Suspension rod for suspending main magnet of magnetic resonance device, shielding assembly comprising suspension rod, and magnetic resonance device comprising shielding assembly

Abstract

The invention relates to a suspension rod (12) for suspending a main magnet (17) of a magnetic resonance device (11), comprising a first end, a second end and a collar (51) configured to deflect thermal radiation, the collar (51) being mechanically connected to the suspension rod (12), and the suspension rod (12) being mechanically connected to the first end and the second end. A collar (51) circumferentially surrounds the suspension rod (12) along a section of the suspension rod (12) located between the first end and the second end. In addition, the invention relates to a shielding assembly (31) comprising the suspension rod (12) of the invention and a magnetic resonance device (11) comprising the shielding assembly (31) of the invention.

Description

Technical Field

[0001] The present invention relates to a suspension rod for suspending a main magnet of a magnetic resonance apparatus, and further relates to a shielding assembly comprising the suspension rod and a magnetic resonance apparatus comprising the shielding assembly. Background Art

[0002] Regardless of grammatical usage of the term, individuals with male or female gender identities are also included in the term.

[0003] Cryogenic devices, such as magnetic resonance imaging devices, typically include one or more thermal radiation shields maintained at an intermediate temperature between the cryogenic application and the ambient temperature. These thermal radiation shields surround the cryogenic device's cryogenic cooling components to prevent thermal radiation from reaching the components. Typically, the cryogenic cooling components and the one or more thermal shields are enclosed in a vacuum vessel to protect the components from the surrounding environment and reduce heat transfer due to convection.

[0004] Cryogenically cooled components are often supported by specialized support structures that must be routed through the thermal radiation shield. For example, a superconducting magnet in a magnetic resonance imaging device may be suspended via specialized suspension elements that pass through holes in the thermal radiation shield. These holes must be sealed or made opaque to prevent thermal radiation from entering the area surrounded by the thermal radiation shield.

[0005] In cryogenic devices with only a single thermal shield, the hole in the thermal shield can be accessed from outside the vacuum vessel before the cryogenic device is closed. Alternatively, the hole can be sealed before the cryogenic cooling components and thermal radiation shield are loaded into the vacuum vessel. For example, a specially designed multi-layer insulation blanket can be wrapped around the hole in the thermal shield to provide a seal against thermal radiation.

[0006] In cryogenic devices comprising two or more thermal shields, for example an inner thermal shield and at least one outer thermal shield surrounding the inner thermal shield, accessibility to the inner thermal shield may be significantly reduced. Furthermore, not only the construction tolerances of the cryogenic device but also the transportation of the cryogenic device require that the seal allow relative movement between the suspension element and the thermal radiation shield. Summary of the Invention

[0007] It is an object of the present invention to allow sealing of holes in heat shields in confined spaces with reduced accessibility.It is a further object of the present invention to allow relative movement between a support structure of a cryogenically cooled component and a heat shield.

[0008] These objects are achieved by the suspension rod and shielding assembly according to the invention.Other advantageous embodiments are described in detail in the other aspects of the invention.

[0009] The suspension rod of the present invention is configured to suspend a main magnet of a magnetic resonance device. The suspension rod of the present invention comprises a first end, a second end, and a collar configured to deflect thermal radiation.

[0010] Preferably, the suspension rod is made of a material with high tensile strength. Examples of suitable materials are metal, particularly stainless steel, or composite materials such as fiber-reinforced plastic. According to one embodiment, the shaft of the suspension rod comprises carbon fiber. For example, the shaft of the suspension rod can be made of carbon fiber reinforced polymer.

[0011] The suspension rod may have a cylindrical or prismatic shape. For example, the suspension rod may correspond to a rod or bar having an elliptical or polygonal cross section. Preferably, the suspension rod has an elongated or oblong shape.

[0012] The first end and the second end of the suspension rod can each include an anchor or a ferrule. The anchor or ferrule can be attached to the suspension rod via any suitable mechanical connection such as a form-locking connection, a force-locking connection and / or a material bond. For example, the anchor or ferrule can be clamped, wedged and / or glued to the suspension rod. However, any suitable mechanical connection can be used. The anchor or ferrule can be configured to mechanically engage with a supporting structure such as an external vacuum chamber, a supporting structure of the main magnet, etc.

[0013] The collar may comprise a support element encased in a thermally insulating material. For example, the support element may be encased in a multi-layer thermal insulation. However, the collar may also consist of a thermally insulating material, such as a multi-layer thermal insulation. In a preferred embodiment, the collar is configured to deflect or block thermal radiation. Preferably, the thermally insulating material has a low emissivity (i.e. the effectiveness of emitting energy in the form of thermal radiation), for example in the range of 0.01 to 0.05. Suitable thermally insulating materials may be polymers or plastics, such as polyethylene, polyurethane, polyimide (i.e. Kapton), or carbon, carbon composites, silica composites, etc. The thermally insulating material may have a low thermal conductivity, for example less than 1 W / (m·K), less than 0.5 W / (m·K), or less than 0.1 W / (m·K) at temperature levels below 100K.

[0014] According to a preferred embodiment, the collar comprises or is composed of a low-emissivity material. For example, the collar may comprise or be composed of multi-layer insulation. Multi-layer insulation (MLI) may be composed of several layers of metal-evaporated plastic foil held at a distance by spacers. For example, the foil may be composed of a polyester or polyimide sheet that is aluminized on both sides. The spacers may be composed of a woven or non-woven sheet or gauze made of polyester or polyimide.

[0015] When providing the suspension rod of the present invention including the collar, the effectiveness of blocking or deflecting thermal radiation passing through the hole or channel covered by the collar in the thermal shield can be advantageously improved. Thus, the heat load in the cryogenic cooling component of the cryogenic device can be advantageously reduced.

[0016] In an embodiment of the suspension rod according to the present invention, the section of the suspension rod between the collar and the second end is encased in a thermally insulating material. The thermally insulating material may correspond to the embodiment described above. Preferably, the thermally insulating material has low emissivity. It is also conceivable that the section of the suspension rod between the collar and the first end is encased in a thermally insulating material. According to a preferred embodiment, the thermally insulating material is a multi-layer insulation element.

[0017] When sections of the suspension rod of the cryogenic device are encased with thermal insulation material, a portion of the blackbody radiation emitted by the suspension rod can advantageously be deflected or prevented from reaching the cryogenically cooled components of the cryogenic device.

[0018] According to the present invention, the collar is mechanically connected to the hanger rod. In particular, the hanger rod can provide mechanical support for the collar. For example, the collar can be adhered, glued, tied and / or welded to the shaft of the hanger rod. However, the collar can be mechanically connected to the hanger rod via any suitable mechanical connection such as a form-locking connection, a force-locking connection and / or a material bond. In some embodiments, the collar can be clamped, bolted and / or screwed to the hanger rod.

[0019] The collar circumferentially surrounds the suspension rod along a section of the suspension rod between the first end and the second end. Preferably, the collar is attached to the suspension rod so as to prevent thermal radiation from passing through an interface region between the collar and the suspension rod. In particular, the collar can form a light-tight seal around the axis of the suspension rod.

[0020] According to embodiments described below, the collar can be configured to abut the thermal shield and / or cover a hole or channel in the thermal shield of the shield assembly. For example, the collar is disposed between a first end and a second end of a suspension rod such that the collar contacts or abuts the thermal shield when the first end of the suspension rod is mechanically connected to the main magnet and the second end of the suspension rod is mechanically connected to an external vacuum chamber of the magnetic resonance apparatus.

[0021] The hanger bar of the present invention can advantageously allow for sealing channels or holes in thermal radiation shields in confined or inaccessible spaces. Consequently, requirements regarding accessibility to the thermal shield can be advantageously relaxed. The hanger bar of the present invention can also reduce the size or footprint of a cryogenic device including the hanger bar compared to conventional cryogenic devices.

[0022] The suspension rod of the present invention can advantageously facilitate the manufacturing process of cryogenic devices, such as magnetic resonance imaging devices. For example, when positioned in a predetermined relative position relative to a heat shield, the suspension rod can automatically prevent thermal radiation from passing through holes or passages in the heat shield. Thus, the separate step or process of sealing the passages in the heat shield can be advantageously eliminated.

[0023] Furthermore, the suspension rod of the present invention allows for mechanical decoupling of a cryogenic device's cryogenic cooling components from a thermal shield. In particular, the suspension rod of the present invention, including a collar, can advantageously allow for relative movement between the suspension rod and the thermal shield while still preventing thermal radiation from passing through a gap between the suspension rod and the thermal shield.

[0024] The suspension rod of the present invention can not only advantageously reduce the manufacturing cost of the cryogenic device, but also reduce the heat load on the cryogenic cooling components of the cryogenic device.

[0025] According to an embodiment of the suspension rod according to the invention, the collar consists of a flexible material and comprises the shape of a cone.

[0026] The flexible material may be a material that can be manually deformed. Preferably, the collar is composed of an MLI blanket or a single polymer sheet metallized on both sides. For example, the collar may include or consist of a metallized polymer sheet, particularly BoPET (biaxially oriented polyethylene terephthalate) with a thickness of 6 μm to 12 μm. The polymer sheet may include an aluminum film with a thickness of 20 nm to 100 nm on each side.

[0027] The collar may include a tapered section. In particular, the collar may taper toward the second end of the suspension rod. For example, a first diameter of the collar section closer to the first end of the suspension rod may exceed a second diameter of the collar section closer to the second end of the suspension rod. The collar may be shaped as a cone, a frustum, a hemisphere, or the like.

[0028] The collar can be formed by cutting a flat, flexible material into a circular shape. A portion of the circle, such as a quarter or a third of the circle, can be cut away, and the edges of the remaining circles can be joined to form the cone. The edges can be joined using tape, particularly low-emissivity tape, adhesive, particularly epoxy resin, and / or staples. Of course, other ways of joining the edges are also conceivable.

[0029] The hanger rod of the present invention can be formed by sliding a collar onto the shaft of the hanger rod. The collar can be secured to the hanger rod via tape, cable ties, adhesives, or any suitable mechanical connection. The cone of the collar can be inverted to stabilize the collar and / or provide a reliable seal between a section of the collar's cone and the periphery of the channel in the thermal shield.

[0030] When providing the collar with a tapered shape, manufacturing tolerances of the cryogenic device can be advantageously compensated. In particular, the tapered section of the collar can advantageously compensate for misalignment or relative movement between the suspension rod and the heat shield.

[0031] According to another embodiment of the suspension rod according to the invention, the collar comprises a rigid or semi-rigid material and comprises a disc shape.

[0032] The rigid material can be any material capable of retaining a predetermined shape when subjected to moderate force, particularly manual force. The rigid material can include or consist of plastic, composite materials, metal, etc. Preferably, the disc-shaped collar is formed from sheet metal, particularly aluminum. However, the collar can also include a supporting element made from plastic, metal, or a composite material. According to the above embodiment, the supporting element can be encased in a thermally insulating material, particularly a low-emissivity material. For example, the supporting element can be encased in an MLI blanket.

[0033] It is also conceivable that the collar comprises a semi-rigid material. A semi-rigid material may be any material that is capable of reversibly deforming upon application of a moderate force. Preferably, the semi-rigid material is configured to return to its original shape after the applied force is withdrawn. The collar may comprise a supporting element made of thin metal, plastic or composite material. According to the above embodiment, the supporting element may be wrapped in an insulating material, in particular an MLI blanket. For example, the semi-rigid material of the collar may comprise or consist of a metallized polymer sheet, in particular a BoPET with a thickness of 125 μm to 500 μm. The polymer sheet may comprise an aluminum film with a thickness of 20 nm to 100 nm on each side.

[0034] The collar can be configured to cover or block the passage in the heat shield. Preferably, the collar has a diameter that exceeds the diameter of the passage in the heat shield. In one embodiment, the collar is arranged between the first end and the second end of the hanger rod such that when the hanger rod is routed through the passage in the heat shield, the collar, in particular a circumferential section of the collar, abuts the heat shield.

[0035] When providing the suspension rod of the present invention including a rigid or semi-rigid collar, a particularly strong and / or reliable seal can be provided between the suspension rod and the thermal shield. When installed in a shield assembly of the present invention according to the embodiments described below, the suspension rod of the present invention can advantageously accommodate movement of the suspension rod and construction tolerances in the local plane of the thermal shield surface.

[0036] According to one embodiment of the suspension rod of the present invention, the collar comprises a semi-rigid material. The collar comprises a first section and a second section, wherein the first section comprises a disk or cone shape, and wherein a side surface of the second section is angled relative to a side surface of the first section.

[0037] The semi-rigid material may correspond to the materials described above. The first and second sections of the collar may be formed from a single piece. According to one embodiment, the tapering of the side surface of the first section may deviate from the tapering of the side surface of the second section. For example, the second section may be bent or deformed such that the second section is angled relative to the first section. In a preferred embodiment, the first section of the collar comprises a disc-like shape, while the side surface of the second section tapers toward the first end of the suspension rod.

[0038] It is also conceivable that the first section and the second section represent separate pieces that are joined along the periphery of the first section, for example via adhesive, staples and / or (low-emissivity) tape.

[0039] A suspension rod according to the present invention, comprising a collar having at least a first section and a second section angled relative to the first section, can advantageously provide a well-defined contact area between the collar and the area surrounding the hole or channel in the heat shield. Furthermore, the collar according to the above-described embodiments, comprising the first and second sections, can advantageously provide increased flexibility compared to collars having a disc or cone shape. Thus, the suspension rod according to the present invention can advantageously allow for compensation of relative movement between the suspension rod and the heat shield.

[0040] According to an embodiment of the suspension rod according to the invention, the longitudinal axis of the collar is angled relative to the longitudinal axis of the shaft of the suspension rod.

[0041] The longitudinal axis of the collar may correspond to the cone axis or the cylinder axis of the collar. It is conceivable that the collar has a rotationally symmetrical shape. In this case, the rotationally symmetrical axis of the collar may be angled relative to the longitudinal axis of the shaft of the suspension rod.

[0042] Due not only to space requirements but also to mechanical design considerations, the hanger rod may need to be routed through the passage in the heat shield at an oblique or non-perpendicular angle relative to the heat shield. A collar made of a rigid or semi-rigid material may prevent a consistent or uninterrupted seal around the hole or passage in the heat shield. Therefore, the collar may be mechanically attached to the hanger rod such that the longitudinal axis of the collar is angled relative to the longitudinal axis of the shaft of the hanger rod.

[0043] In one embodiment, the suspension rod comprises a base element configured to orient the collar so that the longitudinal axis of the collar is angled relative to the longitudinal axis of the shaft of the suspension rod. The base element can be configured to mechanically connect the collar to the suspension rod. It is conceivable that the base element comprises a movable joint or hinge configured to modify the angle between the longitudinal axis of the collar and the longitudinal axis of the shaft of the suspension rod. However, the base element can also be configured to attach the collar to the suspension rod in a predetermined or fixed orientation. The base element can be used in combination with a collar consisting of a flexible material according to the above-described embodiment.

[0044] A collar having a longitudinal axis that is angled relative to the longitudinal axis of the shaft of the suspension rod can advantageously provide a seal against the heat shield even when the suspension rod is arranged at an oblique angle relative to the heat shield. When the collar is mounted on a base element that includes a movable joint or hinge, the base element can advantageously compensate for relative movement between the suspension rod and the heat shield, for example, not only during installation of the suspension rod but also during transportation of the cryogenic device.

[0045] In a preferred embodiment, the suspension rod of the present invention comprises a heat interceptor, wherein the heat interceptor comprises a thermal link thermally and mechanically connected to the heat interceptor. The heat interceptor is configured to thermally connect the suspension rod to a heat sink.

[0046] The thermal interceptor can represent a thermal connector, a thermal bond or a thermal joint. The thermal interceptor is thermally and mechanically connected to the suspension rod. For example, the thermal interceptor can represent a heat-conducting element attached to the suspension rod. The heat-conducting element can include a bracket, a clamp, a tube, a ring, a sleeve or the like. The heat-conducting element can be mechanically connected to the suspension rod via a force-locking connection, a form-locking connection and / or a material bond. For example, the heat-conducting element can be clamped, forged and / or pressed onto the suspension rod. It is also conceivable that the heat-conducting element is attached to the suspension rod via an adhesive, in particular a heat-conducting adhesive. Preferably, the heat-conducting element comprises or consists of a heat-conducting material, such as a metal and / or a heat-conducting composite material.

[0047] According to the present invention, the thermal interception element comprises a thermal link that is thermally and mechanically connected to the thermal interception element. It is conceivable that the thermal link forms part of the thermal interception element and / or the heat-conducting element. However, the thermal link may also represent a separate component that is thermally and mechanically connected to the thermal interception element and / or the heat-conducting element. In a preferred embodiment, the heat-conducting element and / or the thermal link may comprise or consist of a flexible thermal conductor, such as a copper braid.

[0048] The thermal interceptor is configured to thermally connect the hanger rod to a heat sink. Specifically, the thermal interceptor can be configured to absorb thermal energy from the hanger rod and transfer the thermal energy to a heat sink that is thermally and mechanically connected to the thermal link. The heat sink can be any component connected to a cooling stage of the cryocooler, such as a component of a heat shield or shield assembly according to the embodiments described below, or it can be a cooling stage of the cryocooler itself.

[0049] According to the present invention, the thermal interceptor is thermally and mechanically connected to the section of the suspension rod located between the first end and the collar. In particular, the position of the thermal interceptor can correspond to the position of the collar. Preferably, the distance between the thermal interceptor and the first end of the suspension rod exceeds the distance between the thermal interceptor and the second end of the thermal interceptor. It is contemplated that the distance between the thermal interceptor and the second end of the suspension rod is at least 10 cm, at least 15 cm, at least 20 cm, at least 30 cm, or at least 40 cm.

[0050] The thermal link is separated from the suspension rod along the section of the suspension rod between the thermal interception member and the second end. For example, the thermal link maintains a certain distance from the suspension rod along the section of the suspension rod between the thermal interception member and the second end. The thermal link can also be guided or arranged at a certain distance from the suspension rod along the section of the suspension rod between the thermal interception member and the second end. Preferably, the thermal link maintains a distance of at least 0.5 mm, at least 1 mm or at least 2 mm from the axis of the suspension rod along the section of the suspension rod between the thermal interception member and the second end. The distance between the thermal link and the axis of the suspension rod can vary along the section of the suspension rod between the thermal interception member and the second end. According to one embodiment, contact between the thermal link and the axis of the suspension rod along the section of the suspension rod between the thermal interception member and the second end is avoided. In a preferred embodiment, a thermal insulation material is provided between the thermal link and the axis of the suspension rod. The insulating material may be configured to space or separate the thermal link from the hanger rod, but may also maintain a distance between the thermal link and the hanger rod.

[0051] In a preferred embodiment of the suspension rod of the present invention, the thermal link comprises a flexible thermal conductor. The flexible thermal conductor is capable of plastically or elastically deforming. In particular, the flexible thermal conductor can be deformed manually. It is conceivable that the flexible thermal conductor is configured to bend and / or deform to allow the suspension rod to be installed in the shielding assembly of the present invention. In particular, when the thermal link is mechanically connected to a cold source, such as a thermal shield, the flexible thermal conductor can allow obstacles or components of other supporting structures of the shielding assembly and / or the cryogenic device to be bypassed. It is also conceivable that the flexible thermal conductor is configured to be arranged around a bend or corner, preferably around a bend or corner when the suspension rod is attached to the main magnet (or the supporting structure supporting the main magnet) and the external vacuum chamber of a magnetic resonance device according to the following embodiments.

[0052] According to one embodiment of the suspension rod of the present invention, the flexible thermal conductor consists of a flexible metal fabric, such as a metal braid, a metal mesh or a metal weaving. Preferably, the flexible thermal conductor consists of a copper braid.

[0053] A thermal link comprising a flexible thermal conductor advantageously allows for thermal connection of a suspension rod to a heat sink that is spatially separated or spaced apart from the heat interceptor. Furthermore, the flexible thermal conductor can be guided or routed around obstacles, such as corners or components of the support structure of the shield assembly and / or cryogenic device. Thus, thermal connection of a single suspension rod to a heat sink can be advantageously facilitated in complex three-dimensional arrangements of the shield assembly.

[0054] The collar can surround the hanger bar and the thermal link along a section of the hanger bar between the thermal interception member and the second end of the hanger bar. Preferably, the collar is mechanically connected to the thermal interception member and / or the thermal link. In particular, the thermal interception member can be configured to provide mechanical support to the collar. For example, the collar can be adhered, glued and / or welded to the thermal interception member and / or the thermal link. Preferably, the collar is attached to the hanger bar and / or the thermal interception member so as to prevent thermal radiation from passing through the interface area between the collar and the thermal interception member and / or the thermal link.

[0055] The shield assembly of the present invention comprises a suspension rod according to the above-described embodiment, a heat shield and an outer vacuum chamber.

[0056] The thermal shield can be configured to reduce the transfer of thermal energy to the cryogenic cooling components of a cryogenic device, in particular, the main magnet of a magnetic resonance device. The transfer of thermal energy can be characterized not only by heat transfer mechanisms such as thermal radiation and thermal conduction, but also by thermal convection. The thermal shield can be configured to circumferentially surround the main magnet of the magnetic resonance device. For example, the thermal shield can form a vessel configured to enclose the main magnet. In a preferred embodiment, the thermal shield includes an outer wall, an inner wall, and an annular end wall connecting the outer wall and the inner wall. In particular, the thermal shield can form a double-walled hollow cylindrical body, which is configured to enclose the main magnet between the outer wall, the inner wall, and the annular end wall. The cylindrical axis of the thermal shield can be parallel to or correspond to the rotational symmetry axis defined by the solenoid coil of the main magnet.

[0057] The heat shield may be an intermediate heat shield. For example, the heat shield may be maintained at a temperature level between 4 K and 60 K. It is conceivable that the heat shield is configured to prevent thermal energy, in particular thermal radiation, from entering an area enclosed by the heat shield (e.g., an area enclosed between an outer wall and an inner wall of the heat shield).

[0058] The heat shield can include or be composed of a coated or galvanized plastic or polymer. For example, the heat shield can be composed of an aluminized plastic, such as polyethylene terephthalate (PET), or other polymer. In certain embodiments, the plastic or polymer can be coated, plated, or laminated with a thermally conductive metal, such as gold, silver, aluminum, copper, or platinum. Preferably, the heat shield has a low emissivity, for example, less than 0.1 or less than 0.05.

[0059] In a preferred embodiment, the heat shield corresponds to an inner heat shield enclosed by an outer heat shield or another heat shield.

[0060] The outer vacuum chamber can form a vessel that is substantially impermeable to fluids such as liquid or gaseous refrigerants. The vacuum chamber can be configured to maintain a vacuum within an interior volume enclosed by the vacuum chamber. Preferably, the outer vacuum chamber encloses cryogenically cooled components of the magnetic resonance apparatus. For example, the outer vacuum chamber encloses the refrigerant vessel, the thermal shield, another thermal shield, and the main magnet.

[0061] According to one embodiment, the outer vacuum chamber includes an outer shell, an inner shell, and an annular end wall connecting the outer shell and the inner shell. The outer vacuum chamber may form a double-walled hollow cylindrical body configured to enclose the main magnet and the thermal shield between the outer shell, the inner shell, and the annular end wall. The cylindrical axis of the outer vacuum chamber may be parallel to or correspond to the rotational symmetry axis defined by the solenoid coil of the main magnet. The inner shell of the outer vacuum chamber may correspond to the patient bore of the magnetic resonance apparatus.

[0062] The main magnet of the magnetic resonance apparatus may include one or more electromagnets or superconducting magnets or be composed of one or more electromagnets or superconducting magnets. In particular, the main magnet may include one or more solenoids or cylindrical superconducting magnets or superconducting coils or be composed of one or more solenoids or cylindrical superconducting magnets or superconducting coils. The main magnet may include a dedicated support structure that is configured to carry the main magnet and / or provide support for the main magnet. Therefore, the term main magnet as used herein may include not only one or more solenoid superconducting coils, but also a dedicated support structure.

[0063] According to the invention, the second end of the suspension rod is mechanically connected to the external vacuum chamber.

[0064] In a preferred embodiment, the suspension rods are configured to provide a mechanical connection between the external vacuum chamber and the main magnet of the magnetic resonance apparatus. The external vacuum chamber can be configured to provide mechanical support for the suspension rods and the main magnet. The external vacuum chamber can also be configured to provide mechanical support for the thermal shield and / or another thermal shield. For example, the thermal shield and / or another thermal shield can be carried or suspended by the external vacuum chamber.

[0065] As described above, the first end and / or the second end of the suspension rod may include an anchor or a collar. The anchor or collar at the first end of the suspension rod may be configured to mechanically engage with the main magnet of the magnetic resonance device. Similarly, the anchor or collar at the second end of the suspension rod may be configured to mechanically engage with the external vacuum chamber. Therefore, when the suspension rod is mechanically connected to the main magnet and the external vacuum chamber, the suspension rod can remain tensioned. The suspension rod can be mechanically connected to the main magnet and the external vacuum chamber via any suitable mechanical connection. For example, the suspension rod can be screwed, clamped and / or bolted to the main magnet (or a supporting structure that supports the main magnet). It is also conceivable that the suspension rod is mechanically connected to the external vacuum chamber and / or the main magnet via a hook.

[0066] According to the present invention, a suspension rod is routed through a channel in the thermal shield. A channel in the thermal shield can refer to a hole, aperture, slot, or cavity extending through the material or wall of the thermal shield. The suspension rod can be routed through the channel in the thermal shield to provide a mechanical connection between the main magnet and the external vacuum chamber.

[0067] The collar is configured to engage the heat shield and cover a gap between the heat shield and the hanger rod.

[0068] For example, the collar can cover and / or block a passage in the heat shield. It is conceivable that a portion or section of the collar extends through the passage in the heat shield. In particular, the collar can be configured to block the gap between the suspension rod and the heat shield. According to one embodiment, the collar is configured to abut the heat shield and thereby prevent thermal radiation from passing through the passage in the heat shield.

[0069] In a preferred embodiment, the collar comprises a low-emissivity material, such as MLI. The MLI can be configured to block or deflect thermal radiation. When installed in the shield assembly of the present invention, the suspension rod comprising the collar made of MLI can support the establishment of a stable thermal gradient between the thermal shield and the outer vacuum chamber surrounding the thermal shield.

[0070] As described above, the collar can include a tapered section. According to one embodiment, the tapered section has a first diameter that is smaller than the diameter of the passage in the other heat shield, and a second diameter that exceeds the diameter of the passage in the other heat shield. Thus, the collar can form a plug configured to block or obstruct the passage in the heat shield when the hanger rod is installed in the shield assembly in a desired relative position relative to the heat shield.

[0071] The collar may also be shaped as a disk. In this case, the collar may be configured to rest against the heat shield, thereby blocking or covering any potential gap between the channel in the other heat shield and the hanger rod.

[0072] In a preferred embodiment, the position of the collar along the suspension rod may substantially correspond to the position of the heat shield along the suspension rod.

[0073] The shield assembly of the present invention has the advantages of the suspension rod of the present invention according to the above-described embodiment. In particular, the shield assembly of the present invention can reduce or offset the limitations, in particular geometric limitations, associated with sealing the gap between the suspension rod and the heat shield, especially in the presence of at least one other heat shield.

[0074] When providing a shield assembly including a suspension rod with a collar according to the present invention, the amount of heat radiation passing through the gap or interface region between the suspension rod and the thermal shield can be reduced or minimized. Consequently, the cooling capacity required to maintain the main magnet at superconducting temperatures can be advantageously reduced. Furthermore, the shield assembly according to the present invention not only advantageously allows for relative movement between the suspension rod and the thermal shield without compromising sealing effectiveness, but also compensates for structural tolerances of the shield assembly.

[0075] According to a preferred embodiment, the shield assembly according to the invention comprises a further heat shield.

[0076] The further heat shield can form a vessel comprising an outer wall, an inner wall, and an annular end wall connecting the outer wall and the inner wall. In particular, the further heat shield can form a double-walled hollow cylindrical body configured to enclose the heat shield between the outer wall, the inner wall, and the annular end wall of the further heat shield. The longitudinal axis or barrel axis of the further heat shield can be parallel to or correspond to an axis of rotational symmetry defined by the heat shield and / or defined by the solenoid coil of the main magnet enclosed by the further heat shield.

[0077] Preferably, the further heat shield comprises or is composed of a material having high electrical and / or thermal conductivity. For example, the further heat shield may be composed of copper or aluminum, in particular a copper alloy or an aluminum alloy. The further heat shield may also comprise gold, platinum, silver, or another material having high thermal conductivity. In one embodiment, the further heat shield is coated or galvanized with gold, platinum, or another metal having high thermal conductivity.

[0078] According to the present invention, the suspension rod is routed through a channel in the other heat shield. Preferably, the suspension rod extends through the channel in the heat shield and the channel in the other heat shield. In particular, the suspension rod can extend through the channels in the heat shield and the other heat shield to provide a mechanical connection between the external vacuum chamber and the main magnet of the magnetic resonance apparatus.

[0079] In a preferred embodiment, the further heat shield corresponds to the main heat shield or the 50K shield of the magnetic resonance device.

[0080] In another embodiment of the shield assembly of the present invention, the thermal link is thermally and mechanically connected to another thermal shield. For example, the thermal interceptor of the suspension rod can be mechanically and thermally connected to another thermal shield via a copper braid.

[0081] The other heat shield includes a thermal insulation member configured to cover a gap between the other heat shield and the hanger rod.

[0082] For example, another thermal shield can be wrapped in an MLI blanket assembly, the MLI blanket assembly being configured to provide thermal insulation relative to an area surrounding the other thermal shield. Preferably, at least one MLI patch of the MLI blanket assembly can abut against a hanger rod to cover a gap between the hanger rod and the MLI blanket assembly. The at least one MLI patch can be adhered to the MLI blanket assembly.

[0083] According to one embodiment, the heat intercepting member of the hanger rod is mechanically and thermally connected to the other heat shield via a thermal link. Preferably, the thermal link is configured to bridge the distance between the heat intercepting member and the other heat shield. Thus, the thermal link can extend through a passage in the heat shield. In particular, the thermal link can provide a thermal and mechanical connection between the heat intercepting member and the other heat shield. The heat intercepting member can be mechanically connected to a section of the hanger rod between the first end of the hanger rod and the heat shield.

[0084] In a preferred embodiment, the further heat shield is thermally connected to the cryocooler, in particular the first stage of the cryocooler.Thus, the suspension rod can be thermally connected to the cryocooler via the heat interceptor, the heat link and the further heat shield.

[0085] When providing a shield assembly including a further heat shield according to the present invention, the portion of heat radiation entering the area or volume immediately surrounding the main magnet of the magnetic resonance apparatus can be reduced or minimized, thereby advantageously reducing the cooling capacity required for cooling the main magnet.

[0086] According to one embodiment, the shield assembly of the present invention includes another heat shield, wherein the hanger rod is routed through a channel in the other heat shield, and the hanger rod includes another collar configured to engage with the other heat shield and cover a gap between the other heat shield and the hanger rod.

[0087] The further heat shield may correspond to the main heat shield or the 50K heat shield as described above.

[0088] The further collar may correspond to the embodiments of the collar described above. For example, the further collar may be mechanically connected to the suspension rod and / or to a base element mechanically connected to the suspension rod. The further collar may comprise a cone, a disk or a combination thereof.

[0089] The other collar can be arranged along the suspension rod such that the other collar contacts or abuts the other heat shield when the suspension rod is installed in the shield assembly in a desired relative position relative to the other heat shield. For example, the other collar can form a plug configured to block or obstruct a gap between the suspension rod and the other heat shield.

[0090] Providing a suspension rod comprising a collar and another collar can advantageously facilitate the process of sealing or covering channels in a plurality of thermal shields. For example, when using the suspension rod of the present invention, a plurality of channels in a plurality of thermal shields can be automatically covered when the suspension rod is mechanically connected to the main magnet and the external vacuum chamber of the magnetic resonance apparatus.

[0091] The shield assembly of the present invention includes a hanger rod, a thermal shield, and an outer vacuum chamber.

[0092] The thermal shield and the outer vacuum chamber may be constructed according to the above embodiments. It is conceivable that, according to the above embodiments, the suspension rod comprises a thermal interceptor and a thermal link. The suspension rod of the shield assembly of the present invention described below may be implemented without a collar.

[0093] The second end of the suspension rod is mechanically connected to the external vacuum chamber, and the suspension rod is routed through a channel in the thermal shield.According to the above embodiment, the suspension rod may extend through a channel in the thermal shield.

[0094] According to the invention, the heat shield comprises a cover comprising a heat insulating material, wherein the cover is mechanically attached to the heat shield such that a passage in the heat shield is blocked.The hanger rod pierces the cover to pass through the passage in the heat shield.

[0095] The thermal insulation material may correspond to the thermal insulation material described above. Preferably, the thermal insulation material comprises or consists of one or more MLI blankets. For example, the surface of the thermal shield including the channel may be wrapped in one or more MLI blankets. It is conceivable that the thermal insulation material comprises a flexible substrate that carries one or more MLI blankets.

[0096] The hanger rod can pierce the thermal insulation material where the hanger rod extends through the thermal shield. Preferably, the thermal insulation material is configured to provide a seal around the axis of the hanger rod. For example, the thermal insulation material may include an elastic material that is configured to adhere to the hanger rod that pierces the material. According to one embodiment, the hanger rod includes a taper or anchoring element positioned between the first end and the second end. The taper or anchoring element can provide an extension of the cross-sectional area of the hanger rod. In particular, the taper or anchoring element can prevent the thermal insulation material from sliding on the taper or anchoring element in a direction toward the first end of the hanger rod. The anchoring element can include a nut, a ring, a sleeve, etc. The anchoring element can be mechanically connected to the axis of the hanger rod. For example, the anchoring element can be clamped, swaged, glued or welded to the hanger rod.

[0097] Preferably, the insulating material forms a pocket or sock in the region of the channel.Thus, the insulating material can advantageously allow relative movement between the suspension rod and the heat shield without being torn or damaged.

[0098] The shield assembly of the present invention may advantageously allow for sealing of gaps between the hanger rods and the heat shield without requiring direct access to the passages in the heat shield when assembling the shield assembly.

[0099] According to an embodiment of the suspension bar according to the invention, the cover is mechanically connected to the surface of the heat shield comprising the channels.

[0100] In a preferred embodiment, the cover is mechanically connected to the radially outer surface of the heat shield or to the surface of the heat shield facing the outer vacuum chamber wall.

[0101] The cover forms a protrusion arranged above the channel in the thermal shield. For example, the cover may form a pocket or a sock arranged above the channel in the thermal shield. The pocket or sock may be configured to extend through the channel in the thermal shield. Preferably, the cover forms a pocket or a sock configured to extend through the channel in the thermal shield to a side of the thermal shield that is opposite to or opposite to the surface of the thermal shield that is mechanically connected to the cover. For example, the pocket or sock of the cover may be configured to extend through the channel in the thermal shield to a side of the thermal shield that is opposite to the outer wall of the external vacuum chamber. However, the pocket or sock may also be accommodated on the side of the thermal shield that faces the outer wall of the external vacuum chamber, or extend along the side of the thermal shield that faces the outer wall of the external vacuum chamber.

[0102] The cover can include or consist of a flexible material, particularly a flexible material with low emissivity. For example, the cover can include or consist of one or more MLI blankets, or one or more metallized or bimetallized polymer sheets, particularly BoPET sheets. Preferably, the cover consists of a BoPET sheet with a thickness of 6 to 12 μm. The BoPET sheet can include an aluminum film with a thickness of 20 to 100 nm on each side.

[0103] When the cover is formed into a bag-like or sock-like portion, the thermal insulation material can be prevented from being torn or damaged, thereby advantageously allowing relative movement between the suspension rod and the thermal shield. This also facilitates the manufacture of the shield assembly, thereby advantageously improving the reliability of sealing the gap between the suspension rod and the thermal shield.

[0104] According to one embodiment, the shield assembly of the present invention includes a fastener configured to attach a portion of the cover to the hanger rod.

[0105] For example, the fastener may comprise a tie, a cable tie and / or an anchoring element according to the above-described embodiments.

[0106] Preferably, the sock or pocket formed by the cover includes excess material, which allows the suspension rod to be mechanically connected to the cover via fasteners before the suspension rod is mechanically connected to the external vacuum chamber. For example, the shield assembly can be configured to allow at least a portion of the suspension rod to be retracted within the area surrounded by the thermal shield. The suspension rod can then be retracted from the area surrounded by the thermal shield through a passage in the thermal shield to mechanically connect the suspension rod to the external vacuum chamber.

[0107] A shield assembly including the fastener of the present invention can advantageously allow significant relative movement between the hanger rod and the thermal shield.Thus, the process of installing the hanger rod into the shield assembly of the present invention can be advantageously facilitated.

[0108] The magnetic resonance apparatus of the present invention is configured to acquire magnetic resonance data from a subject positioned within an imaging region of the magnetic resonance apparatus.

[0109] Preferably, the magnetic resonance apparatus is configured to acquire magnetic resonance image data, in particular diagnostic magnetic resonance image information, from an object positioned within the imaging region. The object may be a patient, in particular a human or an animal.

[0110] Preferably, the magnetic resonance apparatus of the present invention is a closed-bore scanner. The closed-bore scanner may include a generally cylindrical bore that circumferentially encloses an imaging region. The main magnet of the closed-bore scanner may include one or more solenoid coils that circumferentially surround the imaging region along the axial direction or rotational symmetry axis of the cylindrical bore. The one or more solenoid coils may include wire having negligible resistance at (or below) superconducting temperatures. The direction of the main magnetic field provided by the main magnet may be substantially parallel to the direction in which the object approaches the imaging region and / or the axial direction of the cylindrical bore.

[0111] According to the present invention, a magnetic resonance apparatus includes the shielding assembly according to the above-described embodiment.

[0112] The magnetic resonance apparatus may include at least one cryocooler. The at least one cryocooler may be configured to cool components of the magnetic resonance apparatus. For example, the at least one cryocooler may be configured to cool a main magnet, a shield assembly, a heat shield, another heat shield, a cryogen vessel, a support structure, etc.

[0113] The at least one cryogenic cooler may be configured to provide a temperature close to or lower than the superconducting temperature of the superconducting material of the main magnet. For example, the superconducting temperature of the main magnet may be in the range of 3K to 100K, preferably in the range of 3K to 6K, 30K to 60K, or 60K to 90K. The at least one cryogenic cooler may be implemented as a pulse tube refrigerator, a Gifford-McMahon refrigerator, a Stirling refrigerator, a Joule-Thomson refrigerator, or the like.

[0114] In a preferred embodiment, at least one cryogenic cooler is thermally and mechanically connected to the main magnet and the further thermal shield. The at least one cryogenic cooler can be configured to maintain the main magnet and the further thermal shield at different temperature levels. For example, the at least one cryogenic cooler can include at least a first cooling stage and a second cooling stage. The first cooling stage can be thermally and mechanically connected to the shield assembly. The second cooling stage can be thermally and mechanically connected to the main magnet. Preferably, the temperature level of the first cooling stage exceeds the temperature level of the second cooling stage. For example, the first cooling stage can be configured to provide a temperature in the range of 30K to 180K, preferably in the range of 40K to 60K, 60K to 100K or 100K to 180K. The second cooling stage can be configured to provide a temperature level close to the superconducting temperature of the main magnet.

[0115] The magnetic resonance apparatus of the present invention can represent a "dry" system, containing minimal or no refrigerant. For example, the magnetic resonance apparatus of the present invention can include one or more small refrigerant vessels thermally connected to the main magnet via a solid thermal conductor. The small refrigerant vessels can hold a refrigerant volume of less than 10 liters, less than 5 liters, or less than 1 liter. In one embodiment of the magnetic resonance apparatus of the present invention, the refrigerant vessels are omitted. Thus, the main magnet can be cooled entirely by thermal conduction.

[0116] The cryogen vessel may be configured to store or preserve a fluid, in particular a cryogen, at a predetermined temperature level. Preferably, the fluid or cryogen exhibits a low boiling point, such as argon, nitrogen, neon, helium, etc. The predetermined temperature level may substantially correspond to the superconducting temperature of the main magnet.

[0117] It is conceivable that components of the magnetic resonance device, such as the main magnet, the heat shield, the further heat shield, one or more suspension rods and / or the cryogen vessel, are thermally connected to at least one cryocooler, preferably via solid thermal conductors, convection circuits and / or heat pipes.

[0118] As described above, the shielding assembly can be configured to reduce the transfer of thermal energy to the main magnet. Preferably, the thermal shield and / or another thermal shield is configured to prevent thermal radiation from reaching the main magnet. For example, the outer wall of the thermal shield can be configured to block or deflect incident thermal radiation from the direction of the ambient environment, while the inner wall of the thermal shield can be configured to block or deflect incident thermal radiation from the direction of the patient bore of the magnetic resonance device. The surface of the thermal radiation shield that is directed away from the main magnet can be encased in an MLI and / or include a cover according to the above-described embodiments. The magnetic resonance device can include another thermal shield having an outer wall and an inner wall, which is configured to block or deflect incident thermal radiation from the ambient environment and the patient bore in a similar manner.

[0119] In a preferred embodiment, the main magnet is suspended from the outer housing of the vacuum chamber via a plurality of suspension rods.

[0120] The magnetic resonance apparatus of the present invention enjoys the advantages of the suspension rod of the present invention and the shielding assembly of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0121] Further advantages and details of the present invention can be seen from the following description of the embodiments and the accompanying drawings. In the drawings:

[0122] Figure 1 A schematic diagram showing an embodiment of a magnetic resonance apparatus according to the present invention is shown,

[0123] Figure 2 A schematic diagram showing an embodiment of a magnetic resonance apparatus according to the present invention is shown,

[0124] Figure 3a 、 Figure 3b A schematic diagram showing an embodiment of a suspension rod of the present invention,

[0125] Figure 4a 、 Figure 4b A schematic diagram showing an embodiment of a shielding assembly of the present invention,

[0126] Figure 5a 、 Figure 5b A schematic diagram showing an embodiment of a shielding assembly of the present invention,

[0127] Figure 6a 、 Figure 6b A schematic diagram showing an embodiment of a shielding assembly of the present invention,

[0128] Figure 7 A schematic diagram showing an embodiment of a shielding assembly of the present invention,

[0129] Figure 8a 、 Figure 8b A schematic diagram showing an embodiment of a shielding assembly of the present invention,

[0130] Figure 9a 、 Figure 9b A schematic diagram illustrating an embodiment of a shielding assembly of the present invention is shown. DETAILED DESCRIPTION

[0131] Figure 1 An embodiment of a magnetic resonance apparatus 11 according to the present invention is shown. In the illustrated example, the magnetic resonance apparatus 11 includes a static magnetic field magnet 17 (or main magnet) configured to provide a uniform static magnetic field 18 (B0 field) including an isocenter 38. The static magnetic field 18 permeates a cylindrical imaging region 36 configured to receive an imaging object, such as a patient 15. The imaging region 36 can substantially correspond to the volume of a patient bore configured to accommodate the patient 15 during a magnetic resonance measurement. The imaging region 36 is surrounded circumferentially by a field generating unit 30.

[0132] In the depicted example, the magnetic resonance apparatus 11 includes a patient support 16 that is configured to transport a patient 15 into an imaging region 36. The patient support 16 can transport a diagnostically relevant body region of the patient 15 into an imaging volume defined by an isocenter 38 of the magnetic resonance apparatus 11. Typically, the field generating unit 30 of the magnetic resonance apparatus 11 is concealed in a housing 41.

[0133] The magnetic resonance apparatus 11 may include a gradient system 19 configured to provide magnetic gradient fields for spatially encoding magnetic resonance signals acquired during a magnetic resonance measurement. The gradient system 19 is activated or controlled by a gradient controller 28 via appropriate current signals. It is contemplated that the gradient system 19 includes one or more gradient coils for generating magnetic gradient fields in different, preferably orthogonally oriented spatial directions.

[0134] The magnetic resonance imaging device 11 may include an integrated radio frequency antenna 20 (i.e., a body coil). The radio frequency antenna 20 is operated via a radio frequency controller 29, which controls the radio frequency antenna 20 to generate a high-frequency magnetic field and transmit radio frequency excitation pulses into the imaging region 36. The magnetic resonance imaging device 11 may also include a local coil 21 positioned on or near a diagnostically relevant region of the patient 15. The local coil 21 may be configured to transmit radio frequency excitation pulses into the patient 15 and / or receive magnetic resonance signals from the patient 15. It is contemplated that the local coil 21 is controlled via the radio frequency controller 29.

[0135] The magnetic resonance apparatus 11 also includes a control unit 23 configured to control the magnetic resonance apparatus 11. The control unit 23 may include a processing unit 24 configured to process magnetic resonance signals and reconstruct magnetic resonance images. The processing unit 24 may also be configured to process input from a user of the magnetic resonance apparatus 11 and / or provide output to the user. To this end, the processing unit 24 and / or the control unit 23 may be connected to a display unit 25 and an input unit 26 via suitable signal connections. To prepare for a magnetic resonance measurement, preparation information, such as imaging parameters or patient information, may be provided to the user via the display unit 25. The input unit 26 may be configured to receive information and / or imaging parameters from the user.

[0136] The magnetic resonance imaging apparatus 11 may include other components generally provided in a magnetic resonance imaging apparatus. The general operation of the magnetic resonance imaging apparatus 11 is known to those skilled in the art, and thus a more detailed description is omitted.

[0137] Figure 2 Shown Figure 1 , a cross-sectional view of the magnetic resonance apparatus 11 of the present invention is shown in FIG. In the depicted example, the outer vacuum chamber 42 provides an outer enclosure for components of the field generating unit 30, such as the shield assembly 31 and the main magnet 17. In particular, the outer vacuum chamber 42 separates the surrounding environment 70 from the vacuum region 71 enclosed by the outer vacuum chamber 40. The outer vacuum chamber 42 may be a double-walled hollow cylindrical body comprising an outer shell and an inner shell connected via an annular end wall (not shown). The inner shell of the outer vacuum chamber 42 may correspond to the patient aperture 37 that circumferentially encloses the imaging region 36.

[0138] exist Figure 2 In the example shown in FIG, the shield assembly 31 includes an inner heat shield 33 and an outer heat shield 34. Both the inner heat shield 33 and the outer heat shield 34 can be formed as a double-walled hollow cylindrical body with an annular end wall (not shown) according to the above-mentioned embodiment. The inner heat shield 33 and the main magnet 17 can be enclosed between the outer wall and the inner wall of the outer heat shield 34. The main magnet 17 can be enclosed between the outer wall and the inner wall of the inner heat shield 33.

[0139] The shield assembly 31 includes one or more suspension rods 12 that are mechanically connected to the outer vacuum chamber 42 and the main magnet 17. The suspension rods 12 extend through channels 60a in the inner thermal shield 33 and channels 60b in the outer thermal shield 34 to provide a mechanical connection between the outer vacuum chamber 42 and the main magnet 17.

[0140] The magnetic resonance apparatus 11 further includes a cryocooler 32 mounted on the outer vacuum chamber 42. The cryocooler 32 may be configured to cool not only the main magnet 17, the inner thermal shield 33, and the outer thermal shield 34, but also other components of the field generating unit 30, such as a cryogen vessel (not shown).

[0141] The cryocooler 32 typically includes a compressor (not shown) that supplies pressurized gas to the cryocooler 32. According to the embodiment shown in Figure 3, the cryocooler 32 includes a cooling head including one or more cooling stages 32a and 32b. Preferably, the first cooling stage 32a of the cooling head is thermally connected to the external thermal shield 34, while the second cooling stage 32b of the cooling head is thermally connected to the main magnet 17. In a preferred embodiment, the first cooling stage 32a provides a temperature level of approximately 50K, while the second cooling stage 32b provides a temperature level of approximately 4K. In a "dry" magnetic resonance apparatus, the cooling stages 32a and 32b of the cryocooler 32 can be mechanically connected to components of the field generating unit 30 via solid thermal conductors 39a and 39b. It is also conceivable that the magnetic resonance imaging apparatus 11 includes one or more small refrigerant vessels (not shown) that are thermally connected to the cryocooler 32 via solid thermal conductors, heat pipes and / or convection circuits. One or more cryogen vessels may be thermally connected to the main magnet 17 via a heat exchanger and / or solid thermal conductors 39 .

[0142] During operation of the magnetic resonance apparatus 11 , the outer thermal shield 34 may be maintained at an intermediate temperature, for example between 40 K and 60 K, preferably approximately 50 K. The outer thermal shield 33 may include or consist of an electrically conductive material configured to protect the main magnet 17 from blackbody radiation emitted in the region 72 .

[0143] Figure 3a and Figure 3b An embodiment of the suspension rod 12 of the present invention is shown. Figure 3a In the example depicted in FIG, the hanger rod 12 includes a collar 51 having a conical shape. A section of the shaft of the hanger rod 12 is wrapped in a low-emissivity thermal insulation material 54, preferably one or more MLI blankets. The hanger rod 12 includes a threaded shaft and a nut 64, which serves as an anchoring element to prevent the collar 51 from sliding along the shaft of the hanger rod 12. Preferably, the collar 51 is directed toward the second end 55b of the hanger rod 12 (see FIG. Figure 2 ) is tapered, the second end 55b being mechanically connected to the outer vacuum chamber 42. In other examples, the anchoring element can be glued, clamped, crimped, swaged and / or welded to the hanger rod 12.

[0144] exist Figure 3b In the example depicted in FIG, the collar 51 is mechanically connected to the thermal interceptor 50 via fasteners 62, such as cable ties or cable ties. Preferably, the thermal interceptor 50 is clamped, swaged, glued, and / or welded to the shaft of the hanger rod 12. The thermal interceptor provides a thermal and mechanical connection between the shaft of the hanger rod 12 and the thermal link 52. In the example depicted, the thermal link 52 is arranged between the thermal interceptor 50 and the collar 51. The cone of the collar 51 is inverted according to the above embodiment to improve the stability of the collar 51.

[0145] Figure 4a and Figure 4b A schematic diagram of an embodiment of the shielding assembly 31 of the invention is shown. In the depicted example, the suspension rod 12 comprises a collar 51 having a cone shape according to FIG. Figure 4a An embodiment is depicted in which the hanger bar 12 is housed within an area 71 surrounded by the inner heat shield 34. The hanger bar 12 includes a thermal link 52 that is routed through the channel 60a and is thermally and mechanically connected to the outer heat shield 34. Preferably, the thermal link 52 is constructed of copper braid to allow relative movement between the hanger bar 12 and the outer heat shield 34, such as when the hanger bar 12 is retracted from the area 71 (see FIG. Figure 4b ) and mechanically connected to the external vacuum chamber 42 (see Figure 2 ), relative movement between the suspension rod 12 and the external heat shield 34 is allowed.

[0146] according to Figure 4a, the suspension rod 12 is arranged far enough in the region 71 so that the outer thermal shield 34 and the outer vacuum chamber 42 can be slid or placed over the inner thermal shield 33. Once the inner thermal shield 33, the outer thermal shield 34, and the outer vacuum chamber 42 are arranged in their intended final positions, the suspension rod 12 can be pulled upward from the region 71 and attached to the outer vacuum chamber 42.

[0147] The process of pulling the suspension rod 12 upward causes the collar 51 to move into the channel 60a in the inner heat shield 33 to block it (see Figure 4b The flexible material of the collar 51 not only compensates for any relative movement between the suspension rod 12 and the inner heat shield 33, but also compensates for construction tolerances of the shield assembly 31. If the inner heat shield 33 is made of a flexible material, particularly a non-self-stabilizing material, the collar 51 and the suspension rod 12 can provide mechanical support for the inner heat shield 33. As a result, sagging of sections of the inner heat shield 33 can be advantageously reduced or avoided.

[0148] To seal the channel 60b, the outer thermal shield 34 can be wrapped in an assembly of MLI blankets 44. Preferably, at least one MLI patch of the assembly of MLI blankets 44 abuts against the insulation 54 (see FIG3 ) wrapped around the hanger rod 12. The at least one MLI patch can be adhered to the assembly of MLI blankets 44.

[0149] Figure 5a and Figure 5b 1 shows another embodiment of the shield assembly 31 of the present invention. In the depicted embodiment, the collar 51 of the hanger rod 12 comprises a disc-like shape. The collar 51 is configured to abut against the inner surface of the inner heat shield 33 and seal the gap between the inner heat shield 33 and the hanger rod 12. Figure 4a and Figure 4b Similar to the embodiment of the suspension rod 12 depicted in Figure 5a and Figure 5b The suspension rod 12 shown in FIG is configured to be received in the region 71 to allow the outer thermal shield 34 and the outer vacuum chamber 42 to be positioned above the inner thermal shield 33 (see FIG. Figure 5a When the suspension rod is pulled in the direction of the outer vacuum chamber 42 and mechanically connected to the outer vacuum chamber 42, the collar 51 abuts against the inner heat shield 33 and seals the channel 60a (see Figure 5b ).

[0150] The collar 51 may be connected via any suitable mechanical connection such as a nut (see Figure 3a), cable ties or the like to be fixed to the suspension rod 12. Depending on the desired angle between the suspension rod 12 and the internal heat shield 33, a base element 63 may be provided which is configured to maintain the disc-shaped collar 51 in an orientation parallel to the surface of the internal heat shield 33. The base element 63 may maintain the collar 51 in a fixed orientation relative to the internal heat shield 33. However, the base element 63 may also include a movable joint 65 which is configured to adjust the orientation or angle of the collar 51 relative to the surface of the internal heat shield 33 in a variably manner. According to one embodiment, the collar 51 is loosely mounted on the suspension rod 12, for example via the movable joint 65. Thus, as the collar 51 is pulled against the internal heat shield 33, the collar 51 may orient itself correctly.

[0151] After the thermal shields 33, 34 and the outer vacuum chamber 42 have been assembled, similar to Figure 5a and Figure 5b The suspension rod 12 of the embodiment depicted in FIG can be advantageously mounted from the surrounding environment 70. For example, the channel 60b can be larger than the channel 60a, so that the collar 51 can pass through the channel 60b and rest on the outer surface of the inner thermal shield 33 (e.g., the surface of the inner thermal shield 33 facing the outer vacuum chamber 42), thereby blocking the channel 60a. In addition, the suspension rod 12 can advantageously compensate for construction tolerances and relative movement between the suspension rod 12 and the inner thermal shield 33 in the local plane of the surface of the inner thermal shield 33 including the channel 60a.

[0152] Figure 6a and Figure 6b A representation of another embodiment of the shield assembly 31 of the present invention is shown. In the depicted embodiment, the collar 51 of the hanger rod 12 includes a first segment 51a and a second segment 51b, wherein the first segment 51a includes a disc-like shape, and wherein the second segment 51a is angled relative to the first segment 51a.

[0153] According to the above embodiment, the collar 51 can be made of a semi-rigid material. Preferably, the collar 51 starts as a flat disk that is cut radially at multiple locations around the circumference of the disk. Figure 6a and Figure 6b As depicted in FIG, the resulting sheet can be folded over to form a funnel or cone-shaped structure having a first section 51a and a second section 51b. The sheet portion of the second section 51b can at least partially overlap. Once the cone-shaped section 51b is formed, the sheet portion can compensate for movement along the axial direction of the suspension rod 12 and in the local plane of the surface of the internal thermal shield 33 including the channel 60a, while remaining relatively opaque. The process of installing the suspension rod 12 in the shield assembly 31 can correspond to that described with reference to FIG. Figure 4a 、 Figure 4b 、 Figure 5a and Figure 5b In one embodiment, Figure 6a and Figure 6b Both parts 51a and 51b of the collar 51 shown in FIG. 5 may comprise a cone shape.

[0154] exist Figure 6a In the example depicted in , the collar 51 of the hanger rod 12 is attached to the movable joint 65. However, the collar 51 can also be mounted to the hanger rod 12 in a predetermined position or orientation required to seal the channel 60a in the internal heat shield 33.

[0155] Figure 7 Schematic diagram of an embodiment of the suspension rod 12 of the present invention is shown, the suspension rod 12 comprising a first collar 51.1 and a second collar 51.2. According to the above embodiment, the collars 51.1 and 51.2 can be mechanically connected to the suspension rod 12. Preferably, the collars 51.1 and 51.2 are arranged so that when the suspension rod is pulled toward the external vacuum chamber 42 and / or mechanically connected to the external vacuum chamber 42, the first collar 51.1 seals the channel 60a and the second collar 51.2 seals the channel 60b. The process of installing the suspension rod 12 in the shielding assembly 31 can correspond to the process described with reference to FIG. Figure 4a 、 Figure 4b 、 Figure 5a and Figure 5b Describe the process.

[0156] Figure 8a and Figure 8b A representation of an alternative embodiment of the shield assembly 31 of the present invention is shown, wherein the internal heat shield 33 includes a cover 61 having an insulating material, wherein the cover 61 is mechanically attached to the internal heat shield 33 such that the passage 60a in the internal heat shield 34 is blocked, and wherein the hanger rod 12 pierces the cover 61 to pass through the passage 60a in the internal heat shield 33.

[0157] Preferably, the cover 61 forms a pocket or sock at the channel 60a. In the depicted example, the cover 61 is attached to the surface of the inner thermal shield 33 that faces the outer vacuum chamber 42. The cover 61 can be mechanically connected to the inner thermal shield 33 via tape, adhesive, rivets, staples, etc. The pocket or sock of the cover 61 can include excess material to allow the pocket or sock to extend through the channel 60a. The suspension rod 12 can slide through the sock. Preferably, the cover includes or consists of a flexible, low-emissivity material according to the above-described embodiments.

[0158] like Figure 8aAs depicted in FIG, the hanger bar 18 can be configured to be received in the region 71 so that the outer thermal shield 34 and the outer vacuum chamber 42 can be placed over or slid over the inner thermal shield 33. Once the inner thermal shield 33, the outer thermal shield 34, and the outer vacuum chamber 42 are installed in their desired final positions, the hanger bar 12 can be pulled out of the region 71 (see FIG. Figure 8b ) and attached to the outer vacuum chamber 42. Figure 4a and Figure 4b As shown in FIG, the passage 60b in the outer heat shield 34 can be sealed with an assembly consisting of an MLI blanket 44. Figure 8a and Figure 8b In the embodiment depicted in , the suspension rods 12 are preferably guided through the cover 61 before the outer heat shield 34 and the outer vacuum chamber 42 are positioned over the inner heat shield 33 .

[0159] Figure 9a and Figure 9b A diagram of another embodiment of the shield assembly 31 of the present invention is shown. In the depicted embodiment, the shield assembly 31 includes a fastener 62 configured to attach a portion of the cover 61 to the hanger rod 12.

[0160] according to Figure 9a and Figure 9b In the embodiment shown in FIG, the cover 61 forming the pocket or sock includes a large amount of excess material. The pocket or sock is coupled to the hanger rod 12 via a suitable fastener 62 such as tape, cable ties, adhesive bonding or any other suitable fastening mechanism. Thus, the hanger rod 12 is prevented from sliding through the cover 61.

[0161] Preferably, the hanger rod 12 is configured to be received in the region 71 so that the outer heat shield 34 and the outer vacuum chamber 42 can be slid over or positioned above the inner heat shield 33. Figure 9a In the stowed position shown in FIG, the portion of the cover 61 forming the sock can be pulled out to its maximum length. Once the inner heat shield 33, the outer heat shield 34 and the outer vacuum chamber are installed in the desired final position (i.e. forming the sock), the outer heat shield 33 and the outer vacuum chamber can be pulled out to their maximum length. Figure 9b ), the suspension rod 12 can be pulled out of the area 71 and attached to the outer vacuum chamber 42. As a result, the sock-like portion of the cover 61 is converted into a relaxed, stowed state.

[0162] like Figure 9b As shown in FIG, the passages 60b in the outer heat shield 34 can be sealed via an assembly consisting of an MLI blanket 44. Figure 9a and Figure 9bIn the embodiment depicted in , the hanger rods 12 are preferably guided through the cover 61 and fastened to the cover 61 before the outer heat shield 34 and the outer vacuum chamber 42 are positioned over the inner heat shield 33 .

[0163] The embodiments described herein should be considered as examples. It should be understood that, if not otherwise stated, each embodiment can be expanded by features of other embodiments or combined with features of other embodiments. Figure 1 The embodiments depicted up to FIG. 9 are illustrations that are not necessarily drawn to scale.

Claims

1. A suspension rod (12) for suspending a main magnet (17) of a magnetic resonance device (11), the suspension rod (12) comprising a first end, a second end and a collar (51) configured to deflect thermal radiation, wherein: The collar (51) is mechanically connected to the suspension rod (12), and wherein the collar (51) circumferentially surrounds the suspension rod (12) along a section of the suspension rod (12) between the first end and the second end.

2. The suspension rod (12) according to claim 1, wherein The collar (51) is made of a flexible material and comprises a cone shape.

3. The suspension rod (12) according to claim 1, wherein The collar (51) comprises a rigid or semi-rigid material and comprises a disc-like shape.

4. The suspension rod (12) according to claim 1, wherein The collar comprises a semi-rigid material, wherein the collar comprises a first section (51a) and a second section (51b), wherein the first section (51a) comprises a disk or cone shape, and wherein a side surface of the second section (51b) is angled relative to a side surface of the first section (51a).

5. A suspension rod (12) according to any one of the preceding claims, wherein The longitudinal axis of the collar (51) is angled relative to the longitudinal axis of the shaft of the suspension rod (12).

6. A suspension rod (12) according to any one of the preceding claims, wherein The collar comprises a low emissivity material.

7. The suspension bar (12) according to any one of the preceding claims, comprising a thermal interception (50), said thermal interception (50) comprising a thermal link thermally and mechanically connected to said thermal interception (50), wherein The thermal interceptor (50) is configured to thermally connect the suspension rod (12) to a cold source, and wherein the thermal interceptor (50) is thermally and mechanically connected to a section of the suspension rod between the first end and the collar (51), wherein the thermal link is spaced apart from the suspension rod (12) along the section of the suspension rod (12) between the thermal interceptor (50) and the second end.

8. A shield assembly (31) comprising a suspension rod (12) according to any one of the preceding claims, a thermal shield (33) and an outer vacuum chamber (42), wherein The second end of the suspension rod (13) is mechanically connected to the external vacuum chamber (42), and wherein the suspension rod (12) is arranged through a channel (60a) in the thermal shield (33), wherein the collar (51) is configured to engage with the thermal shield (33) and cover a gap between the thermal shield (33) and the suspension rod (12).

9. The shield assembly (31) according to claim 8, comprising a further heat shield (34), wherein The suspension rod (12) is routed through a channel (60b) in another heat shield (33a), and wherein the other heat shield (34) includes a thermal insulation configured to cover a gap between the other heat shield (34) and the suspension rod (12).

10. The shield assembly (31) according to claim 8, comprising a further heat shield (33a), wherein The suspension rod (12) is arranged through a channel (60b) in the further heat shield (34), and wherein the suspension rod (12) includes a further collar (51) configured to engage with the further heat shield (34) and cover a gap between the further heat shield (34) and the suspension rod (12).

11. The shielding assembly (31) according to any one of claims 9 or 10, comprising a suspension rod (12) according to claim 7, wherein The thermal link is thermally and mechanically connected to the further thermal shield (34).

12. A shield assembly (31) comprising a suspension rod (12), a thermal shield (33) and an outer vacuum chamber (42), wherein: The second end of the suspension rod (12) is mechanically connected to the external vacuum chamber (42), and wherein the suspension rod (12) is arranged to pass through the channel (60a) in the thermal shield (33), wherein the thermal shield (33) includes a cover, and the cover includes an insulating material, wherein the cover (61) is mechanically attached to the thermal shield (33) so that the channel (60a) in the thermal shield (33) is blocked, and wherein the suspension rod (12) pierces the cover (61) to pass through the channel (60a) in the thermal shield (33).

13. The shielding assembly (31) according to claim 12, wherein: The cover is mechanically connected to a surface of the heat shield (33) comprising the channel (60a), and wherein the cover forms a protrusion arranged on the channel (60a) in the heat shield (33).

14. The shield assembly (31) of claim 13, comprising a fastener configured to attach a portion of the cover to the hanger rod (12).

15. A magnetic resonance apparatus (11) configured to acquire magnetic resonance data from a subject positioned within an imaging region of the magnetic resonance apparatus, and comprising a shielding assembly (31) according to any one of claims 8 to 14.

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