Device with body coil and gradient coil for magnetic resonance system and magnetic resonance system

Abstract

The invention relates to a device (12) for a magnetic resonance system (1) having a body coil (4) and a gradient coil (5), having a cylindrical support element (13) on which the body coil (4) is arranged, the body coil (4) and the gradient coil (5) being arranged at a distance from one another, and an intermediate space (14) extending between the body coil (4) and the gradient coil (5), at least one partial region (15) of the intermediate space (14) is evacuated. The invention further relates to a magnetic resonance system (1).

Description

Technical Field

[0001] The invention relates to a device for a magnetic resonance system with a body coil and a gradient coil. The device has a cylindrical support element, on which the body coil is arranged, wherein the body coil and the gradient coil are spaced apart from each other and an intermediate space extends between the body coil and the gradient coil. The invention also relates to a magnetic resonance system with an imaging mode device. Background Art

[0002] Today's MRI systems have gradient systems with high field strengths (mT / m) and fast switching speeds ("slew rate" SR [T / m / s]). The gradient coil currents of the gradient system flow in the strong static field of the base magnet. The resulting Lorentz forces, when the gradient coils are dynamically excited, generate mechanical vibrations of the coils, which are transmitted via different propagation paths, such as airborne sound and / or structure-borne sound, via the "body-coil", i.e. the body coil, to the patient in the examination room or the user in front of the scanner. Typical maximum values ​​for the noise in the examination room, the so-called "BORE", are approximately 100 to 120 DCL and are in the range that (without additional hearing protection) can lead to permanent hearing loss.

[0003] MRI systems have therefore long been designed to be as acoustically quiet as possible. The noise level is particularly important for a successful examination for patients who have to spend a long time in the MRI system and for whom high noise levels are perceived as negative or burdensome. One of the most important propagation paths for sound in an MRI system is the propagation of vibrations from the gradient coil (GC) into the narrow air gap between the gradient coil and the body coil and then from the support tube of the body coil into the air facing the patient. This is particularly the main propagation path.

[0004] The strong currents on the body coil lead to high radio frequency fields at certain points, in particular at the capacitors of the body coil, but also possibly between the body coil and the shielding. These can lead to flashovers, in particular spark flashovers. These flashovers "only lead to image disturbances" if they are weak, but they are usually strong and lead to burning or carbonization and thus to damage of the corresponding components. Furthermore, the excitation of the body coil can lead to vibrations, so that in addition to the transmission of vibrations from the gradient coils via airborne sound, this can also be caused by the excitation of eddy currents on the body coil conductors, which then drive the Lorentz forces and excite the support tube of the body coil itself to vibrations.

[0005] These disadvantages mainly occur when the MRI system is operated at high power. Summary of the invention

[0006] The technical problem to be solved by the present invention is to reduce electrical flashover and / or acoustic transmission between a body coil and a gradient coil of a magnetic resonance imaging system, so that a particularly acoustically optimized magnetic resonance imaging system can be provided.

[0007] The above-mentioned technical problem is solved by a device and a magnetic resonance imaging system according to the independent claims. Advantageous developments are revealed in the dependent claims.

[0008] One aspect of the invention relates to a device with a body coil and a gradient coil for a magnetic resonance system, the device having a cylindrical support element, on which the body coil is arranged, wherein the body coil and the gradient coil are arranged at a distance from one another and an intermediate space extends between the body coil and the gradient coil, wherein at least a partial region of the intermediate space is evacuated.

[0009] The device according to the invention can realize a body coil-gradient coil arrangement for a magnetic resonance system (MRI system), which can improve the acoustic properties of the magnetic resonance system in particular. By evacuating at least one partial area of ​​the intermediate space and thus having a vacuum degree, the propagation of sound in the intermediate space between the body coil and the gradient coil can be minimized or reduced. By evacuating the partial area of ​​the intermediate space, spark flashover between the gradient coil and the body coil can also be reduced, in particular prevented. The propagation of sound between the body coil and the gradient coil can be reduced by evacuating the partial area.

[0010] Therefore, when the apparatus according to the present invention is used in a magnetic resonance imaging system, the patient can be examined with minimal noise, thereby reducing or minimizing hearing damage to the patient or the operator of the magnetic resonance imaging system.

[0011] In particular, the disadvantages mentioned in the introduction can be overcome by the device according to the invention.

[0012] The body coil and the gradient coil are in particular cylindrical and therefore have a cylindrical shape. In particular, the body coil can be inserted concentrically into the interior of the gradient coil. In other words, the gradient coil surrounds the body coil. In other words, for the sake of illustration, the body coil and the gradient coil can have the shape of a tube, wherein the gradient coil has a larger diameter in order to accommodate the body coil in the interior.

[0013] The cylindrical support element, like the body coil and the gradient coil, can be a support tube for the body coil. In other words, the body coil can be arranged on the surface of the support element, so that the body coil can be wound around the support element, for example, and the support element is particularly designed to be tubular. In particular, the body coil is inserted into the gradient coil so that the outer wall of the body coil is arranged at a distance from the inner side of the gradient coil and an air gap is thus present. This is particularly the intermediate space, which is also cylindrical and particularly concentrically located between the coils when the tubular body coil is inserted into the gradient coil. When the body coil is inserted concentrically into the inner region of the gradient coil, the intermediate space exists between the body coil and the gradient coil, particularly when viewed in the circumferential direction.

[0014] In particular, at least one partial region of the intermediate space can have a vacuum in order to prevent, in particular reduce, sound propagation between the gradient coil and the body coil. It is also conceivable that the partial region is the entire intermediate space. It is therefore also conceivable that the entire intermediate space is evacuated and that the intermediate space itself is therefore a vacuum.

[0015] In particular, the proposed device provides an arrangement with a gradient coil and a body coil, referred to in English as a "Bodycoil". In this case, at least the body coil and in particular the space or the intermediate space between the support element and the gradient coil is evacuated. In particular, for example, another part of the intermediate space or the intermediate space itself can have a very low pressure compared to the ambient pressure in order to prevent sound transmission.

[0016] In one embodiment, it is further provided that the device has at least one vacuum pump unit, by means of which the partial area can be evacuated, wherein the vacuum pump unit is designed to maintain the vacuum produced in the partial area. At least a partial area or the entire intermediate space can be evacuated by means of an especially electrical, electronic or electromechanical vacuum pump unit or vacuum generating unit. Here, the vacuum pump unit can be connected to the at least one partial area or the intermediate space by a hose connection or a hard pipe connection, respectively, so that a corresponding evacuation can be performed. Here, in particular, the vacuum pump unit is designed so that it can automatically ensure that the vacuum produced in the partial area can be permanently or continuously maintained.

[0017] In one embodiment, it is provided that at least one pressure sensor is arranged in the partial area, wherein the vacuum pump unit can be controlled based on the measurement data of the pressure sensor. At least one pressure sensor or a plurality of pressure sensors can be arranged or distributed in at least one partial area or in the intermediate area itself, so that the respectively existing gas pressure can be monitored or checked. In this way, it can be determined in the simplest way and method whether a vacuum exists at least in this partial area or in other partial areas of the intermediate space. If a vacuum exists only partially or no longer, a control signal corresponding to the pressure sensor can be automatically sent to the vacuum pump unit with the aid of the measurement data so that the vacuum can be maintained again.

[0018] Additionally or alternatively, the partial area, in particular the intermediate space, may have an opening through which the vacuum pump unit can be connected to the partial area. Thus, through the opening, a corresponding hose or tube or other connecting element can be arranged from the vacuum pump unit to the partial area so that the partial area or the intermediate space can be evacuated.

[0019] For example, the vacuum pump unit can be a vacuum pump which is able to maintain a negative pressure in the local area or in the intermediate space itself by virtue of the vacuum pump being permanently operated or being controlled, switched on, switched off and / or regulated by means of a pressure sensor.

[0020] When constructing the body coil and the gradient coil, it is conceivable that they are not detachable but are mechanically flexible (i.e., the acoustic transmission can be minimal) connected to one another, with the air gap or intermediate space between them being accessible via one or more openings. For example, the vacuum generated once in a local area can be permanently maintained and can be re-evacuated, especially in the case of maintenance or malfunctions, by connecting a vacuum pump unit.

[0021] In one embodiment, it is provided that the partial region, in particular the intermediate space, is sealed by one or more sealing elements. Here, a sealing lip can be arranged, for example, as a sealing element at a suitable position or location on the partial region or the intermediate space. As a result, the vacuum generated can be maintained, in particular in the partial region or the intermediate space itself.

[0022] In one embodiment, it is provided that the surface of the outer side of the support element facing the gradient coil is coated with a special paint having electrical insulation properties at least in a region. The body coil arranged in accordance with the regulations therefore has a surface facing the inner side of the gradient coil, in particular the surface of the support element. Therefore, the surface of the support element, in particular the surface of the body coil, is coated with paint, which faces the gradient coil and is therefore spaced close to the gradient coil. In other words, the surface of the outer side of the support element can have at least a region of paint. In particular, the entire surface can be coated with a special paint. Therefore, a special paint layer can be arranged on the surface, which can have a thickness or paint layer thickness of, for example, between 0.05 mm and 2 mm. This paint can be introduced mainly on the electrically critical area on the surface of the support element. This can improve the electrical insulation effect of the support element, in particular the body coil, thereby preventing or reducing voltage flashover or spark flashover between the body coil and the gradient coil or between the body coil and other components.

[0023] Additionally or alternatively, the inner surface of the gradient coil facing the body coil can also be coated at least in regions with a special lacquer having electrically insulating properties. Thus, similar to what has been described above with respect to the body coil, the region of the gradient coil that is directly spaced from the body coil and thus faces the body coil, in particular the support element, can be additionally insulated. When the body coil is inserted into the gradient coil concentrically in accordance with the specification, the outer side of the support element approaches the inner side of the gradient coil at a distance. The special lacquer on the gradient coil and the special lacquer on the support element of the body coil can be identical or different.

[0024] By means of a specially applied lacquer, areas where high voltage drops may occur can be better isolated or insulated from one another. The arrangement is therefore primarily designed in such a way that flashovers cannot occur, in particular are minimized, on structures with high electrical fields. In other words, the specially applied lacquer can provide additional insulation.

[0025] The paint can be applied manually or in an automated painting process.

[0026] In one embodiment, it is provided that the electrical components of the body coil arranged on the support element are electrically insulated by a protective cover, and / or the electrical components of the gradient coil are electrically insulated by a protective cover. As a result, points with particularly high voltage drops can be better isolated from one another. In particular, the electrical properties of the device can thereby be improved, since flashovers between components on the body coil and gradient coil side can be prevented or reduced. The protective cover can be, for example, a protective cap, which is applied or mounted on critical locations, in particular on the electrical components. For example, the electrical components of the body coil and the gradient coil can be electrical components, such as capacitors. Thus, such a protective cover can be applied around the capacitor as an electrical component to provide better electrical insulation.

[0027] In one embodiment, it is provided that the region between the electrical connections of at least one of the electrical components of the body coil is equipped with an electrically insulating element. Thus, for example, at least one electrically insulating element, such as an electrically insulating barrier, can be installed between soldered connections or electrical connections of capacitors. Thus, sparks or other voltage flashovers can be prevented between these soldered connections, in particular electrical connections. Additionally or alternatively, the region between the electrical connections of the electrical components of a plurality of electrical components of the gradient coil can also be similarly equipped with an electrically insulating element and insulated thereby.

[0028] In one embodiment, it is provided that at least one antenna element of the body coil is at least partially enveloped by an electrically insulating protective film, in particular the protective film is designed as a shrink film. In other words, an insulating layer in the form of a film can be applied to the "Body-Coil-Antenne" or the antenna element of the body coil. In other words, viewed in the circumferential direction of the body coil, the antenna element is at least partially, optionally completely, enveloped or encapsulated by the insulating protective film. The antenna element can thus be electrically insulated accordingly well, so that electrical flashovers can also be prevented here.

[0029] Similarly, additionally or alternatively, the gradient coil antenna element can be at least partially enclosed by an electrically insulating protective covering. In this case, in particular, the protective film can also be designed as a shrink film.

[0030] The protective film with insulating effect can be realized mainly as a shrink film, so that during the winding process of the antenna element, the shrink film can be better formed onto the surface of the antenna element. Usually, the shrink film can be attached to the corresponding antenna element by large-area or local heating of the film. In this way, a high electrical insulation or insulating effect can be achieved.

[0031] In one embodiment, it is provided that a cylindrical shielding element is arranged on the inner side of the gradient coil facing the body coil. Therefore, in particular, additional electromagnetic shielding can be applied on the inner side of the gradient coil facing the outer side of the body coil or the support element to provide additional shielding between the body coil and the gradient coil. The shielding element is, for example, a radio frequency shielding device to be able to shield radio frequency fields. For example, the radio frequency shielding device can be an "RF shield". Voltage flashovers on the shielding device can be prevented by the above-mentioned optional solution or additional electrical insulation on the gradient coil side or on the gradient coil side.

[0032] In an alternative, it can be provided that the shielding element is already integrated into the inner side of the gradient coil.

[0033] Therefore, the entire radio frequency shielding device or the complete shielding element, in particular including possible shunt capacitors, is not mounted on the outermost surface of the gradient coil exposed to air, but can be directly encased or cast in the gradient coil and here in the inner side itself by means of a thin coating. Thus, a better corresponding high-frequency shielding can be provided or achieved.

[0034] In one embodiment, it is provided that an additional layer is arranged between the body coil and the gradient coil, by means of which voltage flashovers between the body coil and the gradient coil can be prevented. In particular, the additional layer can be of cylindrical design, for example having a thickness of between 0.1 mm and 5 mm. In particular, the additional layer can be a tubular element, i.e. a tube, which is inserted into the intermediate space between the gradient coil and the body coil. In particular, voltage flashovers between the body coil and the radio frequency shielding on the gradient coil can thereby be prevented.

[0035] In particular, the body coil and in particular the gradient coil can be designed in such a way that the electrical structure has a small surface in order to avoid eddy currents of the gradient field on the antenna elements of the body coil and the resulting vibrations.

[0036] In one embodiment, it is provided that the electrical conductor structure of the body coil is indirectly mechanically fixed to the support element. Since vibrations, oscillations or other negative characteristics are directly transmitted to the support element and thus to the body coil when the electrical conductor structure, such as the electrical components of the body coil, are directly connected, the electrical conductor structure should not be directly mechanically fixed to the support element in order to prevent or reduce especially sound propagation, especially vibrations. The mechanical connection of the electrical conductor structure on the body coil to the support tube or the support element is correspondingly designed as a mechanically soft connection, so that the vibrations generated by eddy currents on the antenna element or antenna of the body coil are not directly transmitted to the support tube, and thus do not excite the support tube itself to vibrate. In particular, the body coil itself can be constructed in such a way that the antenna structure associated with the antenna element of the body coil itself is less likely to vibrate due to the eddy currents of the gradient coil on the conductor or conductor structure of the body coil. For this purpose, a thin copper layer can be used relative to the conductor structure or the printed conductor. In addition, large surfaces can be avoided. Surface gaps and capacitor bridging can also be avoided. In this way, the acoustic properties of the body coil can be improved, and thus the layout and, in particular, the magnetic resonance imaging system can be improved.

[0037] In one embodiment, it is provided that the electrical conductor structure is mechanically fixed to the flexible supporting layer, and the flexible supporting layer is fixed to the supporting element. The electrical conductor structure is thus indirectly connected to the supporting element via the flexible supporting layer.

[0038] The electrical conductor structure can be designed as a copper layer or conductor track with a thickness between 5 micrometers and 100 micrometers. In particular, the electrical conductor structure can be made of copper.

[0039] The support layer can be a thin and mechanically flexible carrier. Thus, oscillations, vibrations from the conductor structure to the support element are prevented or reduced by means of the support layer.

[0040] In one embodiment, it is provided that the support layer is made of a composite material, and a plastic layer, a rubber layer or a foam layer is arranged on the side of the support layer directly connected to the support element. The support layer can thus be arranged on the support layer or the support tube in a flexible and, in particular, mechanically decoupled manner. In particular, the electrical conductor structure can thus be arranged on the support tube in a particularly vibration-minimizing and sound-minimizing manner.

[0041] For example, the support layer can be made of a non-flammable and flame-retardant composite material, such as "FR4" material. The side of the support layer that lies against the support element and can therefore be called the bottom side of the support layer, in particular opposite the conductor structure, can be made of soft plastic, foam, rubber or other easily compressible and deformable plastics, such as soft plastic, soft PVC or polyolefin.

[0042] The supporting layer can have, for example, a thickness of between 0.1 mm and 15 mm, in particular between 0.5 mm and 5 mm.

[0043] In one embodiment, it is provided that the body coil and the gradient coil are manufactured in a common manufacturing process so that they are mechanically connected to each other in an inseparable manner and form an intermediate space. Thus, the gradient coil and the body coil can be manufactured simultaneously in one manufacturing method or one process step and connected to each other accordingly. In other words, the body coil is inserted concentrically into the inner region of the gradient coil. The body coil can be connected to the gradient coil via specific mechanical connection points. In particular, the body coil can be suspended inside the gradient coil. An intermediate space or air gap is formed between the gradient coil and the body coil accordingly.

[0044] In particular, the arrangement according to the invention can be used to realize a body coil structure with a gradient coil, wherein an evacuated layer, i.e. an intermediate space, is present between the body coil and the gradient coil in order to achieve better acoustic properties for the magnetic resonance imaging system and to solve the problem of voltage flashover caused by high radio frequency voltages on the body coil.

[0045] A further aspect of the invention relates to a magnetic resonance system having an imaging mode device and a device designed according to the preceding aspect or an advantageous development thereof.

[0046] The magnetic resonance system accordingly comprises a body coil and a gradient coil, which are designed accordingly by means of the above-mentioned arrangement.

[0047] Magnetic resonance systems or magnetic resonance imaging devices are used to examine objects or patients using magnetic resonance imaging.

[0048] The present invention also includes an improved design of the magnetic resonance system according to the invention, which has the same features as those already described in conjunction with the improved design of the device according to the invention. Therefore, the corresponding improved design of the magnetic resonance system according to the invention is not described in detail.

[0049] A design solution of one aspect should be considered an advantageous design solution of the other aspect, and vice versa.

[0050] The invention even comprises combinations of features of the described embodiments.

[0051] The embodiments described below are preferred embodiments of the present invention. In these embodiments, the components are respectively individual, mutually unrelated features of the present invention, which also improve the present invention independently of each other and thus also constitute components of the present invention individually or in a different manner than the combination shown. In addition, the embodiments can also be supplemented by other already described features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The present invention will now be explained in more detail with reference to the accompanying drawings, in which:

[0053] Figure 1 A schematic diagram of a magnetic resonance system is shown;

[0054] Figure 2 Shown with Figure 1 Example cross-sectional views of the layout of body coils and gradient coils for a magnetic resonance imaging system;

[0055] Figure 3 Show Figure 1 A schematic cross-sectional view of an unfolded support tube and unfolded antenna elements of a body coil of a magnetic resonance imaging system;

[0056] Figure 4 is based on Figure 3 Another schematic cross-sectional view of a body coil, showing a possible solution for better electrical insulation of the body coil;

[0057] Figure 5 is based on Figure 2 Another schematic cross-sectional view of a body coil, showing a possible solution for better electrical insulation of the body coil;

[0058] Figure 6 A schematic diagram of a possible layer structure is shown in order to electrically insulate a body coil. DETAILED DESCRIPTION

[0059] The examples described in more detail below are preferred embodiments of the present invention.

[0060] The embodiments described below are preferred embodiments of the present invention. In these embodiments, the components are respectively individual, mutually unrelated features of the present invention, which also improve the present invention independently of each other and thus also constitute components of the present invention individually or in a different manner than the combination shown. In addition, the embodiments can also be supplemented by other already described features of the present invention.

[0061] Elements with the same function are provided with the same reference symbols in the figures.

[0062] Figure 1 A schematic diagram shows an exemplary embodiment of a (magnetic resonance imaging) system 1 (also called magnetic resonance system) according to the invention.

[0063] The magnetic resonance imaging system 1 comprises a magnet arrangement with a field magnet 3, which generates a static magnetic field for the orientation of the nuclear spins of an object 8, such as a patient, in an imaging region. The imaging region is characterized by a very uniform static magnetic field, wherein the uniformity relates in particular to the magnetic field strength or the magnetic field amplitude. The imaging region is located in a patient channel 2, which extends through the magnet unit in the longitudinal direction Z. For example, the field magnet 3 can be a superconducting magnet, which can generate a magnetic field with a magnetic flux density of up to 3 T or more. However, for lower field strengths, permanent magnets or electromagnets with normal conducting coils can also be used. A patient table or examination table 7 can be moved in the patient channel 2.

[0064] Furthermore, the magnet unit comprises at least one gradient coil 5. It is also conceivable that the gradient coil 5 is composed of an arrangement of a plurality of partial gradient coils. The gradient coil 5 is used to superimpose gradient fields, i.e. position-dependent magnetic fields, on the static magnetic field in three spatial directions in order to spatially resolve the scanned image area within the imaging area. For example, the gradient coil 5 can be designed as a coil composed of normally conducting wires, which can, for example, generate mutually orthogonal magnetic fields or magnetic field gradients within the imaging area.

[0065] The magnet unit comprises a transmitting coil arrangement, which can, for example, comprise a body coil 4 (also referred to as a whole body coil or body coil) as a transmitting antenna, which is designed to transmit high-frequency signals or excitation signals into the imaging region. The body coil 4 can therefore be understood as a radio frequency transmitting coil arrangement or part of a radio frequency transmitting coil arrangement of the magnetic resonance imaging system 1. In some embodiments, the body coil 4 can also be used to receive resonant magnetic resonance signals emitted by the object 8. In this case, the body coil 4 can also be regarded as part of a signal detection device of the magnetic resonance imaging system 1. Optionally, the signal detection device comprises a local coil 6 or a local coil, which can be arranged directly in the vicinity of the object 8, for example on the object 8 or in the patient table 7. The local coil 6 can serve as a receiving coil or a receiving antenna as an alternative or in addition to the body coil 4.

[0066] The magnetic resonance imaging system 1 further comprises a control and computing system 9. The control and computing system 9 may comprise a transceiver control unit 10, which is connected to the body coil 4, the gradient coil 5 and / or the local coil 6. Based on the detected magnetic resonance signals, the transceiver control unit 10 (which may comprise an analog-to-digital converter, ADC) may generate corresponding magnetic resonance data, especially in k-space. The transceiver control unit or the transceiver control unit 10 may also be connected to the body coil 4 and control it to generate radio frequency pulses, such as excitation pulses and / or refocusing pulses. In addition, the transceiver control unit 10 of the control and computing system 9 may also be connected to the gradient coil 5 and control it to switch the slice selection gradient, the gradient for frequency and / or phase encoding and / or the readout gradient.

[0067] For example, the magnetic resonance imaging system 1 has an imaging mode device 11. The imaging mode device 11 may have at least a magnet unit, a patient table 7 and a patient channel 2.

[0068] Figure 2 An exemplary arrangement 12 of a body coil 4 and a gradient coil 5 is shown in FIG. In particular, a sectional view is shown here.

[0069] The body coil 4 and the gradient coil 5 can have a cylindrical shape and can be designed, for example, figuratively as a "tube". For example, the diameter of the body coil 4 can be smaller than the diameter of the gradient coil 5, so that the body coil 4 and in particular the units associated with the body coil 4 can be inserted or introduced concentrically into the inner region or inner space of the gradient coil 5 or the units of the gradient coil 5. For this purpose, Figure 2 It can be seen in the exemplary sectional view in how the individual components of the device 12 have a tubular, round or cylindrical shape. In particular, the body coil 4 and the gradient coil 5 can be designed as hollow cylinders. In other words, they can be "hollow tubes".

[0070] The body coil 4 can be supported or accommodated, in particular, by a cylindrical support element 13 (also referred to as a support tube or BC support tube). Components of the body coil 4, in particular antenna elements, such as a transmitting antenna, can be arranged on the support element 13. It can also be seen from this that the body coil 4 can be inserted into the gradient coil 5 so that the body coil 4 and the gradient coil 5 are arranged at a distance from each other. Therefore, the intermediate space 14 extends between the body coil 4 and the gradient coil 5. Viewed in the circumferential direction, the intermediate space 14 extends in the Z direction of the coils 4, 5.

[0071] For example, the body coil 4 and the gradient coil 5 can be produced in a common production process, so that they are mechanically connected to one another in an inseparable manner and essentially form the intermediate space 14. The intermediate space can be an air gap.

[0072] Since the magnetic field of the magnetic resonance imaging system 1 is generated by various coils, vibrations are always generated in the magnetic resonance imaging system 1, especially due to interactions. In this case, the vibrations are mainly transmitted between the individual components of the magnetic resonance imaging system, which weaken the acoustic properties of the magnetic resonance imaging system 1. Waves can be propagated mainly between the gradient coil 5 and the body coil 4, so that sound propagation can take place here. The sound propagates through the gradient coil 5 via the body coil 4 and from there in the direction of the patient 8, so that noise pollution is generated during the examination by the magnetic resonance imaging system 1 and the hearing of the patient 8 is especially damaged. In order to minimize, especially to prevent, this sound propagation, the intermediate space 14 can be specially designed.

[0073] For this purpose, in particular at least a subregion 15 of the intermediate space 14 is evacuated (see Figure 4 ) or the entire intermediate space 14. In other words, a vacuum can be formed or provided in the partial region 15 or the intermediate space 14. This can minimize and in particular prevent the propagation of sound from the gradient coil 5 to the body coil 4.

[0074] To generate the vacuum, a vacuum pump unit 16 (see Figure 1). Thus, at least the partial area 14 can be evacuated. Since the vacuum should be maintained permanently, at least the vacuum pump unit 16 can be designed by a corresponding control unit so that the vacuum pump unit can continuously ensure the existence of vacuum and re-establish the corresponding negative pressure when the vacuum is lost or the pressure in the intermediate space 15 or the partial area 14 increases again. For this purpose, at least one or more pressure sensors 17 can be arranged or fixed mainly in the partial area 14. Therefore, the air pressure in the intermediate space 14 and especially the air pressure between the partial areas 15 of the intermediate space 14 can be monitored and it can be determined accordingly whether there is sufficient vacuum. Accordingly, the vacuum pump unit 16 can be automatically controlled according to which measurement data or measurement values ​​the pressure sensor 17 provides. Therefore, a constant vacuum can be set in the partial area 15 of the intermediate space 14. In order to enable the vacuum pump unit 16 to generate or set the corresponding vacuum, at least the partial area 15 and especially the intermediate space 14 can have an opening 18, so that the vacuum pump unit 16 can be connected to the intermediate space 14 through a hard pipe, a hose or other connecting elements, so that the corresponding vacuum can be generated.

[0075] In order to maintain the vacuum, at least parts, regions or other locations of the intermediate space 14 , in particular the partial region 15 , can be sealed by a sealing element, such as a sealing lip. For example, the sealing element can be arranged in particular in the region of the opening 18 .

[0076] In addition, in order to improve the electrical properties of the device 12 and thus the electrical properties of the magnetic resonance imaging system 1 in addition to reducing the sound propagation, a special shielding device can also be provided to shield electromagnetic fields, such as radio frequency fields. A shielding element 19 can be provided here. This can be a radio frequency shielding device. It can preferably be installed or arranged on the gradient coil 5. In particular, the shielding element 19 can be arranged on the inner side 20 of the gradient coil 5. The shielding element 19 is also designed to be cylindrical.

[0077] In particular, the inner side 20 is arranged so as to be oriented toward the gradient coil 4 .

[0078] There are various possibilities for arranging the shielding element 19 on the gradient coil 5. On the one hand, it can be arranged against the surface or the top side of the inner side 20. It is also conceivable that the shielding element 20 is a component of the inner side 20 and thus a component of the gradient coil 5 itself.

[0079] Figure 3 , a schematic cross-sectional view of the support element 13 in the circumferential direction 21 and in the z-direction is shown. In particular, a development of the support element 13 and the antenna element 22 is shown here. The antenna element 22 is, for example, a transmitting antenna of the body coil 4. Furthermore, it can be seen here that an electrical component 23, for example a capacitor, is arranged between the coil planes associated with the antenna elements of the antenna element 22.

[0080] In order to prevent electrical flashover or sparkover, in particular between the gradient coil 5 and the body coil 4, the region between the body coil 4 and the gradient coil 5 can be additionally insulated. Figure 4 A possible solution is shown in .

[0081] Figure 4 The cross-sectional and expanded views are shown in FIG. Figure 3 of the view.

[0082] In this view, since the components 22, 23 face the gradient coil 5, a flashover, for example, occurs in particular at these elements 22, 23 relative to the gradient coil 5. For this purpose, the component 23 (for example an electronic component such as a capacitor) can be electrically insulated by a protective cap 24.

[0083] For example, the protective cover 24 can be a protective cap. It can partially or completely surround the corresponding electrical components 23 so that these components 23 are electrically insulated. Figure 4 As shown, the component 23 is at least partially surrounded in an insulating manner by a corresponding protective cover 24 or, when viewed from above, is covered.

[0084] In a similar manner, it can be carried out or used for components of the gradient coil 5, such as capacitors. Not shown here. Therefore, components or elements can also be electrically insulated by protective elements or protective covers, which are oriented or arranged in the direction of the gradient coil 5 toward the body coil 4 and here again lead to flashovers.

[0085] Another possible solution for better insulating the device 12 is to insert an electrically insulating element 25, such as an insulating barrier. It can be positioned or installed mainly at the locations where the electrical connections are present relative to the component 23. In other words, these electrically insulating elements 25 can be installed in particular at the soldering points of the corresponding electrical connections of the component 23, so that no electrical flashover occurs mainly between the connections of the relative components 23. In particular, it can also be arranged in the area between these electrical connections. In a similar manner, it can also be carried out in the area of ​​the electrical connections of the electrical components of the gradient coil 5, which is not shown here.

[0086] Another point that can cause voltage flashovers, especially high voltage drops, is the antenna element 22 of the body coil 4. Flashovers can occur at this radiating element, which is especially designed as a coil winding. For this purpose, the antenna element 22 can be at least partially, especially completely, covered or encapsulated with an electrically insulating protective film 26. In order to make the protective film 25 particularly advantageously adapted to the structure or geometry of the antenna element 22, the protective film 26 can be designed as a shrink film. By inputting heat, the shrink film can be fitted to the geometry or shape of the antenna element 22. Thus, effective insulation is formed. Similarly, such a protective film can be correspondingly arranged on the antenna element of the gradient coil 5. It is also not shown.

[0087] exist Figure 5 Again shown in Figure 2 Device 12. Here, it is now explained which embodiments may exist in order to provide additional electrical insulation with respect to the device 12 and in particular for the coils 4, 5. In order to primarily electrically insulate the body coil 4 and parts of the body coil 4 from the gradient coil 5 and parts of the gradient coil 5 from each other, and primarily to prevent flashover between these two areas of the body coil 4 and the gradient coil 5, the gradient coil 5 and / or areas of the body coil 4 can be specially painted. In this case, primarily an electrically insulating paint can be used. For example, the outer side 29 of the support element 13 and therefore the surface or circumference of the body coil 4 can be coated with a special paint 27. The paint 27 has, in particular, electrically insulating properties. In particular, the outer side 29 is oriented toward the inner side 20 of the gradient coil 4. Here, the paint 27, in particular a paint layer, can partially, partially or completely cover the surface of the outer side 29. In addition, a corresponding paint 28 or a paint layer can also be provided or applied to the surface or circumference of the inner side 20 of the gradient coil 5. Thus, for example, Figure 5 As shown, the lacquer layer or lacquer 27 , 28 can surround the intermediate space 15 and thus provide corresponding electrical insulation.

[0088] Figure 6 , an exemplary sectional view is shown in which individual layers are shown with regard to the possibility of electrical insulation with respect to the body coil 4 or the supporting element 13 .

[0089] On the one hand, the lacquer 27 can be seen as the uppermost region. This in turn can surround the antenna element 22 and in particular the electrical conductor structure 32 of the body coil 4 (see Figure 3 ). In order to avoid vibration or other transmission as much as possible, it is advantageous that the conductor structure 32, such as components 22, 23, is not directly, but indirectly mechanically connected or fixed to the support element 13. For this purpose, the conductor structure 32 including all antenna elements, electronic components and other components of the body coil 4 can be installed or fixed on a flexible support layer 30. The support layer 30 can be a flexible substrate, for example, made of composite materials such as FR4 or PE. In order to mainly achieve acoustic decoupling, a plastic layer 31 can also be constructed on the side of the support layer 30 facing the support element 13, especially on the bottom side. It is also conceivable to replace the plastic layer 31 with a rubber layer, a foam layer or a soft plastic layer. Therefore, the plastic layer 31 is first directly attached to the support element 13 and therefore also on the body coil 4 and subsequently on other layer structures, as described above. Therefore, acoustic decoupling can be achieved, thereby mainly reducing the sound propagation between the body coil and the gradient coil, especially between the body coil and the patient 8 as much as possible.

[0090] Furthermore, it is also conceivable to arrange or install additional layers between the body coil 4 and the gradient coil 5 in order to further minimize voltage flashovers.

Claims

1. A device (12) for a magnetic resonance system (1) having a body coil (4) and a gradient coil (5), the device (12) having a cylindrical support element (13) on which the body coil (4) is arranged, wherein: - the body coil (4) and the gradient coil (5) are arranged spaced apart from each other, and - an intermediate space (14) extends between the body coil (4) and the gradient coil (5), It is characterized in that At least one partial region (15) of the intermediate space (14) is evacuated.

2. The device (12) according to claim 1, characterized in that A vacuum pump unit (16) is provided, by means of which the sub-region (15) can be evacuated, wherein the vacuum pump unit (16) is designed to maintain the vacuum produced in the sub-region (15).

3. The device (12) according to claim 2, characterized in that At least one pressure sensor (17) is arranged in the partial area (15), wherein the vacuum pump unit (16) can be controlled based on measurement data of the pressure sensor (17), and in particular the partial area (15) can have an opening (18) through which the vacuum pump unit (16) can be connected to the partial area (15).

4. The device (12) according to any one of the preceding claims, characterized in that The partial region (15) is sealed by a sealing element.

5. The device (12) according to any one of the preceding claims, characterized in that The surface of the outer side (29) of the support element (13) facing the gradient coil (5) is coated at least in regions with a special lacquer (27) having electrical insulating properties, and / or the surface of the inner side (20) of the gradient coil (5) facing the body coil (4) is coated at least in regions with a special lacquer (28) having electrical insulating properties.

6. The device (12) according to any one of the preceding claims, characterized in that The electrical components (23) of the body coil (4) arranged on the support element (13) are electrically insulated by the protective cover (24), and / or the electrical components of the gradient coil (5) are electrically insulated by the protective cover.

7. The device (12) according to claim 6, characterized in that The area between the electrical connections of at least one of the electrical components (23) of the body coil (4) is equipped with an electrical insulation element (25), and / or the area between the electrical connections of at least one of the electrical components of the gradient coil (5) is equipped with an electrical insulation element.

8. The device (12) according to any one of the preceding claims, characterized in that At least one antenna element (22) of a body coil (4) is at least partially enveloped by an electrically insulating protective film (26), in particular the protective film (26) is designed as a shrink film, and / or at least one antenna element of a gradient coil (5) is at least partially enveloped by an electrically insulating protective film, in particular the protective film is designed as a shrink film.

9. The device (12) according to any one of the preceding claims, characterized in that In particular, the cylindrical shielding element (19) is arranged on the inner side (20) of the gradient coil (5) facing the body coil (4), or the shielding element (19) is integrated into the inner side (20) of the gradient coil (5).

10. The device (12) according to any one of the preceding claims, characterized in that An additional layer is arranged between the body coil (4) and the gradient coil (5), and voltage flashover between the body coil (4) and the gradient coil (5) can be prevented by the additional layer.

11. The device (12) according to any one of the preceding claims, characterized in that The electrical conductor structure (32) of the body coil (4) is indirectly mechanically fastened to the support element (13).

12. The device (12) according to claim 11, characterized in that The electrical conductor structure (32) is mechanically fixed to the flexible supporting layer (30), and the flexible supporting layer (30) is fixed to the supporting element (13).

13. The device (12) according to claim 12, characterized in that The supporting layer (30) is made of a composite material, and a plastic layer (31), a rubber layer or a foam layer is arranged on the side of the supporting layer (30) directly connected to the supporting element (13).

14. The device (12) according to any one of the preceding claims, characterized in that The body coil (4) and the gradient coil (5) are manufactured in a common manufacturing process so that they are mechanically connected to each other in an inseparable manner and form an intermediate space (14).

15. A magnetic resonance system (1) comprising an imaging mode device (11) and a device (12) according to one of the preceding claims 1 to 14.

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