Gradient polarity detection method, device and equipment for magnetic resonance imaging equipment

Abstract

The invention relates to a gradient polarity detection method, a gradient polarity detection device and gradient polarity detection equipment for magnetic resonance imaging equipment. The gradient polarity detection method comprises the following steps: fixing an imaging die body on an examination bed; wherein the imaging die body is provided with a mark part; determining a scanning positioning point based on the mark part; scanning the imaging die body based on the scanning positioning point to obtain a first scanning image of the imaging die body; establishing an image coordinate system of the first scanning image, and determining coordinate information of imaging of the mark part in the image coordinate system; and determining the gradient polarity connection condition of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging equipment based on the coordinate information. According to the method, only one imaging die body with the mark part is selected, and the gradient polarity connection condition of the X-axis gradient field direction and the Y-axis gradient field direction is detected according to the coordinate information of the image of the mark part in the first scanning image, so that the complexity of gradient polarity detection is effectively reduced, and the detection accuracy is improved. The problem that the gradient polarity cannot be simply, conveniently and efficiently detected is solved.

Description

Technical Field

[0001] The present application relates to the technical field of magnetic resonance imaging, and particularly to a method, device, and equipment for detecting the gradient polarity of a magnetic resonance imaging device. Background Art

[0002] The gradient system of magnetic resonance consists of multiple coils and electrical components, involving complex circuit connections and control systems, and electrical connection errors may occur, such as axial interchange, reverse polarity connection, etc. The polarity of the gradient system generally refers to the positive and negative nature of its gradient direction. The correct electrical connection method can ensure that the gradient direction is consistent with the expectation and can provide accurate position information during the imaging process. When using a magnetic resonance scanning system for examination, if there are problems with the electrical connection, it may lead to layer selection and coding errors during imaging. Therefore, it is necessary to detect the gradient polarity of the magnetic resonance scanning system to ensure that all electrical connections are correct.

[0003] Currently, it is usually necessary to use two water phantoms with different sizes and shapes together for magnetic resonance imaging, and the connection situation of the gradient polarity is judged by observing the positions of the two water phantoms in the imaging. However, it is not convenient to use two water phantoms each time, and at the same time, the imaging of the smaller water phantom is not clear enough for easy observation, resulting in the gradient polarity detection not being simple and efficient enough.

[0004] Regarding the problem that the gradient polarity cannot be simply and efficiently detected in the related art, no effective solution has been proposed yet. Summary of the Invention

[0005] In the present embodiment, a method, device, and equipment for detecting the gradient polarity of a magnetic resonance imaging device are provided to solve the problem that the gradient polarity cannot be simply and efficiently detected in the related art.

[0006] In the first aspect, in the present embodiment, a method for detecting the gradient polarity of a magnetic resonance imaging device is provided, including:

[0007] Fix the imaging phantom on the examination table; wherein, there is a marked part on the imaging phantom;

[0008] Based on the marked part, determine the scanning positioning point;

[0009] Scan the imaging phantom based on the scanning positioning point to obtain the first scan image of the imaging phantom;

[0010] Establish an image coordinate system of the first scan image, and determine the coordinate information of the imaging of the marked part in the image coordinate system;

[0011] Based on the coordinate information, determine the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

[0012] In some embodiments, the first scanned image includes a sagittal plane image.

[0013] In some embodiments, the determining the coordinate information of the imaging of the landmark part in the image coordinate system includes:

[0014] Perform binarization processing on the first scanned image to obtain a binarized image;

[0015] Based on the interpolation traversal algorithm, obtain the number of target pixel points in all rows and columns of the binarized image;

[0016] Obtain the target row numbers and target column numbers where the target pixel points meeting the preset conditions are located;

[0017] Based on the target row numbers and the target column numbers, determine the coordinate information of the imaging of the landmark part in the image coordinate system.

[0018] In some embodiments, the preset conditions include: a target row number preset condition and a target column number preset condition;

[0019] The target row number preset condition includes: if the difference between the maximum value and the mode of the number of target pixel points in all rows is greater than a preset threshold, record the row number where the number of target pixel points of the maximum value is located;

[0020] The target column number preset condition includes: if the mode of the number of target pixel points in all columns is a preset multiple of the minimum non-zero value, record the column number where the minimum non-zero number of target pixel points is located.

[0021] In some embodiments, the based on the coordinate information, determining the gradient polarity detection result of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device includes:

[0022] Based on the coordinate system quadrant where the coordinate information is located and a preset rule, obtain the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction.

[0023] In some embodiments, the based on the coordinate system quadrant where the coordinate information is located and a preset rule, obtaining the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction includes:

[0024] If the coordinate system quadrant where the coordinate information is located conforms to the preset quadrant in the preset rule, confirm that the gradient polarity connection of the X-axis gradient field direction and the Y-axis gradient field direction is correct;

[0025] If the quadrant of the coordinate system where the coordinate information is located is opposite to the preset quadrant in the X-axis gradient field direction, it is confirmed that the gradient polarity connection of the X-axis gradient field direction is incorrect;

[0026] If the quadrant of the coordinate system where the coordinate information is located is opposite to the preset quadrant in the Y-axis gradient field direction, it is confirmed that the gradient polarity connection of the Y-axis gradient field direction is incorrect.

[0027] In some of the embodiments, establishing the image coordinate system of the first scanned image includes:

[0028] Select an origin in the binarized image, and establish an image coordinate system based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction.

[0029] In some of the embodiments, it further includes:

[0030] Based on the scanning positioning point, scan to obtain a second scanned image of the imaging phantom;

[0031] Move the examination table a preset distance along the Z-axis gradient field direction, and scan the imaging phantom again to obtain a third scanned image;

[0032] Based on the second scanned image and the third scanned image, obtain the gradient polarity connection condition of the Z-axis gradient field direction.

[0033] In some of the embodiments, the second scanned image includes cross-sectional images.

[0034] In some of the embodiments, obtaining the gradient polarity connection condition of the Z-axis gradient field direction based on the second scanned image and the third scanned image includes:

[0035] If there are differences between the second scanned image and the third scanned image, it is confirmed that the gradient polarity connection of the Z-axis gradient field direction is correct;

[0036] If the second scanned image and the third scanned image are consistent, it is confirmed that the gradient polarity connection of the Z-axis gradient field direction is incorrect.

[0037] In a second aspect, in the present embodiment, a method for detecting the gradient polarity of a magnetic resonance imaging device is provided, including:

[0038] Fix the imaging phantom on the examination table; wherein, there is a marked part on the imaging phantom;

[0039] Based on the marked part, determine the scanning positioning point;

[0040] Scanning the imaging phantom based on the scanning positioning points to obtain a second scan image of the imaging phantom;

[0041] Moving the examination table a preset distance along the Z-axis gradient field direction, and scanning the imaging phantom again to obtain a third scan image;

[0042] Based on the second scan image and the third scan image, obtaining the gradient polarity connection condition in the Z-axis gradient field direction.

[0043] In some embodiments, the second scan image includes cross-sectional images.

[0044] In some embodiments, the obtaining the gradient polarity connection condition in the Z-axis gradient field direction based on the second scan image and the third scan image includes:

[0045] If there are differences between the second scan image and the third scan image, it is confirmed that the gradient polarity connection in the Z-axis gradient field direction is correct;

[0046] If the second scan image and the third scan image are consistent, it is confirmed that the gradient polarity connection in the Z-axis gradient field direction is incorrect.

[0047] In some embodiments, it further includes:

[0048] Scanning to obtain a first scan image of the imaging phantom based on the scanning positioning points;

[0049] Establishing an image coordinate system of the first scan image and determining the coordinate information of the imaging of the marked part in the image coordinate system;

[0050] Based on the coordinate information, determining the gradient polarity connection condition in the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

[0051] In some embodiments, the first scan image includes sagittal plane images.

[0052] In a third aspect, in the present embodiment, a gradient polarity detection device for a magnetic resonance imaging device is provided, including:

[0053] A first scanning module, configured to determine scanning positioning points based on a marked part, and scan an imaging phantom based on the scanning positioning points to obtain a first scan image of the imaging phantom; wherein, the imaging phantom is fixed on an examination table, and the imaging phantom has a marked part;

[0054] A first gradient polarity detection module is configured to establish an image coordinate system for the first scanned image, and determine the coordinate information of the imaging of the marked part in the image coordinate system; based on the coordinate information, determine the gradient polarity connection condition of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

[0055] Fourth aspect, in this embodiment, a gradient polarity detection device for a magnetic resonance imaging device is provided, including:

[0056] A second scanning module is configured to determine a scanning positioning point based on the marked part; scan an imaging phantom based on the scanning positioning point to obtain a second scanned image of the imaging phantom; wherein, the imaging phantom is fixed on the examination bed, and there is a marked part on the imaging module; and,

[0057] The examination bed is moved a preset distance along the Z-axis gradient field direction to scan the imaging phantom again to obtain a third scanned image;

[0058] A second gradient polarity detection module is configured to obtain the gradient polarity connection condition of the Z-axis gradient field direction based on the second scanned image and the third scanned image.

[0059] Fifth aspect, in this embodiment, a magnetic resonance imaging device is provided, including a magnetic resonance scanning device, a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the gradient polarity detection method of the magnetic resonance imaging device described in the first aspect or the second aspect above is implemented.

[0060] Sixth aspect, in this embodiment, a storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the gradient polarity detection method of the magnetic resonance imaging device described in the first aspect or the second aspect above is implemented.

[0061] Compared with the related art, in the gradient polarity detection method, device and equipment of the magnetic resonance imaging equipment provided in this embodiment, the imaging phantom is fixed on the examination bed; wherein, there is a marked part on the imaging phantom; based on the marked part, the scanning positioning point is determined; based on the scanning positioning point, the imaging phantom is scanned to obtain the first scan image of the imaging phantom; an image coordinate system of the first scan image is established, and the coordinate information of the imaging of the marked part in the image coordinate system is determined; based on the coordinate information, the gradient polarity connection situation of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging equipment is determined. In this application, only one imaging phantom with a marked part is selected, an image coordinate system is established in the first scan image, and according to the coordinate information of the imaging of the marked part in the first scan image, the gradient polarity connection situations of the X-axis gradient field direction and the Y-axis gradient field direction are respectively detected, effectively reducing the complexity of gradient polarity detection and solving the problem that the gradient polarity cannot be simply and efficiently detected in the related art.

[0062] 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 concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The drawings described herein are used to provide a further understanding of this application, form a part of this application, and the illustrative embodiments and descriptions thereof are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0064] Figure 1 is a hardware structural block diagram of a terminal of the gradient polarity detection method of the magnetic resonance imaging equipment in one embodiment;

[0065] Figure 2 is a flowchart of the gradient polarity detection method of the magnetic resonance imaging equipment in one embodiment;

[0066] Figure 3 is a top view schematic diagram of an imaging phantom in one embodiment;

[0067] Figure 4a is a sagittal plane image in the first scan image in one embodiment;

[0068] Figure 4b is a coronal plane image in the first scan image in one embodiment;

[0069] Figure 5 is a schematic diagram of a sagittal plane image in a binary image in one embodiment;

[0070] Figure 6 is a schematic diagram of an image coordinate system in a binary image in one embodiment;

[0071] Figure 7a is the cross-sectional image in the second scan image in an embodiment;

[0072] Figure 7b is the cross-sectional image in the third scan image in an embodiment;

[0073] Figure 8 is the flowchart of the gradient polarity detection method of the magnetic resonance imaging device in another embodiment;

[0074] Figure 9 is the flowchart of the gradient polarity detection method of the magnetic resonance imaging device in yet another embodiment;

[0075] Figure 10 is the structural block diagram of the gradient polarity detection device of the magnetic resonance imaging device in an embodiment;

[0076] Figure 11 is the structural block diagram of the gradient polarity detection device of the magnetic resonance imaging device in another embodiment.

[0077] In the figure: 102, processor; 104, memory; 106, transmission device; 108, input / output device; 10, first scan module; 20, first gradient polarity detection module; 30, second scan module; 40, second gradient polarity detection module. Detailed implementation manners

[0078] To understand the purpose, technical solution and advantages of the present application more clearly, the present application will be described and illustrated below with reference to the accompanying drawings and embodiments.

[0079] Unless otherwise defined, technical or scientific terms used in this application shall have the ordinary meanings as understood by those of ordinary skill in the technical field to which this application belongs. In this application, words such as "a", "an", "one", "the", "these" and the like do not indicate a limitation in quantity and can be singular or plural. The terms "include", "comprise", "have" 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 includes a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent in these processes, methods, products or devices. The terms "connected", "coupled" and the like used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" used in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Usually, the character " / " indicates that the objects associated before and after are in an "or" relationship. The terms "first", "second", "third" and the like used in this application are only used to distinguish similar objects and do not represent a specific order of the objects.

[0080] The method embodiments provided in this embodiment may be executed on a terminal, a computer or a similar computing device. For example, it runs on a terminal such as a magnetic resonance imaging device. Figure 1 It is a block diagram of the hardware structure of the terminal for the gradient polarity detection method of the magnetic resonance imaging device in this embodiment. As Figure 1 shown, the terminal may include one or more ( Figure 1 only one is shown in the figure) processors 102 and a memory 104 for storing data. Among them, the processor 102 may include, but is not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those of ordinary skill in the art can understand that Figure 1 the structure shown is only schematic and does not limit the structure of the above terminal. For example, the terminal may further include more or fewer components than those shown in Figure 1 the figure, or have a different configuration from that shown in Figure 1 the figure.

[0081] The memory 104 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the gradient polarity detection method of the magnetic resonance imaging device in this embodiment. The processor 102 executes various functional applications and data processing by running the computer program stored in the memory 104, that is, the above-mentioned method is implemented. The memory 104 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some instances, the memory 104 may further include a memory remotely disposed relative to the processor 102, and these remote memories can be connected to the terminal through a network. Examples of the above-mentioned network include but are not limited to the Internet, intranet, local area network, mobile communication network, and combinations thereof.

[0082] The transmission device 106 is used to receive or send data via a network. The above-mentioned network includes a wireless network provided by a communication provider of the terminal. In one instance, the transmission device 106 includes a network adapter (Network Interface Controller, abbreviated as NIC), which can be connected to other network devices through a base station and thus can communicate with the Internet. In one instance, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0083] The gradient system of nuclear magnetic resonance consists of multiple coils and electrical components, involving complex circuit connections and control systems. The polarity of the gradient system usually refers to the positive and negative of its gradient direction. The correct electrical connection method can ensure that the gradient direction is consistent with the expectation and can provide accurate position information during the imaging process. When using a nuclear magnetic resonance device for examination, if there are problems with the electrical connection, it may lead to layer selection and coding errors during imaging. Therefore, it is necessary to detect the gradient polarity of the magnetic resonance scanning system to ensure that all electrical connections are correct.

[0084] The QA (Quality Assurance) tool used to check the gradient electrical connection is usually a multi-purpose digital multimeter, which can be used to measure parameters such as resistance, voltage, and current, and check whether the circuit and connection are normal by comparing the measurement results. However, in practical applications, the QA tool is easily restricted by the environment and is not convenient to use.

[0085] Currently, it is usually selected to use two water phantoms with different sizes and shapes together for magnetic resonance imaging, and the connection situation of the gradient polarity is judged by observing the positions of the two water phantoms in the imaging. However, it is not convenient to use two water phantoms each time, and the imaging of the smaller water phantom is not clear enough for observation, resulting in the gradient polarity detection not being simple and efficient enough.

[0086] In this embodiment, a method for detecting the gradient polarity of a magnetic resonance imaging device is provided. Figure 2 It is a flowchart of the method for detecting the gradient polarity of the magnetic resonance imaging device in this embodiment, as Figure 2 shown. The method includes the following steps:

[0087] Step S210: Fix the imaging phantom on the examination couch; wherein, there is a marked part on the imaging phantom.

[0088] Specifically, the imaging phantom is a water phantom, an oil phantom, etc. commonly used at present, and its shape can be cylindrical or square, and there is no limit to its specific shape. Optionally, the imaging phantom can be a cylindrical water phantom with a diameter of 110 cm - 170 cm. There is a marked part on the imaging phantom, and the marked part includes, but is not limited to, marked parts such as protrusions or pits that can be distinguished in shape.

[0089] Step S220: Determine the scanning positioning point based on the marked part.

[0090] Specifically, in magnetic resonance scanning, positioning is a pre-scanning imaging operation. According to the specific shape and marked part of the imaging phantom, the scanning positioning point is correspondingly determined, which can better display the imaging of the marked part in the first scanning image for observation, and is beneficial to detecting the gradient polarity according to the imaging of the marked part in the subsequent steps. Figure 3 It is a top view schematic diagram of the imaging phantom in this embodiment, as Figure 3 shown. Taking the cylindrical water phantom as an example of the imaging phantom, usually in order to prevent the phantom from rolling, a protrusion will be set on it. Optionally, the protrusion is used as the marked part, and about 2 cm directly below the protrusion is used as the scanning positioning point. For marked parts such as pits and engraved lines on the imaging phantom, the corresponding scanning positioning points are determined by taking this as an example.

[0091] Further, before the formal imaging scan after positioning, Fre calibration and Tra calibration are performed. Since the system resonance frequency and the RF emission voltage corresponding to the flip angle change when the scanning environment (such as temperature, main magnetic field, and scanning part, etc.) changes, Fre calibration and Tra calibration are required. Among them, Fre calibration is used to accurately distinguish the hydrogen proton frequencies in water, fat, or silicone for scanning parts such as those with more fat or containing breast prostheses when the system resonance frequency changes, and calibrate to determine the correct water peak frequency; Tra calibration is used to calibrate and obtain the reference emission voltage corresponding to the standard pulse under actual conditions when the RF emission voltage corresponding to the flip angle changes, so as to calculate the emission voltage corresponding to any flip angle according to the reference emission voltage in the subsequent imaging sequence.

[0092] Step S230: Scan the imaging phantom based on the scanning positioning point to obtain the first scanning image of the imaging phantom.

[0093] Specifically, in magnetic resonance imaging (MRI), the gradient system mainly consists of gradient coils, gradient amplifiers, analog-to-digital converters, gradient controllers, etc. Its main function is to generate the gradient magnetic field required for imaging. By passing currents of different magnitudes and directions through the gradient coils, the magnitude and direction of the gradient magnetic field can be controlled. Currently, there are mainly three pairs of gradient coils in MRI devices, which can generate gradient magnetic fields in three directions respectively, thus obtaining three gradient field directions, namely the X-axis gradient field direction, the Y-axis gradient field direction, and the Z-axis gradient field direction.

[0094] Use a pulse sequence to scan the imaging phantom based on the scan positioning points to obtain a first scan image corresponding to the gradient field direction. Among them, the first scan image contains the imaging of the marked part.

[0095] Step S240: Establish an image coordinate system for the first scan image and determine the coordinate information of the imaging of the marked part in the image coordinate system.

[0096] Specifically, select an origin in the first scan image and establish an image coordinate system based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction. According to the pixel distribution in the first scan image, detect the imaging of the marked part in the first scan image through an interpolation traversal algorithm, and further determine the coordinate information of the imaging of the marked part.

[0097] Step S250: Based on the coordinate information, determine the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction of the MRI device.

[0098] Specifically, according to the coordinate information of the imaging of the marked part, determine the coordinate system quadrant where the imaging of the marked part is located in the first scan image. If the coordinate system quadrant where it is located does not conform to the preset rules, it indicates that the gradient polarity connection of the corresponding X-axis gradient field direction or Y-axis gradient field direction is incorrect. If the coordinate system quadrant where it is located conforms to the preset rules, it indicates that the gradient polarity connections of the X-axis gradient field direction and the Y-axis gradient field direction are correct.

[0099] Furthermore, when judging the coordinate system quadrant where the imaging of the marked part is located, judge the coordinate system quadrant where the imaging of the marked part is located according to the positions of most pixel points in the imaging of the marked part.

[0100] By scanning through the above steps, a first scanned image of the imaging phantom is obtained. According to the coordinate information of the imaging of the marked part in the first scanned image, the connection conditions of the gradient polarities in the X-axis gradient field direction and the Y-axis gradient field direction are respectively detected. Compared with the prior art where the connection conditions of the gradient polarities need to be judged by the positions of two water phantoms in imaging, in this embodiment, only one imaging phantom with a marked part needs to be selected, effectively reducing the complexity and cost of gradient polarity detection and solving the problem in the related art that the gradient polarity cannot be detected simply and efficiently.

[0101] In some of these embodiments, the above first scanned image includes a sagittal plane image.

[0102] Specifically, by performing magnetic resonance scanning on the imaging phantom, a sagittal plane image in the first scanned image is obtained, and the first scanned image includes the imaging of the marked part. Wherein, corresponding to the gradient field direction, the first scanned image may further include a coronal plane image. In this embodiment, according to the coordinate information of the imaging of the marked part in the sagittal plane image, the connection conditions of the gradient polarities in the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device can be detected. Scanning the coronal plane image is not an essential step.

[0103] In some of these embodiments, the coordinate information of the imaging of the marked part in the image coordinate system in the above step S240 can be achieved through the following steps:

[0104] Step S241, perform binarization processing on the first scanned image to obtain a binarized image.

[0105] Specifically, obtain the signal-to-noise ratio of the first scanned image, and filter out the first scanned images with too low signal-to-noise ratio. Specifically, the pre-filtering can be set according to the actual scanning application by setting a signal-to-noise ratio threshold.

[0106] By performing binarization processing on the first scanned image, the pixel values of the imaging phantom in the first scanned image are assigned 255, and the background part is assigned 0, to obtain the binarized image.

[0107] Taking Figure 3 the imaging phantom shown in Figure 4a - Figure 4b as an example, Figure 5 which are respectively the sagittal plane image and the coronal plane image in the first scanned image, and the sagittal plane image includes the imaging of the marked part. By performing binarization processing on this sagittal plane image,

[0108] Step S242, based on the interpolation traversal algorithm, obtain the number of target pixel points in all rows and columns of the binarized image.

[0109] Specifically, the target pixel points are determined according to the pixel values. For example, during the above binarization process, the pixel values of the imaging phantom are assigned 255, and the background part is assigned 0. In this embodiment, the pixel points with a pixel value of 255 are used as the target pixel points. If different binarization processes are adopted, the target pixel points need to be adjusted accordingly.

[0110] Interpolate and traverse all rows and all columns of the binarized image respectively, and calculate the number of target pixel points in each row and each column.

[0111] Step S243: Obtain the target row number and target column number where the target pixel points meeting the preset conditions are located.

[0112] Further, the preset conditions include a target row number preset condition and a target column number preset condition; among them, the target row number preset condition includes: if the difference between the maximum value and the mode of the number of target pixel points in all rows is greater than the preset threshold, record the row number where the number of target pixel points with the maximum value is located;

[0113] The target column number preset condition includes: if the mode of the number of target pixel points in all columns is a preset multiple of the minimum non-zero value, record the column number where the minimum non-zero number of target pixel points is located.

[0114] Specifically, according to the number of target pixel points in each row and each column, further combined with the shape characteristics (such as protrusions, depressions, etc.) of the marked part in the imaging, and according to the preset conditions in the image width direction and the image length direction, determine the target row number and target column number where the imaging of the marked part in the binarized image is located.

[0115] Taking Figure 5 the schematic diagram of the sagittal plane image in the binarized image as an example, when traversing all rows (i.e., the image length direction), according to the number of target pixel points in each row, respectively determine the maximum value and the mode of the number of target pixel points. If the difference between the maximum value and the mode is greater than the preset threshold, it is considered that there is an imaging of the marked part in this direction, and record the row number where the maximum number of target pixel points is located as the target row number.

[0116] When traversing all columns (i.e., the image width direction), according to the number of target pixel points in each row, respectively determine the minimum non-zero value and the mode of the number of target pixel points. If the mode is a preset multiple of the minimum non-zero value, it is considered that there is an imaging of the marked part in this direction, and record the column number where the minimum non-zero number of target pixel points is located as the target column number. Exemplarily, the preset multiple is 50 - 70 times. According to the target row number and target column number, the position of the imaging of the marked part is obtained.

[0117] Step S244: Based on the target row number and target column number, determine the coordinate information of the imaging of the marked part in the image coordinate system.

[0118] Specifically, since the target number of rows and the target number of columns represent the imaging of the marked part in the first scanned image, the target number of rows and the target number of columns are not unique.

[0119] In some of these embodiments, an origin is selected in the binary image, and an image coordinate system is established based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction.

[0120] Optionally, the center of the binary image is used as the preset origin, and the position of the imaging of the marked part (the target number of rows a and the target number of columns b) is converted into coordinate information (M, N) in the image coordinate system. The conversion formula is as follows:

[0121] M = -W / 2 + b;

[0122] N = H / 2 - a;

[0123] Wherein, W and H respectively represent the width and height of the binary image.

[0124] In this embodiment, by establishing an image coordinate system, the coordinate information of the imaging of the marked part in the image coordinate system is determined, so as to detect the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction using the coordinate information in subsequent steps.

[0125] In some of these embodiments, in the above step S250, based on the coordinate information, determining the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device includes the following steps:

[0126] Based on the coordinate system quadrant where the coordinate information is located and a preset rule, obtain the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction.

[0127] Wherein, if the coordinate system quadrant where the coordinate information is located conforms to the preset quadrant in the preset rule, it is confirmed that the gradient polarity connection of the X-axis gradient field direction and the Y-axis gradient field direction is correct;

[0128] If the coordinate system quadrant where the coordinate information is located is opposite to the preset quadrant in the X-axis gradient field direction, it is confirmed that the gradient polarity connection of the X-axis gradient field direction is incorrect;

[0129] If the coordinate system quadrant where the coordinate information is located is opposite to the preset quadrant in the Y-axis gradient field direction, it is confirmed that the gradient polarity connection of the Y-axis gradient field direction is incorrect.

[0130] Specifically, since the imaging of the landmark may be an irregular shape, the quadrant of the coordinate system where the coordinate information is located is determined, and the quadrant of the coordinate system where the imaging of the landmark is located is determined according to the position where most of the coordinate information is located. Among them, the quadrant of the coordinate system where the coordinate information is located at a preset ratio is used as the standard. Exemplarily, assume that the number of coordinate information of the imaging of the landmark is 9, and the coordinate information is distributed in two quadrants. There are 6 coordinate information in the third quadrant and 3 coordinate information in the fourth quadrant. Then it is determined that the quadrant of the coordinate system where the imaging of the landmark is located is the third quadrant.

[0131] Among them, the preset rule includes a preset quadrant, and the preset quadrant indicates the quadrant of the coordinate system where the coordinate information is located when the gradient polarity connection is correct.

[0132] Figure 6 is a schematic diagram of the image coordinate system in the binary image in this embodiment. On the basis of Figure 5 , taking the center of the image as the preset origin, an image coordinate system as shown in Figure 6 is established with the X-axis gradient field direction and the Y-axis gradient field direction. Figure 6 In [the figure], the width of the image is 1054 and the height is 1064. Among them, the target row numbers a are 612, 613, 614, 615, 616, 617, 618, 623, 624, and the target column number b is 154. After conversion, the coordinate information (M, N) of the imaging of the landmark has nine combinations of (-373, -80), (-373, -81), (-373, -82), (-373, -83), (-373, -84), (-373, -85), (-373, -86), (-373, -91), (-373, -92), and all the coordinate information is in the third quadrant.

[0133] Taking Figure 6 as an example, the preset quadrant is the third quadrant. If the coordinate information is located in the fourth quadrant, which is opposite to the preset quadrant in the X-axis gradient field direction, it indicates that the gradient polarity connection in the X-axis gradient field direction is incorrect; if the coordinate information is located in the second quadrant, which is opposite to the preset quadrant in the Y-axis gradient field direction, it indicates that the gradient polarity connection in the Y-axis gradient field direction is incorrect; if the coordinate information is located in the third quadrant, it indicates that the gradient polarity connections in both the X-axis and Y-axis gradient field directions are correct.

[0134] In addition, a coronal plane image in the first scanned image can also be obtained for detection. If it is detected that there is no imaging of the landmark in it, it indicates that the gradient polarity connections in both the X-axis gradient field direction and the Y-axis gradient field direction are correct.

[0135] In this embodiment, according to the quadrant of the coordinate system where the imaging of the landmark is located, and in combination with the preset rule, the gradient polarity connection conditions in the X-axis gradient field direction and the Y-axis gradient field direction are detected, which can effectively reduce the complexity of the overall algorithm.

[0136] In some of these embodiments, for the connection condition of the gradient polarity in the Z-axis gradient field direction, existing methods can be adopted. For example, a multi-purpose digital electric meter for checking gradient electrical connections, or observing the positions of two water phantoms in imaging to determine the connection condition of the gradient polarity in the Z-axis gradient field direction, without specific limitation.

[0137] In addition, in the following embodiments, an embodiment for detecting the connection condition of the gradient polarity in the Z-axis gradient field direction is also provided.

[0138] In some of these embodiments, the above method further includes the following steps:

[0139] Step S260: Based on the scan positioning point, scan to obtain a second scan image of the imaging phantom.

[0140] Specifically, in magnetic resonance scanning, positioning is a pre-operation for scan imaging. According to the specific shape and marked part of the imaging phantom, the scan positioning point is correspondingly determined for subsequent observation. Use a pulse sequence to scan the imaging phantom based on the scan positioning point to obtain a second scan image corresponding to the gradient field direction. Optionally, Figure 3 the protrusion of the imaging phantom shown is used as the marked part, and about 2 cm directly below the protrusion is used as the scan positioning point.

[0141] Step S270: Move the examination table a preset distance along the Z-axis gradient field direction, and scan the imaging phantom again to obtain a third scan image.

[0142] Specifically, the imaging phantom moves under the drive of the examination table. After moving the examination table a preset distance along the Z-axis gradient field direction, a new scan positioning point is determined, and the imaging phantom is scanned again with the new scan positioning point to obtain a third scan image. Among them, the second scan image and the third scan image are images obtained by scanning with different scan positioning points. Optionally, the preset distance is determined according to the distance between the marked part and the scan positioning point. After moving the examination table, the marked part is used as the new scan positioning point. The imaging of the marked part included in the third scan image obtained thereby can better display the imaging of the marked part in the third scan image, which is beneficial to comparing the second scan image and the third scan image in the subsequent steps for gradient polarity detection.

[0143] Furthermore, the moving direction of the examination table is not limited, and it can move along the positive or negative direction of the Z-axis gradient field, specifically depending on the position and shape of the marked part on the imaging phantom.

[0144] Step S280: Based on the second scan image and the third scan image, obtain the connection condition of the gradient polarity in the Z-axis gradient field direction.

[0145] Specifically, since the marked part is a recognizable shape feature such as a protrusion or a pit on the imaging phantom, after moving the examination table, the shape of the imaging phantom will change in the third scanned image obtained by scanning. Based on this, by comparing the second scanned image and the third scanned image, the gradient polarity connection in the Z-axis gradient field direction is detected.

[0146] In this embodiment, after moving the imaging phantom along the Z-axis gradient field direction and then scanning and imaging again, by comparing the two images, the gradient polarity connection in the Z-axis gradient field direction is detected. The operation is simple and effectively reduces the complexity of the overall algorithm.

[0147] In some of these embodiments, the second scanned image includes a cross-sectional image.

[0148] Specifically, by performing magnetic resonance scanning on the imaging phantom, a cross-sectional image in the second scanned image is obtained. Correspondingly, after moving the examination table, a cross-sectional image in the third scanned image is acquired. Wherein, corresponding to the gradient field direction, the second scanned image and the third scanned image may also include a coronal plane image and a sagittal plane image. In this embodiment, by using the cross-sectional images in the second scanned image and the third scanned image, the gradient polarity connection in the Z-axis gradient field direction of the magnetic resonance imaging device can be detected. Scanning of the coronal plane image and the sagittal plane image is not an essential step.

[0149] Taking Figure 3 the imaging phantom shown in Figure 7a and the three gradient field directions given in the above embodiments as an example, Figure 7b is the cross-sectional image in the second scanned image. After moving the imaging phantom a preset distance along the Z-axis gradient field direction, the cross-sectional image in the third scanned image as shown in

[0150] In some of these embodiments, in step S480 above, obtaining the gradient polarity connection in the Z-axis gradient field direction based on the second scanned image and the third scanned image includes the following steps:

[0151] If there are differences between the second scanned image and the third scanned image, it is confirmed that the gradient polarity connection in the Z-axis gradient field direction is correct; if the second scanned image and the third scanned image are the same, it is confirmed that the gradient polarity connection in the Z-axis gradient field direction is incorrect.

[0152] Specifically, the shapes in the second scanned image and the third scanned image are respectively determined by edge detection, taking Figure 7a and Figure 7bFor example, the shapes in the second scan image and the third scan image are circular or non-circular. If there are differences between the second scan image and the third scan image, confirm that the gradient polarity connection in the Z-axis gradient field direction is correct; if the second scan image and the third scan image are the same, confirm that the gradient polarity connection in the Z-axis gradient field direction is incorrect.

[0153] In this embodiment, by using the shape characteristics of the marked part on the imaging phantom and comparing the shape differences in the two imaging processes, the connection condition of the gradient polarity in the Z-axis gradient field direction is detected. The operation is simple and the complexity of the overall algorithm is effectively reduced.

[0154] In this embodiment, another method for detecting the gradient polarity of a magnetic resonance imaging device is provided. Figure 8 It is a flowchart of the method for detecting the gradient polarity of the magnetic resonance imaging device in this embodiment, as Figure 8 shown, this method includes the following steps:

[0155] Step S810, fix the imaging phantom on the examination couch; wherein, there is a marked part on the imaging phantom.

[0156] Specifically, the imaging phantom is a water phantom, an oil phantom, etc. that are commonly used at present. The shape can be cylindrical or square, and there is no limitation on its specific shape. Optionally, the imaging phantom can be a cylindrical water phantom with a diameter of 110 cm - 170 cm. There is a marked part on the imaging phantom, and the marked part includes but is not limited to marked parts such as protrusions or depressions that can be distinguished in shape.

[0157] Step S820, based on the marked part, determine the scan positioning point.

[0158] Specifically, in magnetic resonance scanning, positioning is a pre-scan imaging operation. According to the specific shape of the imaging phantom and the marked part, the scan positioning point is determined accordingly, which can better display the imaging of the marked part in the first scan image for observation, and is beneficial to detecting the gradient polarity according to the imaging of the marked part in the subsequent steps. Figure 3 It is a top view schematic diagram of the imaging phantom in this embodiment, as Figure 3 shown. Taking the cylindrical water phantom as the imaging phantom as an example, usually in order to prevent the phantom from rolling, a protrusion will be set on it. Optionally, use this protrusion as the marked part, and take about 2 cm directly below the protrusion as the scan positioning point. For marked parts such as depressions and engraved lines on the imaging phantom, the corresponding scan positioning points are determined by taking this as an example.

[0159] Further, before the formal imaging scan after positioning, Fre calibration and Tra calibration are performed.

[0160] Step S830, scan the imaging phantom based on the scan positioning point to obtain the second scan image of the imaging phantom.

[0161] Specifically, a pulse sequence is used to scan the imaging phantom based on the scanning positioning points, and a second scanned image corresponding to the gradient field direction is obtained.

[0162] Step S840: Move the examination table a preset distance along the Z-axis gradient field direction, and scan the imaging phantom again to obtain a third scanned image.

[0163] Specifically, the imaging phantom moves under the drive of the examination table. After moving the examination table a preset distance along the Z-axis gradient field direction, a new scanning positioning point is determined, and the imaging phantom is scanned again with the new scanning positioning point to obtain a third scanned image. Among them, the second scanned image and the third scanned image are images obtained by scanning with different scanning positioning points. Optionally, the preset distance is determined according to the distance between the marked part and the scanning positioning point. After moving the examination table, the marked part is used as the new scanning positioning point. The imaging of the marked part is included in the obtained third scanned image, which can better display the imaging of the marked part in the third scanned image, facilitating the comparison of the second scanned image and the third scanned image in the subsequent steps for gradient polarity detection.

[0164] Furthermore, the moving direction of the examination table is not limited. It can move along the positive or negative direction of the Z-axis gradient field, specifically depending on the position and shape of the marked part on the imaging phantom.

[0165] Step S850: Based on the second scanned image and the third scanned image, obtain the gradient polarity connection condition in the Z-axis gradient field direction.

[0166] Specifically, since the marked part is a recognizable shape feature such as a protrusion or a pit on the imaging phantom, after moving the examination table, the shape of the imaging phantom will change in the third scanned image obtained by scanning. Based on this, by comparing the second scanned image and the third scanned image, the gradient polarity connection condition in the Z-axis gradient field direction is detected.

[0167] In this embodiment, by moving the imaging phantom along the Z-axis gradient field direction and then scanning and imaging again, and comparing the two images, the gradient polarity connection condition in the Z-axis gradient field direction is detected. Compared with the prior art that needs to use the positions of two water phantoms in imaging to judge the gradient polarity connection condition, only one imaging phantom with a marked part needs to be selected in this embodiment, which has simple operation and effectively reduces the complexity and cost of gradient polarity detection, solving the problem that the gradient polarity cannot be detected simply and efficiently in the related art.

[0168] In some of these embodiments, the second scanned image includes a cross-sectional image.

[0169] Specifically, by performing magnetic resonance scanning on the imaging phantom, a cross-sectional image in the second scan image is obtained. Correspondingly, after moving the examination table, a cross-sectional image in the third scan image is acquired. Among them, corresponding to the gradient field direction, the second scan image and the third scan image may also include a coronal plane image and a sagittal plane image. In this embodiment, through the cross-sectional images in the second scan image and the third scan image, the gradient polarity connection condition of the Z-axis gradient field direction of the magnetic resonance imaging device can be detected. Scanning the coronal plane image and the sagittal plane image is not an essential step.

[0170] Taking Figure 3 the imaging phantom shown in and the three gradient field directions given in the above embodiments as examples, Figure 7a is the cross-sectional image in the second scan image. After moving the imaging phantom a preset distance along the Z-axis gradient field direction, the cross-sectional image in the third scan image as shown in Figure 7b is obtained.

[0171] In some of these embodiments, the above step S850 of obtaining the gradient polarity connection condition of the Z-axis gradient field direction based on the second scan image and the third scan image includes the following steps:

[0172] If there are differences between the second scan image and the third scan image, it is confirmed that the gradient polarity connection of the Z-axis gradient field direction is correct; if the second scan image and the third scan image are consistent, it is confirmed that the gradient polarity connection of the Z-axis gradient field direction is incorrect.

[0173] Specifically, the shapes in the second scan image and the third scan image are respectively determined through edge detection. Taking Figure 7a and Figure 7b as examples, the shapes in the second scan image and the third scan image are circular or non-circular. If there are differences between the second scan image and the third scan image, it is confirmed that the gradient polarity connection of the Z-axis gradient field direction is correct; if the second scan image and the third scan image are consistent, it is confirmed that the gradient polarity connection of the Z-axis gradient field direction is incorrect.

[0174] In this embodiment, the shape features of the marked parts on the imaging phantom are utilized to detect the gradient polarity connection condition of the Z-axis gradient field direction by comparing the shape differences in the two imaging processes. The operation is simple, and the complexity of the overall algorithm is effectively reduced.

[0175] In some of these embodiments, for the gradient polarity connection conditions of the X-axis gradient field direction and the Y-axis gradient field direction, existing methods can be adopted. For example, a multi-purpose digital electric meter used to check gradient electrical connections, or observing the positions of two water phantoms in the imaging to judge the gradient polarity connection condition of the Z-axis gradient field direction, without specific limitations.

[0176] In addition, in the following embodiments, an embodiment for detecting the gradient polarity connection of the X-axis gradient field direction and the Y-axis gradient field direction is also provided.

[0177] In some of these embodiments, the following steps are further included:

[0178] Step S860, based on the scanning positioning point, scan to obtain the first scan image of the imaging phantom.

[0179] Step S870, establish an image coordinate system for the first scan image, and determine the coordinate information of the imaging of the marked part in the image coordinate system.

[0180] Step S880, based on the coordinate information, determine the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

[0181] Specifically, use a pulse sequence to scan the imaging phantom based on the scanning positioning point to obtain the first scan image corresponding to the gradient field direction. Among them, the first scan image contains the imaging of the marked part.

[0182] Select the origin in the first scan image, and establish an image coordinate system based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction. According to the pixel distribution in the first scan image, detect the imaging of the marked part in the first scan image through an interpolation traversal algorithm, and further determine the coordinate information of the imaging of the marked part.

[0183] According to the coordinate information of the imaging of the marked part, determine the coordinate system quadrant where the imaging of the marked part is located in the first scan image. If the coordinate system quadrant where it is located does not conform to the preset rule, it indicates that the gradient polarity connection of the corresponding X-axis gradient field direction or Y-axis gradient field direction is incorrect. If the coordinate system quadrant where it is located conforms to the preset rule, it indicates that the gradient polarity connections of the X-axis gradient field direction and the Y-axis gradient field direction are correct.

[0184] Further, when judging the coordinate system quadrant where the imaging of the marked part is located, judge the coordinate system quadrant where the imaging of the marked part is located according to the position where most pixel points in the imaging of the marked part are located.

[0185] In this embodiment, the first scan image of the imaging phantom is obtained by scanning. According to the coordinate information of the imaging of the marked part in the first scan image, the gradient polarity connections of the X-axis gradient field direction and the Y-axis gradient field direction are respectively detected, effectively reducing the complexity and cost of gradient polarity detection.

[0186] In some of these embodiments, the first scan image includes a sagittal plane image.

[0187] By performing magnetic resonance scanning on an imaging phantom, a sagittal image in the first scan image is obtained, and the imaging of the marked part is included in the first scan image. Correspondingly to the gradient field direction, the first scan image may further include a coronal image. In this embodiment, according to the coordinate information of the imaging of the marked part in the sagittal image, the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device can be detected. For the scanning of the coronal image, it is not an essential step.

[0188] In some of these embodiments, the coordinate information of the imaging of the marked part in the image coordinate system determined in step S870 above can be achieved through the following steps:

[0189] Step S241, perform binarization processing on the first scan image to obtain a binarized image.

[0190] Specifically, obtain the signal-to-noise ratio of the first scan image, and screen out the first scan images with too low signal-to-noise ratio. Specifically, a signal-to-noise ratio threshold can be set according to the actual scanning application for pre-screening.

[0191] By performing binarization processing on the first scan image, the pixel value of the imaging phantom in the first scan image is assigned 255, and the background part is assigned 0, to obtain the binarized image.

[0192] Taking Figure 3 the imaging phantom shown in Figure 4a - Figure 4b as an example, Figure 5 they are respectively the sagittal image and the coronal image in the first scan image, and the imaging of the marked part is included in the sagittal image. By performing binarization processing on this sagittal image,

[0193] Step S242, based on the interpolation traversal algorithm, obtain the number of target pixel points in all rows and columns of the binarized image.

[0194] Specifically, the target pixel points are determined according to the pixel value. For example, when performing the above binarization processing, the pixel value of the imaging phantom is assigned 255, and the background part is assigned 0. In this embodiment, the pixel points with a pixel value of 255 are used as the target pixel points. If different binarization processing is adopted, the target pixel points need to be adjusted accordingly.

[0195] Perform interpolation traversal on all rows and all columns of the binarized image respectively, and calculate the number of target pixel points in each row and each column.

[0196] Step S243, obtain the target row numbers and target column numbers where the target pixel points meeting the preset conditions are located.

[0197] Further, the preset conditions include a target row number preset condition and a target column number preset condition; wherein, the target row number preset condition includes: if the difference between the maximum value and the mode of the number of target pixels in all rows is greater than a preset threshold, record the row number where the number of target pixels with the maximum value is located;

[0198] The target column number preset condition includes: if the mode of the number of target pixels in all columns is a preset multiple of the minimum non-zero value, record the column number where the minimum non-zero number of target pixels is located.

[0199] Specifically, according to the number of target pixels in each row and each column, further combined with the shape characteristics (such as protrusions, depressions, etc.) of the marked part in the imaging, and according to the corresponding preset conditions in the image width direction and the image length direction, determine the target row number and target column number where the imaging of the marked part in the binary image is located.

[0200] Taking Figure 5 the schematic diagram of the sagittal plane image in the binary image as an example, when traversing all rows (i.e., the image length direction), according to the number of target pixels in each row, respectively determine the maximum value and the mode of the number of target pixels. If the difference between the maximum value and the mode is greater than the preset threshold, it is considered that there is an imaging of the marked part in this direction, and record the row number where the maximum number of target pixels is located as the target row number.

[0201] When traversing all columns (i.e., the image width direction), according to the number of target pixels in each row, respectively determine the minimum non-zero value and the mode of the number of target pixels. If the mode is a preset multiple of the minimum non-zero value, it is considered that there is an imaging of the marked part in this direction, and record the column number where the minimum non-zero number of target pixels is located as the target column number. Exemplarily, the preset multiple is 50 - 70 times. According to the target row number and the target column number, obtain the position of the imaging of the marked part.

[0202] Step S244, based on the target row number and the target column number, determine the coordinate information of the imaging of the marked part in the image coordinate system.

[0203] Specifically, since the target row number and the target column number represent the imaging of the marked part in the first scanned image, the target row number and the target column number are not unique.

[0204] In some of the embodiments, select the origin in the binary image, and establish an image coordinate system based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction.

[0205] Optionally, take the center of the binary image as the preset origin, and convert the position of the imaging of the marked part (target row number a and target column number b) into the coordinate information (M, N) in the image coordinate system. The conversion formula is as follows:

[0206] M = -W / 2 + b;

[0207] N = H / 2 - a;

[0208] Wherein, W and H respectively represent the width and height of the binary image.

[0209] In this embodiment, by establishing an image coordinate system, the coordinate information of the imaging of the marked part in the image coordinate system is determined, so as to detect the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction by using the coordinate information in the subsequent steps.

[0210] In some of these embodiments, based on the coordinate information in the above step S880, determining the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device includes the following steps:

[0211] Based on the coordinate system quadrant where the coordinate information is located and a preset rule, obtain the gradient polarity connection of the X-axis gradient field direction and / or the Y-axis gradient field direction.

[0212] Wherein, if the coordinate system quadrant where the coordinate information is located conforms to the preset quadrant in the preset rule, it is confirmed that the gradient polarity connection of the X-axis gradient field direction and the Y-axis gradient field direction is correct;

[0213] If the coordinate system quadrant where the coordinate information is located is opposite to the preset quadrant in the X-axis gradient field direction, it is confirmed that the gradient polarity connection of the X-axis gradient field direction is incorrect;

[0214] If the coordinate system quadrant where the coordinate information is located is opposite to the preset quadrant in the Y-axis gradient field direction, it is confirmed that the gradient polarity connection of the Y-axis gradient field direction is incorrect.

[0215] Specifically, since the imaging of the marked part may be an irregular shape, therefore, the coordinate system quadrant where the coordinate information is located is judged, and according to the position where most of the coordinate information is located, the coordinate system quadrant where the imaging of the marked part is located is judged. Among them, the coordinate system quadrant where the preset proportion of the coordinate information is located is used as the standard. Exemplarily, assume that the number of coordinate information of the imaging of the marked part is 9, and the coordinate information is distributed in two quadrants, there are 6 coordinate information in the third quadrant and 3 coordinate information in the fourth quadrant, then it is judged that the coordinate system quadrant where the imaging of the marked part is located is the third quadrant.

[0216] Wherein, the preset rule includes a preset quadrant, which indicates the coordinate system quadrant where the coordinate information is located when the gradient polarity connection is correct.

[0217] Figure 6 is a schematic diagram of the image coordinate system in the binary image of this embodiment. On the basis of Figure 5 taking the center of the image as the preset origin, and establishing with the X-axis gradient field direction and the Y-axis gradient field direction asFigure 6 The image coordinate system shown Figure 6 In the figure, the width of the image is 1054 and the height is 1064. Among them, the target row numbers a are 612, 613, 614, 615, 616, 617, 618, 623, 624, and the target column number b is 154. After conversion, there are nine combinations of the coordinate information (M, N) of the imaging of the marked part, namely (-373, -80), (-373, -81), (-373, -82), (-373, -83), (-373, -84), (-373, -85), (-373, -86), (-373, -91), (-373, -92), and all the coordinate information is in the third quadrant.

[0218] Take Figure 6 as an example. The preset quadrant is the third quadrant. If the coordinate information is in the fourth quadrant, which is opposite to the preset quadrant in the X-axis gradient field direction, it indicates that the gradient polarity connection in the X-axis gradient field direction is incorrect; if the coordinate information is in the second quadrant, which is opposite to the preset quadrant in the Y-axis gradient field direction, it indicates that the gradient polarity connection in the Y-axis gradient field direction is incorrect; if the coordinate information is in the third quadrant, it indicates that the gradient polarity connections in both the X-axis and Y-axis gradient field directions are correct.

[0219] In addition, the coronal plane image in the first scan image can also be obtained for detection. If it is detected that there is no imaging of the marked part in it, it indicates that the gradient polarity connections in both the X-axis gradient field direction and the Y-axis gradient field direction are correct.

[0220] In this embodiment, according to the coordinate quadrant where the imaging of the marked part is located, and in combination with the preset rules, the gradient polarity connection conditions in the X-axis gradient field direction and the Y-axis gradient field direction are detected, which can effectively reduce the complexity of the overall algorithm.

[0221] The following describes and illustrates this embodiment through preferred embodiments.

[0222] Figure 9 is the flowchart of the gradient polarity detection method of the magnetic resonance imaging device in this embodiment. As Figure 9 shown, the gradient polarity detection method includes the following steps:

[0223] Step S910, fix the imaging phantom on the examination bed; determine the scanning positioning points based on the marked parts on the imaging phantom; scan the imaging phantom based on the scanning positioning points to obtain the first scan image and the second scan image of the imaging phantom.

[0224] Step S920, perform binarization processing on the first scan image to obtain a binarized image; based on the interpolation traversal algorithm, obtain the number of target pixel points in all rows and columns of the binarized image; obtain the target row numbers and target column numbers where the target pixel points that meet the preset conditions are located.

[0225] Step S930: Select an origin in the binary image, and establish an image coordinate system based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction; determine the coordinate information of the imaging of the marked part in the image coordinate system based on the target number of rows and the target number of columns.

[0226] Step S940: Obtain the gradient polarity connection situation of the X-axis gradient field direction and / or the Y-axis gradient field direction based on the coordinate system quadrant where the coordinate information is located and a preset rule.

[0227] Step S950: Move the examination couch a preset distance along the Z-axis gradient field direction, use the marked part as the scanning positioning point, and scan the imaging phantom again to obtain a third scanned image.

[0228] Step S960: Obtain the gradient polarity connection situation of the Z-axis gradient field direction by comparing whether the second scanned image and the third scanned image are consistent.

[0229] In this embodiment, the first scanned image and the second scanned image of the imaging phantom are obtained through scanning. According to the coordinate information of the imaging of the marked part in the first scanned image, the gradient polarity connection situations of the X-axis gradient field direction and the Y-axis gradient field direction are respectively detected. And after moving the imaging phantom along the Z-axis gradient field direction and scanning it again to obtain a third scanned image, by comparing the second scanned image and the third scanned image, the gradient polarity connection situation of the Z-axis gradient field direction is detected. Compared with the prior art where two water phantoms are required to determine the gradient polarity connection situation based on their positions in imaging, only one imaging phantom with a marked part needs to be selected in this embodiment, effectively reducing the complexity and cost of gradient polarity detection and solving the problem that gradient polarity cannot be simply and efficiently detected in the related art.

[0230] It should be noted that the steps shown in the above process or the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0231] In this embodiment, a gradient polarity detection device for a magnetic resonance imaging device is also provided. This device is used to implement the above embodiment and the preferred implementation manners, and those that have been described will not be repeated here. The following terms such as "module", "unit", "sub-unit", etc. can be a combination of software and / or hardware that can achieve a predetermined function. Although the device described in the following embodiments is preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0232] Figure 10It is a structural block diagram of the gradient polarity detection device of the magnetic resonance imaging device in this embodiment. As Figure 10 shown, the device includes:

[0233] The first scanning module 10 is configured to determine a scanning positioning point based on a marked part; scan an imaging phantom based on the scanning positioning point to obtain a first scanned image of the imaging phantom; wherein, the imaging phantom is fixed on the examination bed, and there is a marked part on the imaging phantom.

[0234] The first gradient polarity detection module 20 is configured to establish an image coordinate system of the first scanned image, determine the coordinate information of the imaging of the marked part in the image coordinate system; based on the coordinate information, determine the gradient polarity connection condition of the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

[0235] Through the device provided in this embodiment, a first scanned image of the imaging phantom is scanned and obtained, and based on the coordinate information of the imaging of the marked part in the first scanned image, the gradient polarity connection conditions of the X-axis gradient field direction and the Y-axis gradient field direction are respectively detected. Compared with the prior art that needs to use the positions of two water phantoms in imaging to judge the gradient polarity connection condition, only one imaging phantom with a marked part needs to be selected in this embodiment, effectively reducing the complexity and cost of gradient polarity detection, and solving the problem that the gradient polarity cannot be simply and efficiently detected in the related art.

[0236] Figure 11 It is a structural block diagram of the gradient polarity detection device of the magnetic resonance imaging device in this embodiment. As Figure 11 shown, the device includes:

[0237] The second scanning module 30 is configured to determine a scanning positioning point based on a marked part; scan an imaging phantom based on the scanning positioning point to obtain a second scanned image of the imaging phantom; wherein, the imaging phantom is fixed on the examination bed, and there is a marked part on the imaging module; and,

[0238] is configured to move the examination bed a preset distance along the Z-axis direction and scan the imaging phantom again to obtain a third scanned image;

[0239] The second gradient polarity detection module 40 is configured to obtain the gradient polarity connection condition of the Z-axis gradient field direction based on the second scanned image and the third scanned image.

[0240] With the device provided in this embodiment, the imaging phantom is moved along the Z-axis gradient field direction and then scanned and imaged again. By comparing the two images, the connection condition of the gradient polarities in the Z-axis gradient field direction is detected. Compared with the prior art where two water phantoms are required to determine the connection condition of the gradient polarities based on their positions in the imaging, only one imaging phantom with a marked part needs to be selected in this embodiment, which is simple to operate and effectively reduces the complexity and cost of gradient polarity detection, solving the problem in the related art that the gradient polarity cannot be detected simply and efficiently.

[0241] It should be noted that the above-mentioned various modules can be functional modules or program modules, which can be implemented either by software or by hardware. For the modules implemented by hardware, the above-mentioned various modules can be located in the same processor; or the above-mentioned various modules can also be located in different processors in any combined form.

[0242] In this embodiment, a magnetic resonance imaging device is also provided, which includes a magnetic resonance scanning device, a memory, and a processor. A computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0243] Optionally, the above magnetic resonance imaging device may further include a transmission device and an input / output device. Among them, the transmission device is connected to the above processor, and the input / output device is connected to the above processor.

[0244] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation manners, and will not be repeated in this embodiment.

[0245] In addition, in combination with the gradient polarity detection method of the magnetic resonance imaging device provided in the above embodiment, a storage medium can also be provided to implement it in this embodiment. A computer program is stored on the storage medium; when the computer program is executed by the processor, any one of the gradient polarity detection methods of the magnetic resonance imaging device in the above embodiment is implemented.

[0246] It should be understood that the specific embodiments described here are only used to explain this application, rather than to limit it. According to the embodiments provided in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of this application.

[0247] Obviously, the accompanying drawings are only some examples or embodiments of the present application. For those of ordinary skill in the art, the present application can also be applied to other similar situations based on these drawings without creative efforts. Additionally, it can be understood that although the work done during the development process may be complex and time-consuming, for those of ordinary skill in the art, certain design, manufacturing, or production changes based on the technical content disclosed in the present application are only conventional technical means and should not be regarded as insufficient disclosure of the present application.

[0248] The term "embodiment" in the present application means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the specification and does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. Those of ordinary skill in the art can clearly or implicitly understand that the embodiments described in the present application can be combined with other embodiments without conflict.

[0249] The above-described embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for detecting the gradient polarity of a magnetic resonance imaging device, characterized in that, Including: Fixing an imaging phantom to an examination table; wherein, a marked part is provided on the imaging phantom; Determining a scanning positioning point based on the marked part; Scanning the imaging phantom based on the scanning positioning point to obtain a first scan image of the imaging phantom; Establishing an image coordinate system of the first scan image and determining coordinate information of the imaging of the marked part in the image coordinate system; Determining the gradient polarity connection condition of the X-axis gradient field direction and / or Y-axis gradient field direction of the magnetic resonance imaging device based on the coordinate information.

2. The method according to claim 1, characterized in that, The first scan image includes a sagittal plane image.

3. The method according to claim 2, wherein The determining the coordinate information of the imaging of the marked part in the image coordinate system includes: Performing binarization processing on the first scan image to obtain a binarized image; Obtaining the number of target pixel points in all rows and columns of the binarized image based on an interpolation traversal algorithm; Obtaining the target row number and target column number where the target pixel points meeting a preset condition are located; Determining the coordinate information of the imaging of the marked part in the image coordinate system based on the target row number and the target column number.

4. The method according to claim 3, wherein The preset condition includes a target row number preset condition and a target column number preset condition; The target row number preset condition includes: if the difference between the maximum value and the mode of the number of the target pixel points in all rows is greater than a preset threshold, recording the row number where the number of the target pixel points with the maximum value is located; The target column number preset condition includes: if the mode of the number of the target pixel points in all columns is a preset multiple of the minimum non-zero value, recording the column number where the minimum non-zero number of the target pixel points is located.

5. The method according to claim 3, characterized in that, The determining the gradient polarity detection result of the X-axis gradient field direction and / or Y-axis gradient field direction of the magnetic resonance imaging device based on the coordinate information includes: Obtaining the gradient polarity connection condition of the X-axis gradient field direction and / or Y-axis gradient field direction based on the coordinate system quadrant where the coordinate information is located and a preset rule.

6. The method according to claim 5, wherein The obtaining the gradient polarity connection condition of the X-axis gradient field direction and / or Y-axis gradient field direction based on the coordinate system quadrant where the coordinate information is located and a preset rule includes: If the coordinate system quadrant where the coordinate information is located conforms to a preset quadrant in the preset rule, confirming that the gradient polarity connections of the X-axis gradient field direction and the Y-axis gradient field direction are correct; If the coordinate system quadrant where the coordinate information is located is opposite to the preset quadrant in the X-axis gradient field direction, confirming that the gradient polarity connection of the X-axis gradient field direction is incorrect; If the coordinate system quadrant where the coordinate information is located is opposite to the preset quadrant in the Y-axis gradient field direction, confirming that the gradient polarity connection of the Y-axis gradient field direction is incorrect.

7. The method according to claim 3, characterized in that, The establishing the image coordinate system of the first scan image includes: Selecting an origin in the binarized image and establishing an image coordinate system based on the origin, the X-axis gradient field direction, and the Y-axis gradient field direction.

8. The method according to any one of claims 1 to 7, characterized in that, Also including: Scanning and acquiring a second scan image of the imaging phantom based on the scanning positioning point; Moving the examination table a preset distance along the Z-axis gradient field direction and scanning the imaging phantom again to obtain a third scan image; Based on the second scan image and the third scan image, obtain the gradient polarity connection condition in the Z-axis gradient field direction.

9. The method according to claim 8, wherein The second scan image includes cross-sectional images.

10. The method according to claim 8, wherein The obtaining the gradient polarity connection condition in the Z-axis gradient field direction based on the second scan image and the third scan image includes: If there are differences between the second scan image and the third scan image, confirm that the gradient polarity connection in the Z-axis gradient field direction is correct; If the second scan image and the third scan image are consistent, confirm that the gradient polarity connection in the Z-axis gradient field direction is incorrect.

11. A method for detecting the gradient polarity of a magnetic resonance imaging device, characterized in that, Includes: Fix the imaging phantom on the examination table; wherein, there is a marked part on the imaging phantom; Based on the marked part, determine the scan positioning point; Scan the imaging phantom based on the scan positioning point to obtain the second scan image of the imaging phantom; Move the examination table a preset distance along the Z-axis gradient field direction, and scan the imaging phantom again to obtain the third scan image; Based on the second scan image and the third scan image, obtain the gradient polarity connection condition in the Z-axis gradient field direction.

12. The method according to claim 11, wherein The second scan image includes cross-sectional images.

13. The method according to claim 11, wherein The obtaining the gradient polarity connection condition in the Z-axis gradient field direction based on the second scan image and the third scan image includes: If there are differences between the second scan image and the third scan image, confirm that the gradient polarity connection in the Z-axis gradient field direction is correct; If the second scan image and the third scan image are consistent, confirm that the gradient polarity connection in the Z-axis gradient field direction is incorrect.

14. The method according to any one of claims 11 to 13, characterized in that Further includes: Based on the scan positioning point, scan and obtain the first scan image of the imaging phantom; Establish the image coordinate system of the first scan image, and determine the coordinate information of the imaging of the marked part in the image coordinate system; Based on the coordinate information, determine the gradient polarity connection condition in the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

15. The method according to claim 14, wherein The first scan image includes sagittal plane images.

16. A gradient polarity detection device for a magnetic resonance imaging apparatus, characterized in that, Includes: A first scan module, configured to determine a scan positioning point based on a marked part; Scan the imaging phantom based on the scan positioning point to obtain the first scan image of the imaging phantom; wherein, the imaging phantom is fixed on the examination table, and there is a marked part on the imaging phantom; A first gradient polarity detection module, configured to establish the image coordinate system of the first scan image, determine the coordinate information of the imaging of the marked part in the image coordinate system; and based on the coordinate information, determine the gradient polarity connection condition in the X-axis gradient field direction and / or the Y-axis gradient field direction of the magnetic resonance imaging device.

17. A gradient polarity detection device for a magnetic resonance imaging apparatus, characterized in that, Includes: A second scan module, configured to determine a scan positioning point based on a marked part; Scan the imaging phantom based on the scan positioning point to obtain the second scan image of the imaging phantom; wherein, the imaging phantom is fixed on the examination table, and there is a marked part on the imaging module; and, For moving the examination table a preset distance along the Z-axis direction and scanning the imaging phantom again to obtain the third scan image; The second gradient polarity detection module is configured to obtain the gradient polarity connection condition of the Z-axis gradient field direction based on the second scan image and the third scan image.

18. A magnetic resonance imaging device, comprising: A magnetic resonance scanning device, a memory, and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute the gradient polarity detection method of the magnetic resonance imaging device according to any one of claims 1 to 10 or claims 11 to 15.

19. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the gradient polarity detection method according to any one of claims 1 to 10 or claims 11 to 15 are implemented.

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