Model body position measuring method and device, computer readable storage medium and electronic equipment

Abstract

The invention provides a motif position measurement method and device, a computer readable storage medium and electronic equipment, and relates to the technical field of motif position measurement, and the method comprises the steps: obtaining the ray attenuation data of each pixel at different rotation angles through rotating and scanning a motif; according to the ray attenuation data of each pixel at different rotation angles, determining a peak value of the ray attenuation data of a target pixel corresponding to each target row detector unit at different rotation angles, and extracting a target rotation angle corresponding to each target pixel at the peak value; and for each target row detector unit, determining the position of a die body according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning equipment. The technical effect of rapidly measuring the position of the cylindrical die body is achieved.

Description

Technical Field

[0001] The present disclosure relates to the technical field of phantom position measurement, and in particular to a phantom position measurement method, device, computer-readable storage medium, and electronic device. Background Art

[0002] Scanning equipment, such as medical scanning equipment, uses a certain medium (such as X-rays, electromagnetic fields, ultrasound, etc.) to interact with the human body to show the structure and density of internal tissues and organs in the form of images. Take CT (Computed Tomography) equipment as an example, which uses X-ray beams to perform layer-by-layer scans on the human body and uses computer processing to produce detailed images of the internal structure of the body.

[0003] In some CT calibration processes, the phantom needs to be placed in a specific position. If the phantom placement error is large, it will affect the subsequent data processing results. At present, in the relevant technology, the phantom position is obtained by rotating the scanning phantom, reconstructing the phantom cross-sectional image through the back-projection algorithm, and then measuring the phantom position in the image domain.

[0004] However, since the back-projection algorithm often takes a long time, this measurement method has disadvantages such as taking a long time. Therefore, the related technology cannot quickly measure the position of the phantom. Summary of the invention

[0005] The main purpose of the present disclosure is to provide a method and device for measuring the position of a phantom, a computer-readable storage medium and an electronic device, so as to solve the problem in the related art that the position of a phantom cannot be measured quickly.

[0006] In order to achieve the above-mentioned object, a first aspect of the present disclosure provides a method for measuring a phantom position, which is applied to a scanning device, wherein the scanning device includes a detector, wherein the detector includes N rows and M columns of detector units, wherein one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and both N and M are integers greater than 1; the method includes: By rotating the scanning phantom, the ray attenuation data of each pixel at different rotation angles is obtained; wherein the phantom is a cylindrical phantom; According to the ray attenuation data of each pixel at different rotation angles, the peak values ​​of the ray attenuation data of the target pixels corresponding to each target row detector unit at different rotation angles are determined, and the target rotation angle corresponding to each target pixel at the peak value is extracted; wherein a target row detector unit is a row of detector units among the N rows of detector units in the detector, the number of rows of all the target row detector units is less than or equal to N, and one target row detector corresponds to one target pixel; For each of the target row detector units, the phantom position is determined according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, wherein the parameters of the scanning device include: N, M, the distance from the ray source to the detector, the distance from the ray source to the rotation center, the width of all channels corresponding to the M columns of detector units of the detector, and the length of the N rows of detector units; the phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, and the angle of the phantom central axis.

[0007] Optionally, further, for the target pixel corresponding to any of the target row detector units, the target pixel is a pixel located in a central channel of the detector, and the central channel is used to indicate a channel corresponding to a column of detector units pointed to by a beam of rays from the ray source through the rotation center to reach the detector; determining the peak value of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, comprises: Determining first distribution information of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles; For each of the target pixels, determining a peak value in the first distribution information according to the first distribution information corresponding to the target pixel; If the rotation angle corresponding to the peak value in the first distribution information is located at the boundary of the first distribution information, then according to the periodic symmetry of the rotation scan, corresponding data is intercepted from the latter part of the first distribution information to fill the missing content in the front part at the boundary, so as to update the first distribution information; If the rotation angle corresponding to the peak value in the first distribution information is not located at the boundary of the first distribution information or after the first distribution information is updated, the first distribution information is filtered to extract the maximum value in the first distribution information by extracting low-frequency fluctuations, and the maximum value is used as the peak value.

[0008] Optionally, further, the target rotation angle is multiple, and for each of the target row detector units, determining the position of the phantom according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device includes: For each of the target row detector units, according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, determine the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit; Sampling two rows of detector units from all the target rows of detector units, and calculating the angle between the central axis of the phantom according to the center coordinates of the cross section of the phantom corresponding to each of the sampled rows of detector units and the distance between the two sampled rows of detector units; The position of the phantom is determined according to the center coordinates of the phantom cross section and the diameter of the phantom cross section corresponding to each target row detector unit and the angle of the phantom center axis.

[0009] Optionally, further, for each of the target row detector units, determining the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, comprises: For each target row detector unit, the following operations are performed: According to the second distribution information of the ray attenuation data of all channels of the detector unit of the target row at each target rotation angle, the width of the phantom projection at each target rotation angle is calculated by filtering and deriving each of the second distribution information respectively; Calculate the distance from the center of the cross section of the phantom to the rotation center according to the width of the phantom projection at each target rotation angle and the distance from the ray source to the rotation center; Calculate the cross-sectional diameter of the phantom corresponding to the detector unit of the target row according to the width of the phantom projection at each target rotation angle, the distance from the ray source to the rotation center, and the distance from the ray source to the detector; Determining a phantom deflection angle according to each of the target rotation angles; The center coordinates of the cross section of the phantom corresponding to the detector unit of the target row are determined according to the distance from the center of the cross section of the phantom to the rotation center and the deflection angle of the phantom.

[0010] Optionally, further, the method further includes: Detecting the phantom coverage according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data, and determining a target row of detector units; Wherein, the target row detector unit includes any of the following: Scanning at least one row of detector units of the phantom and / or at least one row of detector units with normal ray attenuation data; at least one row of detector units in the detector; After determining that at least one row of detector units of the phantom is not scanned and / or at least one row of detector units with abnormal ray attenuation data is determined, the position of the phantom is adjusted so that the detector can scan the phantom and / or each row of detector units with normal ray attenuation data.

[0011] Optionally, further, detecting the phantom coverage according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data includes: For each pixel, according to the ray attenuation data of the pixel at different rotation angles, the ray attenuation data of the pixel at all rotation angles are averaged to obtain third distribution information corresponding to each row of detector units, and the third distribution information corresponding to any row of detector units is used to represent the distribution of average attenuation data of any row of detector units in each channel; Determining, according to the third distribution information corresponding to each row of detector units, at least one row of detector units that has not scanned the phantom; and / or, Determine each edge row of detector units and a middle row of detector units from each row of detector units of the detector, sort the average attenuation data of each edge row of detector units, and calculate the difference between the average attenuation data of each edge row of detector units and the average attenuation data of the middle row of detector units after sorting; if the variance of the difference between the average attenuation data of at least one row of detector units among all the edge rows of detector units and the average attenuation data of the middle row of detector units is greater than a first variance threshold, then determine that the ray attenuation data of at least one row of detector units among all the edge rows of detector units is abnormal.

[0012] Optionally, further, obtaining the ray attenuation data of each pixel at different rotation angles by rotating the scanning phantom includes: By rotating the scanning phantom, scanning data based on the phantom at different rotation angles is collected, wherein the scanning data is used to represent the ray intensity value corresponding to each pixel; Scanning the air under conditions consistent with the scanning of the phantom, and collecting scanning data based on the air at different rotation angles; According to the scanning data based on the phantom and the scanning data based on the air, ray attenuation data of each pixel at different rotation angles is obtained.

[0013] A second aspect of the present disclosure provides a phantom position measurement device, which is applied to a scanning device, wherein the scanning device includes a detector, wherein the detector includes N rows and M columns of detector units, wherein one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and N and M are both integers greater than 1; the device further includes: A first processing unit is used to obtain ray attenuation data of each pixel at different rotation angles by rotating the scanning phantom; wherein the phantom is a cylindrical phantom; A second processing unit is used to determine the peak values ​​of the ray attenuation data of the target pixels corresponding to each target row detector unit at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, and extract the target rotation angle corresponding to each target pixel at the peak value; wherein a target row detector unit is a row of detector units among the N rows of detector units in the detector, the number of rows of all the target row detector units is less than or equal to N, and one target row detector corresponds to one target pixel; The third processing unit is used to determine the position of the phantom for each of the target row detector units according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, wherein the parameters of the scanning device include: N, M, the distance from the ray source to the detector, the distance from the ray source to the rotation center, the width of all channels corresponding to the M columns of detector units of the detector, and the length of the N rows of detector units; the phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, and the angle of the phantom central axis.

[0014] A third aspect of the present disclosure provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the phantom position measurement method provided in any one of the first aspects.

[0015] The fourth aspect of the present disclosure provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor executes the phantom position measurement method provided in any one of the first aspects.

[0016] A fifth aspect of the present disclosure provides a computer program product, which includes a computer program. When the computer program is executed by a processor, the method for measuring the position of a phantom provided in any one of the first aspects is implemented.

[0017] In the phantom position measurement method provided in the embodiment of the present disclosure, it is applicable to any cylindrical phantom. By rotating and scanning the phantom, the ray attenuation data of each pixel at different rotation angles is obtained, and the phantom position is subsequently measured based on the ray attenuation data to ensure the accuracy of the measurement; then, based on the ray attenuation data of each pixel at different rotation angles, the peak value of the ray attenuation data of the target pixel corresponding to each target row detector unit at different rotation angles is determined, and the target rotation angle corresponding to each target pixel at the peak value is extracted, and then for any target row detector unit, the phantom position is calculated according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device. Since the above calculation process does not require back projection and image reconstruction, the purpose of accurately measuring the position of the cylindrical phantom is achieved, thereby reducing the time for measuring the phantom position, achieving the technical effect of ensuring the measurement accuracy while improving the efficiency of the cylindrical phantom position measurement, thereby solving the technical problem that the related technology cannot quickly measure the phantom position. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of a phantom provided in an embodiment of the present disclosure; Figure 2 A schematic diagram of a detector provided in an embodiment of the present disclosure; Figure 3 A schematic diagram of a flow chart of a method for measuring a phantom position provided in an embodiment of the present disclosure; Figure 4 A schematic diagram of average attenuation distribution detected by all channels of a row of detector units provided in an embodiment of the present disclosure; Figure 5 A schematic diagram of average attenuation distribution of a row of detector units that fail to scan a phantom provided by an embodiment of the present disclosure; Figure 6 A schematic diagram of average attenuation distribution detected by all channels of a central row of detector units and a certain edge row of detector units provided in an embodiment of the present disclosure; Figure 7 A schematic diagram of the distribution of the average attenuation values ​​of the center row of detector units after sorting and the average attenuation values ​​of a certain edge row after sorting provided by an embodiment of the present disclosure; Figure 8A schematic diagram of the distribution of original data and low-pass filtered data provided in an embodiment of the present disclosure; Fig. 9 A schematic diagram of the distribution of original data and filled data provided in the embodiment of the present disclosure; Fig.10 A schematic diagram of the distribution of attenuation values ​​of all channels corresponding to two extreme angles provided in an embodiment of the present disclosure; Fig.11 A block diagram of a phantom position measurement device provided in an embodiment of the present disclosure; Fig.12 A block diagram of an electronic device provided for an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the scheme of the present disclosure, the technical scheme in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present disclosure.

[0021] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0022] In the present disclosure, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present disclosure and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0023] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this disclosure can be understood according to specific circumstances.

[0024] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] At present, in the related art, the position of the phantom is obtained by rotating and scanning the phantom, reconstructing the cross-sectional image of the phantom through the back-projection algorithm, and then measuring the position of the phantom in the image domain. However, since the back-projection algorithm often takes a long time, this measurement method has the disadvantage of being time-consuming. Therefore, the related art cannot quickly measure the position of the phantom.

[0027] In order to solve the above problems, the technical concept of the present disclosure is to use scanning data to directly measure the position of the phantom without back projection and image reconstruction, thereby achieving rapid measurement of the phantom position while ensuring measurement accuracy.

[0028] In practical applications, the execution subject of the present disclosure may be a phantom position measurement device, which may be deployed in an electronic device, such as a scanning device, and includes: at least one processor; and a memory connected to the at least one processor in communication; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor executes the phantom position measurement method described in any one of the first aspects. The scanning device may also include a detector, which includes N rows and M columns of detector units, one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and N and M are both integers greater than 1.

[0029] For example, the model body is a cylindrical water model, for example, the model body is a cylindrical water model with a diameter of 200 mm and a thickness of 80 mm. Figure 1 As shown, Figure 1A schematic diagram of a phantom provided in an embodiment of the present disclosure, Figure 1 shows the dimensions of the example phantom. Figure 1 The black straight line running through the phantom is defined as the central axis of the phantom.

[0030] Example detectors such as Figure 2 As shown, Figure 2 Example detector geometries are shown: Figure 2 The apex of the cone represents the ray source, and the bottom represents the detector. The detector contains 64 rows and 850 columns of detector units. One detector unit is called a pixel (i.e. one detector unit corresponds to one pixel), and one column of detector units is called a channel (i.e. one column of detector units corresponds to one channel or detection channel, and the following explanations are all based on channels, so they will not be repeated); the distance from the ray source to the detector is 1200 mm, and the distance from the ray source to the rotation center is 700 mm. Each pixel unit is 1.1 mm wide, and the total width of the 850 channels is 935 mm (i.e. 1.1 850=935); pixel length is 1.2 mm, and the total length of 64 rows is 76.8 mm (i.e. 1.2 64=76.8).

[0031] Specifically, the process of phantom position measurement may include: Step a1: Example motif (see Figure 1 example) and detector geometry (see Figure 2 example).

[0032] Step a2: Phantom scanning and data preprocessing. Rotate the scanning phantom to collect scanning data at different rotation angles; perform air correction on the scanning data to obtain ray attenuation data.

[0033] Step a3: Phantom coverage detection. The attenuation data at all rotation angles are averaged to reduce statistical errors.

[0034] Step a4: Calculate the cross-sectional diameter and center coordinates of the phantom.

[0035] Step a5: Phantom mid-axis inclination.

[0036] The phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, the phantom central axis angle, and the phantom coverage area.

[0037] Through the phantom position measurement of the above application scenarios, the present invention calculates the ray attenuation data through scanning data, and directly calculates the phantom position based on the ray attenuation data and the parameters of the scanning device. The calculation process does not require back projection and image reconstruction, thereby ensuring the measurement accuracy while improving the efficiency of the phantom position measurement.

[0038] It should be noted that in the technical solution of the present invention, the collection, storage, use, processing, transmission, provision and disclosure of information such as parameters and scanning data involved are in compliance with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0039] The following specific embodiments are used to describe the technical solution of the present disclosure in detail. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0040] The present disclosure provides a method for measuring the position of a phantom. Figure 3 As shown, the method includes the following steps S301 to S303: Step S301: obtaining ray attenuation data of each pixel at different rotation angles by rotating and scanning a phantom; wherein the phantom is a cylindrical phantom.

[0041] Step S302: Determine the peak value of the ray attenuation data of the target pixels corresponding to each target row detector unit at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, and extract the target rotation angle corresponding to each target pixel at the peak value; wherein, a target row detector unit is a row of detector units among the N rows of detector units in the detector, the number of rows of all the target row detector units is less than or equal to N, and one target row detector corresponds to one target pixel.

[0042] Step S303: For each of the target row detector units, determine the position of the phantom according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, the parameters of the scanning device include: N, M, the distance from the ray source to the detector, the distance from the ray source to the rotation center, the width of all channels corresponding to the M columns of detector units of the detector and the length of the N rows of detector units, and the phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, and the angle of the phantom central axis.

[0043] In the disclosed embodiment, by rotating the scanning phantom, the ray attenuation data of each pixel at different rotation angles is obtained, and the position of the phantom is subsequently measured based on the ray attenuation data to ensure the accuracy of the measurement; then, based on the ray attenuation data of each pixel at different rotation angles, the peak value of the ray attenuation data of the target pixel corresponding to each target row detector unit at different rotation angles is determined, and the target rotation angle corresponding to each target pixel at the peak value is extracted, and then for any target row detector unit, the position of the phantom is calculated based on the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device. Since the above calculation process does not require back projection and image reconstruction, the purpose of accurately measuring the position of the phantom is achieved, thereby reducing the time for measuring the position of the phantom, and achieving the goal of ensuring the measurement accuracy while improving the efficiency of the phantom position measurement.

[0044] Among them, the model position measurement method is applied to a scanning device, that is, the executor of the model position measurement method is a scanning device, and the scanning device includes a detector, and the detector includes N rows and M columns of detector units, one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and N and M are both integers greater than 1.

[0045] The following takes the scanning device as a CT device (the CT device includes a detector, the detector includes N rows and M columns of detector units, one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and N and M are both integers greater than 1) as an example to describe the method for measuring the position of the phantom in detail. For example, see Figure 1 and Figure 2 As shown, N is 64 and M is 850 as an example.

[0046] Optionally, obtaining the ray attenuation data of each pixel at different rotation angles by rotating the scanning phantom includes: By rotating the scanning phantom, scanning data based on the phantom at different rotation angles is collected, wherein the scanning data is used to represent the ray intensity value corresponding to each pixel; Scanning the air under conditions consistent with the scanning of the phantom, and collecting scanning data based on the air at different rotation angles; According to the scanning data based on the phantom and the scanning data based on the air, ray attenuation data of each pixel at different rotation angles is obtained.

[0047] In the embodiment of the present disclosure, step a2 includes phantom scanning and data preprocessing. The specific process is as follows: based on the scan data based on the phantom and the scan data based on the air, the ray attenuation data of each pixel at different rotation angles is calculated by the first formula; wherein the ray attenuation data of each pixel at different rotation angles is the ray attenuation data of each detector unit at different rotation angles; the first formula (i.e., formula (1)) is: (1) Exemplary, combined Figure 1 The example motifs and Figure 2 The detector geometry shown is taken as an example of X-ray (ray attenuation data, here is X-ray attenuation data) (other rays are similar and are not specifically limited here), and 1100 scanning data at different angles are collected in each circle (the different angles here are different rotation angles) as an example, and the scanning data (here refers to the scanning data based on the phantom) is recorded as ,in: Represents the channel number, Represents the row number, Represents the rotation angle number.

[0048] Perform air correction on the scan data to obtain X-ray attenuation data . Optionally, the air correction scheme is: scan the air under the same conditions as the phantom scan, and the scan data (here refers to the air-based scan data) is recorded as ,but .

[0049] in, It is the raw data collected by the CT device, indicating the X-ray intensity value received by the j-th row and i-th channel of the detector at the k-th rotation angle.

[0050] Optionally, the method further comprises: Detecting the phantom coverage according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data, and determining a target row of detector units; Wherein, the target row detector unit includes any of the following: Scanning at least one row of detector units of the phantom and / or at least one row of detector units with normal ray attenuation data; at least one row of detector units in the detector; After determining that at least one row of detector units of the phantom is not scanned and / or at least one row of detector units with abnormal ray attenuation data is determined, the position of the phantom is adjusted so that the detector can scan the phantom and / or each row of detector units with normal ray attenuation data.

[0051] The target row detector unit here is used for subsequent calculation of the model position. The number of rows of the target row detector unit can be multiple; wherein, the target row detector unit can be each row of detectors (a row here refers to a row of detector units, which will not be repeated below), or a row within the coverage range of the detected model, or a row that is detected to have not scanned the model and / or a row with abnormal data, and after adjusting the model position, each row of detectors can scan the model or the row with normal data. Here, no specific restrictions are made on which rows the target row detector units are.

[0052] In the embodiment of the present disclosure, combined with step a3, for any row of detector units, the attenuation data corresponding to each detector unit (or each channel) in the row of detector units at all rotation angles is averaged to reduce statistical errors. After the average is calculated, the average attenuation distribution (for example, the third distribution information) detected by all channels in a row is as follows: Figure 4 As shown ( Figure 4 shows the distribution of the average attenuation detected by all channels in a row of detectors after averaging over all rotation angles). Figure 4 The horizontal axis is the detector channel number, and the vertical axis is the average attenuation value (i.e., the average attenuation data, which will not be described in detail below). Figure 4 The distribution of the detection channels of the first row is compared with the average attenuation distribution detected by all channels of other rows, so as to determine the row that did not scan the phantom (here refers to at least one row of detector units that did not scan the phantom) and / or the row with abnormal data (here refers to at least one row of detector units with abnormal ray attenuation data).

[0053] Optionally, the detecting the phantom coverage according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data includes: For each pixel, according to the ray attenuation data of the pixel at different rotation angles, the ray attenuation data of the pixel at all rotation angles are averaged to obtain third distribution information corresponding to each row of detector units, and the third distribution information corresponding to any row of detector units is used to represent the distribution of average attenuation data of any row of detector units in each channel; Determining, according to the third distribution information corresponding to each row of detector units, at least one row of detector units that has not scanned the phantom; and / or, Determine each edge row of detector units and a middle row of detector units from each row of detector units of the detector, sort the average attenuation data of each edge row of detector units, and calculate the difference between the average attenuation data of each edge row of detector units and the average attenuation data of the middle row of detector units after sorting; if the variance of the difference between the average attenuation data of at least one row of detector units among all the edge rows of detector units and the average attenuation data of the middle row of detector units is greater than a first variance threshold, then determine that the ray attenuation data of at least one row of detector units among all the edge rows of detector units is abnormal.

[0054] Optionally, the variance may be calculated for each row of detector units in the detector, including but not limited to calculating edge rows, which can further ensure the accuracy of the measurement.

[0055] Optionally, determining, according to the third distribution information corresponding to each row of detector units, that at least one row of detector units of the phantom is not scanned may include: For any row of detector units, perform the following operation: if the variance of the average attenuation data corresponding to the current row of detector units and the average attenuation data corresponding to other rows of detector units is less than the second variance threshold (i.e., the set variance critical value) corresponding to the detector, it is determined that the current row of detector units has not scanned the model.

[0056] In the embodiment of the present disclosure, in combination with step a3, the phantom coverage detection may include determining a row where the phantom is not scanned and / or determining a row with abnormal data.

[0057] Specifically, for the row that does not scan the phantom: when a row of detectors (or a row of detector units, which will not be described in detail below) does not scan the phantom, its average attenuation distribution (here refers to the third distribution information, which will not be described in detail below) is as follows: Figure 5 As shown (taking a row of detector units that fail to scan the phantom as an example, Figure 5 shows the distribution of the average attenuation detected in a row when only air is scanned). Figure 5 The horizontal axis is the detector channel number, and the vertical axis is the average attenuation value. Figure 4 In contrast, the Figure 5 The variance of the distribution is much smaller than the variance of the corresponding data of the row that scanned the phantom. A critical value (here referred to as the second variance threshold) is set according to the specific situation of the detector. When the variance of the average attenuation distribution detected in a row is less than the critical value, it is determined that the phantom is not scanned.

[0058] For rows with abnormal data: In some cases, the data of the entire row of detectors may be abnormal. For example, the edge row only scans part of the model, or when scanning a water model with a plastic shell, the edge row only scans the plastic shell but not the water. To detect rows with abnormal data, take the difference between the ray attenuation data of each row (each row here can be the rows in the detector except the middle row, or the rows in the edge row, which is not specifically limited here) and the data of the middle row. When the variance of the difference is greater than a certain critical value (here refers to the first variance threshold), the data of the row is determined to be abnormal.

[0059] Among them, it was noted that when the phantom was tilted, even if all rows were correctly covered, there were still obvious differences between different rows, e.g. Figure 6 As shown, Figure 6 The average attenuation distribution of the center row and the average attenuation distribution of a certain edge row (i.e. Figure 6 The figure shows the distribution of the average attenuation detected by the center row and a certain edge row when not sorted. Due to the tilt of the model, there is a significant difference between the two). Figure 6 The horizontal axis is the detector channel number, and the vertical axis is the average attenuation value. To avoid misjudgment caused by such differences, when calculating the difference between any two rows of data, the attenuation data of each row (here refers to the ray attenuation data, which will not be repeated below) can be sorted separately, and then the difference between different rows can be calculated, such as Figure 7 As shown, Figure 7 The average attenuation value of the center row after sorting is shown in Figure 2. Figure 7 Shown Figure 6 The distribution of the two rows of data after sorting shows that the difference between the two rows is significantly smaller). Figure 7 The horizontal axis is the detector channel number, and the vertical axis is the average attenuation value. The comparison of the average attenuation values ​​of the center row and a row before and after sorting is shown in the figure below. Figure 6 and Figure 7 As shown, it can be seen that the difference between the two rows of data is significantly reduced after sorting.

[0060] Optionally, based on the determined rows that did not scan the phantom and / or rows with abnormal data, step a3 can be continued by adjusting the position of the phantom so that all rows of the detector can scan the phantom and / or the data are normal. The specific process will not be repeated here.

[0061] Optionally, determining the peak values ​​of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles includes: Determining first distribution information of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles; For each of the target pixels, determining a peak value in the first distribution information according to the first distribution information corresponding to the target pixel; If the rotation angle corresponding to the peak value in the first distribution information is located at the boundary of the first distribution information, then according to the periodic symmetry of the rotation scan, corresponding data is intercepted from the latter part of the first distribution information to fill the missing content in the front part at the boundary, so as to update the first distribution information; If the rotation angle corresponding to the peak value in the first distribution information is not located at the boundary of the first distribution information or after the first distribution information is updated, the first distribution information is filtered to extract the maximum value in the first distribution information by extracting low-frequency fluctuations, and the maximum value is used as the peak value.

[0062] Wherein, for the target pixel corresponding to any target row of detector units, the target pixel is a pixel located in the central channel of the detector, and the central channel is used to represent a channel corresponding to a column of detector units pointed to by a beam of rays from the ray source through the rotation center to reach the detector. The first distribution information is used to represent different rotation angles and a distribution diagram consisting of ray attenuation data corresponding to each rotation angle.

[0063] In the embodiment of the present disclosure, the following takes the ray attenuation data of a row of detector units as an example, and the attenuation data detected by the central channel at all rotation angles is distributed as follows: Figure 8 As shown by the black dashed line, Figure 8 The distribution of raw data (the raw data here refers to the scan data or the ray attenuation data or attenuation value corresponding to the scan data, the attenuation value is taken as an example below, and no further details are given below) and the distribution of low-pass filtered data (the low-pass filtered data here refers to the scan data after low-pass filtering or the ray attenuation data after low-pass filtering or the attenuation value after low-pass filtering, the attenuation value is taken as an example below, and no further details are given below) are shown. Figure 8 Shown is the attenuation distribution detected by the center channel of a row at all rotation angles. Figure 8 The two peaks in are caused by the channel detecting the X-rays attenuated by the phantom twice. The black dotted line is the original data, and the black solid line is the filtered data); Figure 8 The horizontal axis shown is the rotation angle number, and the vertical axis is the attenuation value (i.e., ray attenuation data, which will not be described in detail below). Figure 8 Medium attenuation data distribution, such as the first distribution information.

[0064] The central channel refers to the channel corresponding to a column of detector units pointed to by the beam of light from the ray source through the rotation center to the detector, and each row of detectors has one pixel located in the central channel. Figure 8It can be seen that in one rotation, the detector unit pixel measures the X-rays passing through the cross-sectional diameter of the phantom twice, forming two peaks. The rotation angle of the detector at the two peaks can be extracted through the following steps a4.1-step a4.3, and the projection width under the extreme angle (here refers to the target rotation angle, which will not be repeated below) can be obtained through step a4.4. Then, based on the projection width, the distance of the phantom from the rotation center can be calculated through step a4.5, the cross-sectional diameter of the phantom can be calculated through step a4.6, and the cross-sectional center coordinates (or the cross-sectional center coordinates of the phantom, which will not be repeated below) can be calculated through step a4.7. Among them, step a4 includes steps a4.1-step a4.7.

[0065] Specifically, step a4.1: boundary processing.

[0066] By extracting Figure 8 The extreme value of the distribution shown by the black dashed line can measure the rotation angle when the detector unit detects attenuation at the diameter of the phantom. Sometimes this rotation angle is just at the boundary of the distribution, such as Fig. 9 As shown by the black solid line in the middle, it is not conducive to the subsequent extreme value extraction. In order to facilitate the subsequent extreme value extraction, considering the periodic symmetry of the rotation scan, some data is intercepted from the latter part of the distribution and filled to its beginning, as shown in Fig. 9 As shown by the black dashed line, Fig. 9 The original data distribution and the filled data distribution are shown (the filled data here refers to the scan data after filling or the ray attenuation data after filling or the attenuation value after filling. The attenuation value is taken as an example below and will not be repeated below) (i.e. Fig. 9 The solid black line in the middle shows the attenuation data of a central channel at all rotation angles, with a peak located right at the boundary. Fig. 9 The black dotted line in the middle represents the data intercepted from the back of the solid line and filled to its beginning). Among them, Fig. 9 The horizontal axis is the rotation angle number, and the vertical axis is the attenuation value.

[0067] Step a4.2: Filtering processing.

[0068] Considering that there may be no sampling at the rotation angle when the X-ray just passes through the diameter of the phantom, resulting in missing data. In addition, the statistical fluctuation of the data is not conducive to the subsequent extraction of extreme values. It is necessary to filter the data, extract low-frequency fluctuations, and then extract two maximum values.

[0069] Optionally, the low-pass filtering method is: finding the average of several points near a certain point as the value of the point after filtering. Figure 8 The black dashed line in the middle is distributed as shown by the black solid line in the figure after appropriate filtering. The specific filtering parameters need to be adjusted according to the specific conditions of the detector (such as noise, sampling frequency, etc.), and high-frequency fluctuations should be eliminated as much as possible, and only low-frequency fluctuations caused by changes in the phantom projection should be retained.

[0070] Step a4.3: Extracting the extreme angle (or extreme angle, which refers to the target rotation angle here and will not be described in detail below).

[0071] By taking the derivative of the filtered distribution, we can quickly obtain Figure 8 The two maximum values ​​in the distribution (here refers to the peak value), record the corresponding rotation angles (here refers to the target rotation angle).

[0072] Optionally, there are multiple target rotation angles, and for each target row detector unit, determining the position of the phantom according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device includes: For each of the target row detector units, according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, determine the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit; Sampling two rows of detector units from all the target rows of detector units, and calculating the angle between the central axis of the phantom according to the center coordinates of the cross section of the phantom corresponding to each of the sampled rows of detector units and the distance between the two sampled rows of detector units; The position of the phantom is determined according to the center coordinates of the phantom cross section and the diameter of the phantom cross section corresponding to each target row detector unit and the angle of the phantom center axis.

[0073] In the disclosed embodiment, taking the ray attenuation data of a row of detector units as an example, the rotation angle of the detectors at two peaks can be extracted through the above steps a4.1 to a4.3, and the projection width under the extreme angle can be obtained through step a4.4. Then, based on the projection width, the distance of the phantom corresponding to the row of detector units from the rotation center can be calculated through step a4.5, the cross-sectional diameter of the phantom corresponding to the row of detector units can be calculated through step a4.6, and the cross-sectional center coordinates corresponding to the row of detector units can be calculated through step a4.7. Since the phantom is three-dimensional, a row of data can only give the position of a certain cross section of the phantom. Therefore, based on the above steps a4.1 to a4.7, the cross-sectional diameter of the phantom corresponding to each row of detector units and the cross-sectional center coordinates of the phantom corresponding to each row of detector units (or the cross-sectional center coordinates, which will not be repeated below) can be calculated, and the complete three-dimensional position obtained by arranging all rows (for example, 64 rows) of cross sections together can be obtained, and the inclination angle of the phantom center axis can be calculated through step a5, thereby determining the position of the phantom. It should be noted that the diameters of all rows of an ideal cylindrical phantom should be the same. Due to factors affecting the actual cylindrical phantom, the cross-sectional diameters of the phantom corresponding to each row of detector units may differ slightly. If the cross-sectional diameters of the phantom calculated for each row of detectors differ, the following methods can be used: Average: Calculate the average of all row diameters as the cross-sectional diameter of the phantom.

[0074] Fitting: Determine the overall diameter of the phantom by fitting the diameter data.

[0075] Calibration: Check the detector, scanning method and data processing process to eliminate sources of errors.

[0076] Specifically, step a5 includes: sampling two rows of detector units, taking the first row of detector units and the last row of detector units as examples, calculating the cross-sectional center coordinates of the first row according to step a4, and then calculating the cross-sectional center coordinates of the last row, and calculating the angle between the center axis of the phantom and the rotation axis according to the following second formula (i.e., formula (2)): (2) In the second formula, β is the required angle. is the distance between the two rows of detectors for sampling, are the center coordinates of the two cross sections. It can be determined by the length (and width) of the N, M, N rows of detector units or the length (and width) of each pixel in the parameters.

[0077] Optionally, for each of the target row detector units, determining the center coordinates of a phantom cross section corresponding to the target row detector unit and a phantom cross section diameter corresponding to the target row detector unit according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, comprises: For each target row detector unit, the following operations are performed: According to the second distribution information of the ray attenuation data of all channels of the detector unit of the target row at each target rotation angle, the width of the phantom projection at each target rotation angle is calculated by filtering and deriving each of the second distribution information respectively; Calculate the distance from the center of the cross section of the phantom to the rotation center according to the width of the phantom projection at each target rotation angle and the distance from the ray source to the rotation center; Calculate the cross-sectional diameter of the phantom corresponding to the detector unit of the target row according to the width of the phantom projection at each target rotation angle, the distance from the ray source to the rotation center, and the distance from the ray source to the detector; Determining a phantom deflection angle according to each of the target rotation angles; The center coordinates of the cross section of the phantom corresponding to the detector unit of the target row are determined according to the distance from the center of the cross section of the phantom to the rotation center and the deflection angle of the phantom.

[0078] In the disclosed embodiment, taking a row of detector units as an example, the projection width at the extreme angle is obtained through step a4.4, and then based on the projection width, the distance of the model corresponding to the row of detector units from the rotation center can be calculated through step a4.5, the cross-sectional diameter of the model corresponding to the row of detector units can be calculated through step a4.6, and the cross-sectional center coordinates corresponding to the row of detector units can be calculated through step a4.7.

[0079] Specifically, step a4.4: projection width at the extreme angle.

[0080] Under the above two extreme angles (i.e., target rotation angles), the data distribution of all channels in a row is as follows: Fig.10 As shown by the black solid line and the black dotted line, Fig.10 The data of all channels corresponding to the two extreme angles are shown (the data here may refer to ray attenuation data or attenuation value, which will not be repeated below), that is, Fig.10 shows the data distribution of all channels under a certain extreme angle (for example, the first extreme angle) ( Fig.10 The data distribution of all channels under another extreme angle (for example, the second extreme angle) is shown in the dashed line in the middle) Fig.10 (shown by the solid line in the middle) Fig.10The distribution of all channel data in a row at two extreme angles is shown. It can be seen that the width of the model projection at one angle is narrower than that at the other. Fig.10 The horizontal axis is the detector channel number, and the vertical axis is the attenuation value (here the ray attenuation data). Fig.10 The data distribution of all channels in, such as the second distribution information.

[0081] Among them, the narrower the phantom projection is, the farther the phantom is from the ray source at this angle; the wider the phantom projection is, the closer the phantom is to the ray source at this angle. By filtering and differentiating the two distributions respectively, the width of the phantom projection at the two extreme angles can be calculated.

[0082] Step a4.5: The eccentric distance of the phantom (i.e. the distance from the center of the phantom cross section to the center of rotation).

[0083] The width of the narrow projection (the width of the model projection corresponding to the narrower extreme angle of the projection) is recorded as , the other (i.e. the width of the wide projection: the width of the model projection corresponding to the wider extreme angle of the projection) is recorded as According to the third formula, the distance from the center of the cross section of the phantom to the center of rotation can be calculated: (3) Among them, the third formula (i.e. formula (3)) is the distance from the center of the phantom section to the rotation center, is the distance from the ray source to the center of rotation.

[0084] Step a4.6: Phantom cross-sectional diameter.

[0085] After obtaining the eccentric distance, the cross-sectional diameter of the phantom can be calculated according to the following fourth formula (Formula (4)): (4) Among them, in formula (4) is the cross-sectional diameter of the phantom, is the distance from the radiation source to the detector.

[0086] Step a4.7: Phantom deflection angle and cross-section center coordinates.

[0087] To facilitate the description of the position of the phantom, we define that when the phantom is eccentric to the top relative to the rotation center, its deflection angle is zero, and when the phantom is eccentric to the bottom relative to the rotation center, its deflection angle is 180. It can be concluded that the extreme angle with a wider projection is the deflection angle of the phantom, and the other extreme angle (here refers to the extreme angle with a narrower projection) differs from its deflection angle by 180. After obtaining the eccentric distance and deflection angle of the phantom, its cross-sectional center coordinates (here refers to the cross-sectional center coordinates of the phantom, for example: the cross-sectional center coordinates of the phantom corresponding to the row of detector units) are obtained by the following fifth formula (i.e., formula (5)): (5) Among them, in formula (5) is the deflection angle of the phantom, and (X, Y) is the coordinate of the center of the phantom section (i.e., the center of the phantom cross section or the center of the cross section, which will not be repeated below).

[0088] The measurement results obtained by using the example data are of high accuracy, and compared with the related art, the time taken by the phantom position measurement method provided by the present disclosure is significantly less than the latter.

[0089] Therefore, the present disclosure is applicable to all cylindrical phantoms, regardless of material or size; in the process of measuring the position of the phantom, back-projection and image reconstruction are not required, thus saving measurement time.

[0090] From the above description, it can be seen that the present disclosure achieves the following technical effects: the phantom position is measured based on ray attenuation data and the mean, thereby ensuring the accuracy of the measurement; at the same time, since the calculation process does not require back projection and image reconstruction, the time for measuring the phantom position is reduced, thereby ensuring the measurement accuracy while improving the efficiency of the phantom position measurement.

[0091] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0092] The present disclosure also provides a phantom position measurement device for implementing the phantom position measurement method embodiment, which is applied to a scanning device, wherein the scanning device includes a detector, wherein the detector includes N rows and M columns of detector units, wherein one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and both N and M are integers greater than 1. Fig.11As shown, the phantom position measurement device 110 includes: a first processing unit 1101, used to obtain the ray attenuation data of each pixel at different rotation angles by rotating and scanning the phantom; wherein the phantom is a cylindrical phantom; a second processing unit 1102, used to determine the peak value of the ray attenuation data of the target pixels corresponding to each target row detector unit at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, and extract the target rotation angle corresponding to each target pixel at the peak value; wherein a target row detector unit is a row of detector units in N rows of detector units in the detector, and all the target rows The number of rows of detector units is less than or equal to N, and one target row detector corresponds to one target pixel; the third processing unit 1103 is used to determine the position of the phantom for each target row detector unit according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, the parameters of the scanning device including: N, M, the distance from the ray source to the detector, the distance from the ray source to the rotation center, the width of all channels corresponding to the M columns of detector units of the detector and the length of the N rows of detector units, and the phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, and the angle of the phantom central axis.

[0093] Optionally, for the target pixel corresponding to any of the target row detector units, the target pixel is a pixel located in a central channel of the detector, and the central channel is used to indicate a channel corresponding to a column of detector units pointed to by a beam of rays from the ray source through the rotation center to reach the detector; the second processing unit 1102, when executing to determine the peak values ​​of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, specifically includes: determining the first peak values ​​of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles; distribution information; for each of the target pixels, determine the peak value in the first distribution information according to the first distribution information corresponding to the target pixel; if the rotation angle corresponding to the peak value in the first distribution information is located at the boundary of the first distribution information, then according to the periodic symmetry of the rotation scan, intercept the corresponding data from the latter part of the first distribution information to fill the missing content in the former part at the boundary, so as to update the first distribution information; if the rotation angle corresponding to the peak value in the first distribution information is not located at the boundary of the first distribution information or after updating the first distribution information, filter the first distribution information to extract the maximum value in the first distribution information by extracting low-frequency fluctuations, and the maximum value is used as the peak value.

[0094] Optionally, there are multiple target rotation angles, and the third processing unit 1103, when executing for each of the target row detector units, determining the position of the phantom according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, specifically includes: determining, for each of the target row detector units, the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device; sampling two rows of detector units from all the target row detector units, and calculating the angle between the phantom center axes according to the center coordinates of the phantom cross sections corresponding to the sampled rows of detector units, and the distance between the sampled two rows of detector units; determining the position of the phantom according to the center coordinates of the phantom cross section and the phantom cross section diameter and the angle between the phantom center axes corresponding to each of the target row detector units.

[0095] Optionally, the third processing unit 1103, when executing, for each of the target row detector units, according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, determining the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit, specifically includes: for each of the target row detector units, performing the following operations: according to the second distribution information of the ray attenuation data of all channels of the target row detector unit at each of the target rotation angles, by filtering and deriving each of the second distribution information, calculating each The width of the phantom projection at the target rotation angle; according to the width of the phantom projection at each target rotation angle and the distance from the ray source to the rotation center, the distance from the center of the phantom cross section to the rotation center is calculated; according to the width of the phantom projection at each target rotation angle, the distance from the ray source to the rotation center and the distance from the ray source to the detector, the phantom cross-sectional diameter corresponding to the target row detector unit is calculated; according to each target rotation angle, the phantom deflection angle is determined; according to the distance from the center of the phantom cross section to the rotation center and the phantom deflection angle, the center coordinates of the phantom cross section corresponding to the target row detector unit are determined.

[0096] Optionally, the phantom position measuring device is further used to perform the following operations: detecting the phantom coverage range according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data, and determining a target row of detector units; wherein the target row of detector units includes any one of the following: at least one row of detector units that have scanned the phantom and / or at least one row of detector units with normal ray attenuation data; at least one row of detector units in the detector; after determining at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data, adjusting the phantom position so that the detector can scan the phantom and / or each row of detector units with normal ray attenuation data.

[0097] Optionally, the phantom position measuring device, when executing the detection of the phantom coverage range according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data, specifically includes: for each pixel, according to the ray attenuation data of the pixel at different rotation angles, averaging the ray attenuation data of the pixel at all rotation angles to obtain third distribution information corresponding to each row of detector units, and the third distribution information corresponding to any row of detector units is used to indicate the distribution of the average attenuation data of any row of detector units in each channel; according to the ray attenuation data corresponding to each row of detector units, averaging the ray attenuation data of the pixel at all rotation angles to obtain third distribution information corresponding to each row of detector units. The third distribution information is used to determine that at least one row of detector units of the model has not been scanned; and / or, edge row detector units and middle row detector units are determined from the rows of detector units of the detector, and the average attenuation data of the edge row detector units are sorted respectively, and the difference between the average attenuation data of the edge row detector units and the average attenuation data of the middle row detector units after sorting is calculated; if the variance of the difference between the average attenuation data of at least one row of detector units and the average attenuation data of the middle row detector units in all the edge rows of detector units is greater than the first variance threshold, then it is determined that the ray attenuation data of at least one row of detector units in all the edge rows of detector units is abnormal.

[0098] Optionally, when the first processing unit 1101 executes the method of obtaining the ray attenuation data of each pixel at different rotation angles by rotating the scanning phantom, the method specifically includes: collecting scanning data based on the phantom at different rotation angles by rotating the scanning phantom, wherein the scanning data is used to represent the ray intensity value corresponding to each pixel; scanning the air under conditions consistent with the scanning of the phantom, and collecting scanning data based on the air at different rotation angles; and obtaining the ray attenuation data of each pixel at different rotation angles according to the scanning data based on the phantom and the scanning data based on the air.

[0099] The specific manner in which each unit in the above device embodiment performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0100] The present disclosure also provides an electronic device, such as Fig.12 As shown, the electronic device includes one or more processors 121 and a memory 122. Fig.12 A processor 121 is taken as an example.

[0101] The controller may further include: an input device 123 and an output device 124 .

[0102] The processor 121, the memory 122, the input device 123 and the output device 124 may be connected via a bus or other means. Fig.12 The example of connecting through bus is taken in the following.

[0103] The processor 121 may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips. The general-purpose processor may be a microprocessor or any conventional processor.

[0104] The memory 122 is a non-transitory computer-readable storage medium that can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as program instructions / modules corresponding to the control method in the embodiment of the present disclosure. The processor 121 executes various functional applications and data processing of the server by running the non-transitory software programs, instructions and modules stored in the memory 122, that is, the phantom position measurement method of the above method embodiment is implemented.

[0105] The memory 122 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of a processing device operated by the server, etc. In addition, the memory 122 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 122 may optionally include a memory remotely arranged relative to the processor 121, and these remote memories may be connected to a network connection device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0106] The input device 123 can receive input digital or character information, and generate key signal input related to user settings and function control of the processing device of the server. The output device 124 can include display devices such as a display screen.

[0107] One or more modules are stored in the memory 122 , and when executed by one or more processors 121 , the method as described above is performed.

[0108] The embodiment of the present disclosure further provides a scanning device, which is used to implement the phantom position measurement method as described above.

[0109] The embodiment of the present disclosure further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the phantom position measurement method as described above.

[0110] The embodiment of the present disclosure further provides a computer program product, including a computer program, which implements the phantom position measurement method as described above when executed by a processor.

[0111] Those skilled in the art can understand that the implementation of all or part of the processes in the above method embodiments can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when the program is executed, it can include the processes in the above method embodiments. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (FM), a hard disk (HDD), or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above types of memory.

[0112] Although the embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for measuring a phantom position, characterized in that: Applied to a scanning device, the scanning device includes a detector, the detector includes N rows and M columns of detector units, one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and N and M are both integers greater than 1; the method includes: By rotating the scanning phantom, the ray attenuation data of each pixel at different rotation angles is obtained; wherein the phantom is a cylindrical phantom; According to the ray attenuation data of each pixel at different rotation angles, the peak values ​​of the ray attenuation data of the target pixels corresponding to each target row detector unit at different rotation angles are determined, and the target rotation angle corresponding to each target pixel at the peak value is extracted; wherein a target row detector unit is a row of detector units among the N rows of detector units in the detector, the number of rows of all the target row detector units is less than or equal to N, and one target row detector corresponds to one target pixel; For each of the target row detector units, the phantom position is determined according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, wherein the parameters of the scanning device include: N, M, the distance from the ray source to the detector, the distance from the ray source to the rotation center, the width of all channels corresponding to the M columns of detector units of the detector, and the length of the N rows of detector units; the phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, and the angle of the phantom central axis.

2. The method according to claim 1, characterized in that For the target pixel corresponding to any of the target row detector units, the target pixel is a pixel located in the central channel of the detector, and the central channel is used to indicate a channel corresponding to a column of detector units pointed to by a beam of rays from the ray source through the rotation center to reach the detector; determining the peak value of the ray attenuation data of the target pixel corresponding to each target row detector unit at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, including: Determining first distribution information of the ray attenuation data of the target pixels corresponding to the detector units of each target row at different rotation angles according to the ray attenuation data of each pixel at different rotation angles; For each of the target pixels, determining a peak value in the first distribution information according to the first distribution information corresponding to the target pixel; If the rotation angle corresponding to the peak value in the first distribution information is located at the boundary of the first distribution information, then according to the periodic symmetry of the rotation scan, corresponding data is intercepted from the latter part of the first distribution information to fill the missing content in the front part at the boundary, so as to update the first distribution information; If the rotation angle corresponding to the peak value in the first distribution information is not located at the boundary of the first distribution information or after the first distribution information is updated, the first distribution information is filtered to extract the maximum value in the first distribution information by extracting low-frequency fluctuations, and the maximum value is used as the peak value.

3. The method according to claim 1, characterized in that There are multiple target rotation angles, and for each target row detector unit, determining the position of the phantom according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, including: For each of the target row detector units, according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, determine the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit; Sampling two rows of detector units from all the target rows of detector units, and calculating the angle between the central axis of the phantom according to the center coordinates of the cross section of the phantom corresponding to each of the sampled rows of detector units and the distance between the two sampled rows of detector units; The position of the phantom is determined according to the center coordinates of the phantom cross section and the diameter of the phantom cross section corresponding to each target row detector unit and the angle of the phantom center axis.

4. The method according to claim 3, characterized in that The method of determining, for each of the target row detector units, the center coordinates of the phantom cross section corresponding to the target row detector unit and the phantom cross section diameter corresponding to the target row detector unit according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, comprises: For each target row detector unit, the following operations are performed: According to the second distribution information of the ray attenuation data of all channels of the detector unit of the target row at each target rotation angle, the width of the phantom projection at each target rotation angle is calculated by filtering and deriving each of the second distribution information respectively; Calculate the distance from the center of the cross section of the phantom to the rotation center according to the width of the phantom projection at each target rotation angle and the distance from the ray source to the rotation center; Calculate the cross-sectional diameter of the phantom corresponding to the detector unit of the target row according to the width of the phantom projection at each target rotation angle, the distance from the ray source to the rotation center, and the distance from the ray source to the detector; Determining a phantom deflection angle according to each of the target rotation angles; The center coordinates of the cross section of the phantom corresponding to the detector unit of the target row are determined according to the distance from the center of the cross section of the phantom to the rotation center and the deflection angle of the phantom.

5. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Detecting the phantom coverage according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data, and determining a target row of detector units; Wherein, the target row detector unit includes any of the following: Scanning at least one row of detector units of the phantom and / or at least one row of detector units with normal ray attenuation data; at least one row of detector units in the detector; After determining that at least one row of detector units of the phantom is not scanned and / or at least one row of detector units with abnormal ray attenuation data is determined, the position of the phantom is adjusted so that the detector can scan the phantom and / or each row of detector units with normal ray attenuation data.

6. The method according to claim 5, characterized in that The method of detecting the phantom coverage according to the ray attenuation data of each pixel at different rotation angles to determine at least one row of detector units that have not scanned the phantom and / or at least one row of detector units with abnormal ray attenuation data includes: For each pixel, according to the ray attenuation data of the pixel at different rotation angles, the ray attenuation data of the pixel at all rotation angles are averaged to obtain third distribution information corresponding to each row of detector units, and the third distribution information corresponding to any row of detector units is used to represent the distribution of average attenuation data of any row of detector units in each channel; Determining, according to the third distribution information corresponding to each row of detector units, at least one row of detector units that has not scanned the phantom; and / or, Determine each edge row of detector units and a middle row of detector units from each row of detector units of the detector, sort the average attenuation data of each edge row of detector units, and calculate the difference between the average attenuation data of each edge row of detector units and the average attenuation data of the middle row of detector units after sorting; if the variance of the difference between the average attenuation data of at least one row of detector units among all the edge rows of detector units and the average attenuation data of the middle row of detector units is greater than a first variance threshold, then determine that the ray attenuation data of at least one row of detector units among all the edge rows of detector units is abnormal.

7. The method according to any one of claims 1 to 4, characterized in that: The step of obtaining the ray attenuation data of each pixel at different rotation angles by rotating the scanning phantom includes: By rotating the scanning phantom, scanning data based on the phantom at different rotation angles is collected, wherein the scanning data is used to represent the ray intensity value corresponding to each pixel; Scanning the air under conditions consistent with the scanning of the phantom, and collecting scanning data based on the air at different rotation angles; According to the scanning data based on the phantom and the scanning data based on the air, ray attenuation data of each pixel at different rotation angles is obtained.

8. A phantom position measuring device, characterized in that: Applied to a scanning device, the scanning device includes a detector, the detector includes N rows and M columns of detector units, one detector unit corresponds to one pixel, one column of detector units corresponds to one channel, and N and M are both integers greater than 1; the device includes: A first processing unit is used to obtain ray attenuation data of each pixel at different rotation angles by rotating the scanning phantom; wherein the phantom is a cylindrical phantom; A second processing unit is used to determine the peak values ​​of the ray attenuation data of the target pixels corresponding to each target row detector unit at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, and extract the target rotation angle corresponding to each target pixel at the peak value; wherein a target row detector unit is a row of detector units among the N rows of detector units in the detector, the number of rows of all the target row detector units is less than or equal to N, and one target row detector corresponds to one target pixel; The third processing unit is used to determine the position of the phantom for each of the target row detector units according to the ray attenuation data of all channels of the target row detector at the target rotation angle and the parameters of the scanning device, wherein the parameters of the scanning device include: N, M, the distance from the ray source to the detector, the distance from the ray source to the rotation center, the width of all channels corresponding to the M columns of detector units of the detector, and the length of the N rows of detector units; the phantom position includes the phantom cross-sectional diameter, the center coordinates of the phantom cross-sectional area, and the angle of the phantom central axis.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the phantom position measurement method according to any one of claims 1 to 7.

10. An electronic device, characterized in that: The electronic device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor executes the phantom position measurement method described in any one of claims 1 to 7.

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