Magnetic resonance imaging spiral acquisition method, device, equipment and storage medium

Abstract

The application relates to the technical field of medical imaging, and discloses a magnetic resonance imaging spiral acquisition method, device, equipment and storage medium, the method comprising the following steps: acquiring a long side and a short side of a rectangular field of view; determining a radial field of view and a circumferential field of view of spiral acquisition based on the long side and the short side of the rectangular field of view; the product of the radial field of view and the circumferential field of view is equal to the product of the long side and the short side of the rectangular field of view; determining a radial sampling interval and a circumferential sampling interval that satisfy the Nyquist sampling law based on the radial field of view and the circumferential field of view; determining a magnetic field gradient function based on a preselected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, a maximum gradient amplitude limit and a maximum gradient change rate limit; exciting a magnetic resonance signal in an imaging region based on the magnetic field gradient function, and acquiring the magnetic resonance signal. The spiral trajectory design scheme provided by the application can be applied to the acquisition density requirement of the rectangular field of view.

Description

Technical Field

[0001] This invention relates to the field of medical imaging technology, specifically to a magnetic resonance imaging helical acquisition method, apparatus, device, and storage medium. Background Technology

[0002] Magnetic Resonance Imaging (MRI) is a non-invasive medical imaging technique that uses strong magnetic fields and radio frequency pulses to excite hydrogen nuclei (protons) within the human body, reconstructing images by receiving their relaxation signals. MRI offers excellent soft tissue contrast, emits no ionizing radiation, and is widely used in the diagnosis of diseases of the brain, joints, and abdomen. Its core components include spatial encoding (filling data in k-space using gradient magnetic fields) and image reconstruction. Traditional sampling often uses Cartesian trajectories, but non-Cartesian trajectories (such as spiral and radial trajectories) can improve scanning efficiency or reduce motion artifacts.

[0003] The field of view (FOV) is the physical area covered by a single data acquisition in MRI, determining the anatomical extent of the imaging. FOVs are typically square (1:1 aspect ratio), but when scanning long, narrow tissues such as the arm or spine, or when using local excitation, rectangular FOVs (e.g., 2:1 or 3:1 aspect ratios) often provide better coverage. The space containing the FOV is called image space. k-space, on the other hand, is the mathematical space used in MRI to store raw data. It represents the spatial frequency domain, recording the frequency and phase information of the MR signal, and can be converted back to image space using a Fourier transform.

[0004] The shape of the field of view (FOV) influences the choice of acquisition strategy. According to the Nyquist sampling theorem, the FOV is inversely proportional to the sampling interval in the k-space (i.e., the smaller the FOV, the larger the required sampling interval). Figure 1 As shown, for a rectangular FOV, due to the decrease in the length of the shorter side, the corresponding sampling interval ( The number of data collection points needs to be increased, thus reducing the total number of data collection points.

[0005] Helical acquisition is a non-Cartesian k-space trajectory in MRI, where a gradient magnetic field controls the signal to continuously fill the k-space along a helical path (e.g., ...). Figure 2 (As shown). Compared to traditional Cartesian sampling, helical trajectories offer higher scanning efficiency and better motion robustness, making them suitable for rapid imaging (such as cardiac and functional MRI). Helical trajectories typically employ an Archimedean spiral, with the radial and circumferential (i.e., tangential directions of the spiral) sampling intervals constrained by the Nyquist sampling law, and the sampling interval being inversely proportional to the field of view (FOV). Simultaneously, the gradient must also satisfy limits on the maximum gradient magnitude and the maximum rate of change of gradient.

[0006] However, the current spiral trajectory design cannot adequately meet the sampling density requirements of rectangular FOVs. The current scheme assumes that the minimum sampling density is equal in different directions. But for a rectangular FOV, the minimum sampling density is not equal in different directions (e.g., ...). Figure 1 (As shown in the lower right section), effectively covering the sampling points presents a challenge:

[0007] (1) If the long side FOV is selected to calculate the sampling density, the sampling density in the short side direction will be greater than the minimum sampling density (oversampling), which will increase the total acquisition time and, in the case of non-uniform magnetic field, will lead to the aggravation of magnetic susceptibility artifacts.

[0008] (2) If the short side FOV is selected to calculate the sampling density, the sampling density in the long side direction will be less than the minimum sampling density, resulting in image artifacts. Summary of the Invention

[0009] In view of this, the present invention provides a magnetic resonance imaging helical acquisition method, apparatus, device and storage medium to solve the problem that the current helical trajectory design scheme cannot well adapt to the acquisition density requirements of rectangular field of view.

[0010] In a first aspect, the present invention provides a magnetic resonance imaging helical acquisition method, the method comprising:

[0011] Obtain the long and short sides of the rectangular field of view;

[0012] Based on the long and short sides of the rectangular field of view, the radial and circumferential fields of view for helical acquisition are determined; the product of the radial and circumferential fields of view is equal to the product of the long and short sides of the rectangular field of view.

[0013] Based on the radial field of view and the circumferential field of view, determine the radial sampling interval and the circumferential sampling interval that satisfy the Nyquist sampling law;

[0014] The magnetic field gradient function is determined based on the pre-selected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, the maximum gradient amplitude limit and the maximum gradient change rate limit;

[0015] Based on the magnetic field gradient function, magnetic resonance signals are excited in the imaging region and acquired.

[0016] In one optional implementation, determining the magnetic field gradient function based on a pre-selected K-space trajectory function, the radial sampling interval, the circumferential sampling interval, the maximum gradient magnitude limit, and the maximum gradient change rate limit includes:

[0017] The first functional relationship is obtained by performing a first-order differential on the K-space trajectory function. The first functional relationship is the functional relationship between the magnetic field gradient and the radial length, the first derivative of the radial length, the circumferential phase, and the first derivative of the circumferential phase.

[0018] The second derivative of the K-space trajectory function is obtained by performing a second functional relationship, which is the functional relationship between the rate of change of the magnetic field gradient and the radial length, the first derivative of the radial length, the second derivative of the radial length, the circumferential phase, the first derivative of the circumferential phase, and the second derivative of the circumferential phase.

[0019] The magnetic field gradient function is determined based on the first functional relationship, the second functional relationship, the radial sampling interval and the circumferential sampling interval, the maximum gradient amplitude limit and the maximum gradient change rate limit.

[0020] In one optional implementation, determining the radial and circumferential field of view for helical acquisition based on the long and short sides of the rectangular field of view includes:

[0021] The longer side of the rectangular field of view is taken as the radial field of view;

[0022] The shorter side of the rectangular field of view is taken as the circumferential field of view.

[0023] In one optional implementation, determining the radial and circumferential field of view for helical acquisition based on the long and short sides of the rectangular field of view includes:

[0024] The longer side of the rectangular field of view is taken as the circumferential field of view;

[0025] The shorter side of the rectangular field of view is taken as the radial field of view.

[0026] In one optional implementation, determining the radial and circumferential field of view for helical acquisition based on the long and short sides of the rectangular field of view includes:

[0027] Calculate the product of the long side and the short side of the rectangular field of view;

[0028] Take the square root of the product of the long side and the short side of the rectangular field of view, and use the resulting non-negative square root as the radial field of view and the circumferential field of view.

[0029] In a second aspect, the present invention provides a magnetic resonance imaging helical acquisition device, the device comprising:

[0030] The acquisition module is used to acquire the long and short sides of the rectangular field of view;

[0031] The first determining module is used to determine the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view; the product of the radial field of view and the circumferential field of view is equal to the product of the long and short sides of the rectangular field of view.

[0032] The second determining module is used to determine the radial sampling interval and the circumferential sampling interval that satisfy the Nyquist sampling law based on the radial field of view and the circumferential field of view.

[0033] The third determining module is used to determine the magnetic field gradient function based on the pre-selected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, the maximum gradient magnitude limit and the maximum gradient change rate limit;

[0034] The acquisition module is used to excite magnetic resonance signals in the imaging region based on the magnetic field gradient function, and to acquire the magnetic resonance signals.

[0035] Thirdly, the present invention provides a magnetic resonance imaging device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the magnetic resonance imaging spiral acquisition method of the first aspect or any corresponding embodiment described above.

[0036] Fourthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to perform the magnetic resonance imaging helical acquisition method of the first aspect or any corresponding embodiment described above.

[0037] Fifthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the magnetic resonance imaging helical acquisition method of the first aspect or any corresponding embodiment described above.

[0038] The magnetic resonance imaging helical acquisition method, apparatus, device, and storage medium of this invention propose a helical trajectory design scheme that is suitable for the acquisition density requirements of rectangular fields of view. Furthermore, while satisfying the Nyquist sampling theorem, this scheme avoids redundant data acquisition and shortens the trajectory length. The shortened trajectory length not only improves image acquisition efficiency but also gives the helical trajectory better resistance to magnetic susceptibility artifacts, thereby improving the quality of the acquired magnetic resonance images. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the acquisition trajectory ("×" represents the point to be acquired) for echo planar imaging (EPI) under square and rectangular field of view (2:1).

[0041] Figure 2 This is a schematic diagram of the spiral acquisition trajectory under a square field of view (in the figure, "×" represents the point to be acquired, "○" represents the actual acquired point, and the lines represent the acquisition trajectory).

[0042] Figure 3 This is a schematic flowchart of a magnetic resonance imaging spiral acquisition method according to an embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of a spiral acquisition trajectory according to an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of another spiral acquisition trajectory according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram of another spiral acquisition trajectory according to an embodiment of the present invention;

[0046] Figure 7 This is a structural block diagram of a magnetic resonance imaging spiral acquisition device according to an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of the hardware structure of the magnetic resonance device according to an embodiment of the present invention. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] According to an embodiment of the present invention, a method for spiral acquisition of magnetic resonance imaging is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of executable computer instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0050] This embodiment provides a magnetic resonance imaging helical acquisition method, which can be used in magnetic resonance equipment (i.e., magnetic resonance scanner). Figure 3 This is a flowchart of a magnetic resonance imaging helical acquisition method according to an embodiment of the present invention, as follows: Figure 3 As shown, the process includes the following steps:

[0051] Step S301: Obtain the long and short sides of the rectangular field of view.

[0052] Specifically, the size of the rectangular field of view can be determined based on the size of the object being scanned, with the longer side denoted as FOV. x The shorter side is denoted as FOV. y .

[0053] Step S302: Based on the long and short sides of the rectangular field of view, determine the radial field of view (FOV) for helical acquisition. r Circumferential (Tangent to the trajectory) Field of View (FOV) θ The radial field of view (FOV) r and the circumferential field of view (FOV) θ The product of the two sides is equal to the product of the long side and the short side of the rectangular field of view.

[0054] That is, FOV r × FOV θ =FOV x × FOV y .

[0055] Step S303: Based on the radial field of view and the circumferential field of view, determine the radial sampling interval and the circumferential sampling interval that satisfy the Nyquist sampling law.

[0056] Specifically, the radial sampling interval Δk r (i.e., the radial velocity of the trajectory) and the circumferential sampling interval The following conditions must be met:

[0057] (1)

[0058] Where R represents the undersampling rate when an undersampling strategy is used. In the absence of undersampling, R=1.

[0059] Step S304: Determine the magnetic field gradient function based on the pre-selected K-space trajectory function, the radial sampling interval, and the circumferential sampling interval.

[0060] Specifically, K-space trajectory functions can be selected here, including Archimedes spiral trajectory functions and their variants.

[0061] The general form of the K-space trajectory function is:

[0062] k(t) = r(t)e iθ(t)

[0063] Where k(t) is the k-space coordinate at time t, r(t) is the radial length (i.e., radial position) of the current coordinate point, and θ(t) is the circumferential phase (i.e., angle) of the current coordinate point.

[0064] In some optional implementations, step S304, namely determining the magnetic field gradient function based on the pre-selected K-space trajectory function, the radial sampling interval, and the circumferential sampling interval, includes:

[0065] Step S304a: Perform first-order differentiation on the K-space trajectory function to obtain a first functional relationship. The first functional relationship is the functional relationship between the magnetic field gradient and the radial length, the first derivative of the radial length, the circumferential phase, and the first derivative of the circumferential phase.

[0066] Specifically, the first functional relationship can be expressed as:

[0067] (2)

[0068] in, For magnetic field gradient, It is the gyromagnetic ratio. These are the radial length, the first derivative of the radial length, the circumferential phase, and the first derivative of the circumferential phase, respectively.

[0069] Step S304b: Perform second-order differentiation on the K-space trajectory function to obtain a second functional relationship. The second functional relationship is the functional relationship between the rate of change of the magnetic field gradient and the radial length, the first derivative of the radial length, the second derivative of the radial length, the circumferential phase, the first derivative of the circumferential phase, and the second derivative of the circumferential phase.

[0070] Specifically, the second functional relationship can be expressed as:

[0071] (3)

[0072] Where S is the rate of change of the magnetic field gradient. These are the radial length, the first derivative of the radial length, the second derivative of the radial length, the circumferential phase, the first derivative of the circumferential phase, and the second derivative of the circumferential phase, respectively.

[0073] Step S304c: Based on the first functional relationship, the second functional relationship, the radial sampling interval, and the circumferential sampling interval, and in combination with the maximum gradient amplitude limit and the maximum gradient change rate limit, determine the magnetic field gradient function.

[0074] The longitudinal sampling interval and the circumferential sampling interval are limited by the formulas for the K-space trajectory function as follows:

[0075] (4)

[0076] The formulas for the maximum gradient magnitude limit and the maximum gradient rate of change limit are expressed as follows:

[0077] (5)

[0078] in, For the maximum gradient magnitude, This represents the maximum gradient rate of change.

[0079] Specifically, the magnitude and direction of the magnetic field gradient that meets the conditions can be calculated point by point by combining formulas (1)-(5).

[0080] Step S305: Based on the magnetic field gradient function, excite the magnetic resonance signal in the imaging area and acquire the magnetic resonance signal.

[0081] Specifically, a radio frequency excitation pulse and a modulated gradient magnetic field can be used to excite the magnetic resonance signal in the imaging region. Based on the calculated gradient magnetic field time series G(t) (i.e., the magnetic field gradient function), the magnitude and direction of the gradient magnetic field are modulated and encoded, and the magnetic resonance signal is acquired along a spiral trajectory.

[0082] Furthermore, after acquiring the magnetic resonance signal, image reconstruction can be performed based on the signal. The image reconstruction process can be completed using the aforementioned magnetic resonance equipment, or the magnetic resonance signal can be transmitted to an external computer device, which will then perform the image reconstruction.

[0083] The magnetic resonance imaging helical acquisition method of this embodiment proposes a helical trajectory design that is suitable for the acquisition density requirements of rectangular fields of view. Furthermore, while satisfying the Nyquist sampling theorem, this scheme avoids redundant data acquisition and shortens the trajectory length. The shortened trajectory length not only improves image acquisition efficiency but also gives the helical trajectory better resistance to magnetic susceptibility artifacts, thereby improving the quality of the acquired magnetic resonance images.

[0084] In some optional implementations, step S302, namely determining the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view, includes:

[0085] The longer side of the rectangular field of view is taken as the radial field of view; the shorter side of the rectangular field of view is taken as the circumferential field of view, i.e., FOV. r =FOV x FOV θ =FOV y .

[0086] Taking a rectangular field of view with an aspect ratio of 2:1 as an example, when FOV r =FOV x FOV θ =FOV y At that time, the designed spiral acquisition trajectory is as follows: Figure 4 As shown in the figure (in the figure, "×" represents the point to be collected, "○" represents the actual point collected, and the lines represent the collection trajectory).

[0087] In some alternative implementations, step S302, namely determining the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view, includes:

[0088] Calculate the product of the long side and the short side of the rectangular field of view; take the square root of the product of the long side and the short side of the rectangular field of view, and use the resulting non-negative square root as the radial field of view and the circumferential field of view, that is... , .

[0089] Taking a rectangular field of view with an aspect ratio of 2:1 as an example, when , At that time, the designed spiral acquisition trajectory is as follows: Figure 5 As shown in the figure (in the figure, "×" represents the point to be collected, "○" represents the actual point collected, and the lines represent the collection trajectory).

[0090] In some other optional implementations, step S302, namely determining the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view, includes:

[0091] The longer side of the rectangular field of view is taken as the circumferential field of view; the shorter side of the rectangular field of view is taken as the radial field of view, i.e., FOV. θ =FOV x FOV r =FOV y .

[0092] Taking a rectangular field of view with an aspect ratio of 2:1 as an example, when FOV θ =FOVx FOV r =FOV y At that time, the designed spiral acquisition trajectory is as follows: Figure 6 As shown in the figure (in the figure, "×" represents the point to be collected, "○" represents the actual point collected, and the lines represent the collection trajectory).

[0093] This embodiment also provides a magnetic resonance imaging helical acquisition device, which is used to implement the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs 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.

[0094] This embodiment provides a magnetic resonance imaging helical acquisition device, such as... Figure 7 As shown, it includes:

[0095] The acquisition module 701 is used to acquire the long and short sides of the rectangular field of view;

[0096] The first determining module 702 is used to determine the radial field of view and the circumferential field of view of the spiral acquisition based on the long side and the short side of the rectangular field of view; the product of the radial field of view and the circumferential field of view is equal to the product of the long side and the short side of the rectangular field of view.

[0097] The second determining module 703 is used to determine the radial sampling interval and the circumferential sampling interval that satisfy the Nyquist sampling law based on the radial field of view and the circumferential field of view.

[0098] The third determining module 704 is used to determine the magnetic field gradient function based on the pre-selected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, the maximum gradient amplitude limit and the maximum gradient change rate limit;

[0099] The acquisition module 705 is used to excite magnetic resonance signals in the imaging region based on the magnetic field gradient function and to acquire the magnetic resonance signals.

[0100] In some optional implementations, the third determining module 704 includes:

[0101] The first functional relationship acquisition unit is used to perform first-order differentiation on the K-space trajectory function to obtain the first functional relationship, which is: the functional relationship between the magnetic field gradient and the radial length, the first derivative of the radial length, the circumferential phase, and the first derivative of the circumferential phase;

[0102] The second functional relationship acquisition unit is used to perform second-order differentiation on the K-space trajectory function to obtain the second functional relationship, which is: the functional relationship between the rate of change of the magnetic field gradient and the radial length, the first derivative of the radial length, the second derivative of the radial length, the circumferential phase, the first derivative of the circumferential phase, and the second derivative of the circumferential phase.

[0103] The magnetic field gradient function determination unit is used to determine the magnetic field gradient function based on the first functional relationship, the second functional relationship, the radial sampling interval and the circumferential sampling interval, and in combination with the maximum gradient change rate limit and the maximum gradient amplitude limit.

[0104] In some optional implementations, the first determining module 702 is specifically used to take the long side of the rectangular field of view as the radial field of view and the short side of the rectangular field of view as the circumferential field of view.

[0105] In some alternative embodiments, the first determining module 702 is specifically used to take the long side of the rectangular field of view as the circumferential field of view and the short side of the rectangular field of view as the radial field of view.

[0106] In some other optional embodiments, the first determining module 702 is specifically used to calculate the product of the long side and the short side of the rectangular field of view; take the square root of the product of the long side and the short side of the rectangular field of view, and use the resulting non-negative square root as the radial field of view and the circumferential field of view.

[0107] Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0108] In this embodiment, the magnetic resonance imaging helical acquisition device is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0109] This invention also provides a magnetic resonance imaging (MRI) device having the above-described features. Figure 7 The magnetic resonance imaging spiral acquisition device shown is shown.

[0110] Please see Figure 8 , Figure 8 This is a schematic diagram of the structure of a magnetic resonance device provided in an optional embodiment of the present invention, as shown below. Figure 8As shown, the magnetic resonance imaging (MRI) device includes one or more processors 10, a memory 20, and interfaces for connecting the various components, including high-speed interfaces and low-speed interfaces. The various components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the MRI device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Figure 8 Take a processor 10 as an example.

[0111] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0112] The memory 20 stores instructions executable by at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0113] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the magnetic resonance imaging (MRI) device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transient memory, such as at least one disk storage device, flash memory device, or other non-transient solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, which can be connected to the MRI device 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.

[0114] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0115] The magnetic resonance imaging (MRI) device also includes an input device 30 and an output device 40. The processor 10, memory 20, input device 30, and output device 40 can be connected via a bus or other means. Figure 8 Taking the example of a connection between China and Israel via a bus.

[0116] Input device 30 can receive input digital or character information, and generate key signal inputs related to user settings and function control of the magnetic resonance device, such as a touch screen, keypad, mouse, trackpad, touchpad, indicator, one or more mouse buttons, trackball, joystick, etc. Output device 40 may include display devices, auxiliary lighting devices (e.g., LEDs), and haptic feedback devices (e.g., vibration motors). The aforementioned display devices include, but are not limited to, liquid crystal displays, light-emitting diodes, displays, and plasma displays. In some alternative embodiments, the display device may be a touch screen.

[0117] The magnetic resonance imaging device also includes a communication interface for communicating with other devices or communication networks.

[0118] Of course, magnetic resonance equipment also includes some components necessary for magnetic resonance imaging. For details, please refer to the relevant technology; they will not be described in detail here.

[0119] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0120] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0121] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A magnetic resonance imaging helical acquisition method, characterized in that, The method includes: Obtain the long and short sides of the rectangular field of view; Based on the long and short sides of the rectangular field of view, the radial and circumferential fields of view for helical acquisition are determined; the product of the radial and circumferential fields of view is equal to the product of the long and short sides of the rectangular field of view. Based on the radial field of view and the circumferential field of view, determine the radial sampling interval and the circumferential sampling interval that satisfy the Nyquist sampling law; The magnetic field gradient function is determined based on the pre-selected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, the maximum gradient amplitude limit and the maximum gradient change rate limit; Based on the magnetic field gradient function, magnetic resonance signals are excited in the imaging region and acquired.

2. The method according to claim 1, characterized in that, The determination of the magnetic field gradient function based on the pre-selected K-space trajectory function, the radial sampling interval, the circumferential sampling interval, the maximum gradient magnitude limit, and the maximum gradient change rate limit includes: The first functional relationship is obtained by performing a first-order differential on the K-space trajectory function. The first functional relationship is the functional relationship between the magnetic field gradient and the radial length, the first derivative of the radial length, the circumferential phase, and the first derivative of the circumferential phase. The second derivative of the K-space trajectory function is obtained by performing a second functional relationship, which is the functional relationship between the rate of change of the magnetic field gradient and the radial length, the first derivative of the radial length, the second derivative of the radial length, the circumferential phase, the first derivative of the circumferential phase, and the second derivative of the circumferential phase. Based on the first functional relationship, the second functional relationship, the radial sampling interval, and the circumferential sampling interval, and in conjunction with the maximum gradient magnitude limit and the maximum gradient change rate limit, the magnetic field gradient function is determined.

3. The method according to claim 1, characterized in that, The determination of the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view includes: The longer side of the rectangular field of view is taken as the radial field of view; The shorter side of the rectangular field of view is taken as the circumferential field of view.

4. The method according to claim 1, characterized in that, The determination of the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view includes: The longer side of the rectangular field of view is taken as the circumferential field of view; The shorter side of the rectangular field of view is taken as the radial field of view.

5. The method according to claim 1, characterized in that, The determination of the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view includes: Calculate the product of the long side and the short side of the rectangular field of view; Take the square root of the product of the long side and the short side of the rectangular field of view, and use the resulting non-negative square root as the radial field of view and the circumferential field of view.

6. A magnetic resonance imaging helical acquisition device, characterized in that, The device includes: The acquisition module is used to acquire the long and short sides of the rectangular field of view; The first determining module is used to determine the radial and circumferential fields of view for helical acquisition based on the long and short sides of the rectangular field of view; the product of the radial field of view and the circumferential field of view is equal to the product of the long and short sides of the rectangular field of view. The second determining module is used to determine the radial sampling interval and the circumferential sampling interval that satisfy the Nyquist sampling law based on the radial field of view and the circumferential field of view. The third determining module is used to determine the magnetic field gradient function based on the pre-selected K-space trajectory function, the radial sampling interval and the circumferential sampling interval, the maximum gradient magnitude limit and the maximum gradient change rate limit; The acquisition module is used to excite magnetic resonance signals in the imaging region based on the magnetic field gradient function, and to acquire the magnetic resonance signals.

7. A magnetic resonance imaging device, characterized in that, include: A memory and a processor are communicatively connected, the memory stores computer instructions, and the processor executes the magnetic resonance imaging spiral acquisition method according to any one of claims 1 to 5 by executing the computer instructions.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the magnetic resonance imaging spiral acquisition method according to any one of claims 1 to 5.

9. A computer program product, characterized in that, Includes computer instructions for causing a computer to perform the magnetic resonance imaging spiral acquisition method according to any one of claims 1 to 5.

Images