Motif Position Measurement Method, Device, Computer Readable Storage Medium and Electronic Device

Abstract

The present disclosure provides a method, apparatus, computer-readable storage medium and electronic device for measuring the position of a phantom, relating to the technical field of phantom position measurement. The method includes: obtaining ray attenuation data of each pixel at different rotation angles by rotating and scanning the phantom; determining the peak values of the ray attenuation data of the target pixels corresponding to each target row of detector units at different rotation angles according to the ray attenuation data of each pixel at different rotation angles, and extracting the target rotation angles corresponding to each target pixel at the peak values; for each target row of detector units, determining the phantom position according to the ray attenuation data of all channels of the target row of detectors at the target rotation angle and the parameters of the scanning device. The present disclosure achieves the technical effect of quickly measuring the position of a cylindrical phantom.

Description

Technical Field

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

[0002] A scanning device, such as a medical scanning device, is an electronic device that uses a certain medium (such as X-rays, electromagnetic fields, ultrasonic waves, etc.) to interact with the human body and presents the internal tissue and organ structure and density of the human body in the form of an image. Taking a CT (Computed Tomography) device as an example, that is, computed tomography, it uses an X-ray beam to perform tomographic scanning on the human body and generates detailed images of the internal structure of the body with the aid of computer processing.

[0003] In some CT calibration and other processes, it is necessary to place the phantom at a specific position. If the placement error of the phantom is large, it will affect the subsequent data processing results. Currently, in related technologies, to obtain the position of the phantom, the phantom is rotated and scanned, and the cross-sectional image of the phantom is reconstructed by the back-projection algorithm, and then the position of the phantom is measured in the image domain.

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

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

[0006] To achieve the above object, a first aspect of the present disclosure provides a phantom position measurement method, which is applied to a scanning device. 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 both N and M are integers greater than 1; the method includes:

[0007] By rotating and scanning the phantom, ray attenuation data of each of the pixels at different rotation angles is obtained; wherein, the phantom is a cylindrical phantom;

[0008] According to the ray attenuation data of each of the pixels at different rotation angles, the peak value of the ray attenuation data of the target pixels corresponding to each target row of detector units at different rotation angles is determined, and the target rotation angle corresponding to each of the target pixels at the peak value is extracted; wherein, one target row of detector units is one row of detector units among the N rows of detector units of the detector, the number of rows of all the target rows of detector units is less than or equal to N, and one target row of detectors corresponds to one target pixel;

[0009] For each of the target row detector units, determine the phantom position 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, where the parameters of the scanning device include: N, M, the distance from the radiation source to the detector, the distance from the radiation source to the rotation center, the widths of all channels corresponding to the M column detector units of the detector, and the lengths of the N row detector units. The phantom position includes the phantom cross-sectional diameter, the phantom cross-sectional center coordinates, and the phantom central axis angle.

[0010] Optionally, further, for the target pixel corresponding to any one 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 represent the channel corresponding to a column of detector units pointed by the beam of rays passing through the rotation center from the radiation source to the detector. The determining, according to 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 includes:

[0011] Determine the first distribution information 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;

[0012] 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;

[0013] 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 rotational scan, intercept the corresponding data from the latter segment of the first distribution information to fill the missing content in the former segment at the boundary to update the first distribution information;

[0014] 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, perform a filtering process on the first distribution information, and extract the maximum value in the first distribution information by extracting the low-frequency fluctuations, and use the maximum value as the peak value.

[0015] Optionally, further, there are multiple target rotation angles. The determining, for each of the target row detector units, the phantom position 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:

[0016] For each of the target row detector units, 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, determine the center coordinates of the phantom cross-section corresponding to the target row detector unit and the diameter of the phantom cross-section corresponding to the target row detector unit;

[0017] Sample two rows of detector units from all the target row detector units, and calculate the included angle of the central axis of the phantom based on the center coordinates of the phantom cross-section corresponding to each sampled row of detector units and the distance between the two sampled rows of detector units;

[0018] Based on the center coordinates of the phantom cross-section corresponding to each target row detector unit, the diameter of the phantom cross-section, and the included angle of the central axis of the phantom, determine the position of the phantom.

[0019] Optionally, further, the step of for each of the target row detector units, 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, determining the center coordinates of the phantom cross-section corresponding to the target row detector unit and the diameter of the phantom cross-section corresponding to the target row detector unit includes:

[0020] For each of the target row detector units, perform the following operations:

[0021] Based on the second distribution information of the ray attenuation data of all channels of the target row detector unit at each target rotation angle, calculate the width of the phantom projection at each target rotation angle by filtering and differentiating each of the second distribution information respectively;

[0022] Based on the width of the phantom projection at each target rotation angle and the distance from the ray source to the rotation center, calculate the distance from the center of the phantom cross-section to the rotation center;

[0023] Based on 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, calculate the diameter of the phantom cross-section corresponding to the target row detector unit;

[0024] Based on each target rotation angle, determine the deflection angle of the phantom;

[0025] Based on the distance from the center of the phantom cross-section to the rotation center and the deflection angle of the phantom, determine the center coordinates of the phantom cross-section corresponding to the target row detector unit.

[0026] Optionally, further, the method further includes:

[0027] According to the ray attenuation data of each pixel at different rotation angles, detect the phantom coverage range 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 determine the target row of detector units;

[0028] Wherein, the target row of detector units includes any one of the following:

[0029] 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;

[0030] At least one row of detector units in the detector;

[0031] 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, adjust the position of the phantom so that the detector can scan the phantom and / or each row of detector units with normal ray attenuation data.

[0032] Optionally, further, the 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 includes:

[0033] For each pixel, according to the ray attenuation data of the pixel at different rotation angles, calculate the average value of the ray attenuation data of the pixel at all rotation angles to obtain the third distribution information corresponding to each row of detector units. The third distribution information corresponding to any row of detector units is used to represent the distribution of the average attenuation data of the any row of detector units in each channel;

[0034] According to the third distribution information corresponding to each row of detector units, determine at least one row of detector units that have not scanned the phantom; and / or,

[0035] Determine each edge row of detector units and the middle row of detector units from each row of detector units in the detector, sort the average attenuation data of each edge row of detector units respectively, and calculate the difference between the average attenuation data of each edge row of detector units after sorting and the average attenuation data of the middle row of detector units. If the variance of the difference between the average attenuation data of at least one row of detector units in all the edge rows of detector units and the average attenuation data of the middle row of detector units is greater than the first variance threshold, determine that the ray attenuation data of the at least one row of detector units in all the edge rows of detector units is abnormal.

[0036] Optionally, further, obtaining the ray attenuation data of each of the pixels at different rotation angles by rotating and scanning the phantom includes:

[0037] By rotating and scanning the phantom, collecting the scanning data based on the phantom at different rotation angles, where the scanning data is used to represent the ray intensity value corresponding to each pixel;

[0038] Scanning air under the condition consistent with the phantom scanning, and collecting the scanning data based on the air at different rotation angles;

[0039] According to the scanning data based on the phantom and the scanning data based on the air, obtaining the ray attenuation data of each pixel at different rotation angles.

[0040] The second aspect of the present disclosure provides a phantom position measuring device applied to a scanning device. 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, and one column of detector units corresponds to one channel, and both N and M are integers greater than 1; the device further includes:

[0041] A first processing unit for obtaining the ray attenuation data of each of the pixels at different rotation angles by rotating and scanning the phantom; where the phantom is a cylindrical phantom;

[0042] A second processing unit for determining the peak value of the ray attenuation data of the target pixels corresponding to each target row of detector units at different rotation angles according to the ray attenuation data of each of the pixels at different rotation angles, and extracting the target rotation angles corresponding to each of the target pixels at the peak value; where one target row of detector units is one row of detector units among the N rows of detector units in the detector, the number of rows of all the target row of detector units is less than or equal to N, and one target row of detector corresponds to one target pixel;

[0043] A third processing unit for, for each of the target row of detector units, determining the phantom position according to the ray attenuation data of all channels of the target row of 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. The phantom position includes the cross-sectional diameter of the phantom, the central coordinates of the phantom cross-section, and the included angle of the central axis of the phantom.

[0044] The third aspect of the present disclosure provides a computer-readable storage medium storing computer instructions for causing a computer to execute the phantom position measurement method provided in any one of the first aspects.

[0045] The fourth aspect of the present disclosure provides an electronic device, which 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 to cause the at least one processor to execute the phantom position measurement method provided in any one of the first aspects.

[0046] The fifth aspect of the present disclosure provides a computer program product, which includes a computer program that, when executed by a processor, implements the phantom position measurement method provided in any one of the first aspects.

[0047] In the phantom position measurement method provided in the embodiments of the present disclosure, it is applicable to any cylindrical phantom. By rotating and scanning the phantom, ray attenuation data of each pixel at different rotation angles is obtained. Subsequently, based on the ray attenuation data, the phantom position is measured, ensuring the accuracy of the measurement. Then, based on 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 of detector units at different rotation angles are determined, and the target rotation angles corresponding to each target pixel at the peak values are extracted. Then, for any target row of detector units, according to the ray attenuation data of all channels of the target row of detectors at the target rotation angle and the parameters of the scanning device, the phantom position is calculated. Since the above calculation process does not require backprojection 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, realizing the technical effect of improving the efficiency of measuring the position of the cylindrical phantom while ensuring the measurement accuracy, and further solving the technical problem that the related art cannot quickly measure the phantom position. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the related art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the related art. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0049] Figure 1 It is a schematic diagram of a phantom provided for the embodiments of the present disclosure;

[0050] Figure 2Schematic diagram of the detector provided by the embodiments of the present disclosure;

[0051] Figure 3 Flow schematic diagram of the phantom position measurement method provided by the embodiments of the present disclosure;

[0052] Figure 4 Schematic diagram of the average attenuation distribution detected by all channels of a certain row of detector units provided by the embodiments of the present disclosure;

[0053] Figure 5 Schematic diagram of the average attenuation distribution where a certain row of detector units does not scan the phantom provided by the embodiments of the present disclosure;

[0054] Figure 6 Schematic diagram of the average attenuation distribution detected by all channels of the central row of detector units and a certain edge row of detector units provided by the embodiments of the present disclosure;

[0055] Figure 7 Schematic diagram of the distribution after sorting the average attenuation values of the central row of detector units and the average attenuation values of a certain edge row after sorting provided by the embodiments of the present disclosure;

[0056] Figure 8 Schematic diagram of the distribution of the original data and the data after low-pass filtering provided by the embodiments of the present disclosure;

[0057] Figure 9 Schematic diagram of the distribution of the original data and the filled data provided by the embodiments of the present disclosure;

[0058] Figure 10 Schematic diagram of the attenuation value distribution of all channels corresponding to two extreme angles respectively provided by the embodiments of the present disclosure;

[0059] Figure 11 Block diagram of the phantom position measurement device provided by the embodiments of the present disclosure;

[0060] Figure 12 Block diagram of the electronic device provided by the embodiments of the present disclosure. Detailed implementation manners

[0061] In order to enable those skilled in the art to better understand the solutions of the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present disclosure.

[0062] It should be noted that the terms "first", "second", etc. in the specification, claims and above-mentioned drawings of the present disclosure are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so as to implement the embodiments of the present disclosure described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily limit to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0063] In the present disclosure, the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present disclosure and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation or be constructed and operated in a specific orientation.

[0064] Moreover, in addition to being used to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the present disclosure can be understood according to specific circumstances.

[0065] In addition, the terms "mounted", "arranged", "provided with", "connected", "linked", "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 directly connected, or indirectly connected through an intermediate medium, or there is 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 the present disclosure can be understood according to specific circumstances.

[0066] It should be noted that, without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other. The present disclosure will be described in detail below with reference to the drawings and in combination with the embodiments.

[0067] Currently, in the related art, to obtain the position of the phantom, the phantom is rotated and scanned, and the cross-sectional image of the phantom is reconstructed by the back-projection algorithm, and then the position of the phantom is measured in the image domain. However, since the back-projection algorithm often takes a long time, this measurement method has disadvantages such as long time consumption. Therefore, the related art cannot quickly measure the position of the phantom.

[0068] To solve the above problems, the technical concept of the present disclosure is to directly measure the position of the phantom using scan data, without performing backprojection and image reconstruction, thereby achieving rapid measurement of the phantom position while ensuring measurement accuracy.

[0069] 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, including: 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 to enable the at least one processor to execute the phantom position measurement method described in any item of the first aspect. Wherein, the scanning device may further 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 both N and M are integers greater than 1.

[0070] Exemplarily, taking a cylindrical water phantom as an example, for instance, the phantom is a cylindrical water phantom with a diameter of 200 mm and a thickness of 80 mm, as Figure 1 shown, Figure 1 which is a schematic diagram of the phantom provided by an embodiment of the present disclosure, Figure 1 showing the dimensions of the exemplary phantom, Figure 1 and the black straight line passing through the phantom is defined as the central axis of the phantom.

[0071] An exemplary detector is as Figure 2 shown, Figure 2 showing the geometric dimensions of the exemplary detector: Figure 2 In which the conical vertex represents the ray source and the bottom surface represents the detector. The detector includes 64 rows and 850 columns of detector units, and 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 hereinafter all are exemplified by channels and will not be elaborated further); 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. The width of each pixel unit is 1.1 mm, and the total width of 850 channels is 935 mm (i.e., 1.1 × 850 = 935); the length of the pixel is 1.2 mm, and the total length of 64 rows is 76.8 mm (i.e., 1.2 × 64 = 76.8).

[0072] Specifically, the process of measuring the phantom position may include:

[0073] Step a1: The exemplary phantom (see Figure 1 example) and the detector geometry (see Figure 2Example).

[0074] Step a2: Phantom scanning and data preprocessing. Rotate and scan the phantom, and acquire scanning data at different rotation angles; perform air correction on the scanning data to obtain ray attenuation data.

[0075] Step a3: Phantom coverage detection. Calculate the average value of the attenuation data at all rotation angles to reduce statistical errors.

[0076] Step a4: Calculate the cross-sectional diameter and central coordinates of the phantom.

[0077] Step a5: Tilt angle of the central axis of the phantom.

[0078] Among them, the phantom position includes the cross-sectional diameter of the phantom, the central coordinates of the phantom cross-section, the included angle of the central axis of the phantom, and the phantom coverage.

[0079] Through the measurement of the phantom position in the above application scenario, the present disclosure calculates the ray attenuation data through the scanning data, and directly calculates the phantom position based on the ray attenuation data and the parameters of the scanning device. This calculation process does not require back-projection and image reconstruction, achieving both ensuring the measurement accuracy and improving the efficiency of phantom position measurement.

[0080] It should be noted that in the technical solution of the present disclosure, the collection, storage, use, processing, transmission, provision, and disclosure of information such as parameters and scanning data comply with the provisions of relevant laws and regulations and do not violate public order and good customs.

[0081] The technical solution of the present disclosure will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

[0082] The embodiment of the present disclosure provides a method for measuring the position of a phantom, as Figure 3 shown, the method includes the following steps S301 to step S303:

[0083] Step S301: Obtain the ray attenuation data of each pixel at different rotation angles by rotating and scanning the phantom; among them, the phantom is a cylindrical phantom.

[0084] Step S302: According to the ray attenuation data of each pixel at different rotation angles, determine the peak value of the ray attenuation data of the target pixel corresponding to each target row detector unit at different rotation angles, and extract the target rotation angle corresponding to each target pixel at the peak value; where a target row detector unit is one row of detector units among N row detector units in the detector, the number of all target row detector units is less than or equal to N, and one target row detector corresponds to one target pixel.

[0085] Step S303: For each of the target row detector units, determine the phantom position 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, where the parameters of the scanning device include: N, M, the distance from the radiation source to the detector, the distance from the radiation source to the rotation center, the widths of all channels corresponding to the M column detector units of the detector, and the length of the N row detector units, and the phantom position includes the phantom cross-sectional diameter, the phantom cross-sectional center coordinates, and the phantom central axis angle.

[0086] In the embodiments of the present disclosure, by rotating and scanning the phantom, the ray attenuation data of each pixel at different rotation angles is obtained. Subsequently, the phantom position is measured based on the ray attenuation data, ensuring the accuracy of the measurement. Then, based on 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 angles corresponding to each target pixel at the peak values are extracted. 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 phantom position is achieved, thereby reducing the time for measuring the phantom position and realizing the improvement of the efficiency of measuring the phantom position while ensuring the measurement accuracy.

[0087] Among them, this phantom position measurement method is applied to a scanning device, that is, the execution subject of this phantom position measurement method is the scanning device. 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 both N and M are integers greater than 1.

[0088] The following takes 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 both N and M are integers greater than 1) as an example to elaborate on the phantom position measurement method. Exemplarily, refer to Figure 1 and Figure 2 As shown, taking N as 64 and M as 850 as an example.

[0089] Optionally, the obtaining the ray attenuation data of each pixel at different rotation angles by rotating and scanning the phantom includes:

[0090] By rotating and scanning a phantom, scan data based on the phantom at different rotation angles is acquired, where the scan data is used to represent the ray intensity value corresponding to each pixel;

[0091] Under the condition consistent with the phantom scan, air is scanned, and scan data based on the air at different rotation angles is acquired;

[0092] Based on the scan data based on the phantom and the scan data based on the air, ray attenuation data of each pixel at different rotation angles is obtained.

[0093] In the embodiment of the present disclosure, step a2 is phantom scan 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, through the first formula, ray attenuation data of each pixel at different rotation angles is calculated; where 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:

[0094] (1)

[0095] Exemplarily, in combination with Figure 1 the example phantom shown and Figure 2 the detector geometry shown, taking the ray as an X-ray (ray attenuation data, here it is X-ray attenuation data) as an example (other rays are similar and will not be specifically limited here), taking 1100 scan data at different angles (here the different angles are different rotation angles) per circle as an example, the scan data (here it refers to the scan data based on the phantom) is denoted as , where: represents the channel number, represents the row number, represents the rotation angle number.

[0096] Air correction is performed on the scan data to obtain X-ray attenuation data . Optionally, the air correction scheme is: Under the condition consistent with the phantom scan, air is scanned, and the scan data (here it refers to the scan data based on the air) is denoted as , then .

[0097] Among them, is the raw data acquired by the CT device, representing the X-ray intensity value received by the i-th channel of the j-th row of the detector at the k-th rotation angle.

[0098] Optionally, the method further includes:

[0099] Detect the phantom coverage range according to the ray attenuation data of each pixel at different rotation angles, so as 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 determine the target row of detector units;

[0100] Wherein, the target row of detector units includes any one of the following:

[0101] 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;

[0102] At least one row of detector units in the detector;

[0103] 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, adjust the position of the phantom so that the detector can scan the phantom and / or each row of detector units with normal ray attenuation data.

[0104] The target row of detector units here is used for subsequent calculation of the phantom position. The number of rows of the target row of detector units can be multiple; among them, the target row of detector units can be each row of the detector (the row here refers to a row of detector units, which will not be elaborated below), or the rows within the detected phantom coverage range, or after detecting the rows that have not scanned the phantom and / or the rows with abnormal data, each row of the detector can scan the phantom or the rows with normal data after adjusting the phantom position. The specific rows of the target row of detector units are not specifically limited here.

[0105] In the embodiment of the present disclosure, in combination with step a3, for any row of detector units, calculate the mean value of the attenuation data corresponding to each detector unit (or each channel) in this row of detector units at all rotation angles to reduce the statistical error. After the mean value calculation, the average attenuation distribution detected by all channels in a certain row (for example, the third distribution information) is as Figure 4 shown ( Figure 4 shows the distribution of the average attenuation detected by all channels of a certain row of detectors after averaging all rotation angles), Figure 4 where the abscissa is the detector channel number and the ordinate is the average attenuation value (that is, the average attenuation data, which will not be elaborated below). Then based on the Figure 4 distribution, compare it with the average attenuation distributions detected by all channels of other rows, and then determine the rows that have not scanned the phantom (here refers to at least one row of detector units that have not scanned the phantom) and / or the rows with abnormal data (here refers to at least one row of detector units with abnormal ray attenuation data).

[0106] Optionally, detecting the phantom coverage based on 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:

[0107] For each pixel, based on the ray attenuation data of the pixel at different rotation angles, calculate the average value of the ray attenuation data of the pixel at all rotation angles to obtain the third distribution information corresponding to each row of detector units. The third distribution information corresponding to any row of detector units is used to represent the distribution of the average attenuation data of the any row of detector units in each channel;

[0108] Based on the third distribution information corresponding to each row of detector units, determine at least one row of detector units that have not scanned the phantom; and / or,

[0109] Determine the edge row detector units and the middle row detector units from each row of detector units of the detector. Sort the average attenuation data of each of the edge row detector units respectively, and calculate the difference between the average attenuation data of each of the sorted edge row detector units and the average attenuation data of the middle row detector units. If the variance of the difference between the average attenuation data of at least one row of detector units among all the edge row detector units and the average attenuation data of the middle row detector units is greater than the first variance threshold respectively, determine that the ray attenuation data of the at least one row of detector units among all the edge row detector units is abnormal.

[0110] Optionally, the variance can be calculated for each row of detector units in the detector, including but not limited to calculating the edge rows, which can further ensure the accuracy of the measurement.

[0111] Optionally, determining at least one row of detector units that have not scanned the phantom based on the third distribution information corresponding to each row of detector units may include:

[0112] For any row of detector units, perform the following operation: If the variance between 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, determine that the current row of detector units has not scanned the phantom.

[0113] In the embodiments of the present disclosure, in combination with step a3, the phantom coverage detection may include determining the rows that have not scanned the phantom and / or determining the rows with abnormal data.

[0114] Specifically, for the rows where the phantom is not scanned: When a row of detectors (or a row of detector units, not elaborated below) does not scan the phantom, its average attenuation distribution (here referring to the third distribution information, not elaborated below) is as Figure 5 shown (taking a row of detector units not scanning the phantom as an example, Figure 5 shows the distribution of the average attenuation detected by a row when only air is scanned), Figure 5 where the abscissa is the detector channel number and the ordinate is the average attenuation value. Compared with Figure 4 , the variance of the distribution of this Figure 5 is much smaller than the variance of the corresponding data of the rows that scan the phantom. A critical value (here referring to the second variance threshold) is set according to the specific situation of the detector. When the variance of the average attenuation distribution detected by a row is less than this critical value, it is determined that the phantom is not scanned.

[0115] For the rows with abnormal data: In some cases, the data of an entire row of detectors may be abnormal. For example, in the edge rows, only part of the phantom is scanned, or when scanning a water phantom with a plastic shell, only the plastic shell is scanned in the edge rows and the water is not scanned. To detect the rows with abnormal data, the difference between the ray attenuation data of each row (here each row can be other rows except the middle row in the detector, or each row in the edge rows, not specifically limited here) and the data of the middle row is taken. When the variance of this difference is greater than a certain critical value (here referring to the first variance threshold), it is determined that the data of this row is abnormal.

[0116] Among them, it should be noted that when the phantom is tilted, even if all rows are correctly covered, there are still obvious differences between different rows, as Figure 6 shown, Figure 6 showing the distribution of the average attenuation values of the central row and the average attenuation values of a certain edge row (i.e., Figure 6 shows the distribution of the average attenuation detected by the central row and a certain edge row before sorting. Due to the tilt of the phantom, there are obvious differences between the two), where Figure 6 the abscissa is the detector channel number and the ordinate 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 referring to the ray attenuation data, not elaborated below) can be sorted first, and then the difference between different rows can be calculated, as Figure 7 shown, Figure 7 showing the distribution of the sorted average attenuation values of the central row and the distribution of the sorted average attenuation values of a certain edge row (i.e., Figure 7 shows Figure 6 the distribution of the two rows of data after sorting, and it can be seen that the difference between the two becomes significantly smaller), where Figure 7 the abscissa is the detector channel number and the ordinate is the average attenuation value. The comparison diagrams of the average attenuation values of the central row and a certain row before and after sorting are respectively asFigure 6 and Figure 7 As shown in and

[0117] , it can be seen that the difference between the two rows of data after sorting is significantly reduced.

[0117] Optionally, based on the determined row(s) without the scanned phantom and / or the row(s) with data anomalies, 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 is normal. The specific process will not be elaborated here.

[0118] Optionally, the determining 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 includes:

[0119] Determining the first distribution information 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;

[0120] For each of the target pixels, determining the peak value in the first distribution information according to the first distribution information corresponding to the target pixel;

[0121] 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 rotational scan, corresponding data is intercepted from the latter segment of the first distribution information to fill the missing content in the former segment at the boundary, so as to update the first distribution information;

[0122] 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, the first distribution information is subjected to a filtering process, and by extracting the low-frequency fluctuations, the maximum value in the first distribution information is extracted, and the maximum value is used as the peak value.

[0123] Wherein, for the target pixel corresponding to any target row detector unit, the target pixel is a pixel located in the central channel of the detector, and the central channel is used to represent a column of detector units corresponding to the beam of rays that passes through the rotation center from the ray source and reaches the detector. The first distribution information is used to represent a distribution diagram composed of different rotation angles and the ray attenuation data corresponding to each rotation angle.

[0124] In the embodiments of the present disclosure, taking the ray attenuation data of a certain row of detector units as an example below, the distribution of the attenuation data detected by the central channel at all rotation angles is as shown by the black dotted line in Figure 8 , Figure 8 as shown by the black dotted line, Figure 8shows the distribution of the original data (here the original data refers to the scan data or the ray attenuation data or attenuation value corresponding to the scan data. Taking the attenuation value as an example below, the same will not be repeated hereinafter), and the distribution of the data after low-pass filtering (here the data after low-pass filtering 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. Taking the attenuation value as an example below, the same will not be repeated hereinafter) (that is Figure 8 shows the attenuation distribution detected by the central channel of a certain row at all rotation angles. Figure 8 The two peaks in are caused by the X-rays attenuated by the phantom detected twice by this channel. The black dashed line is the original data, and the black solid line is the filtered data); among them, Figure 8 The abscissa shown is the rotation angle number, and the ordinate is the attenuation value (that is, the ray attenuation data, the same will not be repeated hereinafter). Figure 8 The attenuation data distribution in, such as the first distribution information.

[0125] The central channel refers to the channel corresponding to a column of detector units pointed by the beam of rays passing through the rotation center from the ray source to the detector. Each row of detectors has one pixel located in the central channel. Through Figure 8 It can be seen that during one week of rotation, the pixel of this detector unit measures the X-rays passing through the cross-sectional diameter of the phantom twice, forming two peaks. Through the following steps a4.1 - step a4.3, the rotation angles of the detector at the two peaks can be extracted. Through step a4.4, the projection width at the extreme angle (here refers to the target rotation angle, the same will not be repeated hereinafter) can be obtained. Then, based on the projection width, through step a4.5, the distance of the phantom deviating from the rotation center can be calculated. Through step a4.6, the cross-sectional diameter of the phantom can be calculated. Through step a4.7, the cross-sectional center coordinates (or the cross-sectional center coordinates of the phantom, the same will not be repeated hereinafter) can be calculated. Among them, step a4 includes steps a4.1 - a4.7.

[0126] Specifically, step a4.1: Boundary processing.

[0127] By extracting Figure 8 the extreme values of the distribution shown by the black dashed line, the rotation angle when this detector unit detects the attenuation at the diameter of the phantom can be measured. Sometimes this rotation angle just lies at the boundary of the distribution, as shown by the black solid line in Figure 9 , which is not conducive to the subsequent extraction of extreme values. For the convenience of subsequent extraction of extreme values, considering the periodic symmetry of the rotational scan, a part of the data is intercepted from the rear section of this distribution and filled to its beginning, as shown by the black dashed line in Figure 9 , Figure 9 shows the original data distribution and the filled data distribution (here the filled data refers to the scan data after filling or the ray attenuation data after filling or the attenuation value after filling. Taking the attenuation value as an example below, the same will not be repeated hereinafter) (that is Figure 9The black solid line shows the attenuation data of a certain central channel at all rotation angles, and one of the peaks is exactly located at the boundary. Figure 9 The black dashed line in the figure represents the data intercepted from the latter part of the solid line and filled to its beginning). Among them, Figure 9 The abscissa shown is the rotation angle number, and the ordinate is the attenuation value.

[0128] Step a4.2: Filtering process.

[0129] 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 data loss. In addition, the statistical fluctuations of the data are also not conducive to the subsequent extraction of extreme values. It is necessary to filter the data, extract the low-frequency fluctuations, and then extract two maximum values.

[0130] Optionally, the low-pass filtering method is: calculate the average value of several points near a certain point as the filtered value of this point. Figure 8 After appropriate filtering, the black dashed line in the figure is distributed as shown by the black solid line in the figure. The specific filtering parameters need to be adjusted according to the specific situation of the detector (such as noise, sampling frequency, etc.), and high-frequency fluctuations should be eliminated as much as possible, and only the low-frequency fluctuations formed by the projection change of the phantom should be retained.

[0131] Step a4.3: Extract the extreme value angle (or extreme angle, that is, the target rotation angle here, which will not be elaborated below).

[0132] Taking the derivative of the filtered distribution can quickly obtain Figure 8 Two maximum values (peaks here) in the distribution, and record the corresponding rotation angles (target rotation angles here).

[0133] Optionally, there are multiple target rotation angles. For each target row of detector units, according to the ray attenuation data of all channels of the target row of detectors at the target rotation angle and the parameters of the scanning device, to determine the position of the phantom, including:

[0134] For each target row of detector units, according to the ray attenuation data of all channels of the target row of detectors at the target rotation angle and the parameters of the scanning device, determine the center coordinates of the cross-section of the phantom corresponding to the target row of detector units and the diameter of the cross-section of the phantom corresponding to the target row of detector units;

[0135] Sample two rows of detector units from all the target rows of detector units, and calculate the included angle of the central axis of the phantom according to the center coordinates of the cross-section of the phantom corresponding to each sampled row of detector units and the distance between the two sampled rows of detector units;

[0136] Determine the position of the phantom based on the center coordinates of the phantom cross-section corresponding to each target row of detector units, the diameter of the phantom cross-section, and the included angle of the central axis of the phantom.

[0137] In the embodiments of the present disclosure, taking the ray attenuation data of a certain row of detector units as an example, the rotation angles of the detectors at the two peak values can be extracted through the above steps a4.1 - a4.3. The projection width at the extreme angle can be obtained through step a4.4. Then, based on the projection width, the distance of the phantom corresponding to this row of detector units from the rotation center can be calculated through step a4.5. The diameter of the phantom cross-section corresponding to this row of detector units can be calculated through step a4.6, and the central coordinates of the phantom cross-section corresponding to this 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 - a4.7, the diameter of the phantom cross-section corresponding to each row of detector units and the central coordinates of the phantom cross-section corresponding to each row of detector units (or the cross-section center coordinates, which will not be elaborated below) can be obtained, and the complete three-dimensional position obtained by arranging the cross-sections of all rows (for example, 64 rows) together can be obtained. Through step a5, the inclination angle of the central axis of the phantom can be calculated, and then the position of the phantom can be determined. It should be noted that the diameters of all rows of an ideal cylindrical phantom should be the same. Due to the influence of factors on the actual cylindrical phantom, there may be slight differences in the diameters of the phantom cross-sections corresponding to each row of detector units. If there are differences in the diameters of the phantom cross-sections calculated for each row of detectors, the following methods can be adopted:

[0138] Average value: Calculate the average value of the diameters of all rows as the diameter of the phantom cross-section.

[0139] Fitting: Determine the overall diameter of the phantom by fitting the diameter data.

[0140] Calibration: Check the detectors, scanning methods, and data processing processes to exclude sources of errors.

[0141] 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 an example, calculate the central coordinates of the cross-section of the first row according to step a4, and then calculate the central coordinates of the cross-section of the last row. According to the following second formula (i.e., formula (2)), the included angle between the central axis of the phantom and the rotation axis can be calculated:

[0142] (2)

[0143] where β in the second formula is the included angle to be obtained, is the distance between the two sampled rows of detectors, are the two cross-section center coordinates. It can be determined by N, M, the length (and width) of the N-row detector unit in the parameters, or the length (and width) of each pixel.

[0144] Optionally, 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 diameter of the phantom cross-section corresponding to the target row detector unit includes:

[0145] For each of the target row detector units, the following operations are performed:

[0146] 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 differentiating each of the second distribution information respectively, calculate the width of the phantom projection at each of the target rotation angles;

[0147] According to the width of the phantom projection at each of the target rotation angles and the distance from the ray source to the rotation center, calculate the distance from the center of the phantom cross-section to the rotation center;

[0148] According to the width of the phantom projection at each of the target rotation angles, the distance from the ray source to the rotation center, and the distance from the ray source to the detector, calculate the diameter of the phantom cross-section corresponding to the target row detector unit;

[0149] According to each of the target rotation angles, determine the deflection angle of the phantom;

[0150] According to the distance from the center of the phantom cross-section to the rotation center and the deflection angle of the phantom, determine the center coordinates of the phantom cross-section corresponding to the target row detector unit.

[0151] In the embodiments of the present disclosure, taking a certain 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 phantom corresponding to this row of detector units deviating from the rotation center can be calculated through step a4.5, the diameter of the phantom cross-section corresponding to this row of detector units can be calculated through step a4.6, and the center coordinates of the cross-section corresponding to this row of detector units can be calculated through step a4.7.

[0152] Specifically, step a4.4: The projection width at the extreme angle.

[0153] At the above two extreme angles (i.e., the target rotation angles), the data distributions of all channels of a certain row are respectively as Figure 10 shown by the black solid line and the black dashed line in Figure 10Shows the data of all channels corresponding to two extreme angles respectively (the data here can refer to ray attenuation data or attenuation values, which will not be elaborated below), that is Figure 10 shows the data distribution of all channels at a certain extreme angle (for example, the first extreme angle) Figure 10 as shown by the dashed line in Figure 10 and the data distribution of all channels at another extreme angle (for example, the second extreme angle) Figure 10 as shown by the solid line in Figure 10 The abscissa is the detector channel number, and the ordinate is the attenuation value (ray attenuation data here). Among them, Figure 10 the data distribution of all channels in

[0154] For example, the second distribution information.

[0155] Step a4.5: The eccentricity distance of the phantom (that is, the distance from the center of the phantom cross-section to the rotation center).

[0156] Record the width of the narrow projection (the width of the phantom projection corresponding to the extreme angle with a narrower projection) as and the other one (that is, the width of the wide projection: the width of the phantom projection corresponding to the extreme angle with a wider projection) as According to the third formula, the distance from the center of the phantom cross-section to the rotation center can be calculated:

[0157] (3)

[0158] Among them, in the third formula (that is, formula (3)) is the distance from the center of the phantom cross-section to the rotation center, is the distance from the radiation source to the rotation center.

[0159] Step a4.6: The diameter of the phantom cross-section.

[0160] After obtaining the eccentricity distance, the diameter of the phantom cross-section can be calculated according to the following fourth formula (formula (4)):

[0161] (4)

[0162] Among them, in formula (4) is the diameter of the phantom cross-section, is the distance from the radiation source to the detector.

[0163] Step a4.7: Phantom deflection angle and cross-sectional center coordinates.

[0164] To facilitate the description of the phantom position, we define that when the phantom is eccentric directly above the rotation center, its deflection angle is zero, and when the phantom is eccentric directly below the rotation center, its deflection angle is 180. It can be obtained that the extreme angle with the wider projection is the deflection angle of the phantom, and the difference between the other extreme angle (here referring to the extreme angle with the narrower projection) and its deflection angle is 180. After obtaining the eccentricity distance and deflection angle of the phantom, its cross-sectional center coordinates (here referring to the cross-sectional center coordinates of the phantom, for example: the cross-sectional center coordinates of the phantom corresponding to this row of detector units) are obtained from the following fifth formula (i.e., formula (5)):

[0165] (5)

[0166] Wherein, in formula (5) is the deflection angle of the phantom, and (X, Y) are the cross-sectional center coordinates of the phantom (i.e., the cross-sectional center of the phantom or the cross-sectional center, which will not be elaborated below).

[0167] The measurement results of the example data have high accuracy, and compared with the related technology, the time used by the phantom position measurement method provided by the present disclosure is significantly less than that of the latter.

[0168] Therefore, the present disclosure is applicable to all cylindrical phantoms, regardless of material and size; backprojection and image reconstruction are not required during the phantom position measurement process, saving measurement time.

[0169] From the above description, it can be seen that the present disclosure achieves the following technical effects: Measuring the phantom position based on ray attenuation data and the mean value ensures the accuracy of the measurement. At the same time, since the backprojection and image reconstruction are not required during the calculation process, the time for measuring the phantom position is reduced, achieving the improvement of the efficiency of measuring the phantom position while ensuring the measurement accuracy.

[0170] It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0171] The embodiment of the present disclosure also provides a phantom position measurement device for implementing the above-described embodiment of the phantom position measurement method, which is applied to a scanning device. 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, and one column of detector units corresponds to one channel, and both N and M are integers greater than 1. As Figure 11As shown, the phantom position measuring device 110 includes: a first processing unit 1101, configured to obtain the ray attenuation data of each of the pixels at different rotation angles by rotating and scanning the phantom; wherein, the phantom is a cylindrical phantom; a second processing unit 1102, configured to determine, according to the ray attenuation data of each of the pixels 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, and extract the target rotation angles corresponding to each of the target pixels at the peak values; wherein, one target row detector unit is one row of detector units among the N row detector units of 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; a third processing unit 1103, configured to, for each of the target row detector units, determine the phantom position 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 widths of all channels corresponding to the M column detector units of the detector, and the lengths of the N row detector units, the phantom position including the cross-sectional diameter of the phantom, the central coordinates of the phantom cross-section, and the included angle of the central axis of the phantom.

[0172] Optionally, for the target pixel corresponding to any one 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 represent the channel corresponding to a column of detector units pointed by the beam of rays passing through the rotation center from the ray source to the detector; when the second processing unit 1102 executes 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 of the pixels at different rotation angles, it specifically includes: determining the first distribution information 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 of the pixels at different rotation angles; for each of the target pixels, determining 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, intercepting the corresponding data from the latter segment of the first distribution information to fill the missing content in the former segment at the boundary 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, performing a filtering process on the first distribution information, and by extracting the low-frequency fluctuations, to extract the maximum value in the first distribution information, and the maximum value is used as the peak value.

[0173] Optionally, there are multiple target rotation angles. When the third processing unit 1103 determines the phantom position for each of the target row detector units according to the ray attenuation data of all channels of the target row detectors at the target rotation angles and the parameters of the scanning device, it specifically includes: for each of the target row detector units, determining the central coordinate of the phantom cross-section corresponding to the target row detector unit and the diameter of the phantom cross-section corresponding to the target row detector unit according to the ray attenuation data of all channels of the target row detectors at the target rotation angles and the parameters of the scanning device; sampling two rows of detector units from all the target row detector units, and calculating the included angle of the phantom central axis according to the central coordinates of the phantom cross-sections respectively corresponding to the sampled rows of detector units and the distance between the two sampled rows of detector units; and determining the phantom position according to the central coordinate of the phantom cross-section corresponding to each of the target row detector units, the diameter of the phantom cross-section, and the included angle of the phantom central axis.

[0174] Optionally, when the third processing unit 1103 determines the central coordinate of the phantom cross-section corresponding to the target row detector unit and the diameter of the phantom cross-section corresponding to the target row detector unit for each of the target row detector units according to the ray attenuation data of all channels of the target row detectors at the target rotation angles and the parameters of the scanning device, it specifically includes: for each of the target row detector units, performing the following operations: calculating the width of the phantom projection at each of the target rotation angles by filtering and differentiating 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; calculating the distance from the center of the phantom cross-section to the rotation center according to the width of the phantom projection at each of the target rotation angles and the distance from the ray source to the rotation center; calculating the diameter of the phantom cross-section corresponding to the target row detector unit according to the width of the phantom projection at each of the target rotation angles, the distance from the ray source to the rotation center, and the distance from the ray source to the detector; determining the deflection angle of the phantom according to each of the target rotation angles; and determining the central coordinate of the phantom cross-section corresponding to the target row detector unit according to the distance from the center of the phantom cross-section to the rotation center and the deflection angle of the phantom.

[0175] Optionally, the phantom position measuring device is further configured to perform the following operations: based on the ray attenuation data of each pixel at different rotation angles, detect the phantom coverage range 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 determine the 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, adjust the phantom position so that all the detector units can scan the phantom and / or each row of detector units with normal ray attenuation data.

[0176] Optionally, when the phantom position measuring device performs the operation of detecting the phantom coverage range based on 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, it specifically includes: for each pixel, based on the ray attenuation data of the pixel at different rotation angles, calculate the mean value of the ray attenuation data of the pixel at all rotation angles to obtain the 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 the average attenuation data of the any row of detector units in each channel; based on the third distribution information corresponding to each row of detector units, determine at least one row of detector units that have not scanned the phantom; and / or, determine each edge row of detector units and the 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 respectively, and calculate the difference between the average attenuation data of each sorted edge row of detector units and the average attenuation data of the middle row of detector units. If the variance of the difference between the average attenuation data of at least one row of detector units in all the edge rows of detector units and the average attenuation data of the middle row of detector units is greater than the first variance threshold, then determine that the ray attenuation data of the at least one row of detector units in all the edge rows of detector units is abnormal.

[0177] Optionally, when the first processing unit 1101 executes to obtain the ray attenuation data of each pixel at different rotation angles by rotating and scanning the phantom, it specifically includes: by rotating and scanning the phantom, collecting the scanning data based on the phantom at different rotation angles, where the scanning data is used to represent the ray intensity value corresponding to each pixel; scanning air under the condition consistent with the phantom scanning, and collecting the 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.

[0178] The specific manners of the operations executed by the units in the above device embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0179] Embodiments of the present disclosure also provide an electronic device, as Figure 12 shown, the electronic device includes one or more processors 121 and a memory 122, Figure 12 Taking one processor 121 as an example.

[0180] The controller may further include: an input device 123 and an output device 124.

[0181] The processor 121, the memory 122, the input device 123, and the output device 124 may be connected through a bus or other means, Figure 12 Taking connection through a bus as an example.

[0182] The processor 121 may be a central processing unit (Central Processing Unit, abbreviated as CPU), and the processor 121 may also be other general-purpose processors, digital signal processors (Digital Signal Processor, abbreviated as DSP), application specific integrated circuits (Application Specific Integrated Circuit, abbreviated as ASIC), field programmable gate arrays (Field-Programmable Gate Array, abbreviated as FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. chips, or a combination of the above various chips. The general-purpose processor may be a microprocessor or any conventional processor.

[0183] The memory 122, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the control method in the embodiments 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, implements the voxel position measurement method in the above method embodiments.

[0184] The memory 122 may include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the processing device of the server operation, etc. In addition, the memory 122 may include high-speed random access memory, and may also include non-transitory memory, such as at least one magnetic disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some embodiments, the memory 122 may optionally include a memory remotely disposed relative to the processor 121, and these remote memories can be connected to the network connection device through a network. Examples of the above networks include but are not limited to the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0185] The input device 123 can receive input digital or character information, and generate key signal inputs related to user settings and function control of the processing device of the server. The output device 124 may include a display device such as a display screen.

[0186] One or more modules are stored in the memory 122, and when executed by one or more processors 121, implement the method as shown above.

[0187] The embodiments of the present disclosure further provide a scanning device, and the scanning device is used to execute and implement the voxel position measurement method as described above.

[0188] The embodiments of the present disclosure further provide a computer-readable storage medium, and the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute and implement the voxel position measurement method as described above.

[0189] The embodiments of the present disclosure further provide a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the voxel position measurement method as described above.

[0190] Those skilled in the art can understand that to implement all or part of the processes in the above method embodiments, it can be completed by instructing relevant hardware through a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes in the above method embodiments. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM for short), a random access memory (RAM for short), a flash memory (FM for short), a hard disk drive (HDD for short), or a solid-state drive (SSD for short), etc.; the storage medium can also include a combination of the above types of memories.

[0191] Although the embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall 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 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 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 of the target row detector units and the angle between the phantom center axes.

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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