书中在不同位置两次或多次提及的“一实施例”或“一个实施例”或“一个替代性实施例”并不一定是指同一实施例。此外，本说明书的一个或多个实施例中的某些特征、结构或特点可以进行适当的组合。
此外，除非权利要求中明确说明，本说明书所述处理元素和序列的顺序、数字字母的使用、或其他名称的使用，并非用于限定本说明书流程和方法的顺序。尽管上述披露中通过各种示例讨论了一些目前认为有用的发明实施例，但应当理解的是，该类细节仅起到说明的目的，附加的权利要求并不仅限于披露的实施例，相反，权利要求旨在覆盖所有符合本说明书实施例实质和范围的修正和等价组合。例如，虽然以上所描述的***组件可以通过硬件设备实现，但是也可以只通过软件的解决方案得以实现，如在现有的服务器或移动设备上安装所描述的***。
同理，应当注意的是，为了简化本说明书披露的表述，从而帮助对一个或多个发明实施例的理解，前文对本说明书实施例的描述中，有时会将多种特征归并至一个实施例、附图或对其的描述中。但是，这种披露方法并不意味着本说明书对象所需要的特征比权利要求中提及的特征多。实际上，实施例的特征要少于上述披露的单个实施例的全部特征。
一些实施例中使用了描述成分、属性数量的数字，应当理解的是，此类用于实施例描述的数字，在一些示例中使用了修饰词“大约”、“近似”或“大体上”来修饰。除非另外说明，“大约”、“近似”或“大体上”表明所述数字允许有±20％的变化。相应地，在一些实施例中，说明书和权利要求中使用的数值参数均为近似值，该近似值根据个别实施例所需特点可以发生改变。在一些实施例中，数值参数应考虑规定的有效数位并采用一般位数保留的方法。尽管本说明书一些实施例中用于确认其范围广度的数值域和参数为近似值，在具体实施例中，此类数值的设定在可行范围内尽可能精确。
针对本说明书引用的每个专利、专利申请、专利申请公开物和其他材料，如文章、书籍、说明书、出版物、文档等，特此将其全部内容并入本说明书作为参考。与本说明书内容不一致或产生冲突的申请历史文件除外，对本说明书权利要求最广范围有限制的文件(当前或之后附加于本说明书中的)也除外。需要说明的是，如果本说明书附属材料中的描述、定义、和/或术语的使用与本说明书所述内容有不一致或冲突的地方，以本说明书的描述、定义和/或术语的使用为准。
最后，应当理解的是，本说明书中所述实施例仅用以说明本说明书实施例的原则。其他的变形也可能属于本说明书的范围。因此，作为示例而非限制，本说明书实施例的替代配置可视为与本说明书的教导一致。相应地，本说明书的实施例不仅限于本说明书明确介绍和描述的实施例。

Claims (20)

  1. 一种数据校正方法，应用于医学扫描设备，所述医学扫描设备包括射线发射装置和探测器，所述探测器包括多个探测器像素单元，其特征在于，所述方法包括：
    获取所述探测器像素单元的空间位置；
    根据所述探测器像素单元的空间位置和所述射线发射装置的焦点空间位置，计算余弦校正数据；
    确定所述探测器的待校正响应数据；
    使用所述余弦校正数据对所述待校正响应数据进行校正，得到目标数据；
    根据所述目标数据确定所述探测器像素单元对应的校正系数；
    根据所述校正系数对待检测对象的响应数据进行校正。
  2. 如权利要求1所述的方法，其特征在于，所述处理器根据所述目标数据确定所述探测器像素单元对应的校正系数，包括：
    对于所述探测器在预设方向上的每一排探测器像素单元，计算所述探测器像素单元对应的目标数据的均值，将所述均值作为所述探测器像素单元的校正数据；
    根据所有所述探测器像素单元的校正数据，确定所述校正系数。
  3. 如权利要求2所述的方法，其特征在于，所述待校正响应数据包括所述探测器响应于不同厚度的均质平板的数据。
  4. 如权利要求3所述的方法，其特征在于，所述根据所有所述探测器像素单元的校正数据，确定所述校正系数，包括：
    建立校正数据与目标数据的线性关系；
    基于对应于所述不同厚度的均质平板的所有所述探测器像素单元的校正数据，对所述校正数据与目标数据的线性关系求解，确定所述校正系数。
  5. 如权利要求1所述的方法，其特征在于，所述获取所述探测器像素单元的空间位置，包括：
    获取测试模体在所述探测器上的投影图像；
    根据所述投影图像，确定所述探测器的响应中心点；
    根据所述响应中心点、所述探测器像素单元之间的距离和所述射线发射装置的焦点与所述响应中心点之间的距离，确定所述探测器像素单元的三维坐标。
  6. 如权利要求5所述的方法，其特征在于，所述根据所述探测器像素单元的三维坐标和所述射线发射装置的焦点空间位置，计算余弦校正数据，包括：
    针对每一个所述探测器像素单元，根据所述探测器像素单元的三维坐标和所述焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到所述余弦校正数据，其中，所述第一连线是指所述探测器像素单元和所述射线发射装置的焦点之间的连线，所述第二连线为所述射线发射装置的焦点与所述探测器上的垂直点之间的连线，所述第二连线垂直于所述探测器。
  7. 如权利要求6所述的方法，其特征在于，所述垂直点为所述响应中心点。
  8. 如权利要求1所述的方法，其特征在于，所述确定所述探测器的待校正响应数据，包括：
    通过所述探测器获取模体数据和空气数据，其中，所述模体数据为所述射线发射装置和所述探测器之间设置测试模体时所述探测器的响应数据，所述空气数据为所述射线发射装置和所述探测器之间未设置所述测试模体时所述探测器的响应数据；
    根据所述空气数据和所述模体数据，确定所述待校正响应数据。
  9. 如权利要求8所述的方法，其特征在于，所述模体为至少两种厚度的均质平板。
  10. 一种数据校正***，其特征在于，包括：
    获取模块，用于获取所述探测器像素单元的空间位置，根据所述探测器像素单元的空间位置和所述射线发射装置的焦点空间位置，计算余弦校正数据；
    确定模块，用于确定所述探测器的待校正响应数据，使用所述余弦校正数据对所述待校正响应数据进行校正，得到目标数据；
    校正模块，用于根据所述目标数据确定所述探测器像素单元对应的校正系数，根据所述校正系数对待检测对象的响应数据进行校正。
  11. 如权利要求10所述的***，其特征在于，所述校正模块还用于：
    对于所述探测器在预设方向上的每一排探测器像素单元，计算所述探测器像素单元对应的目标数据的均值，将所述均值作为所述探测器像素单元的校正数据；
    根据所有所述探测器像素单元的校正数据，确定所述校正系数。
  12. 如权利要求11所述的***，其特征在于，所述待校正响应数据包括所述探测器响应于不同厚度的均质平板的数据。
  13. 如权利要求12所述的***，其特征在于，所述校正模块还用于：
    建立校正数据与目标数据的线性关系；
    基于对应于所述不同厚度的均质平板的所有所述探测器像素单元的校正数据，对所述校正数据与目标数据的线性关系求解，确定所述校正系数。
  14. 如权利要求10所述的***，其特征在于，所述获取模块还用于：
    获取测试模体在所述探测器上的投影图像；
    根据所述投影图像，确定所述探测器的响应中心点；
    根据所述响应中心点、所述探测器像素单元之间的距离和所述射线发射装置的焦点与所述响应中心点之间的距离，确定所述探测器像素单元的三维坐标。
  15. 如权利要求14所述的***，其特征在于，所述获取模块还用于：
    针对每一个所述探测器像素单元，根据所述探测器像素单元的三维坐标和所述焦点坐标，计算第一连线和第二连线之间的夹角余弦，得到所述余弦校正数据，其中，所述第一连线是指所述探测器像素单元和所述射线发射装置的焦点之间的连线，所述第二连线为所述射线发射装置的焦点与所述探测器上的垂直点之间的连线，所述第二连线垂直于所述探测器。
  16. 如权利要求15所述的***，其特征在于，所述垂直点为所述响应中心点。
  17. 如权利要求10所述的***，其特征在于，所述确定模块还用于：
    通过所述探测器获取模体数据和空气数据，其中，所述模体数据为所述射线发射装置和所述探测器之间设置测试模体时所述探测器的响应数据，所述空气数据为所述射线发射装置和所述探测器之间未设置所述测试模体时所述探测器的响应数据；
    根据所述空气数据和所述模体数据，确定所述待校正响应数据。
  18. 如权利要求17所述的***，其特征在于，所述模体为至少两种厚度的均质平板。
  19. 一种数据校正装置，包括处理器，所述处理器用于执行权利要求1～9中任一项所述的数据校正方法。
  20. 一种计算机可读存储介质，所述存储介质存储计算机指令，当计算机读取存储介质中的计算机指令后，计算机执行如权利要求1～9中任一项所述的数据校正方法。
PCT/CN2022/102081 2021-12-23 2022-06-28 一种数据校正方法和*** WO2023115879A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202111594782.2 2021-12-23
CN202111594782.2A CN114469151A (zh) 2021-12-23 2021-12-23 数据校正方法、装置、计算机设备、存储介质和程序产品

Publications (1)

Publication Number Publication Date
WO2023115879A1 true WO2023115879A1 (zh) 2023-06-29

Family

ID=81493629

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/102081 WO2023115879A1 (zh) 2021-12-23 2022-06-28 一种数据校正方法和***

Country Status (2)

Country Link
CN (1) CN114469151A (zh)
WO (1) WO2023115879A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114469151A (zh) * 2021-12-23 2022-05-13 武汉联影生命科学仪器有限公司 数据校正方法、装置、计算机设备、存储介质和程序产品
CN116449445B (zh) * 2023-06-15 2023-09-12 浙江啄云智能科技有限公司 X光探测板输出响应值的修正方法、装置、介质和设备

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5606166A (en) * 1994-05-18 1997-02-25 Sopha Medical Method for correcting the uniformity of a gamma camera
US20040101091A1 (en) * 2002-11-22 2004-05-27 Rosner S. Jeffrey Method for calibrating the intensity profile for a movable x-ray source
JP2010085265A (ja) * 2008-09-30 2010-04-15 Fujifilm Corp 放射線検出装置及び放射線撮影システム
US20140294277A1 (en) * 2013-03-29 2014-10-02 Canon Kabushiki Kaisha Image processing apparatus, image processing method, and storage medium
US20180317868A1 (en) * 2016-01-27 2018-11-08 Canon Kabushiki Kaisha Radiographic imaging apparatus, control method thereof, and computer-readable storage medium
CN111201783A (zh) * 2017-10-19 2020-05-26 索尼公司 成像装置和方法以及图像处理装置和方法
CN114469151A (zh) * 2021-12-23 2022-05-13 武汉联影生命科学仪器有限公司 数据校正方法、装置、计算机设备、存储介质和程序产品

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015067511A1 (en) * 2013-11-08 2015-05-14 Koninklijke Philips N.V. Empirical beam hardening correction for differential phase contrast ct
CN103654833B (zh) * 2013-11-19 2015-10-28 中国科学院过程工程研究所 Ct探测器偏转角的确定方法和装置

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5606166A (en) * 1994-05-18 1997-02-25 Sopha Medical Method for correcting the uniformity of a gamma camera
US20040101091A1 (en) * 2002-11-22 2004-05-27 Rosner S. Jeffrey Method for calibrating the intensity profile for a movable x-ray source
JP2010085265A (ja) * 2008-09-30 2010-04-15 Fujifilm Corp 放射線検出装置及び放射線撮影システム
US20140294277A1 (en) * 2013-03-29 2014-10-02 Canon Kabushiki Kaisha Image processing apparatus, image processing method, and storage medium
US20180317868A1 (en) * 2016-01-27 2018-11-08 Canon Kabushiki Kaisha Radiographic imaging apparatus, control method thereof, and computer-readable storage medium
CN111201783A (zh) * 2017-10-19 2020-05-26 索尼公司 成像装置和方法以及图像处理装置和方法
CN114469151A (zh) * 2021-12-23 2022-05-13 武汉联影生命科学仪器有限公司 数据校正方法、装置、计算机设备、存储介质和程序产品

Also Published As

Publication number Publication date
CN114469151A (zh) 2022-05-13

Similar Documents

Publication Publication Date Title
WO2023115879A1 (zh) 一种数据校正方法和***
CN107095691B (zh) 一种pet成像方法及***
WO2017148094A1 (en) System and method for reconstructing ect image
JP5152202B2 (ja) ポジトロンｃｔ装置
US9582884B2 (en) Image processor, treatment system, and image processing method for determining a position of a point
Johnston et al. Geometric calibration for a dual tube/detector micro‐CT system
US20200138395A1 (en) Medical image diagnostic device, medical image diagnostic method, and storage medium
CN107348969B (zh) 一种pet数据处理方法、***及pet成像设备
US11610753B2 (en) Systems and methods for correction of position of focal point
JP2015198893A (ja) 画像処理装置、治療システム及び画像処理方法
US10932735B2 (en) Nuclear medical diagnostic apparatus and image processing method
US20130299708A1 (en) Positron ct apparatus and a reconstruction method
CN109009204B (zh) 用于调节焦点位置的方法和***
CN111223159B (zh) 锥形束成像方法、装置、计算机设备和存储介质
Zhang et al. Iterative geometric calibration in circular cone-beam computed tomography
CN109658465B (zh) 图像重建过程中的数据处理、图像重建方法和装置
Spronk et al. Feasibility of a stationary head CT scanner using a CNT x-ray source array
CN110687585B (zh) 获取晶体效率的方法、装置、计算机设备和存储介质
Cheng et al. Maximum likelihood activity and attenuation estimation using both emission and transmission data with application to utilization of Lu‐176 background radiation in TOF PET
Jiang et al. Geometric calibration of a stationary digital breast tomosynthesis system based on distributed carbon nanotube X-ray source arrays
US11504083B2 (en) Systems and methods for determining examination parameters
US11494955B2 (en) Data driven reconstruction in emission tomography
KR20150062642A (ko) Pet 검출기 및 양전자방출 단층촬영장치
CN108703769B (zh) Tof数据的校正方法、装置、***和计算机可读存储介质
WO2018105493A1 (ja) 放射線撮影装置、放射線撮影システム、放射線撮影方法、及びプログラム

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22909211

Country of ref document: EP

Kind code of ref document: A1