Performance testing device and evaluation method for a magnetic resonance imaging system

Abstract

The application relates to the technical field of magnetic resonance imaging, in particular to a performance detection device and evaluation method of a magnetic resonance imaging system, which are used for improving the performance detection accuracy of a high spatial resolution magnetic resonance imaging system. The performance detection device comprises a performance detection module, and the performance detection module comprises: a first detection module containing a plurality of wire pair groups, a first wire pair group in the plurality of wire pair groups comprising a plurality of through holes, the wire widths of the plurality of through holes being the same, the wire width of each through hole being the same as the spacing between the through holes, and the wire width of each through hole being less than or equal to a set value; the first detection module is used for detecting the first spatial resolution of the magnetic resonance imaging system; and a second detection module containing a plurality of knife edge structures, the second detection module being used for detecting the second spatial resolution of the magnetic resonance imaging system; the second spatial resolution is higher than the first spatial resolution.

Description

Technical Field

[0001] This application relates to the field of magnetic resonance imaging technology, and in particular to a performance testing device and evaluation method for a magnetic resonance imaging system. Background Technology

[0002] Magnetic Resonance Imaging (MRI) is an advanced medical imaging technology characterized by the absence of ionizing radiation, high soft tissue contrast, and diverse imaging modalities. During long-term, high-intensity clinical operation, factors such as hardware aging and environmental fluctuations can cause varying degrees of degradation in the imaging performance of MRI equipment, thus affecting image quality and diagnostic reliability. Therefore, it is necessary to periodically evaluate key MRI parameters using performance testing devices (containers filled with specific solutions used to simulate the appearance of human tissue in MRI scans) to assess image quality and overall system performance. These performance parameters include high-contrast resolution (spatial resolution), low-contrast resolution, signal-to-noise ratio, homogeneity, geometric distortion, and slice thickness.

[0003] Currently, the ACR phantom designed by the American College of Radiology (ACR) and the Magphan series of phantoms developed by The Phantom Laboratory are widely used internationally for MRI performance evaluation. However, both types of phantoms have significant limitations: the ACR phantom has a high-contrast resolution detection limit of 5.56 Lp / cm, while the Magphan device's high-contrast resolution detection limit is only 11 Lp / cm. Furthermore, the evaluation method relies solely on subjective visual interpretation, meaning that the examiner determines the smallest resolvable line pair by visually observing whether the line pairs in the image are "not stuck, discontinuous, or broken." The interpretation results are greatly affected by subjective factors such as the observer's vision, experience, and ambient lighting. Different examiners may arrive at different interpretations of the same image, and quantitative and precise analysis of phantom images is not possible.

[0004] In summary, both the existing ACR phantom and Magphan phantom have insufficient high contrast resolution, making it difficult to meet the detection requirements of high spatial resolution MRI systems. Summary of the Invention

[0005] This application provides a performance testing device and evaluation method for a magnetic resonance imaging system, which is used to improve the accuracy of performance testing for high spatial resolution magnetic resonance imaging systems.

[0006] In a first aspect, embodiments of this application provide a performance testing device for a magnetic resonance imaging system, the performance testing device including a performance testing module, the performance testing module including: The first detection module includes multiple line pair groups. The first line pair group in the multiple line pair groups includes multiple through holes. The multiple through holes have the same line width, and the line width of each through hole is the same as the spacing between the through holes. The line width of each through hole is less than or equal to a set value. The first detection module is used to detect the first spatial resolution of the magnetic resonance imaging system. The first spatial resolution is used to describe the ability of the magnetic resonance imaging system to distinguish small structures by visual interpretation under high contrast conditions. The second detection module includes multiple blade structures. The second detection module is used to detect the second spatial resolution of the magnetic resonance imaging system. The second spatial resolution is used to describe the ability of the magnetic resonance imaging system to resolve small structures under high contrast conditions. The second spatial resolution is higher than the first spatial resolution.

[0007] In some embodiments, the plurality of line pairs are symmetrically distributed on both sides of the center line of the first detection module, and each line pair includes through holes of various line width specifications; the spatial resolution corresponding to the set value is higher than 11 Lp / cm.

[0008] In some embodiments, the plurality of blade structures are multiple trapezoidal through holes of the same size, the plurality of blade structures are distributed in a rotationally symmetrical manner with the center of the second detection module as the vertex, and the distance between the center of the second detection module and the plurality of blade structures is the same.

[0009] In some embodiments, the performance detection module further includes a third detection module; The third detection module is used to detect the geometric distortion rate and low contrast resolution of the magnetic resonance imaging system. The low contrast resolution is used to describe the ability of the magnetic resonance imaging system to detect target structures from the background under low contrast conditions.

[0010] In some embodiments, the third detection module includes a geometric distortion module, which is a grid structure. The grid structure is formed by grooving grooves on the upper surface of the third detection module. The grid structure includes a plurality of square cells, which are evenly arranged within a first radius centered on the center of the third detection module. There is a groove between any two adjacent square cells. The width of the groove is less than the side length of the cell, and the depth of the groove is less than the thickness of the third detection module.

[0011] In some embodiments, the third detection module further includes a low-contrast resolution module, which includes multiple sets of cylindrical grooves. Each set of cylindrical grooves has a different diameter but the same depth. The sets of cylindrical grooves are evenly distributed on a second radius circumference centered on the center of the third detection module. The cylindrical grooves are evenly distributed in a predetermined order where the diameter of each set of cylindrical grooves decreases along a predetermined direction on the second radius circumference, and the depth of each set of cylindrical grooves decreases along a predetermined direction on the second radius circumference. The second radius is larger than the first radius.

[0012] In some embodiments, the performance testing device further includes an upper bottom module and a lower bottom module, and each performance testing module is disposed between the upper bottom module and the lower bottom module; the upper bottom module, the lower bottom module, and each performance testing module are all disc structures and are provided with mounting holes, and the modules are connected in series by passing through the mounting holes on the upper bottom module, the lower bottom module, and each performance testing module through a rod-shaped structure, and the spacing between the modules is controlled by a sleeve.

[0013] In some embodiments, the upper surface of the third detection module is provided with a first mounting hole, and the lower surface of the third detection module is provided with a second mounting hole. The first mounting hole and the second mounting hole are evenly distributed on a third radius circle with the center of the third detection module as the center, and the first mounting hole and the second mounting hole are staggered on the third radius circle. The depth of the first mounting hole and the second mounting hole is less than the thickness of the third detection module. The first mounting hole on the upper surface of the third detection module corresponds one-to-one with the mounting hole on the lower surface of the upper bottom module; the second mounting hole on the lower surface of the third detection module corresponds one-to-one with the mounting hole of the second detection module, the mounting hole of the first detection module, and the mounting hole on the upper surface of the lower bottom module.

[0014] In some embodiments, the upper surface of the bottom module is provided with a layer thickness module, the layer thickness module including two intersecting wedge blocks, the long sides of the two wedge blocks are close to each other, and the center of the close long sides coincides with the center of the bottom module; the width, height and length of the two wedge blocks are the same.

[0015] Secondly, embodiments of this application provide a performance evaluation method for a magnetic resonance imaging system, the method comprising: Acquire image data from a performance testing device; the performance testing device is the performance testing device of any of the magnetic resonance imaging systems described in the first aspect; The first image data of the first detection module is obtained from the image data. The first spatial resolution is determined based on the line width of the multiple through holes of the first line pair group in the first image data. The first spatial resolution is used to describe the ability of the magnetic resonance imaging system to distinguish small structures by visual interpretation under high contrast conditions. The multiple through holes have the same line width, and the line width of each through hole is the same as the spacing between the through holes. The line width of each through hole is less than or equal to a set value. The second image data of the second detection module is obtained from the image data. The second spatial resolution is determined based on the knife edge image in the second image data and the modulation transfer function of the knife edge image. The second spatial resolution is used to describe the ability of the magnetic resonance imaging system to resolve small structures under high contrast conditions. The second spatial resolution is higher than the first spatial resolution.

[0016] Thirdly, embodiments of this application provide a performance evaluation device for a magnetic resonance imaging system, the device comprising: An acquisition unit is used to acquire image data from a performance testing device; the performance testing device is a performance testing device of any of the magnetic resonance imaging systems described in the first aspect. The first evaluation unit is used to obtain the first image data of the first detection module from the image data, and determine the first spatial resolution based on the line width of the multiple through holes of the first line pair group in the first image data. The first spatial resolution is used to describe the ability of the magnetic resonance imaging system to distinguish small structures by visual interpretation under high contrast conditions. The multiple through holes have the same line width, and the line width of each through hole is the same as the spacing between the through holes. The line width of each through hole is less than or equal to a set value. The second evaluation unit is used to obtain the second image data of the second detection module from the image data, and determine the second spatial resolution based on the knife edge image in the second image data and the modulation transfer function of the knife edge image. The second spatial resolution is used to describe the ability of the magnetic resonance imaging system to resolve small structures under high contrast conditions. The second spatial resolution is higher than the first spatial resolution.

[0017] Fourthly, embodiments of this application provide an electronic device, including: at least one processor, and a memory communicatively connected to the at least one processor, wherein: The memory stores a computer program that can be executed by at least one processor, which enables the at least one processor to perform the performance evaluation method of the magnetic resonance imaging system described above.

[0018] Fifthly, embodiments of this application provide a storage medium in which, when a computer program in the storage medium is executed by a processor of an electronic device, the electronic device is able to execute the performance evaluation method of the magnetic resonance imaging system described above.

[0019] Sixthly, embodiments of this application provide a computer program product, including a computer program stored in a storage medium; when a processor of an electronic device reads the computer program from the storage medium, the processor executes the computer program, causing the electronic device to perform the performance evaluation method of the magnetic resonance imaging system described above.

[0020] In this embodiment, multiple line pair groups are set in the first detection module, and the line width of each through-hole is the same as its spacing, and the line width does not exceed a set value. These line pair groups form a spatial frequency target of known size. When the magnetic resonance imaging system images the first detection module, the spatial resolution capability of the system under high contrast conditions is directly reflected by observing the smallest resolvable line pair in the image. The finer the line width, the higher the corresponding spatial frequency, and the higher the requirement for the system's spatial resolution. By setting the spatial resolution corresponding to the minimum line width to be higher than the detection upper limit of existing detection phantoms (e.g., 11 Lp / cm for the Magphan phantom), this performance detection device can effectively distinguish and evaluate the performance of high spatial resolution magnetic resonance imaging systems, solving the technical problem that existing phantoms cannot accurately evaluate the imaging performance of high-resolution systems due to insufficient line pair group density.

[0021] Simultaneously, by setting up a second detection module containing multiple knife-edge structures, the modulation transfer function (MTF) is calculated using the knife-edge method to evaluate the second spatial resolution of the magnetic resonance imaging system. Since the MTF calculation does not depend on the preset physical line pair density on the performance testing device, the MTF values ​​of the system at different spatial frequencies can be calculated. By reading the spatial frequency corresponding to the preset threshold in the MTF curve as the second spatial resolution, this detection method can theoretically detect spatial frequencies far higher than those corresponding to the physical line density of the line pair group, thus solving the technical defect of the line pair method, which has a detection upper limit due to its dependence on physical line density. The first detection module provides the actual resolution based on human visual interpretation, while the second detection module provides the theoretical limit resolution calculated based on the MTF algorithm. The two complement each other, forming an evaluation system that combines subjective and objective evaluation. This meets the need for accurate quantitative evaluation of high spatial resolution MRI systems while improving the performance testing accuracy and applicability of magnetic resonance imaging systems under high spatial resolution conditions.

[0022] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 A three-dimensional appearance schematic diagram of a performance testing device for a magnetic resonance imaging system provided in this application embodiment; Figure 2 This is a schematic diagram of the overall structure of a performance testing device for a magnetic resonance imaging system provided in an embodiment of this application; Figure 3 This is a schematic diagram showing the dimensions and relative positions of the modules of a performance testing device for a magnetic resonance imaging system provided in an embodiment of this application. Figure 4 This is a three-dimensional structural diagram of a bottom module provided in an embodiment of this application; Figure 5 A three-dimensional structural diagram of a first detection module provided in an embodiment of this application; Figure 6 A plan view of a first detection module provided in an embodiment of this application; Figure 7 A three-dimensional structural diagram of a second detection module provided in an embodiment of this application; Figure 8 A plan view of a second detection module provided in an embodiment of this application; Figure 9 A three-dimensional structural diagram of a third detection module provided in an embodiment of this application; Figure 10 This is another three-dimensional structural diagram of a third detection module provided in an embodiment of this application; Figure 11 A plan view of a third detection module provided in an embodiment of this application; Figure 12 This is a schematic diagram showing the overall dimensions of a third detection module provided in an embodiment of this application; Figure 13 This is a schematic diagram of a scanning slice positioning method provided in an embodiment of this application; Figure 14 This is a schematic diagram of an image of a third detection module provided in an embodiment of this application; Figure 15 This is a schematic diagram of an image of a first detection module provided in an embodiment of this application; Figure 16 This is a schematic diagram of an image of a second detection module provided in an embodiment of this application; Figure 17 A schematic diagram of a modulation transfer function provided in an embodiment of this application; Figure 18 This is a schematic diagram of a bottom module provided in an embodiment of this application; Figure 19 A schematic diagram of a profile line for layer thickness evaluation provided in an embodiment of this application; Figure 20 This is a schematic diagram of image uniformity evaluation provided in an embodiment of this application; Figure 21 This application provides a schematic diagram for evaluating the signal-to-noise ratio of an image. Figure 22 This is a schematic diagram of the structure of a performance evaluation device for a magnetic resonance imaging system provided in an embodiment of this application; Figure 23 This is a schematic diagram of the hardware structure of an electronic device for implementing a performance evaluation method for a magnetic resonance imaging system, provided in an embodiment of this application.

[0024] Figure label: 10-Upper bottom module, 11-Side wall, 11_1-Longitudinal groove, 11_2-Annular groove, 11_3-Water injection hole, 20-Lower bottom module, 21-Wedge block, 30-Third detection module, 31-Geometric distortion module, 32-Low contrast resolution module, 33-Positioning hole, 40-Second detection module, 50-First detection module, 60-Assembly hole, 61-First assembly hole, 62-Second assembly hole, 63-Third assembly hole, 64-Fourth assembly hole, 65-Fifth assembly hole, 66-Sixth assembly hole, 70-Sleeve, 71-First sleeve, 72-Second sleeve, 73-Third sleeve, 74-Fourth sleeve. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0026] The terms "first" and "second" in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive protection. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or devices. The term "multiple" in this application can mean at least two, for example, two, three, or more, and the embodiments of this application do not impose limitations.

[0027] The following description, in conjunction with the accompanying drawings, illustrates exemplary embodiments of this application, including various details to aid understanding. These embodiments should be considered merely exemplary. Therefore, those skilled in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope of this application. Similarly, for clarity and brevity, descriptions of well-known functions and structures are omitted in the following description. It should be noted that in the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solutions of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0028] The acquisition, transmission, storage, and use of data in this application all comply with the requirements of relevant national laws and regulations.

[0029] The following explanations of some terms used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0030] 1. A performance testing device for a magnetic resonance imaging system is a container filled with a specific solution to simulate the behavior of human tissue in magnetic resonance imaging (MRI) scans. In this application, the performance testing device is filled with a copper sulfate solution, which helps to produce clear image contrast in MRI scans.

[0031] 2. The term "line pair" is specific to cinematography, but it's also used in medical imaging techniques like MRI and CT to describe resolution. Specifically, it refers to the number of line pairs an instrument can distinguish within one millimeter. These lines are typically pairs of equally sized bright and dark stripes or regularly spaced pairs of bright and dark stripes. In MRI equipment, by adjusting the window width and level of the image display, a minimum set of line pairs can be visually distinguished, representing the high resolution of the MRI equipment. The more line pairs that can be distinguished, the better the resolution.

[0032] 3. The Modulation Transfer Function (MTF) is a key indicator used to quantify the ability of an optical system or photosensitive material to transmit spatial frequency signals. It describes the imaging system's ability to transmit signals at different spatial frequencies. Spatial frequency refers to the frequency of brightness variations in an image, usually measured in line pairs per millimeter (lp / mm). MTF values ​​range from 0 to 1; a higher value indicates a stronger ability to reproduce details.

[0033] 4. Window Width (WW) refers to the range of gray levels selected when displaying an image, that is, the density range seen in an image. The size of the window width directly affects image contrast and sharpness. In MRI image display, adjusting the window width can change the range of gray levels displayed on the image. When the window width is adjusted to its minimum value, the displayed grayscale range becomes smaller, the image contrast is enhanced, and it is helpful to observe tissue structures with similar densities.

[0034] 5. Window Level (WL): In MRI, the window level refers to the center position of the grayscale values ​​in an image. It is primarily used to adjust the display effect of the image, especially when observing tissues with different densities. In MRI images, different tissues exhibit different grayscale values ​​due to their physical properties (such as density or relaxation time). The window level, along with the window width, determines which grayscale values ​​will be displayed in the image and how they are displayed.

[0035] MRI is an advanced medical imaging technology characterized by non-ionizing radiation, high soft tissue contrast, and diverse imaging modalities. However, under long-term, high-intensity clinical operation, factors such as hardware aging and environmental fluctuations can cause varying degrees of performance degradation in MRI equipment. This can lead to problems such as inconsistent grayscale values ​​in the same tissue, inaccurate identification of small lesions, lesion image distortion, and noise artifacts, thus affecting diagnostic reliability. To better realize the superior performance of MRI equipment and reduce operational risks, quality control and management of MRI equipment are essential.

[0036] To meet the requirements for accurate quality assessment of medical MRI, phantoms have emerged to evaluate key MRI parameters, such as high-contrast resolution (spatial resolution), low-contrast resolution, signal-to-noise ratio, homogeneity, geometric distortion, and slice thickness. Currently, ACR phantoms and Magphan's SMR series phantoms are widely used internationally for MRI performance evaluation. However, both phantoms have significant limitations and can no longer meet the ever-increasing testing demands brought about by the rapid development of MRI technology.

[0037] The Magphan SMR series phantoms are mainly divided into the SMR100 and SMR170 phantoms. The SMR100 phantom shell consists of two acrylic hemispheres with an inner diameter of 200mm; the SMR170 phantom shell is a cylinder with an outer diameter of 200mm, an inner diameter of 190mm, and a wall thickness of 5mm. Both phantoms contain an acrylic test cube with a side length of 100mm. The cube is constructed from a slice thickness bevel, a high-contrast resolution test plate, and a low-contrast resolution test plate. This allows for the measurement of parameters such as slice thickness accuracy, geometric distortion, high-contrast resolution, low-contrast resolution, and image uniformity. However, it also has several limitations. In particular, the 11 line pairs in the high-contrast resolution module are arranged in an L-shape, meaning that in a single imaging session, only the high-contrast resolution performance at the edges of the MRI region can be detected, not in the central imaging region. Furthermore, the highest detectable value is 11 Lp / cm. When the spatial resolution of MRI exceeds 11 Lp / cm, the phantom cannot provide accurate evaluation.

[0038] The ACR phantom is a hollow acrylic cylinder, 148 mm long and 190 mm in inner diameter, closed at both ends. Its high contrast resolution module uses a dot matrix with different aperture sizes for measurement, similar to the Magphan phantom. However, the ACR phantom's high contrast resolution module only has three sets of dots with different aperture sizes (0.9 mm, 1.0 mm, and 1.1 mm, respectively), with a maximum detectable value of 5.56 Lp / cm, which cannot accurately detect the high contrast resolution performance of MRI equipment.

[0039] Furthermore, the existing evaluation methods for phantoms rely solely on subjective visual interpretation, which depends on inspectors visually observing whether the line pairs in the image are "not stuck, discontinuous, or broken" to determine the smallest distinguishable line pair. The interpretation results are greatly affected by subjective factors such as the observer's eyesight, experience, and ambient lighting. Different inspectors may have different interpretations of the same image, and it is impossible to perform quantitative and precise analysis of phantom images.

[0040] Given that the high contrast resolution of both ACR phantoms and Magphan phantoms in related technologies is insufficient, making it difficult to meet the detection requirements of high spatial resolution MRI systems, this application proposes a performance testing device and evaluation method for magnetic resonance imaging systems. By setting multiple line pair groups in a first detection module, ensuring that the line width of each through-hole is the same as its spacing and does not exceed a set value, a spatial frequency target of known size is constructed using these line pair groups. When the magnetic resonance imaging system images the first detection module, the spatial resolution capability of the system under high contrast conditions is directly reflected by observing the smallest resolvable line pair in the image. The finer the line width, the higher the corresponding spatial frequency, and the higher the requirement for the system's spatial resolution. By setting the spatial resolution corresponding to the minimum line width to be higher than the detection limit of existing detection phantoms (e.g., 11 Lp / cm for Magphan phantoms), this performance testing device can effectively distinguish and evaluate the performance of high spatial resolution magnetic resonance imaging systems, solving the technical problem that existing phantoms cannot accurately evaluate the imaging performance of high-resolution systems due to insufficient line pair group density.

[0041] Simultaneously, by setting up a second detection module containing multiple knife-edge structures, the modulation transfer function (MTF) is calculated using the knife-edge method to evaluate the second spatial resolution of the magnetic resonance imaging system. Since the MTF calculation does not depend on the preset physical line pair density on the performance testing device, the MTF values ​​of the system at different spatial frequencies can be calculated. By reading the spatial frequency corresponding to the preset threshold in the MTF curve as the second spatial resolution, this detection method can theoretically detect spatial frequencies far higher than those corresponding to the physical line density of the line pair group, thus solving the technical defect of the line pair method, which has a detection upper limit due to its dependence on physical line density. The first detection module provides the actual resolution based on human visual interpretation, while the second detection module provides the theoretical limit resolution calculated based on the MTF algorithm. The two complement each other, forming an evaluation system that combines subjective and objective evaluation. This meets the need for accurate quantitative evaluation of high spatial resolution MRI systems while improving the performance testing accuracy and applicability of magnetic resonance imaging systems under high spatial resolution conditions.

[0042] See Figures 1-12This application provides a preferred embodiment of a performance testing device for a magnetic resonance imaging system. The device has a cylindrical structure, including a hollow cylindrical tube, an upper base module 10, a lower base module 20, and a multi-layer performance testing module disposed inside the hollow cylindrical tube, between the upper base module 10 and the lower base module 20. The upper base module 10 is fixed to the top of the hollow cylindrical tube, and the lower base module 20 is fixed to the bottom of the hollow cylindrical tube.

[0043] The side wall 11 of the right cylindrical hollow cylinder has three linear grooves. These grooves are used to align with the laser positioning lamp of the magnetic resonance imaging system before scanning to achieve laser positioning. There is one vertical longitudinal groove 11_1 at the front and one at the rear of the side wall 11 of the right cylindrical hollow cylinder, and one annular groove 11_2 at the center of the side wall of the right cylindrical hollow cylinder.

[0044] The upper base module 10 has two water injection holes 11_3 at its edge for injecting solution into the performance testing device; in this application, the injected solution can be copper sulfate solution, which helps to produce clear image contrast in MRI scans.

[0045] The hollow cylindrical tube of the performance testing device contains multiple layers of performance testing modules stacked together. Each module is independent of the others. From top to bottom, the third testing module 30, the second testing module 40, the image uniformity module, the first testing module 50, and the layer thickness module are arranged at intervals.

[0046] The image uniformity module is a uniform water layer between the second detection module 40 and the first detection module 50. The layer thickness module is disposed on the upper surface of the bottom module 20. The third detection module 30 is an integrated module of the geometric distortion module 31 and the low contrast resolution module 32. The geometric distortion module 31 is a grid structure, and the grid shape of the grid structure is determined by grooves on the upper surface of the third detection module 30. The top module 10, the third detection module 30, the second detection module 40, the first detection module 50, and the bottom module 20 are all disk structures.

[0047] The upper bottom module 10, the third detection module 30, the second detection module 40, the first detection module 50, and the lower bottom module 20 are all provided with mounting holes 60. The upper and lower surfaces of the third detection module 30 are each provided with 4 mounting holes. The upper bottom module 10, the second detection module 40, the first detection module 50, and the lower bottom module 20 are all provided with 4 mounting holes. The diameter of each mounting hole is the same. The modules are connected in series by 4 rod-shaped structures with the same diameter as the mounting holes, such as acrylic rods. The spacing between the modules is controlled by sleeves 70 of different lengths.

[0048] The first mounting hole 61 on the upper surface of the third detection module 30 corresponds one-to-one with the third mounting hole 63 on the lower surface of the upper bottom module 10; the second mounting hole 62 on the lower surface of the third detection module 30 corresponds one-to-one with the fourth mounting hole 64 of the second detection module 40, the fifth mounting hole 65 of the first detection module 50, and the sixth mounting hole 66 on the upper surface of the lower bottom module. The depths of the first mounting hole 61 and the second mounting hole 62 are both less than the thickness of the third detection module 30.

[0049] The upper surface of the substrate of the lower base module 20 and the first detection module 50 are separated by four first sleeves 71 with a length of 22.5 mm and a diameter of 10 mm; the upper surface of the first detection module 50 and the second detection module 40 are separated by four second sleeves 72 with a length of 15 mm and a diameter of 10 mm; the upper surface of the second detection module 40 and the third detection module 30 are separated by four third sleeves 73 with a length of 17.5 mm and a diameter of 10 mm; the upper surface of the third detection module 30 and the upper base module 10 are separated by four fourth sleeves 74 with a length of 10 mm and a diameter of 10 mm.

[0050] The layer thickness module provided on the upper surface of the bottom module 20 includes two intersecting wedge blocks 21. The wedge blocks 21 are acrylic wedge blocks. The long sides of the two wedge blocks 21 are close to each other, and the center of the close-fitting long sides coincides with the center of the bottom module 20. The width, height and length of the two wedge blocks 21 are the same.

[0051] The first detection module 50 includes multiple wire pair groups, which are symmetrically and evenly distributed on both sides of the center line of the first detection module 50. Each wire pair group has a hollow design and includes multiple through holes. The through holes have the same line width and length, and the line width of each through hole and the spacing between the through holes are the same. Each side of the wire pair group includes through holes with various line width specifications. In the multiple wire pair groups, the line width of each side of the through hole of the first wire pair group is less than or equal to a set value. The spatial resolution corresponding to this set value is higher than 11 Lp / cm.

[0052] The second detection module 40 has four blade structures, each consisting of four trapezoidal through holes of the same size. These four trapezoidal through holes are distributed in a rotationally symmetrical manner with the center of the second detection module 40 as the vertex, and the distance between the center of the second detection module 40 and the multiple blade structures is the same.

[0053] The third detection module 30 includes a geometric distortion module 31 and a low-contrast resolution module 32. The geometric distortion module 31 is a grid structure, which is formed by grooving grooves on the upper surface of the third detection module 30. The grid structure includes multiple square cells, which are evenly arranged within a first radius centered on the center of the third detection module 30. There is a groove between any two adjacent square cells. The width of the groove is less than the side length of the cell, and the depth of the groove is less than the thickness of the third detection module 30. The low-contrast resolution module 32 includes multiple sets of cylindrical grooves. The diameter of each cylindrical groove in each set of cylindrical grooves is different, but the depth is the same. Each set of cylindrical grooves is evenly distributed on a second radius circumference centered on the center of the third detection module. The diameter of each set of cylindrical grooves decreases along a preset direction on the second radius circumference, and the depth of each set of cylindrical grooves decreases along a preset direction on the second radius circumference. The second radius is greater than the first radius.

[0054] like Figure 1 As shown, Figure 1 This is a three-dimensional appearance diagram of a performance testing device for a magnetic resonance imaging system provided in an embodiment of this application.

[0055] The performance testing device has a cylindrical structure, including a hollow cylindrical tube, an upper base module 10, a lower base module 20, and a multi-layered performance testing module disposed inside the hollow cylindrical tube, between the upper base module 10 and the lower base module 20. Specifically, the hollow cylindrical tube of the performance testing device in this application has a height of 105 mm, an outer diameter of 140 mm, an inner diameter of 120 mm, a sidewall thickness of 10 mm, and both the upper and lower base modules have a thickness of 10 mm.

[0056] like Figure 1 As shown, the side wall 11 of the cylindrical hollow cylinder has three linear grooves. These grooves are used to align with the laser positioning lamp of the magnetic resonance imaging system before scanning to achieve laser positioning. Each linear groove includes at least one longitudinal groove and at least one annular groove. The longitudinal groove penetrates the side wall 11 of the performance testing device, and the annular groove surrounds the side wall 11. In this application, one vertical longitudinal groove 11_1 is provided at the front and rear of the side wall 11, and one annular groove 11_2 is provided at the center of the side wall. The upper bottom module 10 is fixed to the top of the cylindrical hollow cylinder. Two water injection holes 11_3 are located at the edge of the upper bottom module 10 for injecting solution into the performance testing device. In this application, the injected solution can be copper sulfate solution, which helps to produce clear image contrast during MRI scanning.

[0057] like Figure 2 As shown, Figure 2This is a schematic diagram of the overall structure of a performance testing device for a magnetic resonance imaging system provided in an embodiment of this application.

[0058] The hollow cylindrical tube of the performance testing device contains multiple layers of performance testing modules stacked together. Each module is independent of the others. From top to bottom, the third testing module 30, the second testing module 40, the image uniformity module, the first testing module 50, and the layer thickness module are arranged at intervals.

[0059] The image uniformity module is a uniform water layer between the second detection module 40 and the first detection module 50. The layer thickness module is disposed on the upper surface of the bottom module 20. The third detection module 30 is an integrated module of the geometric distortion module 31 and the low contrast resolution module 32. The geometric distortion module 31 is a grid structure, and the grid shape of the grid structure is determined by grooves on the upper surface of the third detection module 30. The top module 10, the third detection module 30, the second detection module 40, the first detection module 50, and the bottom module 20 are all disk structures.

[0060] The upper bottom module 10, the third detection module 30, the second detection module 40, the first detection module 50, and the lower bottom module 20 are all provided with mounting holes 60. The upper and lower surfaces of the third detection module 30 are each provided with 4 mounting holes. The upper bottom module 10, the second detection module 40, the first detection module 50, and the lower bottom module 20 are all provided with 4 mounting holes. The diameter of each mounting hole is the same. The modules are connected in series by 4 rod-shaped structures with the same diameter as the mounting holes, such as acrylic rods. The spacing between the modules is controlled by sleeves 70 of different lengths.

[0061] The first mounting hole 61 on the upper surface of the third detection module 30 corresponds one-to-one with the third mounting hole 63 (not shown in the figure) on the lower surface of the upper bottom module 10; the second mounting hole 62 on the lower surface of the third detection module 30 corresponds one-to-one with the fourth mounting hole 64 of the second detection module 40, the fifth mounting hole 65 of the first detection module 50, and the sixth mounting hole 66 on the upper surface of the lower bottom module. The depths of the first mounting hole 61 and the second mounting hole 62 are both less than the thickness of the third detection module 30. For example, the depths of the first mounting hole 61 and the second mounting hole 62 are both half the thickness of the third detection module 30. This application does not limit this.

[0062] Figure 3 This is a schematic diagram showing the dimensions and relative positions of the modules of a performance testing device for a magnetic resonance imaging system provided in an embodiment of this application.

[0063] Combination Figures 2-3The diameter of each assembly hole is set to 10mm. The upper surface of the substrate of the lower base module 20 is 22.5mm away from the lower surface of the first detection module 50. The distance between the lower base module 20 and the first detection module 50 is controlled by four first sleeves 71 with a length of 22.5mm and a diameter of 10mm. The distance between the upper surface of the first detection module 50 and the lower surface of the second detection module 40 is 15 mm. The distance between the first detection module 50 and the second detection module 40 is controlled by four second sleeves 72 with a length of 15 mm and a diameter of 10 mm. The distance between the upper surface of the second detection module 40 and the lower surface of the third detection module 30 is 17.5 mm. The distance between the second detection module 40 and the third detection module 30 is controlled by four third sleeves 73 with a length of 17.5 mm and a diameter of 10 mm. The upper surface of the third detection module 30 is 10mm away from the lower surface of the upper bottom module 10. The distance between the second detection module 40 and the upper bottom module 10 is controlled by four fourth sleeves 74 with a length of 10mm and a diameter of 10mm.

[0064] The performance testing device has a height of 105mm. The upper base module 10 and the lower base module 20 have a diameter of 140mm and a thickness of 10mm. The first testing module 50, the second testing module 40 and the third testing module 30 all have a diameter of 100mm. The first testing module 50 and the second testing module 40 have a thickness of 5mm and the third testing module 30 has a thickness of 10mm.

[0065] The following section will provide a detailed introduction to each module.

[0066] like Figure 4 As shown, Figure 4 This is a three-dimensional structural diagram of a bottom module provided in an embodiment of this application.

[0067] The bottom module 20 has an overall structure of a disc with a diameter of 140mm and a thickness of 10mm. The upper surface of the bottom module 20 has four sixth mounting holes 66 with a diameter of 10mm. The sixth mounting holes 66 are evenly distributed on a circumference with a diameter of 78mm centered on the bottom module 20, and the four sixth mounting holes 66 are arranged in a square.

[0068] The layer thickness module provided on the upper surface of the bottom module 20 includes two intersecting wedge blocks 21. The wedge blocks 21 are acrylic wedge blocks. The long sides of the two wedge blocks 21 are close to each other, and the center of the close-fitting long sides coincides with the center of the bottom module 20. The width, height and length of the two wedge blocks 21 are the same. In this application, the width of the two wedge blocks 21 is 10mm, the height is 10mm and the length is 50mm.

[0069] The first detection module 50 comprises multiple line pair groups, which are symmetrically and evenly distributed on both sides of the center line of the first detection module 50. Each line pair group has a hollow design and includes multiple through holes with the same line width and length. The line width of each through hole and the spacing between through holes are the same. Each side of the line pair group contains through holes with various line width specifications. In the multiple line pair groups, the line width of each side of the through holes in the first line pair group is less than or equal to a set value, which corresponds to a spatial resolution higher than 11 Lp / cm. The first detection module 50 is used to detect the first spatial resolution of the magnetic resonance imaging system. The first spatial resolution describes the ability of the magnetic resonance imaging system to resolve minute structures visually under high-contrast conditions.

[0070] like Figures 5-6 As shown, where, Figure 5 This is a three-dimensional structural diagram of a first detection module provided in an embodiment of this application. Figure 6 This is a plan view of a first detection module provided in an embodiment of this application.

[0071] The overall structure of the first detection module 50 is a disc with a diameter of 100mm and a thickness of 5mm. The first detection module 50 is provided with four fifth assembly holes 65 with a diameter of 10mm. The fifth assembly holes 65 are evenly distributed on a circumference with a diameter of 78mm centered on the center of the first detection module 50, and the four fifth assembly holes 65 are distributed in a square.

[0072] The first detection module 50 contains 10 wire pair groups, and each wire pair group consists of 4 to 5 rectangular through holes, all of which are 12mm long. The width of the rectangular through holes in each wire pair group is the same as the distance between two adjacent rectangular through holes. Taking a 5mm wire pair group as an example, it consists of 3 rectangular through holes with a length of 12mm and a width of 5mm, with a 5mm interval between each rectangular through hole.

[0073] The number of through holes and the corresponding line width and line spacing for all wire pair groups are shown in Table 1. There are 5 types of wire pair groups with different widths, and 2 wire pair groups for each width, for a total of 10 wire pair groups. The 10 wire pair groups are symmetrically and evenly distributed on both sides of the center line of the first detection module 50, that is, 5 wire pair groups on each side are arranged horizontally, and the 5 wire pair groups on each side correspond to the 5 widths.

[0074] Table 1

[0075] As shown in Table 1, the five line widths are 0.4mm, 0.5mm, 0.6mm, 1.0mm, and 1.2mm, respectively. The line pair corresponding to the 0.4mm line width consists of 5 rectangular through holes, the 0.5mm line width consists of 5 rectangular through holes, the 0.6mm line width consists of 5 rectangular through holes, the 1.0mm line width consists of 5 rectangular through holes, and the 1.2mm line width consists of 4 rectangular through holes.

[0076] Taking the five line pairs distributed on the left as an example, the line pairs corresponding to line widths of 0.4mm, 0.5mm, and 0.6mm are horizontally distributed in one row, from left to right: 0.4mm, 0.5mm, and 0.6mm. The lower right vertex of the 0.6mm line pair is 10mm to the left and 10mm above the center of the circle. The 0.4mm, 0.5mm, and 0.6mm line pairs are spaced 5mm apart. The line pairs corresponding to line widths of 1.0mm and 1.2mm are horizontally distributed in another row, from left to right: 1.2mm and 1.0mm line pairs. The upper right vertex of the 1.0mm line pair is 10mm to the left and 10mm below the center of the circle. The 1.0mm line pair is spaced 5mm apart from the 1.2mm line pair.

[0077] The spatial resolution corresponding to 0.4 mm is 12.5 Lp / cm.

[0078] The second detection module 40 includes multiple blade structures, wherein the multiple blade structures are multiple trapezoidal through holes of the same size, and the multiple blade structures are distributed in a rotationally symmetrical manner with the center of the second detection module 40 as the vertex, and the distance between the center of the second detection module 40 and the multiple blade structures is the same.

[0079] The second detection module 40 is used to detect the second spatial resolution of the magnetic resonance imaging system. The second spatial resolution describes the ability of the magnetic resonance imaging system to resolve minute structures under high contrast conditions, and the second spatial resolution is higher than the first spatial resolution.

[0080] like Figures 7-8 As shown, Figure 7 This is a three-dimensional structural diagram of a second detection module provided in an embodiment of this application. Figure 8 This is a plan view of a second detection module provided in an embodiment of this application.

[0081] The second detection module 40 has an overall structure of a disc with a diameter of 100mm and a thickness of 5mm. The second detection module 40 is provided with four fourth mounting holes 64 with a diameter of 10mm. The fourth mounting holes 64 are evenly distributed on a circumference with a diameter of 78mm centered on the center of the second detection module 40, and the four fourth mounting holes 64 are arranged in a square.

[0082] The second detection module 40 has four blade structures, each consisting of four identical trapezoidal through holes, arranged rotationally symmetrically around the center of the second detection module 40. Each trapezoidal through hole has a short side of 5mm, a long side of 7.5mm, and a height of 25mm. The distance from the center of the second detection module 40 to the height of each trapezoidal through hole is 17.5mm.

[0083] The third detection module 30 includes a geometric distortion module 31 and a low-contrast resolution module 32. The geometric distortion module 31 is a grid structure, which is formed by grooving grooves on the upper surface of the third detection module 30. The grid structure includes multiple square cells, which are evenly arranged within a first radius centered on the center of the third detection module 30. There is a groove between any two adjacent square cells. The width of the groove is less than the side length of the cell, and the depth of the groove is less than the thickness of the third detection module 30. The low-contrast resolution module 32 includes multiple sets of cylindrical grooves. The diameter of each cylindrical groove in each set of cylindrical grooves is different, but the depth is the same. Each set of cylindrical grooves is evenly distributed on a second radius circumference centered on the center of the third detection module 30. The diameter of each set of cylindrical grooves decreases along a preset direction on the second radius circumference, and the depth of each set of cylindrical grooves decreases along a preset direction on the second radius circumference. The second radius is greater than the first radius.

[0084] The third detection module is used to detect the geometric distortion rate and low-contrast resolution of the magnetic resonance imaging system. Low-contrast resolution is used to describe the ability of the magnetic resonance imaging system to detect target structures from the background under low-contrast conditions.

[0085] like Figures 9-12 As shown, Figure 9 This is a three-dimensional structural diagram of a third detection module provided in an embodiment of this application. Figure 10 This is another three-dimensional structural diagram of a third detection module provided in an embodiment of this application. Figure 11 This is a plan view of a third detection module provided in an embodiment of this application. Figure 12 This is a schematic diagram showing the overall dimensions of a third detection module provided in an embodiment of this application.

[0086] The overall structure of the third detection module 30 is a disc with a diameter of 100mm and a thickness of 10mm. The upper surface of the third detection module 30 is provided with a first mounting hole 61, and the lower surface of the third detection module 30 is provided with a second mounting hole 62. The first mounting hole 61 and the second mounting hole 62 are evenly distributed on a circumference with a diameter of 78mm centered on the center of the third detection module 30. The first mounting hole 61 and the second mounting hole 62 are staggered on the circumference with a diameter of 78mm, and the four first mounting holes 61 are arranged in a square and the four second mounting holes 62 are arranged in a square.

[0087] The diameter of the first mounting hole 61 and the second mounting hole 62 are both 10mm, and the depth of both is half the thickness of the third detection module 30, i.e., 5mm.

[0088] The third detection module 30 includes a geometric distortion module 31 and a low-contrast resolution module 32.

[0089] The geometric distortion module 31 has a grid structure, which is formed by grooving grooves on the upper surface of the third detection module 30. The groove depth is 5mm, and the grid structure includes 36 square cells arranged in a 6-fold pattern. 6 are distributed within a first radius of 19.5 mm with a diameter of 37 mm centered on the center of the third detection module 30. The length of the square cell is 5 mm, and there is a groove with a width of 1 mm between two adjacent square cells.

[0090] Among them, such as Figure 10 The dashed rectangle shown represents the low-contrast resolution module 32 in the three-dimensional structural schematic diagram of the third detection module of this application. The low-contrast resolution module 32 includes four groups of cylindrical grooves, three in each group, for a total of twelve cylindrical grooves. The cylindrical grooves in each group have different diameters but the same depth. The diameters of the three cylindrical grooves in each group are 2mm, 4mm, and 6mm, respectively, and the depths of the four groups of cylindrical grooves are 1mm, 0.5mm, 0.25mm, and 0.1mm, respectively.

[0091] Four sets of cylindrical grooves are evenly distributed on a second radius circle with the center of the third detection module 30 as the center. The angle between the first line connecting the center of any first cylindrical groove and the center of the third detection module 30, and the second line connecting the center of the second cylindrical groove adjacent to the first cylindrical groove and the center of the third detection module 30, is 30°.

[0092] Furthermore, the cylindrical grooves in each group of cylindrical grooves are evenly distributed in a counterclockwise direction along the second radius circumference of 28mm, with decreasing diameters and decreasing depths. That is, the four groups of cylindrical grooves in the counterclockwise direction along the second radius circumference of 28mm are as follows: the first group of cylindrical grooves with a depth of 1mm and diameters of 6mm, 4mm, and 2mm respectively; the second group of cylindrical grooves with a depth of 0.5mm and diameters of 6mm, 4mm, and 2mm respectively; the third group of cylindrical grooves with a depth of 0.25mm and diameters of 6mm, 4mm, and 2mm respectively; and the fourth group of cylindrical grooves with a depth of 0.1mm and diameters of 6mm, 4mm, and 2mm respectively.

[0093] The third detection module 30 is also provided with a positioning hole 33 penetrating through the third detection module 30. The positioning hole 33 is a cylindrical groove with a diameter of 2 mm and a depth of 0.1 mm. The line connecting the center of the positioning hole 33 and the center of the third detection module 30 coincides with the line connecting the center of the cylindrical groove with the largest diameter and the deepest diameter among at least one group of cylindrical grooves and the center of the third detection module 30. In this application, the positioning hole 33 is used to mark the first cylindrical groove with a diameter of 6 mm and a depth of 1 mm. That is, the positioning hole 33 and the first cylindrical groove are located at the same radius on the third detection module 30, and the positioning holes 33 are distributed on a circumference with a diameter of 78 mm centered on the center of the third detection module 30.

[0094] To reduce subjective factors and make the evaluation process more objective, this application designs a performance testing device for a magnetic resonance imaging system. In accordance with the provisions of the current standard for the performance testing method of medical magnetic resonance imaging, this application standardizes the evaluation method and forms a performance evaluation method for a magnetic resonance imaging system, which can perform automated performance analysis and processing on data acquired by MRI equipment of different brands and models.

[0095] The performance evaluation method of the magnetic resonance imaging system of the preferred embodiment of this application is performed in the following manner.

[0096] The usage method is as follows: Before acquiring image data, copper sulfate solution is injected into the performance testing device through two water injection holes at the edge of the upper bottom module 10, and degassing is performed to ensure that there are no air bubbles adhering to the inner wall of the performance testing device or the surface of each module.

[0097] Then, place the performance testing device axially inside the head and neck coil on the scanning bed, attach the surface coil, turn on the laser positioning lamp of the MRI equipment, and adjust the position of the performance testing device so that the laser positioning line of the MRI equipment coincides with the longitudinal groove 11_1 and the annular groove 11_2 on the outer shell of the performance testing device.

[0098] Finally, the performance testing device was scanned using a microscopic imaging scanning sequence. A total of 8 slices were set, with a slice thickness of 5 mm. The center of the first slice was set at the center of the wedge block 21 of the lower module 20, ensuring that all modules were centered on the slice position. Figure 13 As shown, where, Figure 13 This is a schematic diagram of a scanning slice positioning method provided in an embodiment of this application. After the scanning parameters are set, the performance testing device of this application can perform continuous scanning. After the scanning is completed, the MRI images of the performance testing device of this application are imported into the performance evaluation software of the magnetic resonance imaging system of this application. The software automatically analyzes and processes geometric distortion, low contrast resolution, high contrast resolution (first spatial resolution, second spatial resolution), slice thickness, uniformity, signal-to-noise ratio, etc., and provides evaluation results.

[0099] After acquiring image data from the performance testing device of the magnetic resonance imaging system, the evaluation method is as follows: like Figure 14 As shown, Figure 14 This is a schematic diagram of a third detection module provided in an embodiment of this application.

[0100] 1. Geometric Distortion: For the performance testing device of this application, when evaluating the geometric distortion performance, the user can arbitrarily select two intersection points on the grid inside the image of the geometric distortion module 31. After selection, the software automatically locates the two intersection points and connects them, such as... Figure 14 For the yellow line, calculate the nominal length of the line segment based on the number of grid cells involved, measure the actual length of the line segment, and calculate the geometric distortion rate using Formula 1: , formula 1; In formula 1: This is the measured value of the line segment length; This is the nominal value of the line segment length.

[0101] 2. Low contrast resolution: For the performance testing device of this application, when evaluating the low contrast resolution performance, the software automatically locates all low contrast circular spots within the image of the low contrast resolution module 32, and draws ROIs inside and around the low contrast circular spots, such as... Figure 14 The red circle represents one of the low-contrast spots. The software automatically reads the magnetic resonance signal intensity of each ROI and calculates the contrast ratio (LCR) of each spot according to Formula 2: , formula 2; In formula 2: The magnetic resonance signal intensity of the region of interest (ROI) within the circular spot. The magnetic resonance signal intensity is relative to the corresponding surrounding ROI.

[0102] like Figure 15 As shown, Figure 15 This is a schematic image of a first detection module provided in an embodiment of this application.

[0103] 3. First spatial resolution: For the performance testing device of this application, when evaluating the performance of the first spatial resolution, the software acquires the first image data of the first detection module 50, automatically identifies the through hole images in each line pair group, adjusts the window width to 0, adjusts the window level, and determines the line width specification corresponding to the smallest resolvable through hole based on the criteria of the through hole images not sticking together, not being continuous, and not being broken. The corresponding spatial frequency is calculated based on the line width specification and used as the first spatial resolution of the magnetic resonance imaging system.

[0104] In one embodiment of this application, the first detection module includes line pair groups with various line width specifications, wherein the finest line width is 0.40 mm. According to the conversion relationship of line pair density (line pair period = line width × 2, line pair density = 10 ÷ line pair period), the spatial frequency corresponding to a 0.40 mm line width is 12.5 LP / cm. The existing Magphan SMR series phantoms have a high contrast resolution detection limit of 11 LP / cm (corresponding to approximately 0.45 mm line width). By setting the finest line width to 0.40 mm, the first detection module of this application can cover and exceed this detection limit. When the spatial resolution of the magnetic resonance imaging system exceeds 11 LP / cm, it can still provide interpretable line pair references, thereby achieving effective evaluation of high spatial resolution systems.

[0105] like Figure 16 As shown, Figure 16 This is a schematic diagram of a second detection module provided in an embodiment of this application.

[0106] 4. Second Spatial Resolution: For the performance testing device of this application, when evaluating the performance of the second spatial resolution, the software can acquire the second image data of the second detection module 40. Based on the knife-edge image and the modulation transfer function of the knife-edge image in the second image data, the second spatial resolution is determined. The software can automatically select two rectangular knife-edge images for the tilted edges of two adjacent trapezoidal images, and calculate the modulation transfer function (MTF) of the two knife-edge images using the knife-edge method. By calculating the modulation transfer function, the image quality can be evaluated more accurately, improving the accuracy of spatial resolution detection of magnetic resonance images. The spatial frequency corresponding to the modulation transfer function value of the threshold is determined, and the spatial frequency is used as the second spatial resolution of the magnetic resonance image. The threshold can be adjusted according to actual needs, such as... Figure 17 As shown, Figure 17 This is a schematic diagram of a modulation transfer function provided in an embodiment of this application. Assuming the threshold is 0.56, in... Figure 17In this study, the spatial frequency corresponding to a modulation transfer function value of 0.56 is determined to be 0.95. Therefore, the second spatial resolution is 0.95 LP / mm, or 9.5 LP / cm. This value is a measured value calculated based on the actual imaging performance of the tested magnetic resonance imaging system and is used for illustrative purposes only. Since the second detection module evaluates spatial resolution through modulation transfer function calculation, its detection upper limit does not depend on the density of physical markings on the phantom. Theoretically, it can calculate the modulation transfer function value of the system at higher spatial frequencies. Therefore, the detection range of the second spatial resolution is much higher than the physical marking detection upper limit of the first spatial resolution.

[0107] like Figure 18 As shown, Figure 18 This is a schematic diagram of a bottom module provided in an embodiment of this application.

[0108] 5. Layer Thickness: For the performance testing device of this application, when evaluating the layer thickness performance, the imaging areas of the two wedge blocks are automatically identified and located based on the positioning marks in the image of the lower module 20; rectangular areas are drawn in the imaging areas of the two wedge blocks respectively, ensuring that the width of the rectangular area is not less than 5 rows of pixels, and each row of pixels contains the entire imaging area (50mm); according to the position of each pixel on the long side signal line of the rectangular area and the magnetic resonance signal intensity, the mean profile line of each row of each rectangular area is drawn. There is one profile line for each of the upper and lower wedge block imaging areas.

[0109] The software automatically measures the lengths w1 and w2 of the two wedge-shaped block thickness measurement areas based on the mean profile line. w1 is the smaller length, and w2 is the larger length, as shown below. Figure 19 As shown, Figure 19 This is a schematic diagram of a profile line for layer thickness evaluation provided in an embodiment of this application.

[0110] Based on the measurement results of w1 and w2, the tilt angle caused by the misalignment of the model is calculated using the following formula 3. And calculate the layer thickness measurement value D according to Formula 4: , formula 3; , formula 4; In the formula, The included angle of the wedge-shaped blocks, for the mold body of this invention, =11.310°; θ is the tilt angle introduced by the improper placement of the model.

[0111] like Figure 20 As shown, Figure 20 This is a schematic diagram of an image uniformity evaluation provided in an embodiment of this application.

[0112] 6. Image Uniformity: For the performance testing device of this application, the image uniformity module is a uniform water layer. When evaluating the image uniformity, the software automatically locates and draws nine ROIs arranged in a nine-square grid in the uniform water layer image, reads the magnetic resonance signal intensity within the nine ROIs, calculates the difference between the maximum and minimum signal values, the sum of the maximum and minimum signal values, and calculates the image uniformity U according to Formula 5.

[0113] In the formula: The maximum value of the magnetic resonance signal among the 9 ROIs; It represents the minimum magnetic resonance signal among the nine ROIs.

[0114] like Figure 21 As shown, Figure 21 This is a schematic diagram illustrating an image signal-to-noise ratio evaluation method provided in an embodiment of this application.

[0115] 7. Image Signal-to-Noise Ratio (SNR): For the performance testing device of this application, when evaluating the image signal-to-noise ratio, the software automatically locates and draws 5 ROIs in the uniform water layer image, including one ROI at the center of the image and one ROI at each of the four corners. Each ROI is less than 100 mm² or contains at least 100 pixels. The software automatically reads the magnetic resonance signal intensity and noise of each ROI and calculates the signal-to-noise ratio (SNR) according to Formula 6: , Formula 6; In the formula: Signal strength at the center ROI; The signal strength of the surrounding background area, specifically the average signal strength of the four ROIs at the corners: = (S1 + S2 + S3 + S4) / 4; Noise centered on the ROI.

[0116] In existing technologies, Magphan and ACR are relatively large, with outer diameters reaching 200 mm. Although they offer a comprehensive range of detection modules, these phantoms cannot be placed within certain miniaturized receiving coils. This application enables the implementation of all detection items of existing medical magnetic resonance performance testing phantoms ACR and Magphan SMR, while also being compatible with various miniaturized coils (such as head and neck coils, surface coils, etc.). The performance testing device of this application redesigns the structure and dimensions of each detection module. The performance testing device has an outer diameter of 140 mm and a height of 105 mm, minimizing the space occupied by the modules within the performance testing device and significantly reducing its volume. This meets the size requirements for scanning some microscopic imaging coils and solves the problem that traditional phantoms, due to their excessive size, cannot fit into the imaging space of miniaturized coils.

[0117] The height of the performance testing device is reduced by integrating the low-contrast resolution module and the geometric distortion module.

[0118] By introducing two different spatial resolution detection modules, namely the line pair evaluation method and the modulation transfer function evaluation method, the spatial resolution of the device can be evaluated through the subjective left-right symmetrical line pair evaluation method to meet the evaluation requirements of left and right inner ear symmetry, and the spatial resolution of micron-level microscopic imaging can be evaluated through the objective modulation transfer function evaluation method.

[0119] In existing technologies, ACR phantoms are non-removable. Their closed design, which prevents solution replacement, leads to increased air bubbles within the phantom due to dissolved oxygen release, severely impacting MRI evaluation results. Furthermore, the closed design makes the phantom untraceable, compromising the accuracy of its measurements. The performance testing device of this application features a rationally arranged module layout, enabling imaging of all modules in a single scan, saving scanning time. All modules are flexibly disassembled and reassembled, featuring a one-piece design that eliminates assembly errors caused by disassembly and reassembly. The independent modules also facilitate phantom traceability.

[0120] The performance evaluation method of the magnetic resonance imaging system of this application can evaluate parameters such as slice thickness, image uniformity, signal-to-noise ratio, first spatial resolution, second spatial resolution, low contrast resolution, and geometric distortion in a single scan. In addition to the existing line pair group of the first detection module of the performance testing device of this application, it can also use the image of the second detection module to calculate the theoretical value of the second spatial resolution performance that the MRI equipment can achieve.

[0121] Based on the same technical concept, this application also provides a performance evaluation device for a magnetic resonance imaging system. The principle of the performance evaluation device for a magnetic resonance imaging system is similar to that of the performance evaluation method for a magnetic resonance imaging system described above. Therefore, the implementation of the performance evaluation device for a magnetic resonance imaging system can refer to the implementation of the performance evaluation method for a magnetic resonance imaging system, and the repeated parts will not be described again.

[0122] Figure 22 This is a schematic diagram of the structure of a performance evaluation device for a magnetic resonance imaging system provided in an embodiment of this application. The performance evaluation device 2200 for the magnetic resonance imaging system includes an acquisition unit 2201, a first evaluation unit 2202, and a second evaluation unit 2203.

[0123] The acquisition unit 2201 is used to acquire image data from the performance testing device; the performance testing device is the performance testing device of any of the magnetic resonance imaging systems described above. The first evaluation unit 2202 is used to obtain the first image data of the first detection module from the image data, and determine the first spatial resolution based on the line width of the multiple through holes of the first line pair group in the first image data. The first spatial resolution is used to describe the ability of the magnetic resonance imaging system to distinguish small structures by visual interpretation under high contrast conditions. The multiple through holes have the same line width, and the line width of each through hole is the same as the spacing between the through holes. The line width of each through hole is less than or equal to a set value.

[0124] The second evaluation unit 2203 is used to obtain the second image data of the second detection module from the image data, and determine the second spatial resolution based on the knife edge image in the second image data and the modulation transfer function of the knife edge image. The second spatial resolution is used to describe the ability of the magnetic resonance imaging system to resolve small structures under high contrast conditions. The second spatial resolution is higher than the first spatial resolution.

[0125] The module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, other division methods are possible. Furthermore, the functional modules in each embodiment of this application can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. Coupling between modules can be achieved through interfaces, typically electrical communication interfaces, but mechanical interfaces or other types of interfaces are also possible. Therefore, modules described as separate components may or may not be physically separate; they can be located in one place or distributed across different locations on the same or different devices. The integrated modules described above can be implemented in hardware or as software functional modules.

[0126] After introducing the performance evaluation method and apparatus of the magnetic resonance imaging system according to the exemplary embodiments of this application, the electronic device according to another exemplary embodiment of this application will be introduced next.

[0127] The following reference Figure 23 To describe an electronic device 130 implemented according to this embodiment of the present application. Figure 23 The electronic device 130 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of this application.

[0128] like Figure 23 As shown, the electronic device 130 is presented in the form of a general electronic device. The components of the electronic device 130 may include, but are not limited to: at least one processor 131, at least one memory 132, and a bus 133 connecting different system components (including memory 132 and processor 131).

[0129] Bus 133 represents one or more of several bus structures, including a memory bus or memory controller, peripheral bus, processor, or local bus using any of the various bus structures.

[0130] The memory 132 may include a readable medium in the form of volatile memory, such as random access memory (RAM) 1321 and / or cache memory 1322, and may further include read-only memory (ROM) 1323.

[0131] The memory 132 may also include a program / utility 1325 having a set (at least one) of program modules 1324, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0132] Electronic device 130 can also communicate with one or more external devices 134 (e.g., keyboard, pointing device, etc.), and with one or more devices that enable a user to interact with electronic device 130, and / or with any device that enables electronic device 130 to communicate with one or more other electronic devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 135. Furthermore, electronic device 130 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 136. As shown, network adapter 136 communicates with other modules used in electronic device 130 via bus 133. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 130, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0133] In an exemplary embodiment, a storage medium is also provided, which, when executed by a processor of an electronic device, enables the electronic device to perform the performance evaluation method of the magnetic resonance imaging system described above. Optionally, the storage medium may be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device.

[0134] In an exemplary embodiment, the electronic device of this application may include at least one processor and a memory communicatively connected to the at least one processor, wherein the memory stores a computer program executable by the at least one processor, and when the computer program is executed by the at least one processor, it enables the at least one processor to perform the steps of the performance evaluation method of any magnetic resonance imaging system provided in the embodiments of this application.

[0135] In an exemplary embodiment, a computer program product is also provided, which, when executed by an electronic device, enables the electronic device to implement any of the exemplary methods provided in this application.

[0136] Furthermore, computer program products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, RAM, ROM, erasable programmable read-only memory (EPROM), flash memory, optical fiber, compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0137] The program product for performance evaluation of a magnetic resonance imaging system in this application embodiment can be a CD-ROM and include program code, and can run on a computing device. However, the program product of this application is not limited to this. In this document, the readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0138] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, carrying readable program code. This propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0139] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, radio frequency (RF), or any suitable combination thereof.

[0140] Program code for performing the operations of this application can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, as well as conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, such as a Local Area Network (LAN) or a Wide Area Network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0141] It should be noted that although several units or sub-units of the device have been mentioned in the detailed description above, this division is merely exemplary and not mandatory. In fact, according to embodiments of this application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided and embodied by multiple units.

[0142] Furthermore, although the operations of the method of this application are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0143] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0144] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0145] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0146] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0147] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0148] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A performance testing device for a magnetic resonance imaging system, characterized in that, The performance testing device includes a performance testing module, which includes: The first detection module includes multiple line pair groups. The first line pair group in the multiple line pair groups includes multiple through holes. The multiple through holes have the same line width, and the line width of each through hole is the same as the spacing between the through holes. The line width of each through hole is less than or equal to a set value. The first detection module is used to detect the first spatial resolution of the magnetic resonance imaging system. The first spatial resolution is used to describe the ability of the magnetic resonance imaging system to distinguish small structures by visual interpretation under high contrast conditions. The second detection module includes multiple blade structures. The second detection module is used to detect the second spatial resolution of the magnetic resonance imaging system. The second spatial resolution is used to describe the ability of the magnetic resonance imaging system to resolve small structures under high contrast conditions. The second spatial resolution is higher than the first spatial resolution.

2. The performance testing device as described in claim 1, characterized in that, The multiple line pairs are symmetrically distributed on both sides of the center line of the first detection module, and each line pair contains through holes of various line width specifications; the spatial resolution corresponding to the set value is higher than 11 Lp / cm.

3. The performance testing device as described in claim 1, characterized in that, The plurality of blade structures are multiple trapezoidal through holes of the same size. The plurality of blade structures are distributed in a rotationally symmetrical manner with the center of the second detection module as the vertex, and the distance between the center of the second detection module and the plurality of blade structures is the same.

4. The performance testing device as described in claim 3, characterized in that, The performance testing module also includes a third testing module; The third detection module is used to detect the geometric distortion rate and low contrast resolution of the magnetic resonance imaging system. The low contrast resolution is used to describe the ability of the magnetic resonance imaging system to detect target structures from the background under low contrast conditions.

5. The performance testing device as described in claim 4, characterized in that, The third detection module includes a geometric distortion module, which is a grid structure. The grid structure is formed by grooving grooves on the upper surface of the third detection module. The grid structure includes multiple square cells, which are evenly arranged within a first radius centered on the center of the third detection module. There is a groove between any two adjacent square cells. The width of the groove is less than the side length of the cell, and the depth of the groove is less than the thickness of the third detection module.

6. The performance testing device as described in claim 5, characterized in that, The third detection module further includes a low-contrast resolution module, which includes multiple sets of cylindrical grooves. Each set of cylindrical grooves has a different diameter but the same depth. The sets of cylindrical grooves are evenly distributed on a second radius circumference centered on the center of the third detection module. The diameter of each set of cylindrical grooves decreases along a preset direction on the second radius circumference, and the depth of each set of cylindrical grooves decreases along a preset direction on the second radius circumference. The second radius is larger than the first radius.

7. The performance testing device as described in any one of claims 4-6, characterized in that, The performance testing device further includes an upper bottom module and a lower bottom module, and each performance testing module is disposed between the upper bottom module and the lower bottom module; the upper bottom module, the lower bottom module, and each performance testing module are all disc structures and are provided with assembly holes, and the modules are connected in series by passing through the assembly holes on the upper bottom module, the lower bottom module, and each performance testing module through a rod-shaped structure, and the spacing between the modules is controlled by a sleeve.

8. The performance testing device as described in claim 7, characterized in that, The upper surface of the third detection module is provided with a first mounting hole, and the lower surface of the third detection module is provided with a second mounting hole. The first mounting hole and the second mounting hole are evenly distributed on a third radius circle with the center of the third detection module as the center, and the first mounting hole and the second mounting hole are staggered on the third radius circle. The depth of the first mounting hole and the second mounting hole is less than the thickness of the third detection module. The first mounting hole on the upper surface of the third detection module corresponds one-to-one with the mounting hole on the lower surface of the upper bottom module; the second mounting hole on the lower surface of the third detection module corresponds one-to-one with the mounting hole of the second detection module, the mounting hole of the first detection module, and the mounting hole on the upper surface of the lower bottom module.

9. The performance testing device as described in claim 7, characterized in that, The upper surface of the bottom module is provided with a layer thickness module, which includes two intersecting wedge blocks with their long sides touching each other and the center of the touching long sides coinciding with the center of the bottom module; the width, height and length of the two wedge blocks are the same.

10. A performance evaluation method for a magnetic resonance imaging system, characterized in that, The method includes: Acquire image data from the performance testing device; the performance testing device is the performance testing device of any one of the magnetic resonance imaging systems described in 1 to 9. The first image data of the first detection module is obtained from the image data. The first spatial resolution is determined based on the line width of the multiple through holes of the first line pair group in the first image data. The first spatial resolution is used to describe the ability of the magnetic resonance imaging system to distinguish small structures by visual interpretation under high contrast conditions. The multiple through holes have the same line width, and the line width of each through hole is the same as the spacing between the through holes. The line width of each through hole is less than or equal to a set value. The second image data of the second detection module is obtained from the image data. The second spatial resolution is determined based on the knife edge image in the second image data and the modulation transfer function of the knife edge image. The second spatial resolution is used to describe the ability of the magnetic resonance imaging system to resolve small structures under high contrast conditions. The second spatial resolution is higher than the first spatial resolution.

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