Parameter calibration method and device, electronic equipment and medium

Abstract

The invention provides a parameter calibration method and device applied to extended third-generation computed tomography equipment, electronic equipment and a medium, and relates to the field of radiation detection. The method comprises the following steps: traversing values of detector center offset and turntable offset; by taking a group of traversed values as equipment parameters, obtaining accumulation of detection errors of a plurality of target imaging modes so as to obtain a target detection error; after traversal is completed, selecting a group of values when the target detection error is minimum, and calibrating the center offset of the detector and the offset of the rotary table; wherein the target imaging mode is detection performed by two correlated ray signals which are emitted by a focus, penetrate through the rotary table in different directions and have the same ray penetrating path in the rotary table; the detection error of the target imaging mode is the absolute value of the difference between two correlated detection signal values detected by the detector for two correlated ray signals in the target imaging mode. According to the invention, accurate calibration of the center offset of the detector and the offset of the rotary table can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of radiation detection, in particular to a parameter calibration method and device applied to an extended third-generation computed tomography (CT) device, an electronic device, a medium and a program product. BACKGROUND

[0002] In the extended third-generation CT mode, deviations in important geometric parameters such as detector center offset and gantry offset can cause problems such as sinusogram misplacement and image artifacts in the reconstructed image. Therefore, accurate detector center offset and gantry offset parameters are very important for image reconstruction in the extended third-generation CT scan. SUMMARY

[0003] Therefore, the present application provides a parameter calibration method and device applied to an extended third-generation computed tomography device, which can accurately calibrate the detector center offset and the gantry offset.

[0004] In a first aspect, the present application provides a parameter calibration method applied to an extended third-generation computed tomography device. The method comprises: based on the value range of the detector center offset and the gantry offset of the extended third-generation computed tomography device, traversing the values of the detector center offset and the gantry offset; after traversing a set of values of the detector center offset and the gantry offset each time, selecting the set of values as the device parameters, obtaining the cumulative value of the detection error of a plurality of target imaging modes to obtain a target detection error; after traversing the values of the detector center offset and the gantry offset, selecting a set of values of the detector center offset and the gantry offset when the target detection error is the smallest, and calibrating the detector center offset and the gantry offset. Wherein, the target imaging mode is the detection of two associated ray signals emitted by the focal point in different directions 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.

[0005] According to an embodiment of the present application, the obtaining the cumulative value of the detection error of the target imaging mode based on the selected set of values of the device parameters comprises: obtaining the positioning information of two associated ray signals in the target imaging mode; determining the positioning information of the detection channel of the detector receiving each of the associated ray signals based on the positioning information of each of the associated ray signals and the device parameters; obtaining two associated detection signal values of the detector 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 receiving each of the associated ray signals; 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 application, the positioning information of the associated ray signal comprises: the rotation angle of the focal point, and a first included angle between the line connecting the focal point and the center of the rotary table and the associated ray signal.

[0007] According to an embodiment of the present application, the obtaining the positioning information of the two associated ray signals comprises: obtaining the positioning information of a first ray signal of the two associated ray signals; determining a first ray penetration path of the first ray signal through the rotary table based on the positioning information of the first ray signal; and determining the positioning information of a second ray signal of the two associated ray signals based on the rotation movement of the focal point and the detector relative to the center of the rotary table.

[0008] According to an embodiment of the present application, the method further comprises: traversing the values of the rotation angle and the first included angle within a preset range of values of the rotation angle and the first included angle, respectively; and taking each set of values of the rotation angle and the first included angle traversed as the positioning information of the first ray signal. Different detection errors of the target imaging mode are obtained corresponding to different values of the rotation angle and the first included angle traversed.

[0009] According to an embodiment of the present application, the positioning information of the detection channel comprises: the arc length of the detection channel to the central channel of the detector.

[0010] According to an embodiment of the present application, the traversing the values of the center offset of the detector and the offset of the rotary table comprises: traversing the values of the center offset of the detector and the offset of the rotary table one by one according to the variation granularity of the range of values of the center offset of the detector and the offset of the rotary table, respectively.

[0011] According to a second aspect of the embodiments of the present application, a parameter calibration device applied to an extended third-generation computed tomography device is provided. The device comprises a first traversal module, a detection module and a parameter calibration module.

[0012] The first traversal module is configured to traverse the values of the detector center offset and the gantry bias based on the value range of the detector center offset and the value range of the gantry bias of the extended third-generation computed tomography device.

[0013] The detection module is configured to, after each set of values of the detector center offset and the gantry bias is traversed, obtain a cumulative value of a detection error of a target imaging mode by taking the set of values as the device parameters, to obtain a target detection error, wherein the target imaging mode is detection of two associated ray signals emitted by a focal point, passing through the gantry in different directions and having the same ray penetration path in the gantry, 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 the detector, and the ray penetration paths corresponding to different target imaging modes are different.

[0014] The parameter calibration module is configured to, after the values of the detector center offset and the gantry bias are traversed, select a set of values of the detector center offset and the gantry bias at which the target detection error is the smallest, and calibrate the detector center offset and the gantry bias.

[0015] The third aspect of the present application provides 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.

[0016] The fourth aspect of the present application further provides a computer-readable storage medium having a computer program or instructions stored thereon, wherein the computer program or instructions are executed by a processor to implement the steps of the method.

[0017] The fifth aspect of the present application further provides a computer program product comprising a computer program or instructions, wherein the computer program or instructions are executed by a processor to implement the steps of the method. BRIEF DESCRIPTION OF DRAWINGS

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

[0019] Figure 1 An illustrative diagram showing definitions of a detector center offset and a gantry bias in an extended third-generation CT scanning mode is shown;

[0020] Figure 2 An illustrative flowchart of a parameter calibration method according to an embodiment of the present application is shown;

[0021] Figure 3A AndFigure 3B A schematic diagram illustrating the principle of the target imaging mode according to an embodiment of the present application is shown;

[0022] Figure 4 A flow chart illustrating the process of obtaining the detection error of the target imaging mode in the parameter calibration method according to an embodiment of the present application is shown;

[0023] Figure 5 A flow chart illustrating the process of obtaining the target detection error in the parameter calibration method according to an embodiment of the present application is shown;

[0024] Figure 6 A block diagram illustrating the parameter calibration device according to an embodiment of the present application is shown; and

[0025] Figure 7 A structural block diagram of an electronic device suitable for implementing the parameter calibration method according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It is to be understood, however, that the description is merely exemplary of the present application, and is not intended to limit the scope of the present application. In the following detailed description of the embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that one or more embodiments of the present application can be practiced without these specific details. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring aspects of the present application.

[0027] The terms used herein are merely used to describe specific embodiments, and are not intended to limit the present application. The terms "include" and "have" and the like used herein indicate the presence of the 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 same meaning as commonly understood by one of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of the present specification, and should not be interpreted in an idealized or overly formal manner.

[0029] In conjunction with Figure 1 , in the extended third-generation CT scanning device, the focal point 10 (the part where the rays are generated on the ray source) and the detector 20 rotate synchronously around the center O of the rotating table 30, wherein 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 arc-shaped array of the detector 20. The first perpendicular line L1 intersects the arc-shaped array of the detector 20, and the distance between the intersection point and the center channel 21 of the detector 20 is defined as the detector center offset Df. It should be noted that the center channel 21 is shown as a circle in the figure only for the purpose of illustrating the definition of the detector center offset Df, and is not intended to limit the structure of the detector 20.

[0031] After the first perpendicular line L1 is drawn from the focal point 10 to the arc-shaped 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 between the center O of the turntable 30 and the foot of the perpendicular intersecting the first perpendicular line L1 on the second perpendicular line L2 is defined as the turntable offset Tf.

[0032] The principle of calibrating the detector center offset Df and the turntable offset Tf in the embodiment of the present application can be explained in combination with Figure 3A and Figure 3B .

[0033] Specifically, referring 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 the straight line passing through the first point J1 and the second point J2, so that the ray penetration paths of the first ray signal R1 and the second ray signal R2 in the turntable 30 are the same, but the directions are different. More accurately, the first ray signal R1 and the second ray signal R2 are two associated ray signals passing through the same ray penetration path in the turntable 30 in opposite directions or close to opposite directions (e.g., the acute angle formed by the straight line on which the first ray signal R1 and the second ray signal R2 are located is less than a preset angle threshold, such as 5°). In the embodiment of the present application, this imaging mode of the first ray signal R1 and the second ray signal R2 is defined as the target imaging mode, that is, the target imaging mode is a set of detections performed by two associated ray signals passing through the turntable 30 in opposite directions or close to opposite directions and having the same ray penetration path in the turntable 30.

[0034] In theory, the detection signal values of the first and second ray signals R1 and R2 detected by the detector 20 are equal, ignoring the influence of ray hardening. However, in practice, when the detection signal values of the first and second ray signals R1 and R2 are taken from the detector 20, the first detection channel dr1 receiving the first ray signal R1 and the second detection channel dr2 receiving the second ray signal R2 are found from the detector 20 according to the relative positional relationship between the focal point 10, the turntable 30 and the detector 20, and other information, and then the corresponding detection signal values are taken from the signals detected by the first and second detection channels dr1 and dr2. When the first and second detection channels dr1 and dr2 are found, if the parameters of the detector center offset Df and the turntable offset Tf used are inaccurate, for example, there is a large deviation, the first and second detection channels dr1 and dr2 found are not actually located on the straight line passing through the first and second points J1 and J2, which can cause the detection signal values of the first and second ray signals R1 and R2 taken from the detector 20 to deviate too much.

[0035] That is, the more accurate the detector center offset Df and the turntable offset Tf are, the more likely the first and second detection channels dr1 and dr2 found are located on the same straight line, and the smaller the error of the detection signal values of the first and second ray signals R1 and R2 taken from the detector 20 is.

[0036] The embodiment of the present application utilizes the feature that the error of the detection signal values of the two associated ray signals in the target imaging mode should be close to zero in theory to realize accurate calibration of the detector center offset Df and the turntable offset Tf. The specific implementation process of the parameter calibration method of the embodiment of the present application will be described in detail below. Figures 2-5 The specific implementation process of the parameter calibration method of the embodiment of the present application will be described in detail below.

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

[0038] As shown in FIG. 2, the parameter calibration method according to the embodiment of the present application can include operations S210-S260. Figure 2

[0039] First, in operation S210, the value range of the detector center offset Df and the value range of the turntable offset Tf are obtained.

[0040] ​Next, in operation S220, initial values of the detector center offset Df and the gantry bias Tf are determined within their respective value ranges, as a set of values traversed for the first time. For example, the initial values of the detector center offset Df and the gantry bias Tf can both be determined as zero. The value ranges of the detector center offset and the gantry bias are traversed one by one according to the variation granularity of the value ranges.

[0041] Then, in operation S230, the detection errors of the target imaging modes are obtained with the set of values of the detector center offset Df and the gantry bias Tf traversed as the equipment parameters, to obtain the target detection error.

[0042] In combination with Figure 3A and Figure 3B , in the embodiment of the present application, the target imaging mode refers to detection performed by two associated ray signals that pass through the gantry 30 in opposite directions or close to opposite directions and have the same ray penetration path in the gantry 30. For example, the detection imaging performed by the first ray signal R1 and the second ray signal R2 belongs to one target imaging mode.

[0043] In the embodiment of the present application, the associated ray signals in different target imaging modes have different ray penetration paths in the gantry 30. For example, as shown in Figure 3A The ray penetration paths passing through the first point J1 and the third point J3 also correspond 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 mode is the absolute value of the difference between the detection signal values of the two associated ray signals in the target detection mode detected by the detector 20. The target detection error corresponding to the set of values of the detector center offset Df and the gantry bias Tf currently determined can be obtained by accumulating the detection errors of the target imaging modes corresponding to different ray penetration paths.

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

[0046] In operation S250, it is determined whether the next set of values is traversed. If the next set of values is traversed, operation S230 is returned. If the next set of values is not traversed, it means that the values of the detector center offset Df and the gantry bias Tf are traversed, and in this case, operation S260 is performed.

[0047] The values of the detector center offset Df and the turntable offset Tf can be traversed one by one according to the variation granularity of the respective value ranges of the detector center offset Df and the turntable offset Tf, for example, traversing and calculating in the value range of the detector center offset Df (for example, ±2 pixel values) and the value range of the turntable offset Tf (for example, ±2 mm).

[0048] After the values of the detector center offset Df and the turntable offset Tf are traversed in operation S260, a set of values of the detector center offset Df and the turntable offset Tf at which the target detection error is the smallest is selected, and the detector center offset Df and the turntable offset Tf are calibrated. Specifically, the set of values of the detector center offset Df and the turntable offset Tf corresponding to the smallest detection error cumulative value in the plurality of target imaging modes can minimize the error of the detection signal value of the two associated ray signals in the target imaging mode as much as possible, and thus the values of the detector center offset Df and the turntable offset Tf at this time are the accurate solutions of the two parameters to be calibrated.

[0049] The embodiment of the present application can traverse the values of the detector center offset Df and the turntable offset Tf, and finally output the values of the detector center offset Df and the turntable offset Tf at which the target detection error is the smallest as the calibration parameters.

[0050] As can be seen, the embodiment of the present application can traverse the values in the respective value ranges of the detector center offset Df and the turntable offset Tf, and calculate the detection error cumulative values in the plurality of target imaging modes by taking each set of values traversed as the device parameters. After the traversal ends, a set of values of the detector center offset Df and the turntable offset Tf at which the detection error cumulative value is the smallest is found as the calibration parameters, which can achieve relatively accurate calibration of the detector center offset Df and the turntable offset Tf.

[0051] Figure 4 A flowchart of operation S230 in the parameter calibration method according to an embodiment of the present application is schematically shown.

[0052] As Figure 4 shown, the acquisition of the detection error of the target imaging mode in operation S230 according to the embodiment of the present application can include operations S401 to S404.

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

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

[0055] Suppose Figure 1The shown position is the initial position of the device, Figure 3A the rotation angle of the focal point in the positioning information of the first radiation signal R1 is , and the first included angle between the first radiation signal R1 and the line connecting the focal point 10 and the center of the turntable 30 is . Based on the rotation angle , it can be determined that the focal point 10 is located at the first point J1, and then the line connecting the focal point 10 and the center of the turntable 30 is rotated by the first included angle , the first radiation signal R1 can be found. It can be seen that the first radiation signal R1 can be determined in space through the rotation angle of the focal point 10 and the first included angle , and correspondingly, the first radiation penetration path of the first radiation signal R1 in the turntable 30 is uniquely determined.

[0056] Next, 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 radiation signal R2 passing through the first radiation penetration path in the opposite direction or close to the opposite direction can be determined. Specifically, in combination with Figure 3A and Figure 3B , the line segment with the first point J1 and the second point J2 as endpoints constitutes a chord on the locus circle of the motion of the focal point 10, and therefore, in Figure 3B , the first included angle between the second radiation signal R2 and the line connecting the focal point 10 and the center of the turntable 30 is also . Further, when the focal point 10 is located at the second point J2, the rotation angle is , wherein represents the allowable error.

[0057] In operation S402, based on the positioning information of each associated radiation signal and the device parameters, the positioning information of the detection channel in the detector 20 receiving each associated radiation signal is determined.

[0058] In one embodiment, the positioning information of the detection channel includes the arc length of the detection channel to the central channel 21 of the detector 20. As Figure 3A , the first arc length between the first detection channel dr1 and the central channel 21 can be calculated as =len1+Df, wherein len1 is the arc length of the arc 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 , the second arc length between the second detection channel dr2 and the central channel 21 can be calculated as =len2-Df, wherein len2 is the arc length of the arc with the second detection channel dr2 as one endpoint and the intersection of the first perpendicular line L1 and the detector 20 as the other endpoint.

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

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

[0061] Next, let the second included angle between the line connecting the focal point 10 and the center O of the turntable 30 and the first perpendicular line L1 be . .

[0062] Then, calculate len1 and len2.

[0063] Specifically, referring to Figure 3A , len1 corresponds to an arc with the first detection channel dr1 as one end point and the intersection of the first perpendicular line L1 and the detector 20 as the other end point, and the angle of the arc is: . Correspondingly .

[0064] Referring to Figure 3B , len2 corresponds to an arc with the second detection channel dr2 as one end point and the intersection of the first perpendicular line L1 and the detector 20 as the other end point, and the angle of the arc is: . Correspondingly .

[0065] In operation S403, 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 detecting the two associated ray signals are obtained.

[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 projection gray value is taken out 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 (for example, represented as .

[0068] Corresponding to the second ray signal R2, the detected projection gray value is taken out 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 (for example, represented as .

[0069] Then, the difference between the two detection signal values can be calculated as . The absolute value of the difference between the two detection errors can be obtained.

[0070] Similarly, the detection error corresponding to each ray penetration path can be obtained, and the target detection error can be obtained by accumulating the detection errors.

[0071] According to the above-mentioned process of obtaining the detection error, it can be seen that when the two associated detection signal values are obtained from the detector 20, it is necessary to first locate which channel or which detector crystal of the detector 20 to obtain the detection value. The positioning process requires the use of the detector center offset Df and the turntable offset Tf. Thus, if the detector center offset Df and the turntable offset Tf deviate greatly from the true value, it is easy to cause the two detection channels actually located to not be on the same straight line. Therefore, the embodiment of the present application can minimize the cumulative value of multiple detection errors by traversing the value range of the detector center offset Df and the turntable offset Tf, so as to find the accurate detector center offset Df and the turntable offset Tf with a high probability.

[0072] In some embodiments, the operation S230 can be to pre-select a plurality of ray penetration paths, and then obtain the detection error of the target imaging mode corresponding to each ray penetration path.

[0073] In other embodiments, the operation S230 can also change the positioning information (such as the values of the first included angle and the rotation angle ) of the associated ray signals according to a certain rule, so as to obtain a series of ray penetration paths, and correspondingly obtain a series of detection errors of the target imaging mode. This method helps to increase the amount of data of the detection errors used for accumulation in the target detection error, thereby improving the accuracy of the final calibration of the detector center offset Df and the turntable offset Tf. A specific implementation process can be referred to the schematic diagram of Figure 5 .

[0074] Figure 5 The schematic diagram shows the flowchart of obtaining the target detection error in the operation S230 of the parameter calibration method according to an embodiment of the present application.

[0075] As shown in Figure 5 , according to the embodiment of the present application, the operation S230 can include the operation S501 to the operation S510.

[0076] In the operation S501, the rotation angle and the first included angle the preset value range of each. For example, the rotation angle is set to vary in the range of 0°—90°, and the first included angle is set to vary in the range of 0°—5°.

[0077] In operation S502, initial values of the rotation angle and the first included angle are determined within the preset value range of each, as a set of values for the first iteration. For example, both are iterated from 0°.

[0078] In operation S503, the set of values of the rotation angle and the first included angle are iterated, as the positioning information of the first ray signal R1 in imaging according to the target imaging mode. 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, a first ray penetration path of the first ray signal R1 through the turntable 30 is determined.

[0080] In operation S505, based on the rotational movement of the focal spot 10 and the detector 20 relative to the center O of the turntable 30, positioning information of a second ray signal R2 passing through the first ray penetration path in the opposite direction or close to the opposite direction is determined. The positioning information of the second ray signal R2 is .

[0081] In operation S506, during the operation of the scanning device, based on the positioning information of the two associated ray signals and the positioning information of the detection channels receiving each associated ray signal, two associated detection signal values obtained by the detector 20 detecting the two associated ray signals are obtained.

[0082] In operation S507, the absolute value of the difference between the two associated detection signal values is calculated to obtain a detection error. For example, the values of and are calculated and the absolute value of the difference is obtained.

[0083] In operation S508, the next set of values is iterated within the preset value range of each of the rotation angle and the first included angle .

[0084] In operation S509, it is determined whether the next set of values is iterated. If the next set of values is iterated, operation S503 is returned. If the next set of values is not iterated, it is indicated that the iteration is completed, and operation S510 is performed.

[0085] The rotation angle and the first included angle each of the rotation angle and the first included angle may be changed in a granularity of 5°.The value of the first included angle may be changed in a granularity of 1°.

[0086] In operation S510, when all values of the rotation angle and the first included angle are traversed, the multiple detection errors obtained in the traversal process are accumulated to obtain a target detection error.

[0087] In this way, the embodiment of the present application can quickly obtain a large number of detection errors of the target detection mode by changing and traversing the value ranges of the rotation angle and the first included angle , and the efficiency is high. Moreover, the calculation amount can be autonomously controlled by controlling the change granularity of the rotation angle and the first included angle , and the precision of the final calibration of the detector center offset Df and the turntable offset Tf can be controlled.

[0088] Figure 6 Fig. 6 schematically shows a block diagram of a parameter calibration device according to an embodiment of the present application.

[0089] As shown in Fig. 6, the parameter calibration device 600 according to the embodiment of the present application can include a first traversal module 610, a detection module 620, and a parameter calibration module 630. Figure 6 The first traversal module 610 is configured to traverse the values of the detector center offset Df and the turntable offset Tf based on the value ranges of the detector center offset Df and the turntable offset Tf of the extended third-generation computed tomography device. In one embodiment, the first traversal module 610 can perform the operations S210, S220, and S240 described above.

[0090]

[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 an embodiment of the present application, any one or more of the first traversal module 610, the probing module 620, the parameter calibration module 630 and the second traversal module 621 can be combined in one module, or any one of them can be split into multiple modules. Alternatively, at least part of the function of one or more of these modules can be combined with at least part of the function of other modules, and implemented in one module. According to an embodiment of the present application, at least one of the first traversal module 610, the probing module 620, the parameter calibration module 630 and the second traversal module 621 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on chip, a system on board, a system on package, an application specific integrated circuit (ASIC), or any other reasonable way of integrating or packaging a circuit, etc. or implemented by hardware or firmware, or implemented in any one of software, hardware and firmware or in a proper combination of any one or more of them. Alternatively, at least one of the first traversal module 610, the probing module 620, the parameter calibration module 630 and the second traversal module 621 can be at least partially implemented as a computer program module which, when executed, can perform the corresponding function.

[0096] Figure 7 A structural block diagram of an electronic device 900 suitable for implementing the parameter calibration method according to an embodiment of the present application is schematically shown.

[0097] As shown in Figure 7 The electronic device 900 according to an embodiment of the present application 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 can include, for example, a general purpose microprocessor (such as a CPU), an instruction set processor and / or a related chipset and / or a special purpose microprocessor (such as an application specific integrated circuit (ASIC)), etc. The processor 901 can also include an on-board memory for cache use. The processor 901 can include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present application.

[0098] In the RAM 903, various programs and data required for the operation of the electronic device 900 are stored. The processor 901, the ROM 902, and the RAM 903 are connected to each other via the bus 904. The processor 901 performs various operations of the method flow according to the embodiments of the present application by executing the programs in the ROM 902 and / or the RAM 903. It should be noted that the programs can also be stored in one or more memories other than the ROM 902 and the RAM 903. The processor 901 can also perform various operations of the method flow according to the embodiments of the present application by executing the programs stored in the one or more memories.

[0099] According to the embodiments of the present application, the electronic device 900 can further include an input / output (I / O) interface 905, which is also connected to the bus 904. The electronic device 900 can further include one or more of the following components connected to the input / output (I / O) interface 905: an input part 906 including a keyboard, a mouse, etc.; an output part 907 including a display such as a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage part 908 including a hard disk, etc.; and a communication part 909 including a network interface card such as a LAN card, a modem, etc. The communication part 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 necessary. A removable recording medium 911 such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc. is attached to the drive 910 as necessary, so that a computer program read therefrom is installed in the storage part 908 as necessary.

[0100] The present application also provides a computer readable storage medium, which can be included in the device / apparatus / system described in the above embodiments; or can exist separately without being assembled into the device / apparatus / system. The above computer readable storage medium carries one or more programs, when the one or more programs are executed, the method according to the embodiments of the present application is implemented.

[0101] According to an embodiment of the present application, the computer readable storage medium can be a non-transitory computer readable storage medium, for example, can include but not limited to: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the present application, the computer readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device. For example, according to an embodiment of the present application, the computer readable storage medium can include one or more memories of the ROM 902 and / or the RAM 903 described above and / or in addition to the ROM 902 and the RAM 903.

[0102] Embodiments of the present application also include a computer program product that includes a computer program containing program code for executing the methods illustrated in the flowcharts. When the computer program product is run in a computer system, the program code is used to make the computer system implement the methods provided by the embodiments of the present application.

[0103] The above-described functions defined in the system / device / apparatus of the embodiments of the present application are performed when the computer program is executed by the processor 901. According to an embodiment of the present application, the system, device, module, unit, etc. described above can be implemented by computer program modules.

[0104] In one embodiment, the computer program can rely on a tangible storage medium such as an optical storage device, a magnetic storage device, etc. In another embodiment, the computer program can also be transmitted, distributed, and downloaded in the form of a signal on a network medium and installed and downloaded through the communication part 909 and / or installed from the detachable medium 911. The program code contained in the computer program can be transmitted by any suitable network medium, including but not limited to wireless, wired, etc., or any suitable combination of the foregoing.

[0105] In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 909 and / or installed from the detachable medium 911. When the computer program is executed by the processor 901, the above-described functions defined in the system of the embodiments of the present application are performed. According to an embodiment of the present application, the system, device, apparatus, module, unit, etc. described above can be implemented by computer program modules.

[0106] According to embodiments of the present application, program code for implementing the computer programs provided by embodiments of the present application can be written in any combination of one or more programming languages, and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. The programming language can include, but is not limited to, Java, C++, python, "C" language, or similar programming languages. The program code can execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the remote computing device, or entirely on the remote computing device or server. In the latter scenario, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computing device, such as through the Internet using an Internet Service Provider.

[0107] The computer program instructions can also be loaded onto a computer or other programmable information processing apparatus to cause a series of operations to be performed on the computer or other programmable information processing apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable information processing apparatus implement the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0108] Those skilled in the art will appreciate that the features recited in the various embodiments of the present application can be combined and / or integrated in a variety of ways, even if such combinations or integrations are not expressly noted in the present application. In particular, the features recited in the various embodiments of the present application can be combined and / or integrated in a variety of ways without departing from the spirit and scope of the present application. All such combinations and / or integrations are within the scope of the present application.

[0109] The embodiments of the present application have been described above. However, these embodiments are merely for the purpose of illustration and are not intended to limit the scope of the present application. Although the embodiments are described separately above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present application, and these substitutions and modifications should fall within the scope of the present application.

Claims

1. A parameter calibration method for extended third-generation computed tomography (CT) scanners, wherein, The method includes: Based on the respective value ranges of the detector center offset and the turntable offset of the extended third-generation computed tomography equipment, the values ​​of the detector center offset and the turntable offset are traversed. After each iteration through a set of values ​​for the detector center offset and the turntable offset, the selected set of values ​​is used as the device parameter to obtain the cumulative value of the detection error of multiple target imaging methods to obtain the target detection error. After iterating through all the values ​​of the detector center offset and the turntable offset, select a set of values ​​of the detector center offset and the turntable offset when the target detection error is minimized, and calibrate the detector center offset and the turntable offset. The target imaging method is the detection of two associated ray signals emitted from the focal point that pass through the turntable in different directions and have the same ray penetration path in 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 in the target imaging method. The ray penetration paths are different for different target imaging methods.

2. The parameter calibration method according to claim 1, wherein, The step of obtaining the cumulative value of the detection error of multiple target imaging methods to obtain the target detection error by using the selected set of values ​​as device parameters includes: Obtain the positioning information of the two associated ray signals in the target imaging method; Based on the location information of each associated ray signal and the device parameters, the location information of the detection channel in the detector that receives 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, two associated detection signal values ​​are obtained by the detector detecting the two associated ray signals; 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 method.

3. The parameter calibration method according to claim 2, wherein, The location information of the associated ray signal includes: The rotation angle of the focal point; and The first angle between the line connecting the focal point and the center of the turntable and the associated ray signal.

4. The parameter calibration method according to claim 3, wherein, The acquisition of the positioning information of the two associated ray signals in the target imaging method includes: Obtain the positioning information of the first ray signal among 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 turntable is determined; Based on the rotational motion of the focus and detector relative to the center of the turntable, the positioning information of the second ray signal of the two associated ray signals is determined.

5. The parameter calibration method according to claim 4, wherein, The step of obtaining the cumulative value of the detection error of multiple target imaging methods to obtain the target detection error by using the selected set of values ​​as device parameters also includes: Within the preset value range of the rotation angle and the first included angle, traverse the values ​​of the rotation angle and the first included angle respectively; Each time the rotation angle and the first included angle are traversed, a set of values ​​is used as the positioning information of the first ray signal; Among them, the detection error of the target imaging mode is obtained for different values ​​of the rotation angle and the first included angle traversed.

6. The parameter calibration method according to claim 2, wherein, The positioning information of the detection channel includes: the arc length of the detection channel from the center channel of the detector.

7. The parameter calibration method according to claim 1, wherein, The values ​​of the traversal of the detector center offset and the turntable offset include: The process is iterated sequentially according to the granularity of the value range of the detector center offset and the turntable offset.

8. A parameter calibration device for an extended third-generation computed tomography (CT) scanner, wherein, The device includes: 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 detector center offset and the turntable offset of the extended third-generation computed tomography equipment. The detection module is used to iterate through a set of values ​​for the detector center offset and the turntable offset, and then, using the selected set of values ​​as device parameters, obtain the cumulative value of the detection errors for 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. 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.

9. An electronic device, comprising: One or more processors; Memory, used to store one or more computer programs. 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 to 7.

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

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