Magnetic resonance imaging optimization method

Abstract

The invention relates to a magnetic resonance imaging method, in particular to a magnetic resonance imaging optimization method, which comprises the following steps: providing an auxiliary material and a protection pad, coating the bottom and the side part of a to-be-detected part by virtue of the protection pad, and covering the to-be-detected part with the auxiliary material, starting the MRI equipment to image the to-be-detected part covered with the auxiliary material; wherein the to-be-detected part has a first magnetic susceptibility, the auxiliary material has a second magnetic susceptibility, and the first magnetic susceptibility is matched with the second magnetic susceptibility. By means of the structure, the auxiliary material can cover the part to be detected, the similar magnetic susceptibility is kept, the fat suppression effect is not thorough, and artifacts are generated, and the imaging quality is improved.

Description

Technical Field

[0001] The invention relates to a magnetic resonance imaging method, and in particular to a magnetic resonance imaging optimization method. Background Art

[0002] The description in this section merely provides background information related to the present disclosure and does not constitute prior art.

[0003] MRI (magnetic resonance imaging) equipment has become an important tool for the diagnosis of foot injuries due to its excellent soft tissue resolution. Among them, the 3D-VIEW-PDWI-SPAIR sequence has high SNR and thin layer thickness, multi-planar reconstruction, good fat suppression, and can clearly display complex foot structures and lesions. It is an important sequence for the diagnosis of foot lesions.

[0004] However, in the actual operation of existing magnetic resonance imaging, due to the complex geometric shape of the distal end of the foot and the gap between the coils of the MRI equipment, the local magnetic field is uneven, resulting in a significant difference in magnetic susceptibility between the air and the soft tissue of the foot, which is prone to produce magnetic susceptibility artifacts, affecting the uniformity of the local magnetic field, resulting in incomplete fat suppression in the distal foot and some areas of the heel, manifested as obvious weakening or enhancement of the local signal, often accompanied by tissue deformation. The artifacts will affect the image quality and increase the difficulty of diagnosis, and may even lead to misdiagnosis.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present invention and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology section of the present invention. Summary of the invention

[0006] The purpose of the present invention is to provide a magnetic resonance imaging optimization method, which can solve the technical problems of incomplete fat suppression and artifacts by covering the part to be detected with auxiliary materials and maintaining similar magnetic susceptibility, thereby improving the imaging quality; and, by covering the part to be detected with a protective pad and specifically designing the auxiliary materials, the specific ranges of the temperature and humidity of the auxiliary materials are limited, thereby achieving better magnetic susceptibility balance effect, ease of use and preservation effect on the basis of controlling costs.

[0007] In order to achieve the above object, the present invention discloses the following magnetic resonance imaging optimization method, which comprises:

[0008] Providing auxiliary materials, covering the auxiliary materials on the part to be detected, and then starting the MRI device to image the part to be detected covered with the auxiliary materials;

[0009] The part to be detected has a first magnetic susceptibility, the auxiliary material has a second magnetic susceptibility, and the first magnetic susceptibility matches the second magnetic susceptibility in value.

[0010] As a further description of the above technical solution, the auxiliary material is set to be an elastomer, a fluid or a granular fluid, and before the step of "starting the MRI device to image the part to be detected covered with the auxiliary material", the depressions and / or protrusions of the part to be detected are filled and flattened with the help of the auxiliary material.

[0011] As a further description of the above technical solution, a protective bag is provided, and the elastomer, fluid or granular fluid for the auxiliary material is arranged inside the protective bag. During the step of "filling and leveling the depressions and / or protrusions of the part to be inspected with the help of the auxiliary material", the protective bag is in direct contact with the part to be inspected.

[0012] As a further description of the above technical solution, the auxiliary material is set to rice, and the protective bag is set to a rice bag made of LDPE sealed plastic material.

[0013] As a further description of the above technical solution, the moisture content of the rice in the rice bag is maintained between 11% and 15%, the temperature is between 16° C. and 20° C., and the relative humidity is 60%.

[0014] As a further description of the above technical solution, the temperature of the imaging area of ​​the MRI device is maintained between 16° C. and 20° C., and the relative humidity is 60%.

[0015] As a further description of the above technical solution, a protective pad is provided. Before the step of "covering the auxiliary material on the part to be detected", the bottom and sides of the part to be detected are covered with the protective pad, and then the auxiliary material is covered on the top position of the part to be detected.

[0016] As a further description of the above technical solution, the protective pad is configured as a sponge with a non-woven fabric on the outside, and a protective belt for fastening the auxiliary material to the part to be detected is installed on the protective pad, so that the protective pad undergoes elastic deformation when covering the part to be detected, so that the part to be detected fits the protective pad, and the auxiliary material is fastened to the part to be detected.

[0017] As a further description of the above technical solution, after "starting the MRI device to image the part to be inspected covered with the auxiliary material" is completed, before the next "covering the auxiliary material on the part to be inspected", it also includes a step of monitoring the weight of the auxiliary material.

[0018] The present invention also discloses a magnetic resonance auxiliary device, wherein the magnetic resonance auxiliary device is composed of the auxiliary material and the protective bag mentioned above.

[0019] By means of the above technical solution, the beneficial effects of the present invention are as follows:

[0020] The magnetic resonance imaging optimization method of the present invention can reduce the difference in magnetic susceptibility between the part to be detected and the air by covering the part to be detected with auxiliary materials and setting matching first and second magnetic susceptibilities, thereby improving the uniformity of the local magnetic field and improving the quality of magnetic resonance imaging.

[0021] The present invention limits the specific temperature, humidity range and specific material of the auxiliary materials, and selects rice bags made of LDPE sealing plastic material to protect the moisture content of rice maintained between 11% and 15%, the temperature between 16°C and 20°C, and the relative humidity of 60%. The cost is controlled, and the rice has good fluidity, comfortable body feel, and a magnetic susceptibility close to that of the human body, which helps to improve the imaging quality and provides a good user experience for the test personnel.

[0022] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a schematic diagram of the placement of the part to be detected in a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0025] Figure 2 It is a schematic diagram of a protective pad covering of a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0026] Figure 3 It is a schematic diagram of fastening a protective belt in a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0027] Figure 4 It is a schematic diagram of the position of the ROI of the part to be detected in a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0028] Figure 5This is a schematic diagram of image classification of a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0029] Figure 6 is a schematic diagram of subjective evaluation results of a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0030] Figure 7 is a schematic diagram of objective evaluation results of a magnetic resonance imaging optimization method provided in an embodiment of this specification;

[0031] In the figure: 100, part to be tested; 1, auxiliary materials; 2, protection pad; 3, protection tape. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0033] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0034] It should be understood that, although the terms "first", "second", "third", etc. may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another component, or one signal from another signal. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0035] See also Figure 1-2 , is a magnetic resonance imaging optimization method of this embodiment, wherein the magnetic resonance imaging optimization method includes:

[0036] Provide auxiliary material 1 and protective pad 2, cover the bottom and side of the part to be detected 100 with the help of the protective pad 2, cover the part to be detected 100 with the auxiliary material 1, and then start the MRI device to image the part to be detected 100 covered with the auxiliary material 1;

[0037] The part to be detected 100 has a first magnetic susceptibility, the auxiliary material 1 has a second magnetic susceptibility, and the first magnetic susceptibility matches the second magnetic susceptibility in value.

[0038] By the above method, before the detection of the part 100 to be detected, the specific data of the first magnetic susceptibility of the part 100 to be detected is first obtained, and then, according to the specific data of the first magnetic susceptibility, the auxiliary material 1 with a second magnetic susceptibility close to or equal to the first magnetic susceptibility is selected, and the part 100 to be detected is effectively protected and covered by the protective pad 2, and the auxiliary material 1 is covered on the part 100 to be detected, so that the gaps that may exist in the detection part 100 are filled with the help of the covering of the auxiliary material 1, especially when the detection part 100 is set as the foot of the human body, at least part of the auxiliary material 1 enters the gap between the toes of the foot, and the part 100 to be detected forms an individual with a regular overall shape and balanced magnetic susceptibility between multiple parts. In the subsequent magnetic resonance imaging of the part 100 to be detected covered with the auxiliary material 1, since the detection part 100 forms a regular overall shape with balanced magnetic susceptibility at various places, the imaging result is significantly better than the situation without the auxiliary material 1. At the same time, due to the covering of the protective pad 2, a better fixing effect can be achieved on the detected part 100, and the problem of unstable magnetic resonance imaging caused by the shaking of the foot can be avoided. Combined with the auxiliary material 1 with corresponding material, temperature and humidity settings, the magnetic susceptibility of the foot is kept close to that of the outside, forming a stable magnetic susceptibility as a whole, thereby minimizing the problem of poor imaging quality caused by the uneven geometric features of the foot.

[0039] Specifically, in the above embodiment, the auxiliary material 1 is used to fill and level the concave and / or convex parts of the part to be detected 100, especially the irregular area at the end of the foot and the toes. That is, after the auxiliary material 1 covers the part to be detected 100, the outer contour of the auxiliary material 1 away from the part to be detected 100 is smooth and flat. Figure 1 The protective bag shown is used to hold the auxiliary material 1, so that the auxiliary material 1 is actually set in a bag shape, which can not only prevent the auxiliary material 1 from leaking into the human body or the MRI equipment area, but also facilitate the convenient taking and placement of the auxiliary material 1.

[0040] On this basis, the auxiliary material 1 can be selected as an elastomer, a fluid or a granular fluid, but it needs to satisfy the second magnetic susceptibility being close to the first magnetic susceptibility of the part to be detected 100, such as the human foot in this embodiment, the magnetic susceptibility of human cells and water is -7.2×10^7emu. In this regard, the present invention can consider homemade water films, homemade saline field shim bags, perfluorocarbon liquid pad devices, silicone oil silicone bags, homemade field shim devices, etc., or other elastomers, fluids or granular fluids that are restricted and contained in protective bags, as long as they can produce a certain degree of deformation themselves and allow part of the auxiliary material 1 to fill the protrusions and depressions of the foot.

[0041] In an embodiment where saline is selected, saline placed near the imaging site may emit a signal, making the region of interest difficult to see. In an embodiment where a perfluorocarbon liquid pad is selected, the cost expenditure is excessive due to the high price of the perfluorocarbon liquid pad.

[0042] Specifically, in this embodiment, rice with low cost and relatively stable properties is selected as auxiliary material 1, and its second magnetic susceptibility is -8.2×10^7emu, which is close to the first magnetic susceptibility. In order to avoid the problem of affecting the performance stability of the homemade device during use, this embodiment imposes certain restrictions on the material and storage of rice to achieve a relatively stable imaging effect. The water content of rice is set between 13.80% and 14.54%. The water state inside the rice can be divided into bound water, immovable water, and free water. When drying occurs, the free water content in the rice decreases significantly, which affects its regulation of magnetic field uniformity and thus reduces the image quality. Therefore, the protective bag selects an LDPE sealed plastic bag that can isolate the rice from the external environment. It is light, transparent, has good biocompatibility and stability, and is a non-polar material. The magnetic susceptibility in the magnetic field environment is close to that of air, ensuring that the bag body will not introduce magnetization artifacts. The bag body can be sealed by hot pressing to avoid the risk of rice overflow, further reduce the possibility of moisture absorption, extend its service life, and always keep the moisture content of the rice within a preset range. At the same time, the rice bag (LDPE sealed plastic bag containing rice) is kept in a hygroscopic equilibrium state, and the temperature and humidity of the rice inside are limited. Specifically, the temperature is between 16°C and 20°C, and the relative humidity is close to 60%. The rice can be stored in a controlled environment for 12 months without obvious deterioration. In order to further meet the use stability, the temperature and humidity in the imaging area of ​​the MRI equipment are also maintained within the above conditions to avoid the properties of the rice from being changed. Furthermore, the temperature and humidity between the nuclear magnetic equipment of the entire MRI equipment are maintained within the above range to ensure the consistency of the measurement results and avoid the degeneration of the rice affecting the measurement results.

[0043] For further information, please refer to Figure 1-Figure 3, this embodiment also provides a protective pad 2. Before the step of "covering the auxiliary material 1 on the part to be detected 100", the bottom and side of the part to be detected 100 are covered with the protective pad, that is, the bottom surface and the surrounding of the foot are tightly attached, and then the auxiliary material 1 is covered on the top position of the part to be detected 100. Specifically, the protective pad 2 is configured as a sponge with a non-woven fabric on the outside, and a protective belt 3 for fastening the auxiliary material 1 to the part to be detected 100 is installed on the protective pad 2, so that the protective pad 2 is elastically deformed when covering the part to be detected 100, so that the part to be detected 100 is fitted with the protective pad 2, and the auxiliary material 1 is fastened to the part to be detected 100. In order to meet the needs of the foot geometry in this embodiment, the protective pad 2 can be provided with two long pads on the sides, a bottom pad at the bottom, and a stop pad at the toe end, and the protective belt 3 is respectively connected to the two long pads on the sides and tightly locks the foot on the protective pad 2.

[0044] With the aid of the above structure, the influence on the imaging effect caused by the movement of the detected part 100 due to discomfort is avoided, and the comfort level is high, the rice bag can fit closely to the tester's footsteps, and it is easy to disassemble and the cost is low.

[0045] In order to prove the effectiveness of rice as auxiliary material 1, the present invention also conducted relevant experiments, the specific contents of which are as follows.

[0046] This experiment selected 30 healthy volunteers recruited by the same hospital on a near date, 13 males, 17 females, aged 21-58 years old, aged 34.83±8.90 years old, and divided into an experimental group (using the rice bag of the present embodiment) and a conventional group (using a conventional fixation method), wherein all volunteers had no metal implants in their feet, no serious foot deformation or disease. Similarly, 30 volunteers with foot lesions were recruited, 16 males, 14 females, aged 14-68 years old, aged 41.67±14.53 years old, all of whom had no metal implants in their feet and suffered from foot diseases. Pregnant women, breastfeeding women, people with severe claustrophobia, people with metal implants in their feet, and people with absolute and relative contraindications were excluded from both groups of volunteers. The MRI equipment was set to Philips 3.0T superconducting magnetic resonance (model Ingenia), and equipped with a 15-channel head orthogonal coil for sagittal 3D-VIEW-PDWI-SPAIR sequence scanning of the foot. The sequence parameters were TR1200ms, TE201ms, FOV145mm×259mm, matrix 196×350, layer thickness 0.74mm, layer spacing -0.04mm, number of layers 200, voxel 0.74mm×0.74mm×0.74mm, number of excitations 1 time, and scanning time 4min43s. The specific method of using the rice bag was unified, which was to place the foot on the side to be examined in the protective pad 2, and then fasten it with the protective belt 3 after covering a uniform number of rice bags.

[0047] The final image evaluation included subjective and objective evaluation. The subjective evaluation was performed by two chief physicians who independently evaluated the image fat suppression effect. If there was a disagreement, a consensus was reached through discussion. The image fat suppression effect was scored in four levels, including level 0: complete image fat suppression, clear foot and ankle tissue layers, and no obvious granularity; level 1: only a small amount of subcutaneous soft tissue fat suppression was incomplete, and the rest of the parts had good fat suppression, and the foot and ankle tissue layers were clear; level 2: poor fat suppression at the distal end of the foot, the palm-to-toe junction, or the heel, but obvious fat suppression in other parts, and the foot and ankle tissue layers were still clear; level 3: poor image fat suppression, and the various tissue layers were not clearly displayed. Objective evaluation was performed using ROI (region of interest, which refers to a specific area selected in the image for in-depth analysis or measurement) technology at the first to fifth proximal phalanges, the soft tissues under the first to fifth proximal phalanges, the first to fifth metatarsals, the soft tissues under the first to fifth metatarsals, the third middle phalanges, the calcaneus, and the soft tissues behind the calcaneus in each sequence. The size of each measurement area was 5 mm2 ROI. The mean intensity (SI) and the standard deviation (SD) of the background noise signal intensity were measured by the same operator. The signal-to-noise ratio (SNR) of each layer was calculated using the formula SI / SD. The SNR directly reflects the degree of adequacy of fat signal suppression. Therefore, a high SNR means that fat suppression is inadequate, and a low SNR means that fat suppression is good. For specific ROI locations, see Figure 4 .

[0048] After collecting the above-mentioned subjective and objective evaluation results, data analysis was performed with the help of SPSS26.0 software.

[0049] Among them, Fisher's exact test is used for the counting data of subjective evaluation to calculate the probability of each possible distribution situation, and add the probabilities of all situations that are more extreme than the observed distribution to obtain a P value. If this P value is less than the set significance level (P < 0.05), the relationship between the variables is considered to be statistically significant, and accidental phenomena are excluded. In the specific results, the foot fat suppression effect of the experimental group in the healthy volunteer group was significantly better than that of the conventional group (P < 0.01), and there was a significant statistical difference between the results of the conventional group and the experimental group. In the subjective evaluation of the sick volunteer group, there were 28 cases of grade 0, 2 cases of grade 1, 0 cases of grade 2, and 0 cases of grade 3. The grade 0 rate was 93.33%. For specific typical embodiments, please refer to Figure 5 , from A to D correspond to one of the examples of level 0 to level 3, indicating that the use of rice bags has a good fat-suppressing effect on the feet. The specific result data can be found in Figure 6 .

[0050] Among them, the quantitative data of objective evaluation were expressed by median. Compared with conventional scanning, after using the rice bag, the first proximal phalanx (ROI1), the soft tissue under the first proximal phalanx (ROI2), the first metatarsal (ROI3), the soft tissue under the first metatarsal (ROI4), the second proximal phalanx (ROI5), the soft tissue under the second proximal phalanx (ROI6), the second metatarsal (ROI7), the soft tissue under the second metatarsal (ROI8), the third proximal phalanx (ROI9), the soft tissue under the third proximal phalanx (ROI10), the third metatarsal (ROI11), the soft tissue under the third metatarsal (ROI12), The SNR of the third middle phalanx (ROI13), fourth proximal phalanx (ROI14), soft tissue under the fourth proximal phalanx (ROI15), fourth metatarsal (ROI16), soft tissue under the fourth metatarsal (ROI17), fifth proximal phalanx (ROI18), soft tissue under the fifth proximal phalanx (ROI19), fifth metatarsal (ROI20), soft tissue under the fifth metatarsal (ROI21), calcaneus (ROI22), and soft tissue under the calcaneus (ROI23) were significantly better than those of the conventional group, and the SNR differences were statistically significant (P<0.01). The data are available. For a summary of the specific results, please refer to Figure 7 .

[0051] Of course, in other embodiments, the rice bag can be used as an auxiliary device on different MRI devices without being limited by the device model. Similarly, the part to be detected 100 can be a part with special geometric shapes such as hands and shoulders in addition to the foot, and still have a good auxiliary imaging optimization effect, in which the protective pad 2 or the protective belt 3 needs to be designed with a corresponding structure.

[0052] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention's specification and drawings are included in the scope of the present invention.

[0053] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0054] Although the present application has been described through embodiments, those skilled in the art will appreciate that there are many modifications and changes to the present application without departing from the spirit of the present application. It is intended that the attached embodiments include these modifications and changes without departing from the present application.

Claims

1. A magnetic resonance imaging optimization method, characterized in that: The magnetic resonance imaging optimization method comprises: Providing auxiliary materials and protective pads, covering the bottom and sides of the part to be detected with the help of the protective pads, and covering the part to be detected with the auxiliary materials, and then starting the MRI device to image the part to be detected covered with the auxiliary materials; The part to be detected has a first magnetic susceptibility, the auxiliary material has a second magnetic susceptibility, and the first magnetic susceptibility matches the second magnetic susceptibility in value.

2. The magnetic resonance imaging optimization method according to claim 1, characterized in that: The auxiliary material is set to be an elastomer, a fluid or a granular fluid. Before the step of "starting the MRI device to image the part to be detected covered with the auxiliary material", the concave and / or convex parts of the part to be detected are filled and leveled with the help of the auxiliary material.

3. The magnetic resonance imaging optimization method according to claim 2, characterized in that: A protective bag is provided, wherein the elastomer, fluid or granular fluid for the auxiliary material is arranged inside the protective bag, and during the step of "filling and leveling the concave and / or convex parts of the part to be inspected with the aid of the auxiliary material", the protective bag is in direct contact with the part to be inspected.

4. The magnetic resonance imaging optimization method according to claim 3, characterized in that: The auxiliary material is rice, and the protective bag is a rice bag made of LDPE sealed plastic material; the moisture content of the rice in the rice bag is maintained between 11% and 15%, the temperature is between 16° C. and 20° C., and the relative humidity is 60%.

5. The magnetic resonance imaging optimization method according to claim 4, characterized in that: The temperature of the imaging area of ​​the MRI device is maintained between 16° C. and 20° C., and the relative humidity is 60%.

6. The magnetic resonance imaging optimization method according to claim 1, characterized in that: The protective pad is configured as a sponge with a non-woven fabric on the outside, and a protective belt for fastening the auxiliary material to the part to be detected is installed on the protective pad, so that the protective pad undergoes elastic deformation when covering the part to be detected, so that the part to be detected fits the protective pad, and the auxiliary material is fastened to the part to be detected.

7. The magnetic resonance imaging optimization method according to claim 1, characterized in that: After "starting the MRI device to image the part to be detected covered with the auxiliary material" is completed, before the next "covering the part to be detected with the auxiliary material", the step of monitoring the weight of the auxiliary material is also included.

8. A magnetic resonance assisted device, characterized in that: The magnetic resonance assisting device is composed of the assisting material and the protective bag according to any one of claims 1 to 9.

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