CN112397271B - High-temperature superconducting magnetic resonance imager - Google Patents
High-temperature superconducting magnetic resonance imager Download PDFInfo
- Publication number
- CN112397271B CN112397271B CN202011017745.0A CN202011017745A CN112397271B CN 112397271 B CN112397271 B CN 112397271B CN 202011017745 A CN202011017745 A CN 202011017745A CN 112397271 B CN112397271 B CN 112397271B
- Authority
- CN
- China
- Prior art keywords
- vacuum
- heat transfer
- dewar
- temperature
- low
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F6/04—Cooling
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
- G01R33/381—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets
- G01R33/3815—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets with superconducting coils, e.g. power supply therefor
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F6/06—Coils, e.g. winding, insulating, terminating or casing arrangements therefor
Abstract
The invention discloses a high-temperature superconducting magnetic resonance imager, which comprises a low-temperature Dewar shell, a low-temperature Dewar cold screen, a Dewar liquid helium container, a cold head and a current lead wire, wherein the low-temperature Dewar shell, the low-temperature Dewar cold screen and the Dewar liquid helium container are sequentially sleeved from outside to inside, the cold head and the current lead wire are connected to the three devices in a penetrating way, a superconducting coil is arranged in the Dewar liquid helium container, and the inner side of the low-temperature Dewar shell and the inner wall of a first vacuum chamber are fixedly enclosed into a first vacuum chamber; a second vacuum device is fixed on one side of the first vacuum inner wall extending towards the human body channel direction; a second vacuum cavity of the second vacuum device is provided with a gradient coil and a radio frequency coil from outside to inside in sequence; the gradient coil and/or the radio frequency coil are made of high-temperature superconducting materials or thin films or thick films, and one end part of the gradient coil and/or the radio frequency coil is provided with a liquid nitrogen container; the end face of the low-temperature Dewar cold shield is connected to the cold shield in the low-temperature Dewar container through at least one heat transfer copper rod passing through the first vacuum inner wall. The resonance imaging system of the invention reduces the background noise of the radio frequency coil, improves the signal-to-noise ratio and the resolution ratio of the image, saves the refrigeration energy and reduces the operation cost.
Description
Technical Field
The invention relates to the technical field of superconducting magnetic resonance, in particular to a high-temperature superconducting magnetic resonance imager.
Background
Superconducting coil magnets, gradient coils and radio frequency coils are essential important components of a magnetic resonance imaging system. Magnetic resonance imaging systems have high requirements for magnets, in addition to requiring strong magnetic fields, for large spatial uniformity and long-term stability. Magnetic resonance magnets are generally classified into permanent magnets and superconducting magnets according to the manner of generation of a magnetic field. Although a superconducting magnet is only one type of electromagnet, since almost all electromagnets for a magnetic resonance system are superconducting electromagnets, no distinction is made, and only a superconducting magnet is discussed. In the case of a stronger magnetic field, superconducting magnets are lighter and more stable, but are more expensive and more expensive to use and maintain, primarily due to the cryogenic system of the superconducting magnet.
Gradient coils are used to generate gradient changes in the magnetic field, so that the frequency and phase of the signals can be analyzed to obtain a spatial distribution of the signal strength, i.e. to realize a so-called spatial encoding, so that images with a very high spatial resolution can be obtained with a small number of signal receivers. To achieve higher image resolution, it is often necessary to pass rapidly changing, very intense current pulses through the gradient coils. As a detrimental consequence, these currents generate significant heat in the gradient coils, requiring an efficient cooling system to be designed in the gradient coils to keep the gradient coils operating properly for a long time. The cooling system of the gradient coil is an important factor that limits the performance of the gradient coil. The cooling system makes the gradient coil larger, heavier and more energy consuming. The radio frequency coil is used to receive magnetic resonance signals, the performance of which directly affects the image quality of the magnetic resonance. Since the background noise of the radio frequency coil is in direct proportion to the resistance of the radio frequency coil, the radio frequency coil is usually made of pure copper with good conductivity.
In prior art superconducting magnetic resonance imaging systems, as shown in figure 1, the magnetic field is generated by currents in superconducting coils. In order to maintain the superconducting state of the coil wire, the coil must be maintained at an extremely low temperature, typically by liquid helium and the cold head of a cryocooler. The superconducting coils are immersed in liquid helium in a liquid helium vessel of a cryogenic dewar. In order to effectively prevent the evaporation of liquid helium by conduction, convection or radiation conduction of external heat to the liquid helium dewar, the superconducting coils and the cryogenic vessel of the dewar must be placed inside the vacuum chamber and the radiation-proof cold shield therein. The vacuum was maintained by a dewar's room temperature vessel. However, no matter the best cryogenic systems, it is not possible to completely eliminate the external heat from entering the liquid helium vessel, and the remaining heat radiation and suspension of the liquid helium vessel in the vacuum are the primary paths for heat leakage. The purpose of the cold head is to remove heat leak from the support member and residual radiation, and also to liquefy helium gas evaporated by the leak back to a liquid state.
The super-low temperature refrigerator for super-conductive magnet is mainly composed of helium compressor and cold head. The high-pressure helium provided by the helium compressor oscillates in the cold head, so that the heat at the low-temperature end of the cold head is taken out of the cold head through the flowing helium, and the effect of cooling is achieved. In order to obtain ultralow temperature, the cold head can be divided into a first-stage cold head and a second-stage cold head, the temperature of the first-stage cold head is generally 20-60K, and the boiling point of liquid helium can be up to below 4.2K. Although the working temperature of the primary cold head is lower than that of the secondary cold head, the primary cold head has larger refrigerating power. For example, the secondary cold head is 1 watt, and the secondary cold head is 80 watts.
Therefore, the existing superconducting magnetic resonance imaging system can only be carried out in a very low temperature environment, the energy consumption for maintaining the low temperature environment is large, and the operation cost is high.
Disclosure of Invention
To overcome the above-described deficiencies of the prior art, the present invention provides a magnet fabricated using a high temperature superconductor in place of a low temperature superconductor, a gradient coil fabricated using a high temperature superconductor in place of a copper conductor, and/or a radio frequency coil fabricated using a high temperature superconductor in place of a copper conductor, and a cooling system configuration for such a system.
The technical scheme adopted by the invention is as follows: the high-temperature superconducting magnetic resonance imager comprises a low-temperature Dewar shell, a low-temperature Dewar cold screen, a Dewar liquid helium container, a cold head and a current lead, wherein the low-temperature Dewar shell, the low-temperature Dewar cold screen and the Dewar liquid helium container are sequentially sleeved from outside to inside, the cold head and the current lead are connected to the low-temperature Dewar shell, the low-temperature Dewar cold screen and the Dewar liquid helium container in a penetrating mode, and a superconducting magnet coil is arranged in the Dewar liquid helium container.
The inner side of the low-temperature Dewar shell is fixedly enclosed into a first vacuum chamber with a first vacuum inner wall to form a first vacuum device for accommodating and sealing the superconducting magnet coil;
a second vacuum device is fixed on one side of the first vacuum inner wall extending towards the human body channel direction;
the second vacuum device comprises two second vacuum end covers and a second vacuum cavity enclosed by the second vacuum inner cylinder;
the second vacuum cavity is internally provided with a gradient coil and a radio frequency coil from outside to inside in sequence and is used for accommodating and sealing the gradient coil and the radio frequency coil;
the gradient coil and/or the radio frequency coil are made of high-temperature superconducting wires or thin films or thick films, and one end part of the gradient coil and/or the radio frequency coil is provided with a liquid nitrogen container;
meanwhile, the end face of the low-temperature Dewar cold shield is connected to the inside of the liquid nitrogen container through at least one heat transfer copper rod penetrating through the first vacuum inner wall.
Preferably, the high-temperature superconducting wire is one or more of a Bi-system superconducting wire, an yttrium barium copper oxide superconducting wire or tape, and a magnesium boride wire.
Preferably, a first heat transfer cylinder is further arranged between the gradient coil and the radio frequency coil.
Preferably, a second heat transfer cylinder is further arranged between the first vacuum inner wall and the gradient coil.
Preferably, a sealing sleeve is arranged between each heat transfer copper rod and the connected inner wall of the first vacuum chamber and the liquid nitrogen container, and the heat transfer copper rods obstruct the gas exchange between the first vacuum chamber and the liquid nitrogen container and simultaneously realize the heat exchange.
Preferably, the low temperature dewar shell low temperature dewar cold shield, the first vacuum inner wall and the dewar liquid helium vessel are made of stainless steel or aluminum alloy, while the second vacuum end cap and the second vacuum inner cylinder are made of non-metallic material.
Preferably, the liquid nitrogen container is made of any one of copper, aluminum, stainless steel, ceramic, and glass fiber reinforced plastic.
Preferably, the first heat transfer cylinder and the second heat transfer cylinder are made of metal with good heat conduction, and the side surfaces of the first heat transfer cylinder and the second heat transfer cylinder are provided with a plurality of longitudinal slits for eliminating eddy currents so as to reduce the influence of eddy current on a magnetic field.
Preferably, a plurality of longitudinal slits are formed in the side surfaces of the first heat transfer cylinder and the second heat transfer cylinder and are uniformly arranged along the circumferential direction of the first heat transfer cylinder and the second heat transfer cylinder.
Preferably, the first heat transfer cylinder and the second heat transfer cylinder are made of nonmetal, specifically, non-metal materials with good heat conductivity such as diamond and carbon fiber, and the better heat transfer effect can be ensured.
Preferably, the end surfaces of the two sides of the low-temperature Dewar cold shield are respectively connected to the insides of the liquid nitrogen containers on the two corresponding sides through at least one heat transfer copper bar penetrating through the first vacuum inner wall.
Compared with the prior art, the invention has the beneficial effects that: according to the high-temperature superconducting magnetic resonance imager, the gradient coil is made of the high-temperature superconducting material instead of a copper material, so that the gradient strength and the switching rate can be improved, and the high-temperature superconducting wire has no or almost no resistance, so that ohmic heat is not generated in the gradient coil, and cooling equipment, cooling water and electric power are reduced.
Because the high-temperature superconducting wire can pass through higher current density, a large amount of copper can be saved, and space can also be saved. These spaces can be used to increase the number of turns of the coil, thereby further improving the gradient strength.
The gradient coil has a self-inductance L as well as the RF coil, and if the coil resistances of the gradient coil and the RF coil are R, the time constants of the coils are
t =R/L
A larger time constant means a larger delay of the coil. Therefore, the high-temperature superconducting wire replaces the copper wire, and the current change speed of the gradient coil can be increased, so that the gradient magnetic field switching speed is increased.
The radio frequency coil is made of the high-temperature superconducting material instead of a copper material, so that the noise of a magnetic resonance signal can be reduced, and the signal-to-noise ratio of an image can be improved. The signal of magnetic resonance is weak, and the noise of a radio frequency receiving coil plays a critical influence on the signal to noise ratio of imaging. The noise of the radio frequency receiving coil comes from the resistance of the coil, and the radio frequency coil made of high-temperature superconducting materials reduces the noise of the coil to the maximum extent because the resistance of the materials of the radio frequency coil is zero.
In summary, the high-temperature superconducting magnetic resonance imager of the invention uses the high-temperature superconducting material to replace the copper material to manufacture the radio frequency coil, so that the background noise of the radio frequency coil can be reduced, the signal to noise ratio of the image can be improved, the superconducting magnetic resonance imaging system can be completed at a relatively high temperature, the refrigeration energy can be saved, and the operation cost can be reduced.
Drawings
FIG. 1 is a schematic cross-sectional view of a prior art superconducting magnetic resonance imaging system;
FIG. 2 is a front view of a high temperature superconducting magnetic resonance imager;
FIG. 3 isbase:Sub>A sectional view A-A of FIG. 2;
FIG. 4 is an enlarged view taken at A of FIG. 3;
FIG. 5 is a left side view of FIG. 2;
fig. 6 is a structural view of an embodiment of the first heat transfer cylinder 13 or the second heat transfer cylinder 14;
wherein: 1-a low-temperature dewar shell, 2-a low-temperature dewar cold screen, 3-a dewar liquid helium vessel, 4-a superconducting coil, 5-a human body channel, 6-a gradient coil, 7-a radio frequency coil, 8-a first vacuum device, 81-a first vacuum inner wall, 82-a first vacuum cavity; 9-a second vacuum device, 91-a second vacuum end cover, 92-a second vacuum cavity and 93-a second vacuum inner cylinder; 10-liquid nitrogen container, 11-cold head, 12-current lead, 13-first heat transfer cylinder, 14-second heat transfer cylinder, 131 and 141-longitudinal gap, 15-, 16-heat transfer copper rod and 17-sealing sleeve.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention and are not to be construed as limiting the present invention.
In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the combination or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, are not to be construed as limiting the present invention. In addition, in the description process of the embodiment of the present invention, the positional relationships of the devices such as "upper", "lower", "front", "rear", "left", "right", and the like in all the drawings are based on fig. 1.
As shown in fig. 2 and fig. 3, the high-temperature superconducting magnetic resonance imager includes a low-temperature dewar shell 1, a low-temperature dewar cold screen 2 and a dewar liquid helium container 3 which are sequentially sleeved from outside to inside, and a cold head 11 and a current lead 12 which are connected to the low-temperature dewar shell 1, the low-temperature dewar cold screen 2 and the dewar liquid helium container 3 in a penetrating manner, and a superconducting coil 4 is arranged in the dewar liquid helium container 3.
The inner side of the low-temperature Dewar shell 1 is fixedly enclosed into a first vacuum chamber 82 through a first vacuum inner wall 81, so that a first vacuum device 8 is formed and is used for accommodating and sealing the superconducting coil;
as shown in detail in fig. 4, the first vacuum inner wall 81 is fixed with the second vacuum device 9 at the side extending towards the body passage 5;
the second vacuum device 9 comprises a second vacuum cavity 92 enclosed by two second vacuum end covers 91 and a second vacuum inner cylinder 93;
a second vacuum chamber 92, which is provided with a gradient coil 6 and a radio frequency coil 7 in sequence from outside to inside, for accommodating and sealing the gradient coil and the radio frequency coil;
the gradient coil 6 and/or the radio frequency coil 7 are made of high-temperature superconducting wires or thin films or thick films, and one end part of the gradient coil is provided with a liquid nitrogen container 10;
meanwhile, the end face of the low-temperature Dewar cold shield 2 is connected to the inside of the liquid nitrogen container 10 through the first vacuum inner wall 81 by at least one heat transfer copper rod 16.
The invention provides a method for manufacturing a radio frequency coil by using a high-temperature superconducting material to replace a copper material, which can reduce the background noise of the radio frequency coil, thereby improving the signal-to-noise ratio of an image. Meanwhile, the high-temperature superconducting magnetic resonance imager is provided with the second vacuum chamber outside the gradient coil 6 and the radio-frequency coil 7 for isolating the gradient coil and the radio-frequency coil, so that the gradient coil and the radio-frequency coil are hermetically sealed in the low-temperature space of the second vacuum chamber isolated from the magnet, and the superconducting coil is separately sealed in the first vacuum chamber, thereby avoiding the influence of the relative high temperature of the second vacuum chamber on the stability of the superconducting magnet. But at the same time, at least one heat transfer copper rod 16 is connected to the inside of the liquid nitrogen container 10 through the first vacuum inner wall 81, so that heat generated by the superconducting coil, the gradient coil and the radio frequency coil can be quickly conducted out through a cold head for refrigeration, and finally the working temperature of the high-temperature superconducting gradient coil and the radio frequency coil is ensured to be below the critical temperature of a high-temperature superconducting material, thereby improving the gradient strength and the gradient switching rate of a gradient field; the background noise of a radio frequency coil of the high-temperature superconducting magnetic resonance imager is reduced, so that the signal-to-noise ratio of an image of an imaging system is improved.
The high-temperature superconducting magnetic resonance imager provided by the invention has the advantages that the high-temperature superconducting wire is one or more of a Bi-system superconducting wire, an yttrium barium copper oxide superconducting wire and a magnesium boride wire, and the superconductivity can be kept at a higher temperature than that of a low-temperature superconducting material (4K or less than 10K), such as a gasification temperature higher than that of liquid nitrogen (77K) and magnesium boride of about 40K. The invention uses the double-low-temperature structure of the two vacuum cavities, and the magnet coil is placed in the first vacuum cavity with lower temperature, thereby ensuring that the field coil of the low-temperature superconducting magnet can work normally; or when the magnetic field magnet is a high-temperature superconducting coil, the high-temperature superconducting magnet is more stable in operation at the low temperature and can bear larger current.
A first heat transfer cylinder 13 is arranged between the gradient coil 6 and the radio frequency coil 7 of the high-temperature superconducting magnetic resonance imager, so that heat generated by the gradient coil and the radio frequency coil can be well transferred out, and finally, the heat is gasified through liquid nitrogen in a liquid nitrogen container 10 and finally, the liquid nitrogen is refrigerated through a primary cold head.
A second heat transfer cylinder 14 is further arranged between the first vacuum inner wall 81 of the high-temperature superconducting magnetic resonance imager and the gradient coil 6, so that the first heat transfer cylinder and the second heat transfer cylinder are respectively arranged on the inner side and the outer side of the liquid nitrogen container 10, the heat conduction speed of the gradient coil and the heat conduction speed of the radio frequency coil are further improved, the heat transfer performance of the gradient coil and the heat conduction speed of the radio frequency coil are enhanced, heat generated by the high-temperature superconducting gradient coil and the heat generated by the radio frequency coil can be rapidly conducted out through cold heads for refrigeration, and the gradient coil and the radio frequency coil are further guaranteed to be in a superconducting state all the time.
A sealing sleeve 17 is arranged between each heat transfer copper rod 16 of the high-temperature superconducting magnetic resonance imager and the connected first vacuum inner wall 81 and the liquid nitrogen container 10, the heat transfer copper rods obstruct gas exchange between the first vacuum chamber and the liquid nitrogen container 10 and simultaneously realize exchange between a cold shield of heat in the first vacuum and nitrogen in the liquid nitrogen container 10, and further play a role in improving the sealing effect between the first vacuum device and the second vacuum device, so that structures in the first vacuum device and structures in the second vacuum device are guaranteed to be in a lower temperature space. The gradient coil and the radio frequency coil are ensured to be in a superconducting state all the time.
A high-temperature superconducting magnetic resonance imager is characterized in that a low-temperature Dewar shell 1, a first vacuum inner wall 81, a low-temperature Dewar cold shield 2 and a Dewar liquid helium container 3 are made of stainless steel or aluminum alloy, and a second vacuum end cover 91 and a second vacuum inner cylinder 93 are made of non-metallic materials, so that no eddy current is generated on a gradient coil 6 and a radio-frequency coil 7, meanwhile, radio-frequency signals can be smoothly transmitted between an imaged object and the coils, and images are guaranteed to have good quality. Although stainless steel or aluminum alloy is a good material for manufacturing the low-temperature dewar, the gradient coil and the radio frequency coil are used for generating a changing magnetic field and a changing electromagnetic wave, and the vacuum shell of the traditional low-temperature dewar is an electric conductor and can generate eddy current under the action of the gradient field and the radio frequency field, so that the gradient field and the radio frequency field are distorted. This can seriously affect the image quality. Therefore, the gradient coil and the radio frequency coil should be hermetically encapsulated in a second cryogen space isolated from the superconducting magnet coil, and a vacuum wall made of a non-metallic material having no effect on electromagnetic wave propagation should be used.
The liquid nitrogen container 10 of the high-temperature superconducting magnetic resonance imager is made of any one of copper, aluminum, stainless steel, ceramics and glass fiber reinforced plastics, the liquid nitrogen containers made of the materials are compact, a closed liquid nitrogen container can be made, the liquid nitrogen container made of the materials has certain pressure bearing capacity, and the service life can be well guaranteed.
As can be seen from fig. 5, the first heat transfer cylinder 13 and the second heat transfer cylinder 14 are made of metal with good heat conduction, and the side surfaces of the first heat transfer cylinder 13 and the second heat transfer cylinder 14 are provided with a plurality of longitudinal slits 131, 141 for eliminating eddy currents, specifically, the heat transfer cylinders can be made of metal such as aluminum, copper, stainless steel, or non-metal material such as diamond, carbon fiber, etc. with good heat conduction performance, so as to ensure good heat conduction effect.
The side surfaces of the first heat transfer cylinder 13 and the second heat transfer cylinder 14 of the high-temperature superconducting magnetic resonance imager are provided with a plurality of longitudinal slits 131, 141 which are uniformly distributed along the circumferential direction of the first heat transfer cylinder 13 and the second heat transfer cylinder 14, and the longitudinal slits 131, 141 are distributed at the length center positions of the first heat transfer cylinder 13 and the second heat transfer cylinder 14, so that the high-temperature superconducting magnetic resonance imager is ensured to have better performance of eliminating worm gears. Preferably, the first heat transfer cylinder 13 and the second heat transfer cylinder 14 are made of nonmetal, specifically, non-metal materials with good heat conductivity such as diamond and carbon fiber, so as to ensure good heat transfer effect. The end surfaces of two sides of the low-temperature Dewar cold shield 2 of the high-temperature superconducting magnetic resonance imager are respectively connected to the insides of the liquid nitrogen containers 10 on two corresponding sides through the first vacuum inner walls 81 through at least one heat transfer copper rod 16, so that the effect of better enhancing cold conduction can be achieved.
The embodiments of the present invention are disclosed as the preferred embodiments, but not limited thereto, and those skilled in the art can easily understand the spirit of the present invention and make various extensions and changes without departing from the spirit of the present invention.
Claims (6)
1. High temperature superconducting magnetic resonance imager, including low temperature dewar shell (1), low temperature dewar cold screen (2) and dewar liquid helium container (3) that cup joint in proper order from outside to inside to and run through cold head (11) and current lead (12) on low temperature dewar shell (1), low temperature dewar cold screen (2) and dewar liquid helium container (3), and be provided with superconducting coil (4), its characterized in that in dewar liquid helium container (3):
the inner side of the low-temperature Dewar shell (1) is fixedly enclosed into a first vacuum chamber (82) through a first vacuum inner wall (81), so that a first vacuum device (8) is formed and is used for accommodating and sealing the superconducting coil;
a second vacuum device (9) is fixed on one side of the first vacuum inner wall (81) extending towards the human body passage (5);
the second vacuum device (9) comprises a second vacuum cavity (92) enclosed by two second vacuum end covers (91) and a second vacuum inner cylinder (93);
the second vacuum cavity (92) is sequentially provided with a gradient coil (6) and a radio frequency coil (7) from outside to inside;
the gradient coil (6) and/or the radio frequency coil (7) are made of high-temperature superconducting wires or thin films or thick films, and one end part of the gradient coil is provided with a liquid nitrogen container (10);
meanwhile, the end face of the low-temperature Dewar cold shield (2) penetrates through the first vacuum inner wall (81) through at least one heat transfer copper rod (16) and is connected to the inside of the liquid nitrogen container (10);
the low-temperature Dewar shell (1), the low-temperature Dewar cold shield (2), the first vacuum inner wall (81) and the Dewar liquid helium container (3) are made of stainless steel or aluminum alloy, and meanwhile, the second vacuum end cover (91) and the second vacuum inner cylinder (93) are made of non-metallic materials;
a first heat transfer cylinder (13) is arranged between the gradient coil (6) and the radio frequency coil (7);
a second heat transfer cylinder (14) is also arranged between the first vacuum inner wall (81) and the gradient coil (6);
the first heat transfer cylinder (13) and the second heat transfer cylinder (14) are made of metal, and a plurality of longitudinal gaps (131, 141) are formed in the side faces of the first heat transfer cylinder (13) and the second heat transfer cylinder (14).
2. A high temperature superconducting magnetic resonance imager as claimed in claim 1, wherein: the high-temperature superconducting wire is one or more of Bi-system superconducting wire, yttrium barium copper oxide superconducting wire and magnesium boride wire.
3. The hts mri apparatus of claim 1, wherein: and a sealing sleeve (17) is arranged between each heat transfer copper rod (16) and the connected first vacuum inner wall (81) and the liquid nitrogen container (10).
4. The hts mri apparatus of claim 1, wherein: the liquid nitrogen container (10) is made of any one of copper, aluminum, stainless steel, ceramics and glass fiber reinforced plastics.
5. A high temperature superconducting magnetic resonance imager as claimed in any one of claims 1 to 4, characterized in that: the side surfaces of the first heat transfer cylinder (13) and the second heat transfer cylinder (14) are provided with a plurality of longitudinal slits (131, 141) which are uniformly distributed along the circumferential direction of the first heat transfer cylinder (13) and the second heat transfer cylinder (14), and the longitudinal slits (131, 141) are distributed at the length center positions of the first heat transfer cylinder (13) and the second heat transfer cylinder (14).
6. A high temperature superconducting magnetic resonance imager as claimed in claim 5, characterized in that: the end surfaces of two sides of the low-temperature Dewar cold screen (2) penetrate through the first vacuum inner wall (81) through at least one heat transfer copper rod (16) and are connected to the insides of the liquid nitrogen containers (10) on two corresponding sides.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011017745.0A CN112397271B (en) | 2020-09-24 | 2020-09-24 | High-temperature superconducting magnetic resonance imager |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011017745.0A CN112397271B (en) | 2020-09-24 | 2020-09-24 | High-temperature superconducting magnetic resonance imager |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112397271A CN112397271A (en) | 2021-02-23 |
| CN112397271B true CN112397271B (en) | 2022-10-04 |
Family
ID=74595709
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011017745.0A Active CN112397271B (en) | 2020-09-24 | 2020-09-24 | High-temperature superconducting magnetic resonance imager |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112397271B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114068132B (en) * | 2021-10-15 | 2023-05-12 | 江苏美时医疗技术有限公司 | Nuclear magnetic resonance ultra-high field magnet circulation refrigerating device based on liquid helium circulation |
| CN114114108B (en) | 2021-11-09 | 2023-01-24 | 中国科学院精密测量科学与技术创新研究院 | Low-cost modular liquid nitrogen low-temperature multi-core magnetic resonance probe |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0562707A1 (en) * | 1992-03-27 | 1993-09-29 | Picker International, Inc. | Magnetic resonance apparatus and methods |
| JPH10116724A (en) * | 1996-08-23 | 1998-05-06 | General Electric Co <Ge> | Superconducting device |
| EP1530058A2 (en) * | 2003-11-06 | 2005-05-11 | Hitachi, Ltd. | Superconducting magnetic resonance imaging apparatus with reduced vibrations |
| CN101896833A (en) * | 2007-12-11 | 2010-11-24 | 皇家飞利浦电子股份有限公司 | Have condenser system and monitor the magnetic resonance system that helium is pressed |
| CN102597794A (en) * | 2009-04-20 | 2012-07-18 | 美时医疗控股有限公司 | Cryogenically cooled superconductor RF head coil array and head-only magnetic resonance imaging (MRI) system using same |
| CN102636765A (en) * | 2011-02-08 | 2012-08-15 | 英国西门子公司 | Stiffened gradient coil |
| JP2012520132A (en) * | 2009-03-10 | 2012-09-06 | タイム メディカル ホールディングス カンパニー リミテッド | MRI system having a main superconducting magnet, a superconducting gradient field coil and a cooled RF coil |
| CN102809240A (en) * | 2011-05-31 | 2012-12-05 | 通用电气公司 | Penetration tube assemblies for reducing cryostat heat load |
| CN103998947A (en) * | 2011-12-20 | 2014-08-20 | 通用电气公司 | System and apparatus for compensating for magnetic field distortion in an MRI system |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AUPQ198899A0 (en) * | 1999-08-03 | 1999-08-26 | University Of Queensland, The | A method of magnet design and magnet configuration |
| US7319327B2 (en) * | 2005-11-17 | 2008-01-15 | General Electric Company | Magnetic resonance imaging system with reduced cooling needs |
| CN100581654C (en) * | 2007-12-17 | 2010-01-20 | 山东华特磁电科技股份有限公司 | Low temperature superconductivity ferromagnetic deironing device |
| CN101307862B (en) * | 2008-05-12 | 2011-03-30 | 中国科学院等离子体物理研究所 | Conduction cooling superconducting magnet dewar convenient for loading and unloading |
| CN101345115A (en) * | 2008-05-16 | 2009-01-14 | 哈尔滨工业大学 | Open type permanent magnet module used for magnetic resonance wave spectrum analyzer |
| CN103105595A (en) * | 2013-01-28 | 2013-05-15 | 江苏美时医疗技术有限公司 | Liquid nitrogen refrigeration magnetic resonance imaging system |
| CN203149098U (en) * | 2013-01-28 | 2013-08-21 | 江苏美时医疗技术有限公司 | Magnetic resonance imaging system with liquid nitrogen refrigeration |
| CN103961102A (en) * | 2014-03-11 | 2014-08-06 | 江苏美时医疗技术有限公司 | Composite type 2T whole-body magnetic resonance imaging device |
-
2020
- 2020-09-24 CN CN202011017745.0A patent/CN112397271B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0562707A1 (en) * | 1992-03-27 | 1993-09-29 | Picker International, Inc. | Magnetic resonance apparatus and methods |
| JPH10116724A (en) * | 1996-08-23 | 1998-05-06 | General Electric Co <Ge> | Superconducting device |
| EP1530058A2 (en) * | 2003-11-06 | 2005-05-11 | Hitachi, Ltd. | Superconducting magnetic resonance imaging apparatus with reduced vibrations |
| CN101896833A (en) * | 2007-12-11 | 2010-11-24 | 皇家飞利浦电子股份有限公司 | Have condenser system and monitor the magnetic resonance system that helium is pressed |
| JP2012520132A (en) * | 2009-03-10 | 2012-09-06 | タイム メディカル ホールディングス カンパニー リミテッド | MRI system having a main superconducting magnet, a superconducting gradient field coil and a cooled RF coil |
| CN102597794A (en) * | 2009-04-20 | 2012-07-18 | 美时医疗控股有限公司 | Cryogenically cooled superconductor RF head coil array and head-only magnetic resonance imaging (MRI) system using same |
| CN102636765A (en) * | 2011-02-08 | 2012-08-15 | 英国西门子公司 | Stiffened gradient coil |
| CN102809240A (en) * | 2011-05-31 | 2012-12-05 | 通用电气公司 | Penetration tube assemblies for reducing cryostat heat load |
| CN103998947A (en) * | 2011-12-20 | 2014-08-20 | 通用电气公司 | System and apparatus for compensating for magnetic field distortion in an MRI system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112397271A (en) | 2021-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5723299B2 (en) | MRI system having a main superconducting magnet, a superconducting gradient field coil and a cooled RF coil | |
| RU2570219C2 (en) | Set of superconducting rf-coils with cryogenic cooling for head and system of magnetic-resonance tomography (mrt) only for head, applying such set of rf-coils | |
| CN112397271B (en) | High-temperature superconducting magnetic resonance imager | |
| EP0840136B1 (en) | Magnetic resonance imager with helium recondensing | |
| RU2572650C2 (en) | Module with gradient coils from superconductor with cryogenic cooling for magnetic-resonance tomography | |
| US20040119472A1 (en) | Conduction cooled passively-shielded mri magnet | |
| US5179338A (en) | Refrigerated superconducting MR magnet with integrated gradient coils | |
| US11009572B2 (en) | Integrated single-sourced cooling of superconducting magnets and RF coils in nuclear magnetic resonance devices | |
| US6965236B2 (en) | MRI system utilizing supplemental static field-shaping coils | |
| US20020063616A1 (en) | Liquid cryogen-free superconducting magnet system | |
| US8171741B2 (en) | Electrically conductive shield for refrigerator | |
| KR100845826B1 (en) | Cooling of receive coil in mri scanners | |
| CN103105595A (en) | Liquid nitrogen refrigeration magnetic resonance imaging system | |
| JPH11329834A (en) | Superconducting device with conductor formed of superconducting material | |
| US7482808B2 (en) | Superconductive magnet apparatus and magnetic resonance imaging apparatus | |
| EP4343355A1 (en) | A cryogen-cooled superconducting magnet assembly for a magnetic resonance imaging scanner | |
| CN117406151A (en) | Thermal bus structure for magnetic resonance imaging device | |
| Qu et al. | A 1.5 T Liquid-Helium-Free Whole-body MRI Superconducting Magnet: Thermal Analysis and Cool-down Time Estimation | |
| WO2005117036A1 (en) | Electrically conductive shield for refrigerator | |
| CN114068132A (en) | Liquid helium circulation-based nuclear magnetic resonance ultrahigh field magnet circulation refrigeration device | |
| Jan et al. | Design of cryogen-free mini-pole superconducting undulator | |
| Thomas | 12 Medical imaging | |
| JP2006095022A (en) | Super-conductive magnet apparatus and magnetic resonance imaging apparatus using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |