A spiral dual-energy scanning method

Abstract

The present invention provides a spiral dual-energy scanning method, comprising the steps of: presetting spiral scanning parameters; performing a first spiral scan, starting a diagnostic bed so that the bed plate of the diagnostic bed moves back and forth in the horizontal direction; performing a first exposure operation according to the spiral scanning parameters, performing a first data acquisition operation to obtain a first angle and a first bed code, and obtaining a delay time; performing a second spiral scan, recording a second angle and a second bed code; obtaining a compensation distance and a second exposure bed code according to the spiral scanning parameters, a first initial angle, a first angle, a first bed code, a second angle, and a second bed code; making the bed plate of the diagnostic bed move in the horizontal direction to compensate for the distance, performing a second exposure operation, and performing a second data acquisition operation after a delay time after the second exposure operation starts. The scanning speed is improved, the continuity in the Z direction is good, the numerical accuracy is high, and artifacts are solved.

Description

Technical Field

[0001] The present invention relates to the field of medical imaging technology, and in particular to a spiral dual-energy scanning method. Background Art

[0002] A computed tomography (CT) scanner is a device that uses X-rays to rotate and irradiate the object being measured, and then obtains a tomographic image of the object through computer processing. CT spectral imaging uses the energy spectrum information of X-rays that penetrate the scanned object for CT imaging. Spectral CT images can show the difference in attenuation of human tissues and lesions to X-rays of different energies, improve the contrast of human tissues and lesions, and achieve more accurate anatomical imaging. Moreover, spectral CT can achieve quantitative analysis and component analysis of substances, which is of great significance in clinical applications such as diagnosis of benign and malignant tumors and analysis of stone properties. There are two key points in CT spectral imaging technology: one is to obtain different energy spectrum projections that are "simultaneous, homologous, and homodirectional"; the other is to achieve basic material decomposition.

[0003] In the prior art, it is difficult to achieve a perfect match between the horizontal movement position and the rotation angle of the bed when performing dual-energy scanning in voltage switching mode, resulting in the dual-energy results failing to meet the "same direction" requirement. There are various problems with using data with poor "same direction" performance for dual-energy decomposition.

[0004] In the prior art, there are usually the following methods to solve the above problems:

[0005] (1) The dual-energy system based on voltage switching uses axial scanning to ensure that each angle and bed position has isotropic data, but it is insufficient in scanning speed and image continuity in the Z direction;

[0006] (2) The image domain dual energy decomposition method is used, but the image domain dual energy decomposition cannot effectively reduce the beam hardening artifacts, and the final numerical accuracy is low and the uniformity is poor.

[0007] (3) When the “same direction” performance is poor, the projection domain data is still used to obtain dual-energy images, but the image may have obvious abnormal images or artifacts at the material boundary, similar to motion artifacts.

[0008] (4) Use direct dual-energy decomposition method, which does not require data to be “co-directional” and avoids beam hardening artifacts. However, this method is computationally complex and time-consuming, taking about 30 minutes per turn, and cannot be used clinically for the time being. Summary of the invention

[0009] In order to overcome the above technical defects, the purpose of the present invention is to provide a spiral dual-energy scanning method, which improves the scanning speed, has good continuity in the Z direction, high numerical accuracy, and solves the problem of artifacts.

[0010] The present invention provides a spiral dual-energy scanning method, comprising the steps of:

[0011] Preset spiral scanning parameters;

[0012] The diagnostic bed is started to make the bed plate of the diagnostic bed reciprocate in the horizontal direction, and a first spiral scan is performed with a first initial bed code corresponding to a first initial angle as the starting scanning position and a first energy as the scanning energy;

[0013] When scanning to the first exposure bed code position, a first exposure operation is performed, and after the first exposure operation starts, a first data acquisition operation is performed to obtain a first angle and a first bed code, and a delay time from the first exposure operation to the first data acquisition operation is recorded;

[0014] acquiring a second initial angle and a second initial bed code according to the first initial angle, the first initial bed code and the scanning parameter, performing a second spiral scan with the second initial bed code as the starting scanning position and the second energy as the scanning energy, and recording the second angle and the second bed code when the bed plate of the diagnostic bed enters a uniform motion state, wherein the second energy is different from the first energy;

[0015] Acquire a compensation distance and a second exposure bed code according to the spiral scanning parameter, the first initial angle, the first angle, the first bed code, the second angle, and the second bed code;

[0016] The bed plate of the diagnostic bed is moved in the horizontal direction by the compensation distance within the reserved time to compensate for the bed position difference, a second exposure operation is performed when the second spiral scan scans to the second exposure bed code, and a second data acquisition operation is performed after the delay time after the start of the second exposure operation.

[0017] Preferably, the spiral scanning parameters include the reserved time, the spiral scanning speed, the bed speed, the first exposure bed code, and the total angle of one spiral scan. The bed speed is the movement speed of the diagnostic bed board when it enters a uniform motion state.

[0018] Preferably, a first exposure operation is performed when scanning to a first exposure bed code position, and a first data acquisition operation is performed after the first exposure operation starts to obtain a first angle and a first bed code, and the step of recording a delay time from the first exposure operation to the first data acquisition operation includes:

[0019] The starting time point of the first exposure operation is recorded to obtain the exposure moment, the starting time point of the first data acquisition operation is recorded to obtain the data acquisition moment, and a subtraction operation is performed on the data acquisition moment and the exposure moment to obtain the delay time.

[0020] Preferably, the step of acquiring the compensation distance and the second exposure bed code according to the spiral scanning parameters, the first initial angle, the first angle, the first bed code, the second angle and the second bed code comprises:

[0021] Acquire displacement time according to the first bed code, the second bed code and the bed speed;

[0022] Acquire an angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed, and the displacement time;

[0023] The compensation distance is acquired according to the angle deviation, the total angle and the bed speed.

[0024] Preferably, the step of acquiring the displacement time according to the first bed code, the second bed code and the bed speed comprises:

[0025] A subtraction operation is performed on the second bed code and the first bed code to obtain a bed position difference, and a division operation is performed on the bed position difference and the bed speed to obtain the displacement time.

[0026] Preferably, the step of acquiring the angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed and the displacement time comprises:

[0027] A division operation is performed on the displacement time and the spiral scanning speed to obtain a proportional value, a multiplication operation is performed on the proportional value and the total angle to obtain a third angle, a subtraction operation is performed on the first angle and the second angle to obtain a first difference, a subtraction operation is performed on the first difference and the third angle to obtain a second difference, and a remainder operation is performed on the second difference and the total angle to obtain the angle deviation.

[0028] Preferably, the step of acquiring the compensation distance according to the angle deviation, the total angle and the bed speed comprises:

[0029] A division operation is performed on the angle deviation and the total angle to obtain a proportional value, and a multiplication operation is performed on the proportional value and the bed speed to obtain the compensation distance.

[0030] Preferably, acquiring the compensation distance and the second exposure bed code according to the spiral scanning parameters, the first initial angle, the first angle, the first bed code, the second angle and the second bed code further comprises the steps of:

[0031] The first bed code and the compensation distance are calculated and operated to obtain a first value, the delay time and the bed speed are multiplied to obtain a second value, and the first value and the second value are added or subtracted to obtain the second exposure bed code.

[0032] Preferably, the spiral dual-energy scanning method further comprises the step of: after the second spiral scan is completed, readjusting the position of the diagnostic bed board according to the compensation distance so that the starting scanning position of the second round of the first spiral scan is consistent with the starting scanning position of the first round of the first spiral scan.

[0033] Preferably, the step of acquiring the second initial angle and the second initial bed code according to the first initial angle, the first initial bed code and the scanning parameter comprises:

[0034] Acquire the second initial angle according to the first initial angle, the reserved time, the spiral scanning speed and the total angle;

[0035] The second initial bed code is acquired according to the first initial bed code, the reserved time and the bed speed.

[0036] After adopting the above technical solution, compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. By presetting spiral scanning parameters and performing the first spiral scan and the second spiral scan to perform dual-energy scanning and dual-energy imaging, the scanning speed is improved and the continuity in the Z direction is good;

[0038] 2. By moving the diagnostic bed board in the horizontal direction by the compensation distance within the reserved time to compensate for the bed position difference, the dual-energy spiral scanning meets the same direction requirement through bed displacement, thereby reducing artifacts and improving data accuracy;

[0039] 3. By delaying the second exposure operation and performing the second data acquisition operation after a delay time, it is ensured that the angle during data acquisition corresponds to the bed code, and the acquired data is in the same direction as the data of the first angle and the first bed code, thereby improving data accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A flow chart of a spiral dual-energy scanning method according to an embodiment of the present invention;

[0041] Figure 2 Flow chart of the spiral dual-energy scanning method in some other embodiments of the present invention;

[0042] Figure 3 Schematic diagram of the positional relationship between the first bed code and the first exposure bed code in an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of the positional relationship between the second initial angle and the first initial angle according to an embodiment of the present invention;

[0044] Figure 5 Schematic diagram of the positional relationship between the first initial bed code and the second initial bed code of the present invention;

[0045] Figure 6 A flowchart of the steps of obtaining the compensation distance and the second exposure bed code according to an embodiment of the present invention;

[0046] Figure 7 Schematic diagram of the positional relationship between the second bed code, the first bed code and the first starting bed code according to an embodiment of the present invention;

[0047] Figure 8 Schematic diagram of the positional relationship between the second angle and the first starting angle according to an embodiment of the present invention;

[0048] Fig. 9 Schematic diagram of the positional relationship between the second initial bed code, the second exposure bed code and the compensation distance in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0050] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0051] The terms used in this disclosure are only for the purpose of describing specific embodiments and are not intended to limit the disclosure. The singular forms "a spiral dual-energy scanning method", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0052] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0053] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0054] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0055] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0056] The present invention provides a spiral dual-energy scanning method, referring to Figure 1 , including the steps of:

[0057] S0: preset spiral scanning parameters;

[0058] S1: starting the diagnostic bed so that the bed plate performs reciprocating motion in the horizontal direction, and performing a first spiral scan with a first initial bed code corresponding to a first initial angle as the starting scanning position and a first energy as the scanning energy;

[0059] S2: performing a first exposure operation when scanning to a first exposure bed code position, performing a first data acquisition operation after the first exposure operation starts to obtain a first angle and a first bed code, and recording a delay time from the first exposure operation to the first data acquisition operation;

[0060] S3: acquiring a second initial angle and a second initial bed code according to the first initial angle, the first initial bed code and the scanning parameters, performing a second spiral scan with the second initial bed code as the starting scanning position and the second energy as the scanning energy, and recording the second angle and the second bed code when the bed plate of the diagnostic bed enters a uniform motion state, wherein the second energy is different from the first energy;

[0061] S4: acquiring a compensation distance and a second exposure bed code according to the spiral scanning parameter, the first initial angle, the first angle, the first bed code, the second angle and the second bed code;

[0062] S5: within the reserved time, the bed plate of the diagnostic bed is moved in the horizontal direction by a compensation distance to compensate for the bed position difference, and a second exposure operation is performed when the second spiral scan scans to the second exposure bed code, and a second data acquisition operation is performed after a delay time after the start of the second exposure operation.

[0063] In some embodiments, during the spiral scanning process, the spiral scanning angle and bed position are recorded, and each bed position is encoded to obtain a bed code, the bed code includes a first initial bed code, a first bed code, a second initial bed code, a second bed code, a first exposure bed code, and a second exposure bed code; the spiral scanning angle includes a first initial angle, a first angle, a second initial angle, and a second angle. Each spiral scanning angle corresponds to a bed code, that is, the first initial angle corresponds to the first initial bed code, the first angle corresponds to the first bed code, the second initial angle corresponds to the second initial bed code, and the second angle corresponds to the second bed code.

[0064] In other embodiments of the present invention, referring to Figure 2 , the spiral dual-energy scanning method further includes step S6: after the second spiral scan is completed, readjusting the position of the diagnostic bed board according to the compensation distance so that the starting scanning position of the first spiral scan of the second round is consistent with the starting scanning position of the first spiral scan of the first round;

[0065] Similarly, when performing the second round of the second spiral scan, the position of the diagnostic bed board is adjusted according to the compensation distance so that the starting scanning position of the second round of the second spiral scan is consistent with the starting scanning position of the first round of the second spiral scan.

[0066] As a preferred embodiment of the present invention, the spiral scanning parameters include reserved time, spiral scanning speed, bed speed, first exposure bed code, and the total angle of one spiral scan. The bed speed is the movement speed of the diagnostic bed board when it enters a uniform motion state.

[0067] In some embodiments, the reserved time is T A , spiral scanning speed is R B , bed speed is V C 、First exposure bed code P G The total angle of one spiral scan is θ D .

[0068] As a preferred embodiment of the present invention, in step S2, a first exposure operation is performed when scanning to a first exposure bed code position, a first data acquisition operation is performed after the first exposure operation starts to obtain a first angle and a first bed code, and a step of recording a delay time from the first exposure operation to the first data acquisition operation includes:

[0069] The starting time point of the first exposure operation is recorded to obtain the exposure moment, the starting time point of the first data collection operation is recorded to obtain the data collection moment, and a subtraction operation is performed on the data collection moment and the exposure moment to obtain the delay time.

[0070] In some embodiments, the first initial angle is θ E , the first initial bed code is P F , the first angle is θ I , the first bed code is P J , the first exposure bed code is P G , the delay time is T H , refer to Figure 3 , the position relationship between the first bed code and the first exposure bed code is:

[0071] P J =P G +T H ×V C .

[0072] As a preferred embodiment of the present invention, in step S3, the step of obtaining the second initial angle and the second initial bed code according to the first initial angle, the first initial bed code and the scanning parameters includes:

[0073] Acquire a second initial angle according to the first initial angle, the reserved time, the spiral scanning speed and the total angle;

[0074] The second initial bed code is acquired according to the first initial bed code, the reserved time and the bed speed.

[0075] In some embodiments, in step S3, the formula for obtaining the second initial angle and the second initial bed code according to the first initial angle, the first initial bed code and the scanning parameter is:

[0076]

[0077] Among them, θ K is the second initial angle, θ E is the first initial angle, T A To reserve time, R B is the spiral scanning speed, θ D is the total angle.

[0078] Reference Figure 4 , Figure 4 The relationship between the second initial angle and the first initial angle is shown.

[0079] When performing spiral scanning, when the diagnostic bed is in the bed-in motion state and the bed-out motion state, the calculation formula of the second initial bed code is different, and is specifically divided into the following two formulas:

[0080] (1) When the diagnostic bed is in the bed moving state, the calculation formula for the second initial bed code is:

[0081] P L =P F -T A ×V C

[0082] Among them, P L is the second initial bed code, P F is the first initial bed code, T A To reserve time, V C The bed speed.

[0083] (2) When the diagnostic bed is in the moving state, the calculation formula for the second initial bed code is:

[0084] P L =P F +T A ×V C

[0085] Among them, P L is the second initial bed code, P F is the first initial bed code, T A To reserve time, V C The bed speed.

[0086] Reference Figure 5 , Figure 5 The relationship between the first initial bed code and the second initial bed code is shown.

[0087] As a preferred embodiment of the present invention, refer to Figure 6 In step S4, the step of obtaining the compensation distance and the second exposure bed code according to the spiral scanning parameters, the first initial angle, the first angle, the first bed code, the second angle and the second bed code includes:

[0088] S41: Obtaining displacement time according to the first bed code, the second bed code and the bed speed;

[0089] S42: Obtaining an angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed, and the displacement time;

[0090] S43: Obtaining a compensation distance according to the angle deviation, the total angle and the bed speed.

[0091] As a preferred embodiment of the present invention, in step S41, the step of obtaining the displacement time according to the first bed code, the second bed code and the bed speed includes:

[0092] A subtraction operation is performed on the second bed code and the first bed code to obtain a bed position difference, and a division operation is performed on the bed position difference and the bed speed to obtain a displacement time.

[0093] In some embodiments, in step S41, the formula for obtaining the displacement time according to the first bed code, the second bed code and the bed speed is:

[0094] L0=P J -P M ;

[0095]

[0096] Among them, L0 is the bed position difference, P J For the second bed code, P M is the first bed code, T P is the displacement time, i.e. the time from the bed plate of the diagnostic bed to P M Shift to P J The time required for V C The bed speed.

[0097] Reference Figure 7 , Figure 7 The positional relationship between the first bed code and the second bed code is shown.

[0098] As a preferred embodiment of the present invention, in step S42, the step of obtaining the angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed and the displacement time includes:

[0099] A division operation is performed on the displacement time and the spiral scanning speed to obtain a proportional value, a multiplication operation is performed on the proportional value and the total angle to obtain a third angle, a subtraction operation is performed on the first angle and the second angle to obtain a first difference, a subtraction operation is performed on the first difference and the third angle to obtain a second difference, and a remainder operation is performed on the second difference and the total angle to obtain an angle deviation.

[0100] In some embodiments, in step S42, the calculation formula for obtaining the angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed and the displacement time is:

[0101]

[0102] Among them, θ Q is the second difference, θ I is the second angle, θ N is the second angle, θ I -θ N is the first difference, is the third angle, θ D is the total angle.

[0103] Since the final required angular deviation refers specifically to the deviation within a circle, the part exceeding one circle is removed, and the calculation formula for the final angular deviation θR is obtained as follows:

[0104] θR =θ Q %θ D

[0105] Among them, θ R is the angle deviation, θ Q is the second difference, θ D is the total angle, θ Q %θ D Indicates the remainder processing, that is, θ Q Divide by θ D , remove the integer part and keep the remainder, the result is the final calculated angle deviation θ D .

[0106] Reference Figure 8 In the figure, θI' is the estimated starting angle of the second data acquisition operation when no compensation is performed. Figure 8 The relationship between the second angle and the first starting angle is shown.

[0107] As a preferred embodiment of the present invention, in step S43, the step of obtaining the compensation distance according to the angle deviation, the total angle and the bed speed includes:

[0108] A division operation is performed on the angle deviation and the total angle to obtain a proportional value, and a multiplication operation is performed on the proportional value and the bed speed to obtain a compensation distance.

[0109] In some embodiments, in step S43, the calculation formula for obtaining the compensation distance according to the angle deviation, the total angle and the bed speed is:

[0110]

[0111] Among them, L S is the compensation distance, θ R is the angle deviation, θ D is the total angle, V C The bed speed.

[0112] As a preferred embodiment of the present invention, in step S4, obtaining the compensation distance and the second exposure bed code according to the spiral scanning parameters, the first initial angle, the first angle, the first bed code, the second angle and the second bed code also includes the steps of:

[0113] S40: Calculate the first bed code and the compensation distance and perform a sum operation to obtain a first value, perform a multiplication operation on the delay time and the bed speed to obtain a second value, and perform an addition operation or a subtraction operation on the first value and the second value to obtain a second exposure bed code.

[0114] In some embodiments, in step S40, during the second spiral scanning process, the calculation method of the second exposure bed code when the diagnostic bed is in the bed-in motion state and the bed-out motion state is different, as follows:

[0115] (1) During the second spiral scan, when the diagnostic bed is in the bed moving state, the calculation formula for the second exposure bed code is:

[0116] P T =P J +L S -T H ×V C

[0117] Among them, P T is the second exposure bed code, P J For the first bed size, L S To compensate for the distance, T H is the delay time, V C The bed speed.

[0118] (2) During the second spiral scanning process, when the diagnostic bed is in the out-of-bed motion state, the calculation formula for the second exposure bed code is:

[0119] P T =P J +L S +T H ×V C

[0120] Among them, P T is the second exposure bed code, P J For the first bed size, L S To compensate for the distance, T H is the delay time, V C The bed speed.

[0121] Reference Fig. 9 In the figure, PJ' is the starting bed position for the second data acquisition operation. Fig. 9 The relationship between the second initial bed code, the second exposure bed code and the compensation distance is shown.

[0122] Since the bed corresponding to the spiral scanning angle during the second spiral scanning process changes the distance moved by the second displacement mechanism based on the first initial bed position, when the second round of the first spiral scanning is repeated, the parameters of the bed position need to be re-registered. The value used for registration is equal to the compensation distance L of the second movement. S , i.e. step S6 of the present invention:

[0123] After the second spiral scan is completed, the position of the diagnostic bed board is readjusted according to the compensation distance so that the starting scanning position of the first spiral scan of the second round is consistent with the starting scanning position of the first spiral scan of the first round;

[0124] Similarly, when performing the second round of the second spiral scan, the position of the diagnostic bed board is adjusted according to the compensation distance so that the starting scanning position of the second round of the second spiral scan is consistent with the starting scanning position of the first round of the second spiral scan.

[0125] After adopting the above technical solution, compared with the prior art, the present invention has the following advantages:

[0126] 1. By presetting spiral scanning parameters and performing the first spiral scan and the second spiral scan to perform dual-energy scanning and dual-energy imaging, the scanning speed is improved and the continuity in the Z direction is good;

[0127] 2. By moving the diagnostic bed board in the horizontal direction to compensate for the distance in the reserved time to compensate for the bed position difference, the bed displacement allows the dual-energy spiral scanning to meet the access requirements, reduce artifacts, and improve data accuracy.

[0128] 3. By delaying the second exposure operation and performing the second data acquisition operation after a delay time, it is ensured that the angle during data acquisition corresponds to the bed code, and the acquired data is in the same direction as the data of the first angle and the first bed code, thereby improving data accuracy.

[0129] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A spiral dual-energy scanning method, characterized in that: Includes steps: Preset spiral scanning parameters; The diagnostic bed is started to make the bed plate of the diagnostic bed reciprocate in the horizontal direction, and a first spiral scan is performed with a first initial bed code corresponding to a first initial angle as the starting scanning position and a first energy as the scanning energy; When scanning to the first exposure bed code position, a first exposure operation is performed, and after the first exposure operation starts, a first data acquisition operation is performed to obtain a first angle and a first bed code, and a delay time from the first exposure operation to the first data acquisition operation is recorded; acquiring a second initial angle and a second initial bed code according to the first initial angle, the first initial bed code and the scanning parameter, performing a second spiral scan with the second initial bed code as the starting scanning position and the second energy as the scanning energy, and recording the second angle and the second bed code when the bed plate of the diagnostic bed enters a uniform motion state, wherein the second energy is different from the first energy; Acquire a compensation distance and a second exposure bed code according to the spiral scanning parameter, the first initial angle, the first angle, the first bed code, the second angle, and the second bed code; The bed plate of the diagnostic bed is moved in the horizontal direction by the compensation distance within the reserved time to compensate for the bed position difference, a second exposure operation is performed when the second spiral scan scans to the second exposure bed code, and a second data acquisition operation is performed after the delay time after the start of the second exposure operation.

2. The spiral dual-energy scanning method according to claim 1, characterized in that: The spiral scanning parameters include the reserved time, the spiral scanning speed, the bed speed, the first exposure bed code, and the total angle of one spiral scan. The bed speed is the movement speed of the diagnostic bed board when it enters a uniform motion state.

3. The spiral dual-energy scanning method according to claim 2, characterized in that: The first exposure operation is performed when scanning to the first exposure bed code position, and the first data acquisition operation is performed after the first exposure operation starts to obtain the first angle and the first bed code. The step of recording the delay time from the first exposure operation to the first data acquisition operation includes: The starting time point of the first exposure operation is recorded to obtain the exposure moment, the starting time point of the first data acquisition operation is recorded to obtain the data acquisition moment, and a subtraction operation is performed on the data acquisition moment and the exposure moment to obtain the delay time.

4. The spiral dual-energy scanning method according to claim 2, characterized in that: The step of acquiring the compensation distance and the second exposure bed code according to the spiral scanning parameters, the first initial angle, the first angle, the first bed code, the second angle and the second bed code comprises: Acquire displacement time according to the first bed code, the second bed code and the bed speed; Acquire an angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed, and the displacement time; The compensation distance is acquired according to the angle deviation, the total angle and the bed speed.

5. The spiral dual-energy scanning method according to claim 4, characterized in that: The step of obtaining the displacement time according to the first bed code, the second bed code and the bed speed comprises: A subtraction operation is performed on the second bed code and the first bed code to obtain a bed position difference, and a division operation is performed on the bed position difference and the bed speed to obtain the displacement time.

6. The spiral dual-energy scanning method according to claim 5, characterized in that: The step of acquiring the angle deviation according to the first initial angle, the second angle, the total angle, the spiral scanning speed and the displacement time comprises: A division operation is performed on the displacement time and the spiral scanning speed to obtain a proportional value, a multiplication operation is performed on the proportional value and the total angle to obtain a third angle, a subtraction operation is performed on the first angle and the second angle to obtain a first difference, a subtraction operation is performed on the first difference and the third angle to obtain a second difference, and a remainder operation is performed on the second difference and the total angle to obtain the angle deviation.

7. The spiral dual-energy scanning method according to claim 6, characterized in that: The step of obtaining the compensation distance according to the angle deviation, the total angle and the bed speed comprises: A division operation is performed on the angle deviation and the total angle to obtain a proportional value, and a multiplication operation is performed on the proportional value and the bed speed to obtain the compensation distance.

8. The spiral dual-energy scanning method according to claim 4, characterized in that: Acquiring the compensation distance and the second exposure bed code according to the spiral scanning parameters, the first initial angle, the first angle, the first bed code, the second angle and the second bed code also includes the steps of: The first bed code and the compensation distance are calculated and operated to obtain a first value, the delay time and the bed speed are multiplied to obtain a second value, and the first value and the second value are added or subtracted to obtain the second exposure bed code.

9. The spiral dual-energy scanning method according to claim 2, characterized in that: The method further comprises the steps of: after the second spiral scan is completed, readjusting the position of the diagnostic bed board according to the compensation distance so that the starting scanning position of the second round of the first spiral scan is consistent with the starting scanning position of the first round of the first spiral scan.

10. The spiral dual-energy scanning method according to claim 2, characterized in that: The step of acquiring the second initial angle and the second initial bed code according to the first initial angle, the first initial bed code and the scanning parameter comprises: Acquire the second initial angle according to the first initial angle, the reserved time, the spiral scanning speed and the total angle; The second initial bed code is acquired according to the first initial bed code, the reserved time and the bed speed.

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