Computed tomography tube current modulation method, apparatus, and electronic device

Abstract

The application relates to a computer tomography tube current modulation method, device and electronic device, wherein the computer tomography tube current modulation method comprises the following steps: acquiring a first moving speed of a scanning bed and a first scanning tube current, wherein the first scanning tube current is a tube current applied by the scanning bed at the first moving speed; acquiring a second moving speed of the scanning bed; and generating a second scanning tube current according to the first moving speed, the second moving speed and the first scanning tube current, wherein the second scanning tube current is a tube current applied by the scanning bed at the second moving speed. Through the application, a computer device can modulate the first scanning tube current applied by the scanning bed at the first moving speed into the second scanning tube current applied at the second moving speed, thereby solving the problem that there is no scanning tube current modulation method for computer tomography under a variable speed state in the prior art.

Description

Technical Field

[0001] This application relates to the field of computed tomography, and in particular to a computed tomography tube current modulation method, apparatus, and electronic device. Background Technology

[0002] Computed tomography (CT) equipment generally consists of several major components, including an X-ray system, a control system, a data acquisition system, and a data processing system. Tomography and spiral scanning are two typical CT applications. During the scan, the patient typically lies on a movable CT table, which is moved to scan the corresponding area. The development of CT technology has also been a process of continuously reducing clinical scan doses. Acquiring images that meet clinical diagnostic requirements at the lowest possible dose is a crucial direction and goal of CT technology development. Dose modulation (DOM) plays a vital role in reducing dose and improving the signal-to-noise ratio.

[0003] In conventional CT clinical scans, data acquisition typically begins after the scan bed speed is constant. However, in dynamic perfusion applications, to obtain the clinically necessary imaging data and assist physicians in qualitative and quantitative analysis and evaluation of blood perfusion in different tissues, it is necessary to control the scan interval. Therefore, data acquisition must occur during the acceleration and deceleration of the scan bed. However, a method for modulating the scan tube current in computed tomography under variable speed conditions is currently lacking. Compared to constant speed scanning, variable speed scanning means that the scan time for some sub-regions in the entire scan area increases, while the scan time for others decreases. If a constant speed scan tube current is used during variable speed scanning, the scan dose for sub-regions with increased scan time will also increase, while the scan dose for sub-regions with decreased scan time will decrease accordingly. Therefore, variable speed scanning suffers from the drawback of some sub-regions receiving excessively high scan doses while others receive insufficient scan doses.

[0004] There is currently no effective solution to the problem that there is a lack of scanning tube current modulation methods for computed tomography under variable speed conditions in related technologies. Summary of the Invention

[0005] This embodiment provides a computed tomography (CT) tube current modulation device and electronic device to solve the problem in the related art of lacking a method for CT tube current modulation under variable speed conditions.

[0006] Firstly, this embodiment provides a method for modulating tube current in computed tomography, the method being used to modulate the tube current applied to the scanning bed at different moving speeds;

[0007] The method includes:

[0008] The first moving speed of the scanning bed and the first scanning tube current are obtained, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed;

[0009] Obtain the second moving speed of the scanning bed;

[0010] A second scan tube current is generated based on the first moving speed, the second moving speed, and the first scan tube current, wherein the second scan tube current is the tube current applied by the scan bed at the second moving speed.

[0011] In some of these embodiments, the first moving speed is a constant first continuous speed, and the second moving speed is a variable second continuous speed;

[0012] The first scanning tube current is the first continuous tube current, and the second scanning tube current is the second continuous tube current.

[0013] In some embodiments, the magnitudes of the first continuous transistor current and the second continuous transistor current are related to the scanning position;

[0014] The magnitudes of the first and second continuous speeds are related to the scanning position.

[0015] In some embodiments, generating the second scan tube current based on the first moving speed, the second moving speed, and the first scan tube current includes:

[0016] Determine the scanning range, which includes at least one of the scanning positions;

[0017] Determine the current scan position from the scan range;

[0018] Based on the current scanning position and the first continuous velocity, determine the first instantaneous velocity corresponding to the current scanning position;

[0019] Based on the current scanning position and the first continuous tube current, determine the first instantaneous tube current corresponding to the current scanning position;

[0020] Based on the current scanning position and the second continuous velocity, a second instantaneous velocity corresponding to the current scanning position is determined;

[0021] Based on the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity, determine the second instantaneous tube current corresponding to the current scanning position;

[0022] The second continuous tube current is generated based on the second instantaneous tube current;

[0023] Update the current scan position from the scan range.

[0024] In some embodiments, determining the second instantaneous tube current corresponding to the current scanning position based on the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity includes:

[0025] Determine the ratio between the second instantaneous velocity and the first instantaneous velocity;

[0026] The first instantaneous tube current is transformed using the ratio relationship to obtain the second instantaneous tube current.

[0027] In some embodiments, generating the second scan tube current based on the first moving speed, the second moving speed, and the first scan tube current includes:

[0028] Determine the scanning range and divide the scanning range into multiple scanning intervals, wherein each scanning interval includes at least one of the scanning positions;

[0029] Determine the current scan interval from the scan range;

[0030] Based on the current scan interval and the first continuous speed, determine the first interval speed corresponding to the current scan interval;

[0031] Based on the current scan interval and the first continuous transistor current, determine the first interval transistor current corresponding to the current scan interval;

[0032] Based on the current scan interval and the second continuous speed, determine the second interval speed corresponding to the current scan interval;

[0033] Based on the first interval velocity, the first interval tube current, and the second interval velocity, determine the second interval tube current corresponding to the current scanning interval;

[0034] The second continuous tube current is generated based on the second interval tube current;

[0035] Update the current scan interval from the scan range.

[0036] In some embodiments, determining the second interval tube current corresponding to the current scanning interval based on the first interval velocity, the first interval tube current, and the second interval velocity includes:

[0037] The first interval time is determined based on the first interval speed, and the interval current product is determined based on the first interval time and the first interval tube current.

[0038] The second interval time is determined based on the second interval velocity, and the second interval tube current is determined based on the product of the second interval time and the interval current.

[0039] In some embodiments, the method further includes:

[0040] Acquire a first scan sequence, wherein the first scan sequence includes a first scan tube current;

[0041] A second scan sequence is generated based on the current of the second scan tube.

[0042] Secondly, this embodiment provides a computed tomography tube current modulation device, which is used to modulate the tube current applied to the scanning bed at different moving speeds;

[0043] The device includes:

[0044] A first acquisition module is used to acquire a first moving speed of the scanning bed and a first scanning tube current, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed;

[0045] The second acquisition module is used to acquire the second moving speed of the scanning bed;

[0046] The result generation module is configured to generate a second scan tube current based on the first scan tube current according to the first moving speed and the second moving speed, wherein the second scan tube current is the tube current applied by the scanning bed at the first moving speed.

[0047] Thirdly, this embodiment provides an electronic device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the computed tomography tube current modulation method described in the first aspect above.

[0048] Fourthly, this embodiment provides a storage medium storing a computer program that, when executed by a processor, implements the computed tomography tube current modulation method described in the first aspect above.

[0049] Compared with related technologies, the computed tomography tube current modulation method provided in this embodiment allows the computer device to modulate the first scan tube current applied to the scanning bed at a first moving speed into a second scan tube current applied at a second moving speed, thereby solving the problem in related technologies that there is a lack of scan tube current modulation methods for computed tomography under variable speed conditions.

[0050] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0051] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0052] Figure 1 This is a hardware structure block diagram of the terminal of the computed tomography tube current modulation method in this embodiment.

[0053] Figure 2 This is a flowchart of the computed tomography tube current modulation method in this embodiment.

[0054] Figure 3 This is a schematic diagram of dose modulation in the Z-direction during conventional CT scans.

[0055] Figure 4 This is a schematic diagram of X-direction dose modulation in a conventional CT scan.

[0056] Figure 5 This is a schematic diagram of the fixed tube current in a conventional CT scan.

[0057] Figure 6 This is a schematic diagram of Z-direction dose modulation in a CT scan according to a preferred embodiment.

[0058] Figure 7 This is a structural block diagram of the computed tomography tube current modulation device in this embodiment. Detailed Implementation

[0059] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0060] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning as understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these,” used in this application, do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to such processes, methods, products, or devices. The terms “connected,” “linked,” and “coupled,” used in this application, are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. The term “multiple” used in this application refers to two or more. The "and / or" operator describes the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: A alone, A and B simultaneously, and B alone. Typically, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," and "third," etc., used in this application are merely for distinguishing similar objects and do not represent a specific ordering of the objects.

[0061] The method embodiments provided in this example can be executed on a terminal, computer, or similar computing device. For example, it can run on a terminal. Figure 1 This is a hardware structure block diagram of the terminal of the computed tomography tube current modulation method in this embodiment. For example... Figure 1 As shown, a terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 and a memory 104 for storing data are also included. The processor 102 may be, but is not limited to, a microprocessor (MCU) or a programmable logic device (FPGA). The terminal may also include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that… Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the terminal described above. For example, the terminal may also include components that are larger than... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown are illustrated.

[0062] The memory 104 can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the computed tomography tube current modulation method in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, thereby implementing the above-described method. The memory 104 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory 104 may further include memory remotely located relative to the processor 102, and these remote memories can be connected to the terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0063] The transmission device 106 is used to receive or send data via a network. This network includes a wireless network provided by the terminal's communication provider. In one example, the transmission device 106 includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 106 can be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0064] This embodiment provides a method for modulating tube current in computed tomography (CT) scans, which modulates the tube current applied to the scanning bed at different travel speeds. Figure 2 This is a flowchart of the computed tomography tube current modulation method of this embodiment, as shown below. Figure 2 As shown, the process includes the following steps:

[0065] Step S210: Obtain the first moving speed of the scanning bed and the first scanning tube current, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed.

[0066] Specifically, the computer equipment first acquires the initial moving speed of the scanning bed and the initial scanning tube current. The moving speed of the scanning bed determines the scanning speed; for example, for the same scanning area of ​​the subject, the faster the moving speed of the scanning bed, the shorter the scanning time for that area. Acquiring the initial scanning tube current means acquiring the tube current intensity applied by the scanning bed at the initial moving speed. Generally, the scan dose is determined by the tube current intensity and the scanning time. For example, for one scanning area of ​​the subject, the product of the tube current intensity applied by the scanning bed to that scanning area and the scanning time is the total scan dose received by that scanning area.

[0067] Step S220: Obtain the second moving speed of the scanning bed.

[0068] Specifically, the computer equipment also acquires a second movement speed of the scanning bed, which differs from the first movement speed. For a single scanned area of ​​the same subject, the scan time for that area changes due to the change in the scanning bed's movement speed. If the first scan tube current is still used for scanning, the total scan dose received by that area will inevitably change. For example, if the second movement speed is greater than the first, the scan time decreases, and the total scan dose received by that area decreases; if the second movement speed is less than the first, the scan time increases, and the total scan dose received by that area increases. Therefore, when the movement speed of the scanning bed changes, the first scan tube current needs to be modulated to change its current intensity and obtain the second scan tube current. At the second movement speed, computed tomography is performed using the second scan tube current, ensuring that the scan dose received by each scanned area of ​​the subject is the same as or close to that at the first movement speed.

[0069] Step S230: Generate a second scanning tube current based on the first moving speed, the second moving speed, and the first scanning tube current, wherein the second scanning tube current is the tube current applied by the scanning bed at the second moving speed.

[0070] Specifically, after acquiring a determined first moving speed, a second moving speed, and a first scanning tube current, the computer device modulates the first scanning tube current based on the relationship between the first and second moving speeds to generate a second scanning tube current. For example, for a scanning area of ​​the subject, if the second moving speed corresponding to that area is greater than the first moving speed, the scanning time is shorter, so the intensity of the first scanning tube current corresponding to that area can be appropriately increased to obtain the second scanning tube current corresponding to that area; conversely, if the second moving speed corresponding to that area is less than the first moving speed, the scanning time is longer, so the intensity of the first scanning tube current corresponding to that area can be appropriately decreased to obtain the second scanning tube current corresponding to that area.

[0071] Through the above steps, the computer equipment can modulate the first scan tube current applied to the scanning bed at the first moving speed into a second scan tube current applied at the second moving speed. Specifically, the intensity of the first scan tube current is adjusted based on the relationship between the first and second moving speeds to generate the second scan tube current. This ensures that when the subject is scanned at the second moving speed, the total scan dose received by each scanned area is the same as or close to that received at the first moving speed. This eliminates or reduces the deviation in scan dose received by each scanned area at different moving speeds. Thus, it solves the problem in related technologies of lacking a scan tube current modulation method for computed tomography under variable speed conditions.

[0072] It should be further clarified that the first and second scan tube currents can be instantaneous or continuous currents, and the conversion between the two scan tube currents occurs during the same scanning state. In actual computed tomography (CT) scanning, the patient can be scanned based on the first scan tube current to generate the first CT image, or the patient can be scanned based on the second scan tube current to generate the second CT image. The two scan tube currents are suitable for two different scanning bed travel speeds.

[0073] Therefore, in some embodiments, the computed tomography tube current modulation method further includes: acquiring a first scan sequence, wherein the first scan sequence includes a first scan tube current; and generating a second scan sequence based on a second scan tube current.

[0074] Specifically, the first scan sequence is first obtained. The scan sequence parameters include the magnitude of the first scan tube current, which is the tube current intensity that the scanning bed should apply to each scan position at the first moving speed. After tube current modulation, the tube current intensity that the scanning bed should apply to each scan position at the second moving speed is obtained, i.e., the second scan tube current. Finally, the second scan sequence is generated based on the second scan tube current. The first and second scan sequences are respectively applicable to the first and second moving speeds of the scanning bed. That is, the first scan sequence is used for scanning at the first moving speed, and the second scan sequence is used for scanning at the second moving speed. It should be noted that the first and second scan sequences correspond to the same scanning state. For example, when scanning the same object at different speeds, the first and second scan sequences can be used for scanning and imaging respectively.

[0075] In some of these embodiments, the first moving speed is a constant first continuous speed, and the second moving speed is a variable second continuous speed;

[0076] The first scanning tube current is the first continuous tube current, and the second scanning tube current is the second continuous tube current.

[0077] Specifically, in this embodiment, the first moving speed is a constant continuous speed, and the second moving speed is a variable continuous speed. Correspondingly, the first and second scanning tube currents are continuous tube currents. Therefore, the computed tomography (CT) tube current modulation method in this embodiment can be better applied to dynamic perfusion in CT scans. Dynamic perfusion requires wire placement and data acquisition during the acceleration and deceleration of the scanning bed. In application, the scanning tube current is obtained based on the constant bed speed of the current conventional dose modulation, and then the non-constant bed speed under dynamic perfusion is obtained. Thus, based on the relationship between the constant and non-constant bed speeds, the first scanning tube current at the constant bed speed is modulated to obtain the second scanning tube current at the non-constant bed speed, thereby meeting the scanning requirements of dynamic perfusion.

[0078] Furthermore, based on the previous embodiment, the magnitudes of the first continuous transistor current and the second continuous transistor current are related to the scanning position; the magnitudes of the first continuous speed and the second continuous speed are related to the scanning position.

[0079] Specifically, both the first and second continuous tube currents are related to the scanning position, meaning the continuous tube current changes with the scanning position, and each defined scanning position corresponds to a defined tube current magnitude. The magnitudes of the first and second continuous speeds are also related to the scanning position, meaning the continuous speed changes with the scanning position. The first continuous speed is a constant speed, meaning the speed is the same for each scanning position. It should be noted that the scanning position is relative to the patient being scanned, and can also be described as the movement position of the scanning bed. Since the patient moves with the scanning bed, each defined scanning bed movement position corresponds to a defined scanning position within the patient's body. In this embodiment, tube current modulation converts the tube current at the same scanning position at different scanning bed movement speeds. For example, at the first movement speed, the tube current magnitude at scanning position a is a1, and the tube current magnitude at scanning position b is b1. After tube current modulation, at the second movement speed, the tube current magnitude at scanning position a is a2, and the tube current magnitude at scanning position b is b2. Here, a2 is obtained from a1, and b2 is obtained from b1.

[0080] As illustrated by the above embodiments, both the first and second persistent transistor currents are related to the scanning position, and the magnitude of the second persistent transistor current at each scanning position is obtained by converting the magnitude of the first persistent transistor current at the corresponding scanning position. Furthermore, the following embodiments provide two specific methods for converting the first and second persistent transistor currents.

[0081] In one specific embodiment, step S230, generating the second scanning tube current based on the first moving speed, the second moving speed, and the first scanning tube current, specifically includes:

[0082] Step S231a: Determine the scanning range, which includes at least one scanning position;

[0083] Step S232a: Determine the current scanning position from the scanning range;

[0084] Step S233a: Determine the first instantaneous velocity corresponding to the current scanning position based on the current scanning position and the first continuous velocity;

[0085] Step S234a: Determine the first instantaneous tube current corresponding to the current scanning position based on the current scanning position and the first continuous tube current;

[0086] Step S235a: Determine the second instantaneous velocity corresponding to the current scanning position based on the current scanning position and the second continuous velocity;

[0087] Step S236a: Determine the second instantaneous tube current corresponding to the current scanning position based on the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity;

[0088] Step S237a: Generate a second continuous tube current based on the second instantaneous tube current.

[0089] Specifically, this embodiment provides a process for converting a first continuous transistor current into a second continuous transistor current. The scanning range refers to the set of all scanning positions; the first continuous velocity is composed of several first instantaneous velocities, each corresponding to a different scanning position; the first continuous transistor current is composed of several first instantaneous transistor currents, each corresponding to a different scanning position; the second continuous velocity is composed of several second instantaneous velocities, each corresponding to a different scanning position. During the conversion process, the current scanning position to be converted needs to be determined first, then the first instantaneous velocity, the first instantaneous transistor current, and the second instantaneous velocity corresponding to the current scanning position need to be determined. Then, based on the relationship between the first and second instantaneous velocities, the first instantaneous transistor current is adjusted to obtain the second instantaneous transistor current, which also corresponds to the current scanning position. Generally, when the second instantaneous velocity is greater than the first instantaneous velocity, the first instantaneous transistor current is increased to obtain the second instantaneous transistor current; when the second instantaneous velocity is less than the first instantaneous velocity, the first instantaneous transistor current is decreased to obtain the second instantaneous transistor current.

[0090] Through the above steps, the first instantaneous tube current corresponding to each scanning position can be converted into a second instantaneous tube current. Finally, all the second instantaneous tube currents are sorted and combined according to the scanning position to form a second continuous tube current (or directly generate a second scanning sequence). It should be noted that all the second instantaneous tube currents belong to the same scanning sequence, so CT scans can be performed based on the combined second instantaneous tube currents to generate CT images.

[0091] It should be further explained that the above content has already described the tube current conversion process for a specific scanning position. Since the scanning range includes several scanning positions, in the actual modulation process, the tube current can be modulated for all scanning positions one by one. That is, after modulating the current scanning position, the current scanning position is updated to the next scanning position. Alternatively, all scanning positions can be modulated simultaneously, thereby obtaining the second instantaneous tube current corresponding to each scanning position at the same time.

[0092] In a specific embodiment, step S236a, determining the second instantaneous tube current corresponding to the current scanning position based on the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity, includes:

[0093] Step S236a1: Determine the ratio between the second instantaneous velocity and the first instantaneous velocity;

[0094] Step S236a2: The first instantaneous tube current is transformed by the ratio relationship to obtain the second instantaneous tube current.

[0095] Specifically, during the conversion process, after determining the first and second instantaneous velocities corresponding to the current scanning position, it is first necessary to calculate the ratio between the second and first instantaneous velocities. Then, based on this ratio, the first instantaneous transistor current is transformed to finally obtain the second instantaneous transistor current. For example, if the first instantaneous velocity is denoted as v1, the second instantaneous velocity as v2, the first instantaneous transistor current as c1, and the second instantaneous transistor current as c2, then the second instantaneous transistor current c2 = c1 * v2 / v1.

[0096] In another embodiment, step S230, generating the second scanning tube current based on the first moving speed, the second moving speed, and the first scanning tube current, specifically includes:

[0097] Step S231b: Determine the scanning range and divide the scanning range into multiple scanning intervals, wherein each scanning interval includes at least one scanning position;

[0098] Step S232b: Determine the current scan interval from the scan range;

[0099] Step S233b: Determine the first interval speed corresponding to the current scanning interval based on the current scanning interval and the first continuous speed;

[0100] Step S234b: Determine the first interval transistor current corresponding to the current scanning interval based on the current scanning interval and the first continuous transistor current;

[0101] Step S235b: Determine the second interval speed corresponding to the current scanning interval based on the current scanning interval and the second continuous speed;

[0102] Step S236b: Determine the second interval tube current corresponding to the current scanning interval based on the first interval velocity, the first interval tube current, and the second interval velocity;

[0103] Step S237b: Generate a second continuous tube current based on the second interval tube current.

[0104] Specifically, this embodiment provides another process for converting the first continuous transistor current into the second continuous transistor current. First, the scanning range is divided into multiple scanning intervals, each including at least one scanning position. The first continuous speed is composed of several first interval speeds, each corresponding to a different scanning interval; the first continuous transistor current is composed of several first interval currents, each corresponding to a different scanning interval; the second continuous speed is composed of several second interval speeds, each corresponding to a different scanning interval. During the conversion process, the current scanning interval to be converted needs to be determined first, then the first interval speed, first interval transistor current, and second interval speed corresponding to the current scanning interval need to be determined. Then, based on the relationship between the first and second interval speeds, the first interval transistor current is adjusted to obtain the second interval transistor current, which also corresponds to the current scanning interval. Generally, when the second interval speed is greater than the first interval speed, the first interval transistor current is increased to obtain the second interval transistor current; when the second interval speed is less than the first interval speed, the first interval transistor current is decreased to obtain the second interval transistor current.

[0105] Through the above steps, the first interval tube current corresponding to each scanning interval can be converted into a second interval tube current. Finally, all the second interval tube currents are sorted and combined according to the scanning intervals to form a second continuous tube current (or directly generate a second scanning sequence). It should be noted that all the second interval tube currents belong to the same scanning sequence, so CT scans can be performed based on the combined second interval tube currents to generate CT images.

[0106] It should be noted that the first interval current can be the current corresponding to any scanning position within the corresponding scanning interval. For example, if a scanning interval has five scanning positions, the current corresponding to any one of the five scanning positions can be taken as the corresponding interval current. Alternatively, the average of the currents corresponding to the five scanning positions can be calculated to obtain the corresponding first interval current.

[0107] Unlike the conversion process in the previous embodiments, where the tube current corresponding to each scan position was converted, this embodiment converts the tube current corresponding to each scan interval, and each scan interval includes at least one scan position. Therefore, the tube current conversion process in this embodiment is simpler and requires less computation.

[0108] It should be further explained that the above content has already described the tube current conversion process for a specific scanning interval. Since the scanning range contains multiple scanning intervals, in the actual modulation process, all scanning intervals can be modulated one by one. That is, after modulating the current scanning interval, the current scanning interval is updated to the next scanning interval. Alternatively, all scanning intervals can be modulated simultaneously, thereby obtaining the second interval tube current corresponding to each scanning interval at the same time.

[0109] In a specific embodiment, step S236b, determining the second interval tube current corresponding to the current scanning interval based on the first interval velocity, the first interval tube current, and the second interval velocity, specifically includes:

[0110] Step S236b1: Determine the first interval time based on the first interval velocity, and determine the interval current product based on the first interval time and the first interval tube current;

[0111] Step S236b2: Determine the second interval time based on the second interval velocity, and determine the second interval tube current based on the product of the second interval time and the interval current.

[0112] Specifically, during the conversion process, once the first interval speed corresponding to the current scanning interval is determined, the interval length is fixed. Therefore, the scanning duration of the current scanning interval can be calculated and denoted as the first interval time. Then, the product of the first interval time and the first interval tube current is calculated to obtain the interval current product, which represents the scanning dose the patient should receive in the current scanning interval. Next, the second interval time is determined based on the second interval speed; the second interval time is the scanning duration of the current scanning interval at the second movement speed. Finally, dividing the interval current product by the second interval time yields the second interval tube current.

[0113] The technical solutions in this application are described and illustrated below through preferred embodiments.

[0114] To better describe the computed tomography tube current modulation method in this preferred embodiment, a brief description of relevant existing modulation methods is first given. Figure 3 This is a schematic diagram of dose modulation in the Z-direction during conventional CT scans. Figure 4 This is a schematic diagram of X-axis dose modulation in a conventional CT scan. Among them, Figure 3 The horizontal axis represents the positions along the CT scanning bed axis, which can be understood as the moving position of the scanning bed or the scanning position, while the vertical axis represents the scanning tube current intensity, specifically describing the curve of the scanning tube current changing with the scanning position. Figure 4 This represents an elliptical model of the patient being scanned on the radial plane (light plane) of the CT scanning bed, where X and Y represent the approximate width and thickness of the patient in the light plane, respectively.

[0115] Reference Figure 3 and Figure 4 Dose modulation in routine CT scans mainly includes Z-axis (CT scan bed axis) dose modulation and X-axis dose modulation (CT light plane). The basic idea is to approximate the scanned object as an elliptical model, obtaining ellipses with different axis lengths in the Z-axis. Locations with greater attenuation have relatively larger elliptical axis lengths, corresponding to larger doses, such as... Figure 3 and Figure 4 The P2 position in the image; a position with low attenuation, relatively small axial length, and correspondingly small dose, such as... Figure 3 and Figure 4 Position P1 in the diagram.

[0116] Figure 5 This is a schematic diagram of the fixed tube current in a conventional CT scan. In conventional clinical CT scans, beam placement and data acquisition typically begin after the scan bed speed has reached a constant. However, in dynamic perfusion applications, to obtain the clinically necessary imaging data and assist physicians in qualitative and quantitative analysis and evaluation of blood perfusion in different tissues, it is necessary to control the scan interval. Therefore, beam placement and data acquisition must occur during the acceleration and deceleration of the scan bed. (Refer to...) Figure 5 Here, we will first use a scan with a fixed mA as an example:

[0117] The first scenario assumes that the scanning bed moves at a constant speed during the scanning process.

[0118] The scanning begins at time P1, and there are three continuous regions: P1→P2→P3→P4, each with a length of L (this is just an example and may vary in practice).

[0119] The scanning bed speed is V0, the scanning tube current is mA0, the tube current-time product is mAs0, and the scanning time is t0, where t0 = L * 3 / V0. mAs0 = mA0 * t0.

[0120] In the second scenario, if scanning begins during the acceleration phase of the scanning bed, reaches V0, and then decelerates to 0 to end the scanning, then the scanning time t is:

[0121] t1:0->V0 acceleration phase, corresponding to the L-length region from P1 to P2;

[0122] t2: The continuous V0 motion phase, corresponding to the L-length region from P2 to P3;

[0123] t3: V0 → 0 deceleration phase, corresponding to P3 to P4.

[0124] t = t1 + t2 + t3, obviously, t > t0.

[0125] If the tube current remains constant, the second case obviously has a longer scan time and a larger tube current-time product than the first case, resulting in a higher scan dose.

[0126] In reality, because the scanning bed accelerates from 0 during the P1 to P2 phase and moves very slowly at the beginning, scanning is still performed using a tube current of mA0, which inevitably leads to a higher dose at the corresponding position during the acceleration phase, thus increasing the overall dose. Therefore, to reduce unnecessary dose loading on the patient, the tube current intensity is modulated in conjunction with the scanning bed movement speed during the acceleration and deceleration of the patient. This ensures the consistency of image noise while also reducing the dose applied to the patient.

[0127] The computed tomography tube current modulation method in this preferred embodiment effectively solves the aforementioned defects of the prior art. Specifically, it provides a dose modulation method under dynamic perfusion scanning. Dynamic perfusion dose modulation combines the dose modulation of conventional scanning with the scanning bed acceleration / deceleration process, thus providing a dose modulation method suitable for non-constant speed conditions based on the constant bed speed of current conventional dose modulation.

[0128] Figure 6 This is a schematic diagram of Z-axis dose modulation in a CT scan according to a preferred embodiment. (Refer to...) Figure 6 The computed tomography tube current modulation method in this preferred embodiment includes the following steps:

[0129] Step (1) divides the scanning range into multiple scanning intervals and determines the tube current before modulation for each scanning interval.

[0130] Within the scanning range, divide it into as many intervals as possible according to the bed code: (P1-P2), (P2-P3), ..., (P... n-1 -P nBased on the equivalent elliptical model of the aforementioned scanned object, and according to the scan position, construct the tube current corresponding to the dose modulation scan curve at a constant bed rate for each interval (assuming all are L), denoted as mA1, mA2, ..., mA. n-1 The scan times for each interval are t1, t2, ..., t. n-1 The scanning bed speed is V (constant speed).

[0131] Step (2) Calculate the tube current after modulation for each scanning interval.

[0132] Matching is performed based on the planned parameters of the scanning bed acceleration / deceleration and the scanning object in time and position; defining (P1-P2), (P2-P3), ..., (P2-P3) for the start of scanning under scanning bed acceleration / deceleration. n-1 -P n The scan times for the intervals are t`1, t`2, ..., t`. n-1 The scanning bed moves at speeds of V`1, V`2, ..., V` n-1 Based on the mA value for each interval when the bed is at a constant speed and the bed speed during variable speed, the corresponding mA`1, mA`2, ..., mA` values ​​can be calculated. n-1 Where mA`1*t`1=mA1*t1, t1=L / V, t`1=L / V`1, thus obtaining mA`1=mA1*V`1 / V; correspondingly mA` n-1 =mA n-1 *V` n-1 / V. Finally, based on mA`1, mA`2, mA` n-1 The generated modulation sequence is then scanned.

[0133] It should be noted that the computed tomography tube current modulation method in this application, besides being applied in the dynamic perfusion scenario of this preferred embodiment, can also be used in clinical applications of variable pitch scanning such as transcatheter aortic valve implantation (TAVI) to reduce patient dose and obtain a higher image signal-to-noise ratio. In helical scanning, pitch refers to the distance the scanning bed moves along its axial direction within one helical scanning cycle. Therefore, variable pitch scanning refers to a scanning method in which the speed of the scanning bed moving along its axial direction continuously changes. Generally, the faster the scanning bed moves, the larger the pitch, and the slower the movement speed, the smaller the pitch.

[0134] This embodiment also provides a computed tomography (CT) tube current modulation device for modulating the tube current applied to the scanning bed at different travel speeds. This device is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. The terms "module," "unit," "subunit," etc., used below refer to combinations of software and / or hardware that implement a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0135] Figure 7 This is a structural block diagram of the computed tomography tube current modulation device in this embodiment, as shown below. Figure 7 As shown, the device includes:

[0136] The first acquisition module 710 is used to acquire the first moving speed of the scanning bed and the first scanning tube current, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed;

[0137] The second acquisition module 720 is used to acquire the second moving speed of the scanning bed;

[0138] The result generation module 730 is used to generate a second scan tube current based on the first scan tube current according to the first moving speed and the second moving speed, wherein the second scan tube current is the tube current applied by the scanning bed at the first moving speed.

[0139] Through the aforementioned module, the modulation device can modulate the first scan tube current applied to the scanning bed at the first moving speed into a second scan tube current applied at the second moving speed. Specifically, the intensity of the first scan tube current is adjusted based on the relationship between the first and second moving speeds to generate the second scan tube current. This ensures that when the subject is scanned at the second moving speed, the total scan dose received by each scanned area is the same as or close to that received at the first moving speed. This eliminates or reduces the deviation in scan dose received by each scanned area at different moving speeds. Thus, it solves the problem in related technologies of lacking a scan tube current modulation method for computed tomography under variable speed conditions.

[0140] It should be noted that the above modules can be functional modules or program modules, and can be implemented through software or hardware. For modules implemented through hardware, the above modules can reside in the same processor; or the above modules can be located in different processors in any combination.

[0141] This embodiment also provides an electronic device, including a memory and a processor, wherein the memory stores a computer program and the processor is configured to run the computer program to perform the steps in any of the above method embodiments.

[0142] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor and the input / output device is connected to the processor.

[0143] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0144] Step A: Obtain the first moving speed of the scanning bed and the first scanning tube current, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed;

[0145] Step B: Obtain the second moving speed of the scanning bed;

[0146] Step C: Generate a second scanning tube current based on the first moving speed, the second moving speed, and the first scanning tube current, wherein the second scanning tube current is the tube current applied by the scanning bed at the first moving speed.

[0147] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated in this embodiment.

[0148] Furthermore, in conjunction with the computed tomography tube current modulation method provided in the above embodiments, this embodiment can also provide a storage medium for implementation. The storage medium stores a computer program; when executed by a processor, the computer program implements any of the computed tomography tube current modulation methods described in the above embodiments.

[0149] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0150] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0151] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

[0152] The term "embodiment" in this application refers to a specific feature, structure, or characteristic described in connection with an embodiment that may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily imply the same embodiment, nor does it imply that it is mutually exclusive with or independent of other embodiments. It will be clearly or implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0153] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method for modulating current in a computed tomography (CT) scanner, characterized in that, The method is used to modulate the tube current applied to the scanning bed at different travel speeds; The method includes: The first moving speed of the scanning bed and the first scanning tube current are obtained, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed; Obtain the second moving speed of the scanning bed; A second scan tube current is generated based on the first moving speed, the second moving speed, and the first scan tube current, wherein the second scan tube current is the tube current applied by the scanning bed at the second moving speed; The first scanning tube current is a first continuous tube current, and the second scanning tube current is a second continuous tube current; the first moving speed is a constant first continuous speed, which is composed of several first instantaneous speeds, each of which corresponds to a different scanning position; the second moving speed is a variable second continuous speed, which is composed of several second instantaneous speeds, each of which corresponds to a different scanning position; the scanning position is the moving position of the scanning bed; wherein, each determined moving position of the scanning bed corresponds to a determined scanning position in the patient's body; The second scanning tube current is determined as follows: the current scanning position to be converted is determined; the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity corresponding to the current scanning position are determined; the first instantaneous tube current is adjusted according to the relationship between the first instantaneous velocity and the second instantaneous velocity to obtain the second instantaneous tube current; all the second instantaneous tube currents are sorted and combined according to the scanning position to form the second continuous tube current.

2. The computed tomography tube current modulation method according to claim 1, characterized in that, The magnitudes of the first and second continuous transistor currents are related to the scanning position; The magnitudes of the first and second continuous speeds are related to the scanning position.

3. The computed tomography tube current modulation method according to claim 1, characterized in that, The step of determining the second instantaneous tube current corresponding to the current scanning position based on the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity includes: Determine the ratio between the second instantaneous velocity and the first instantaneous velocity; The first instantaneous tube current is transformed using the ratio relationship to obtain the second instantaneous tube current.

4. The computed tomography tube current modulation method according to claim 1, characterized in that, Generating the second scan tube current based on the first moving speed, the second moving speed, and the first scan tube current includes: Determine the scanning range and divide the scanning range into multiple scanning intervals, wherein each scanning interval includes at least one of the scanning positions; Determine the current scan interval from the scan range; Based on the current scan interval and the first continuous speed, determine the first interval speed corresponding to the current scan interval; Based on the current scan interval and the first continuous transistor current, determine the first interval transistor current corresponding to the current scan interval; Based on the current scan interval and the second continuous speed, determine the second interval speed corresponding to the current scan interval; Based on the first interval velocity, the first interval tube current, and the second interval velocity, determine the second interval tube current corresponding to the current scanning interval; The second continuous tube current is generated based on the second interval tube current.

5. The computed tomography tube current modulation method according to claim 4, characterized in that, The step of determining the second interval tube current corresponding to the current scanning interval based on the first interval velocity, the first interval tube current, and the second interval velocity includes: The first interval time is determined based on the first interval speed, and the interval current product is determined based on the first interval time and the first interval tube current. The second interval time is determined based on the second interval velocity, and the second interval tube current is determined based on the product of the second interval time and the interval current.

6. The computed tomography tube current modulation method according to any one of claims 1 to 5, characterized in that, The method further includes: Acquire a first scan sequence, wherein the first scan sequence includes a first scan tube current; A second scan sequence is generated based on the current of the second scan tube.

7. A computed tomography (CT) tube current modulation device, characterized in that, The device is used to modulate the tube current applied to the scanning bed at different moving speeds; The device includes: A first acquisition module is used to acquire a first moving speed of the scanning bed and a first scanning tube current, wherein the first scanning tube current is the tube current applied by the scanning bed at the first moving speed; The second acquisition module is used to acquire the second moving speed of the scanning bed; The result generation module is used to generate a second scan tube current based on the first scan tube current according to the first moving speed and the second moving speed, wherein the second scan tube current is the tube current applied by the scanning bed at the first moving speed; The first scanning tube current is a first continuous tube current, and the second scanning tube current is a second continuous tube current; the first moving speed is a constant first continuous speed, which is composed of several first instantaneous speeds, each of which corresponds to a different scanning position; the second moving speed is a variable second continuous speed, which is composed of several second instantaneous speeds, each of which corresponds to a different scanning position; the scanning position is the moving position of the scanning bed; wherein, each determined moving position of the scanning bed corresponds to a determined scanning position in the patient's body; The second scanning tube current is determined as follows: the current scanning position to be converted is determined; the first instantaneous velocity, the first instantaneous tube current, and the second instantaneous velocity corresponding to the current scanning position are determined; the first instantaneous tube current is adjusted according to the relationship between the first instantaneous velocity and the second instantaneous velocity to obtain the second instantaneous tube current; all the second instantaneous tube currents are sorted and combined according to the scanning position to form the second continuous tube current.

8. An electronic device comprising a memory and a processor, characterized in that, The memory stores a computer program, and the processor is configured to run the computer program to perform the computed tomography tube current modulation method according to any one of claims 1 to 6.

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