Parameter calibration methods, devices, electronic equipment and media

Abstract

This invention provides a parameter calibration method, apparatus, electronic device, and medium for extended third-generation computed tomography (CT) equipment, relating to the field of radiation detection. The method includes: traversing the values ​​of detector center offset and turntable offset; using the traversed set of values ​​as equipment parameters, obtaining the cumulative detection errors of multiple target imaging modes to obtain the target detection error; after traversal, selecting the set of values ​​with the smallest target detection error, and calibrating the detector center offset and turntable offset; wherein, the target imaging mode is the detection of two associated ray signals emitted from the focal point, passing through the turntable in different directions, and having the same ray penetration path within the turntable; the detection error of the target imaging mode is the absolute value of the difference between the two associated detection signal values ​​detected by the detector in the target imaging mode. This invention can achieve accurate calibration of the detector center offset and turntable offset.

Description

Technical Field

[0001] This invention relates to the field of radiation detection, and more specifically to a parameter calibration method, apparatus, electronic device, medium, and program product for use in extended third-generation computed tomography (CT) equipment. Background Technology

[0002] In extended third-generation computed tomography (CT) mode, deviations in important geometric parameters such as detector center offset and turntable offset can lead to problems such as sinusoidal misalignment and image artifacts in the reconstructed images. Therefore, accurate detector center offset and turntable offset parameters are crucial for image reconstruction in extended third-generation CT scans. Summary of the Invention

[0003] In view of this, the present invention provides a parameter calibration method, apparatus, electronic device, storage medium and program product for extended third-generation computed tomography equipment that can accurately calibrate detector center offset and turntable offset.

[0004] A first aspect of this invention provides a parameter calibration method for an extended third-generation computed tomography (ECT) scanner. The method includes: traversing the values ​​of the detector center offset and the turntable offset of the ECT scanner based on their respective ranges; after each traversal of a set of values ​​for the detector center offset and the turntable offset, using the selected set of values ​​as equipment parameters to obtain the cumulative value of detection errors for multiple target imaging modes to obtain the target detection error; after traversing all the values ​​of the detector center offset and the turntable offset, selecting a set of values ​​for the detector center offset and the turntable offset when the target detection error is minimized, and calibrating the detector center offset and the turntable offset. The target imaging method involves detecting two associated ray signals emitted from the focal point that pass through the turntable in different directions and have the same ray penetration path within the turntable. The detection error of the target imaging method is the absolute value of the difference between the two associated detection signal values ​​detected by the detector. Different target imaging methods correspond to different ray penetration paths.

[0005] According to an embodiment of the present invention, the step of obtaining the cumulative value of the detection error of multiple target imaging modes to obtain the target detection error by using the selected set of values ​​as device parameters includes: obtaining the positioning information of two associated ray signals in the target imaging mode; determining the positioning information of the detection channel in the detector that receives each associated ray signal based on the positioning information of each associated ray signal and the device parameters; obtaining two associated detection signal values ​​obtained by the detector from detecting the two associated ray signals based on the positioning information of the two associated ray signals and the positioning information of the detection channel that receives each associated ray signal; and calculating the absolute value of the difference between the two associated detection signal values ​​to obtain the detection error of the target imaging mode.

[0006] According to an embodiment of the present invention, the positioning information of the associated ray signal includes: the rotation angle of the focal spot, and a first angle between the line connecting the focal spot and the center of the turntable and the associated ray signal.

[0007] According to an embodiment of the present invention, obtaining the positioning information of the two associated ray signals includes: obtaining the positioning information of the first ray signal among the two associated ray signals; determining the first ray penetration path of the first ray signal through the turntable based on the positioning information of the first ray signal; and determining the positioning information of the second ray signal among the two associated ray signals based on the focal point and the rotational motion of the detector relative to the center of the turntable.

[0008] According to an embodiment of the present invention, the method further includes: traversing the values ​​of the rotation angle and the first included angle within a preset value range for each of the rotation angle and the first included angle; and using a set of values ​​of the rotation angle and the first included angle encountered each time as the positioning information of the first ray signal. Wherein, different detection errors of the target imaging mode are obtained corresponding to different values ​​of the rotation angle and the first included angle encountered.

[0009] According to an embodiment of the present invention, the positioning information of the detection channel includes: the arc length from the detection channel to the center channel of the detector.

[0010] According to an embodiment of the present invention, the step of traversing the values ​​of the detector center offset and the turntable offset includes: traversing the values ​​one by one according to the granularity of the respective value ranges of the detector center offset and the turntable offset.

[0011] A second aspect of this invention provides a parameter calibration device for an extended third-generation computed tomography (CT) scanner. The device includes a first traversal module, a detection module, and a parameter calibration module.

[0012] The first traversal module is used to traverse the values ​​of the detector center offset and the turntable offset based on the respective value ranges of the extended third-generation computed tomography (CT) equipment.

[0013] The detection module is used to iterate through a set of values ​​for the detector center offset and the turntable offset each time, and then use the selected set of values ​​as device parameters to obtain the cumulative value of the detection error of multiple target imaging modes to obtain the target detection error. The target imaging mode is the detection of two associated ray signals emitted from the focal point, passing through the turntable in different directions, and having the same ray penetration path within the turntable. The detection error of the target imaging mode is the absolute value of the difference between the two associated detection signal values ​​detected by the detector for the two associated ray signals in the target imaging mode. Different target imaging modes correspond to different ray penetration paths.

[0014] The parameter calibration module is used to select a set of values ​​for the detector center offset and the turntable offset when the target detection error is minimized after iterating through the values ​​of the detector center offset and the turntable offset, and to calibrate the detector center offset and the turntable offset.

[0015] A third aspect of the present invention provides an electronic device comprising: one or more processors; and a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the method described above.

[0016] A fourth aspect of the present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, wherein the computer program or instructions, when executed by a processor, implement the steps of the above-described method.

[0017] A fifth aspect of the present invention also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the above-described method. Attached Figure Description

[0018] The above and other objects, features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0019] Figure 1 This schematic diagram illustrates the definitions of detector center offset and turntable offset in extended third-generation CT scanning mode.

[0020] Figure 2 A flowchart illustrating a parameter calibration method according to an embodiment of the present invention is shown schematically.

[0021] Figure 3A and Figure 3B A schematic diagram illustrating the principle of a target imaging method according to an embodiment of the present invention is shown.

[0022] Figure 4 This schematically illustrates a flowchart of a parameter calibration method according to an embodiment of the present invention for obtaining the detection error of the target imaging mode;

[0023] Figure 5 This schematically illustrates a flowchart of obtaining target detection error in a parameter calibration method according to an embodiment of the present invention;

[0024] Figure 6 A block diagram of a parameter calibration apparatus according to an embodiment of the present invention is schematically shown; and

[0025] Figure 7 A schematic block diagram of an electronic device suitable for implementing the parameter calibration method according to an embodiment of the present invention is shown. Detailed Implementation

[0026] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0028] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0029] Combination Figure 1 In the extended third-generation CT scanning equipment, the focal spot 10 (the part of the X-ray source that produces X-rays) and the detector 20 rotate synchronously around the center O of the turntable 30. The detector 20 can be an array distributed in an arc shape.

[0030] A first perpendicular line L1 is drawn from the focal point 10 to the arcuate array of the detector 20. The first perpendicular line L1 intersects the arcuate array of the detector 20, and the distance between the intersection point and the central channel 21 of the detector 20 is defined as the detector center offset Df. It should be noted that the central channel 21 in the figure is shown as a circle only to illustrate the definition of the detector center offset Df and is not used to limit the structure of the detector 20.

[0031] After drawing a first perpendicular line L1 from the focal point 10 to the arc array of the detector 20, a second perpendicular line L2 is drawn from the center O of the turntable 30 to the first perpendicular line L1. The distance of the perpendicular segment on the second perpendicular line L2 from the center O of the turntable 30 to the foot of the perpendicular that intersects with the first perpendicular line L1 is defined as the turntable offset Tf.

[0032] The principle of calibrating the detector center offset Df and the turntable offset Tf in this embodiment of the invention can be combined with... Figure 3A and Figure 3B To illustrate.

[0033] Specifically, refer to Figure 3A and Figure 3B The transmission paths of the first ray signal R1 and the second ray signal R2 are both located on a straight line passing through the first point J1 and the second point J2. Therefore, the ray penetration paths of the first ray signal R1 and the second ray signal R2 in the turntable 30 are the same, but their directions are different. More precisely, the first ray signal R1 and the second ray signal R2 are two associated ray signals that pass through the turntable 30 along the same ray penetration path in opposite or nearly opposite directions (e.g., the acute angle formed by the straight lines containing the first ray signal R1 and the second ray signal R2 is less than a preset angle threshold, such as 5°). In this embodiment of the invention, this imaging method of the first ray signal R1 and the second ray signal R2 is defined as the target imaging method, that is, the target imaging method is a set of detections performed by two associated ray signals that pass through the turntable 30 in opposite or nearly opposite directions and have the same ray penetration path in the turntable 30.

[0034] Theoretically, ignoring the effects of X-ray hardening, the detection signal values ​​of the first X-ray signal R1 and the second X-ray signal R2 from detector 20 are equal. However, in practice, when retrieving the detection signal values ​​of the first X-ray signal R1 and the second X-ray signal R2 from detector 20, the first detection channel dr1 receiving the first X-ray signal R1 and the second detection channel dr2 receiving the second X-ray signal R2 are identified from detector 20 based on information such as the relative positional relationship between focus 10, turntable 30, and detector 20. Then, the corresponding detection signal values ​​are extracted from the signals detected by the first detection channel dr1 and the second detection channel dr2. If the parameters used for the detector center offset Df and the turntable offset Tf are inaccurate when searching for the first detection channel dr1 and the second detection channel dr2, such as having a large deviation, the found first detection channel dr1 and the second detection channel dr2 will not actually be located on the straight line passing through the first point J1 and the second point J2. This will result in an excessively large deviation in the detection signal values ​​of the first X-ray signal R1 and the second X-ray signal R2 retrieved from detector 20.

[0035] In other words, the more precise the detector center offset Df and the turntable offset Tf are, the more likely the first detection channel dr1 and the second detection channel dr2 are to be located on the same straight line, and thus the smaller the error of the detection signal values ​​of the first ray signal R1 and the second ray signal R2 extracted from the detector 20.

[0036] This invention utilizes the principle that the error between the detection signal values ​​of two correlated ray signals in a target imaging method should theoretically be close to zero to achieve accurate calibration of the detector center offset Df and the turntable offset Tf. The following will explain... Figures 2-5 The specific implementation process of the parameter calibration method in the embodiments of the present invention will be described in detail.

[0037] Figure 2 A flowchart illustrating a parameter calibration method according to an embodiment of the present invention is shown.

[0038] like Figure 2 As shown, according to an embodiment of the present invention, the parameter calibration method may include operations S210 to S260.

[0039] First, in operation S210, obtain the value ranges of the detector center offset Df and the turntable offset Tf.

[0040] Next, in operation S220, initial values ​​are determined for both the detector center offset Df and the turntable offset Tf within their respective ranges, serving as the first set of values ​​encountered during the initial iteration. For example, the initial values ​​for both the detector center offset Df and the turntable offset Tf can be set to zero. The iteration proceeds sequentially according to the granularity of the changes in the respective ranges of the detector center offset and the turntable offset.

[0041] Then, in operation S230, a set of values ​​of the detector center offset Df and the turntable offset Tf obtained through iteration are used as device parameters to obtain the cumulative value of the detection error of multiple target imaging modes to obtain the target detection error.

[0042] Combination Figure 3A and Figure 3B In this embodiment of the invention, target imaging refers to detection performed by two associated ray signals that pass through the turntable 30 in opposite or nearly opposite directions and have the same ray penetration path within the turntable 30. For example, detection imaging performed by the first ray signal R1 and the second ray signal R2 belongs to one target imaging method.

[0043] In this embodiment of the invention, the radiation penetration paths of the associated ray signals in different target imaging methods are different in the turntable 30. For example, as Figure 3A The ray penetration path passing through the first point J1 and the third point J3 also corresponds to two associated ray signals, which are different from the first ray signal R1 and the second ray signal R2.

[0044] The detection error of the target imaging method is the absolute value of the difference between the detection signal values ​​detected by detector 20 of two related ray signals in the target detection method. The target detection error corresponding to a set of values ​​of the currently determined detector center offset Df and turntable offset Tf can be obtained by accumulating the detection errors of the target imaging methods corresponding to different ray penetration paths.

[0045] Next, in operation S240, the next set of values ​​is traversed within the respective ranges of the detector center offset Df and the turntable offset Tf.

[0046] In operation S250, determine whether the next set of values ​​has been reached. If the next set of values ​​has been reached, return to operation S230. If the next set of values ​​has not been reached, it means that the values ​​of detector center offset Df and turntable offset Tf have been traversed. In this case, execute operation S260.

[0047] The algorithm can iterate through the detector center offset Df and the turntable offset Tf one by one according to their respective value ranges. For example, it can iterate and calculate within the range of the detector center offset Df (e.g., ±2 pixel values) and the range of the turntable offset Tf (e.g., ±2 mm).

[0048] In operation S260, after iterating through the values ​​of detector center offset Df and turntable offset Tf, a set of values ​​for detector center offset Df and turntable offset Tf that minimizes the target detection error is selected, and the detector center offset Df and turntable offset Tf are calibrated. Specifically, the set of values ​​for detector center offset Df and turntable offset Tf that minimizes the cumulative detection error under multiple target imaging methods can minimize the error of the detection signal values ​​of the two correlated ray signals in the target imaging method. Therefore, the values ​​of detector center offset Df and turntable offset Tf at this time are the accurate solutions for calibrating these two parameters.

[0049] The embodiments of the present invention can iterate through the values ​​of detector center offset Df and turntable offset Tf, and finally output the values ​​of detector center offset Df and turntable offset Tf with the smallest target detection error as calibration parameters.

[0050] As can be seen, the embodiments of the present invention can iterate through the value ranges of the detector center offset Df and the turntable offset Tf, and use each set of values ​​obtained in each iteration as device parameters to calculate the cumulative detection error value under multiple target imaging modes. After the iteration is completed, the set of values ​​of the detector center offset Df and the turntable offset Tf with the smallest cumulative detection error value is found as calibration parameters, which can achieve a relatively accurate calibration of the detector center offset Df and the turntable offset Tf.

[0051] Figure 4 The flowchart illustrating the detection error obtained by the target imaging mode imaging in operation S230 of the parameter calibration method according to an embodiment of the present invention is shown.

[0052] like Figure 4 As shown, according to an embodiment of the present invention, the detection error of the target imaging mode in operation S230 may include operations S401 to S404.

[0053] In operation S401, the positioning information of two associated ray signals in the target imaging mode is obtained.

[0054] In one embodiment, the positioning information may include: the rotation angle of the focus 10, and a first angle between the associated ray signal and the line connecting the focus 10 and the center O of the turntable 30.

[0055] set up Figure 1The position shown is the initial position of the device. Figure 3A The rotation angle of the focal point in the positioning information of the first ray signal R1 is: The first angle between the first ray signal R1 and the line connecting the center of focus 10 and the center of turntable 30 is... Based on rotation angle It can be determined that the focal point 10 is located at the first point J1. Then, with the first point J1 as the center of rotation, the line connecting the focal point 10 and the center of the turntable 30 is rotated by the first included angle. The first ray signal R1 can be found. It can be seen that the rotation angle passing through focus 10... and the aforementioned first included angle The first ray signal R1 can then be determined in space, and the first ray penetration path of the first ray signal R1 in the turntable 30 is thus uniquely determined.

[0056] Next, based on the rotational motion of focus 10 and detector 20 relative to the center O of turntable 30, the positioning information of the second ray signal R2 passing through the first ray penetration path in the opposite or nearly opposite direction can be determined. Specifically, combined with Figure 3A and Figure 3B The line segment with endpoints J1 and J2 forms a chord on the trajectory circle of the motion of focus 10. Therefore, in Figure 3B The first angle between the second ray signal R2 and the line connecting the center of focus 10 and the center of turntable 30 is also Furthermore, when focus 10 is located at the second point J2, the rotation angle is... ,in Indicates the allowable error.

[0057] In operation S402, based on the location information and equipment parameters of each associated X-ray signal, the location information of the detection channel in detector 20 that receives each associated X-ray signal is determined.

[0058] In one embodiment, the positioning information of the detection channel includes the arc length from the detection channel to the center channel 21 of the detector 20. For example... Figure 3A In this context, the first arc length between the first detection channel dr1 and the central channel 21 can be calculated as len1 + Df, where len1 is the arc length with the first detection channel dr1 as one endpoint and the intersection of the first perpendicular line L1 and the detector 20 as the other endpoint. Similarly, in Figure 3B In the middle, the second arc length between the second detection channel dr2 and the central channel 21 can be calculated as len2-Df, where len2 is the arc length with the second detection channel dr2 as one endpoint and the intersection of the first vertical line L1 and the detector 20 as the other endpoint.

[0059] In one embodiment, len1 and len2 can be calculated using the following process.

[0060] First, let D be the distance between the foot of the second perpendicular line L2 to the first perpendicular line L1 and the focus 10, and let T be the distance between the foot of the second perpendicular line L2 to the first perpendicular line L1 and the detector 20. Then, D+T is the distance from the focus 10 to the intersection of the first perpendicular line L1 and the detector 20.

[0061] Next, let the second angle between the line connecting focus 10 and the center O of turntable 30 and the first perpendicular line L1 be . Analysis reveals that... .

[0062] Then, calculate len1 and len2.

[0063] Specifically, refer to Figure 3A len1 corresponds to an arc with the first detection channel dr1 as one endpoint and the intersection of the first vertical line L1 and the detector 20 as the other endpoint. The angle of this arc is: Accordingly .

[0064] refer to Figure 3B len2 corresponds to an arc with the second detection channel dr2 as one endpoint and the intersection of the first vertical line L1 and the detector 20 as the other endpoint. The angle of this arc is: Accordingly .

[0065] In operation S403, based on the positioning information of the two associated ray signals and the positioning information of the detection channel that receives each associated ray signal, the two associated detection signal values ​​obtained by the detector 20 in detecting the two associated ray signals are acquired.

[0066] In operation S404, the absolute value of the difference between the two associated detection signal values ​​is calculated to obtain the detection error of the target imaging mode.

[0067] For example, corresponding to the first ray signal R1, the detected projected grayscale value is extracted from the detection channel with an arc length distance of len1+Df from the center channel 21 of the detector 20 to obtain the first detection signal value (e.g., expressed as...). .

[0068] Corresponding to the second ray signal R2, the detected projected grayscale value is extracted from the detection channel with an arc length distance of len2-Df from the center channel 21 of the detector 20 to obtain the second detection signal value (e.g., expressed as...). .

[0069] Then we can calculate and The absolute value of the difference can be used to obtain the detection error corresponding to the two associated ray signals whose ray penetration path lies on the straight line passing through the first point J1 and the third point J3.

[0070] Similarly, different detection errors can be obtained for different ray penetration paths. By accumulating these detection errors, the target detection error can be obtained.

[0071] As can be clearly seen from the above process of obtaining detection errors, when retrieving two associated detection signal values ​​from detector 20, it is necessary to first determine which channel or which detector crystal in detector 20 is taking the detection value. This positioning process requires the use of detector center offset Df and turntable offset Tf. Therefore, if the detector center offset Df and turntable offset Tf deviate significantly from the true values, it is easy for the two actually located detection channels to be not on the same straight line. For this reason, this embodiment of the invention can minimize the cumulative value of multiple detection errors by iterating through the range of values ​​for detector center offset Df and turntable offset Tf, thereby finding accurate detector center offset Df and turntable offset Tf with a higher probability.

[0072] In some embodiments, the above operation S230 may involve pre-selecting multiple ray penetration paths and then obtaining the detection error of the target imaging mode corresponding to each ray penetration path.

[0073] In other embodiments, the above operation S230 can also be performed using the positioning information of the associated ray signal (e.g., the aforementioned first included angle). and rotation angle The values ​​of are varied according to a certain pattern to obtain a series of ray penetration paths, and correspondingly, a series of target imaging detection errors can be obtained. This method helps to increase the amount of detection error data used for accumulation in the target detection error, thereby improving the accuracy of the final calibrated detector center offset Df and turntable offset Tf. A specific implementation process can be found by referring to... Figure 5 The illustration.

[0074] Figure 5 The flowchart illustrating the acquisition of target detection error in operation S230 of a parameter calibration method according to an embodiment of the present invention is shown.

[0075] like Figure 5 As shown, according to an embodiment of the present invention, operation S230 may include operations S501 to S510.

[0076] In operation S501, obtain the rotation angle. and the first angle Each has its own preset value range. For example, setting the rotation angle. The range of variation is 0°–90°, the first included angle The range of variation is 0°–5°.

[0077] When operating S502, at the rotation angle and the first angle Each value is assigned an initial value within its respective range, which is then used as the first set of values ​​encountered during the initial traversal. For example, the traversal starts from 0°.

[0078] In operation S503, to traverse to the rotation angle and the first angle A set of values ​​is used as the positioning information of the first ray signal R1 in the target imaging method. That is, the positioning information of the first ray signal R1 is... .

[0079] In operation S504, based on the positioning information of the first ray signal R1, the first ray penetration path of the first ray signal R1 through the turntable 30 is determined.

[0080] In operation S505, based on the rotational motion of focus 10 and detector 20 relative to the center O of turntable 30, the positioning information of the second ray signal R2, which passes through the first ray's penetration path in the opposite or nearly opposite direction, is determined. The positioning information of the second ray signal R2 is as follows: .

[0081] In operation S506, during the operation of the scanning equipment, based on the positioning information of the two associated X-ray signals and the positioning information of the detection channel that receives each associated X-ray signal, the two associated detection signal values ​​obtained by the detector 20 in detecting the two associated X-ray signals are acquired.

[0082] In operation S507, the absolute value of the difference between two correlated detection signal values ​​is calculated to obtain a detection error. For example, calculating... and Find the value of the difference and calculate the absolute value of the difference.

[0083] When operating S508, at the rotation angle and the first angle Iterate through the next set of values ​​within the range of each value.

[0084] In operation S509, determine whether the next set of values ​​has been reached. If the next set of values ​​has been reached, return to operation S503. If the next set of values ​​has not been reached, it means that the traversal has been completed, and then execute operation S510.

[0085] According to the rotation angle and the first angle Each variable is traversed using its own granularity of change. For example, rotation angle. The value can be changed in 5° increments. First included angle The value can be changed with a granularity of 1°.

[0086] When operating S510, after traversing the rotation angle... and the first angle After considering all possible values, the target detection error is obtained by accumulating the multiple detection errors obtained during the traversal process.

[0087] Thus, embodiments of the present invention can be achieved by rotating the angle. and the first angle By varying and traversing the value range, a large number of target detection methods can be quickly obtained, resulting in high efficiency. Furthermore, the detection error can be obtained by adjusting the rotation angle. and the first angle Control of the granularity of each change, and the rotation angle and the first angle The combination of these factors, the amount of control computation from the master, and the accuracy of the final calibrated detector center offset Df and turntable offset Tf.

[0088] Figure 6 A block diagram of a parameter calibration apparatus according to an embodiment of the present invention is shown schematically.

[0089] like Figure 6 As shown, the parameter calibration device 600 according to an embodiment of the present invention may include a first traversal module 610, a detection module 620 and a parameter calibration module 630.

[0090] The first traversal module 610 is used to traverse the values ​​of the detector center offset Df and the turntable offset Tf based on the respective value ranges of the extended third-generation computed tomography (CT) equipment. In one embodiment, the first traversal module 610 can execute the operations S210, S220, and S240 described above.

[0091] The detection module 620 is used to obtain the cumulative value of the detection error of multiple target imaging modes by using the selected set of values ​​after iterating through a set of values ​​of the detector center offset Df and the turntable offset Tf as device parameters, thereby obtaining the target detection error. The target imaging mode is the detection of two related ray signals emitted from the focal point 10 that pass through the same ray penetration path in the turntable 30 in opposite or nearly opposite directions. The detection error of the target imaging mode is the absolute value of the difference between the two related detection signal values ​​detected by the detector 20. Different target imaging modes correspond to different ray penetration paths. In one embodiment, the detection module 620 can perform the operation S230 described above.

[0092] In one embodiment, the detection module 620 may include a second traversal module 621.

[0093] The second traversal module 621 is used for: based on rotation angle The respective ranges of values ​​for the included angle γ and the first angle, with respect to the rotation angle. and the first angle Perform traversal; traversing up to the rotation angle and the first angle A set of values ​​is used as the positioning information of the first ray signal R1 in the imaging according to the target imaging method; based on the positioning information of the first ray signal R1, the first ray penetration path of the first ray signal R1 through the turntable 30 is determined; based on the rotational motion of the focal point 10 and the detector 20 relative to the center O of the turntable 30, the positioning information of the second ray signal R2 passing through the first ray penetration path in the opposite direction or nearly the opposite direction is determined; during the operation of the scanning equipment, based on the positioning information of the two associated ray signals and the positioning information of the detection channel receiving each associated ray signal, two associated detection signal values ​​obtained by the detector 20 in detecting the two associated ray signals are acquired; the absolute value of the difference between the two associated detection signal values ​​is calculated to obtain a detection error. When the rotation angle is completed... and the first angle After considering all possible values, the multiple detection errors obtained during the traversal process are accumulated to obtain the target detection error. In one embodiment, the second traversal module 621 can execute the operations S501 to S510 described above.

[0094] The parameter calibration module 630 is used to select a set of values ​​for the detector center offset Df and the turntable offset Tf that minimizes the target detection error after iterating through all the possible values ​​of the detector center offset Df and the turntable offset Tf, and then calibrate the detector center offset Df and the turntable offset Tf. In one embodiment, the parameter calibration module 630 can perform the operation S260 described above.

[0095] According to embodiments of the present invention, any plurality of modules among the first traversal module 610, the detection module 620, the parameter calibration module 630, and the second traversal module 621 can be combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least part of the functionality of one or more of these modules can be combined with at least part of the functionality of other modules and implemented in one module. According to embodiments of the present invention, at least one of the first traversal module 610, the detection module 620, the parameter calibration module 630, and the second traversal module 621 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or any other reasonable means of integrating or packaging the circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, at least one of the first traversal module 610, the probe module 620, the parameter calibration module 630, and the second traversal module 621 can be implemented at least partially as a computer program module, which can perform corresponding functions when the computer program module is run.

[0096] Figure 7 The diagram schematically illustrates a structural block diagram of an electronic device 900 suitable for implementing a parameter calibration method according to an embodiment of the present invention.

[0097] like Figure 7 As shown, an electronic device 900 according to an embodiment of the present invention includes a processor 901, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 902 or a program loaded from a storage portion 908 into a random access memory (RAM) 903. The processor 901 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 901 may also include onboard memory for caching purposes. The processor 901 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present invention.

[0098] RAM 903 stores various programs and data required for the operation of electronic device 900. Processor 901, ROM 902, and RAM 903 are interconnected via bus 904. Processor 901 executes various operations of the method flow according to embodiments of the present invention by executing programs in ROM 902 and / or RAM 903. It should be noted that the program may also be stored in one or more memories other than ROM 902 and RAM 903. Processor 901 may also execute various operations of the method flow according to embodiments of the present invention by executing programs stored in one or more memories.

[0099] According to an embodiment of the present invention, the electronic device 900 may further include an input / output (I / O) interface 905, which is also connected to a bus 904. The electronic device 900 may also include one or more of the following components connected to the input / output (I / O) interface 905: an input section 906 including a keyboard, mouse, etc.; an output section 907 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 908 including a hard disk, etc.; and a communication section 909 including a network interface card such as a LAN card, modem, etc. The communication section 909 performs communication processing via a network such as the Internet. A drive 910 is also connected to the input / output (I / O) interface 905 as needed. A removable medium 911, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 910 as needed so that computer programs read from it can be installed into the storage section 908 as needed.

[0100] The present invention also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of the present invention.

[0101] According to embodiments of the present invention, a computer-readable storage medium may be a non-volatile computer-readable storage medium, such as including, but not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of the present invention, a computer-readable storage medium may include ROM 902 and / or RAM 903 and / or one or more memories other than ROM 902 and RAM 903 described above.

[0102] Embodiments of the present invention also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code is used to cause the computer system to implement the methods provided in the embodiments of the present invention.

[0103] When the computer program is executed by the processor 901, it performs the functions defined in the system / apparatus of this invention. According to embodiments of the invention, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0104] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and downloaded and installed via the communication section 909, and / or installed from a removable medium 911. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0105] In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 909, and / or installed from the removable medium 911. When the computer program is executed by the processor 901, it performs the functions defined in the system of this embodiment of the invention. According to embodiments of the invention, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0106] According to embodiments of the present invention, program code for executing the computer programs provided in the embodiments of the present invention can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0107] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0108] Those skilled in the art will understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments of the present invention can be combined and / or combined in various ways without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0109] The embodiments of the present invention have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of the invention. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of the invention, and all such substitutions and modifications should fall within the scope of the invention.

Claims

1. A method for calibrating parameters applied to extend a third generation computed tomography device, wherein, The method comprises: based on the value range of the detector center offset and the gantry bias of the extended third-generation computed tomography device, the value of the detector center offset and the gantry bias is traversed; after traversing a set of values of the detector center offset and the gantry bias each time, the selected set of values is used as the device parameters, the cumulative value of the detection error of multiple target imaging modes is obtained to obtain the target detection error; after traversing the values of the detector center offset and the gantry bias, a set of values of the detector center offset and the gantry bias is selected when the target detection error is the smallest, and the detector center offset and the gantry bias are calibrated; wherein the target imaging mode is the detection of two associated ray signals emitted by the focal point in different directions through the gantry and having the same ray penetration path in the gantry; the detection error of the target imaging mode is the absolute value of the difference between the two associated detection signal values of the two associated ray signals in the target imaging mode; wherein the ray penetration paths corresponding to different target imaging modes are different.

2. The parameter calibration method of claim 1, wherein, The cumulative value of the detection error of multiple target imaging modes is obtained by using the selected set of values as the device parameters to obtain the target detection error, which comprises: obtaining the positioning information of the two associated ray signals in the target imaging mode; based on the positioning information of each associated ray signal and the device parameters, the positioning information of the detection channel of the detector receiving each associated ray signal is determined; based on the positioning information of the two associated ray signals and the positioning information of the detection channel receiving each associated ray signal, the two associated detection signal values obtained by the detector detecting the two associated ray signals are obtained; and the absolute value of the difference between the two associated detection signal values is calculated to obtain the detection error of the target imaging mode.

3. The parameter calibration method of claim 2, wherein, The positioning information of the associated ray signal comprises: the rotation angle of the focal point; and the first included angle between the line connecting the focal point and the center of the gantry and the associated ray signal.

4. The parameter calibration method of claim 3, wherein, The positioning information of the two associated ray signals in the target imaging mode is obtained, which comprises: obtaining the positioning information of the first ray signal of the two associated ray signals; based on the positioning information of the first ray signal, the first ray penetration path of the first ray signal through the gantry is determined; based on the rotational motion of the focal point and the detector relative to the center of the gantry, the positioning information of the second ray signal of the two associated ray signals is determined.

5. The parameter calibration method of claim 4, wherein, The cumulative value of the detection error of multiple target imaging modes is obtained by using the selected set of values as the device parameters to obtain the target detection error, which further comprises: traverse the value of the rotation angle and the first included angle within the preset value range of the rotation angle and the first included angle respectively; each time the rotation angle and the first included angle are traversed to a set of values, the set of values is used as the positioning information of the first ray signal; Corresponding to different values of the rotation angle and the first included angle, different detection errors of the target imaging mode are obtained.

6. The parameter calibration method of claim 2, wherein, The positioning information of the detection channel includes an arc length of the detection channel to a central channel of the detector.

7. The parameter calibration method of claim 1, wherein, The values of the detector center offset and the turntable bias include: The values of the detector center offset and the turntable bias are traversed one by one according to the variation granularity of the value range of each of the detector center offset and the turntable bias.

8. A parameter calibration device applied to extend a third generation computed tomography device, wherein, The apparatus includes: A first traversal module is configured to traverse values of a detector center offset and a turntable bias of an extended third-generation computed tomography device based on value ranges of each of the detector center offset and the turntable bias. A detection module is configured to, after each time a set of values of the detector center offset and the turntable bias is traversed, obtain cumulative values of detection errors of a plurality of target imaging modes to obtain a target detection error by taking the set of values as device parameters, wherein the target imaging mode is detection performed by two associated ray signals emitted by a focal point, passing through a turntable in different directions, and having the same ray penetration path in the turntable, the detection error of the target imaging mode is an absolute value of a difference between two associated detection signal values of the two associated ray signals in the target imaging mode detected by a detector, different target imaging modes correspond to different ray penetration paths, and A parameter calibration module is configured to, after the values of the detector center offset and the turntable bias are traversed, select a set of values of the detector center offset and the turntable bias at which the target detection error is the smallest, and calibrate the detector center offset and the turntable bias.

9. An electronic device, comprising: one or more processors; a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1-7.

10. A computer readable storage medium having stored thereon a computer program or instructions, wherein, The computer program or instructions are executed by the processor to implement the steps of the method according to any one of claims 1-7. The computer program or instructions are executed by the processor to implement the steps of the method according to any one of claims 1-7.

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