MRI system and receiving coil device

Abstract

To provide an MRI system reception coil device 3 for use with a main MRI scanner device.SOLUTION: A device includes: at least one primary reception coil 6 having a first size determined by a first impedance in a predetermined frequency and a cross section defined by the primary reception coil; and at least one auxiliary reception coil 7 having a second size determined by a second impedance in the predetermined frequency and a cross section defined by the auxiliary reception coil. The first impedance is lower than the second impedance, and the first size is larger than the second size.SELECTED DRAWING: Figure 8B

Description

[Technical Field]

[0001] The present invention relates to MRI systems including receive coil arrangements, and in some embodiments to receive coil arrangements for use in MRI systems and in combination systems, such as MR-Linac and PET-MR systems, where the MRI system is used in combination with another system that relies on a radiation source. [Background technology]

[0002] An MRI system typically comprises a main MRI scanner unit, a patient support or bed on which the patient lies during scanning, and, in at least some cases, separate local receive coil units (or body-part-specific receive coils) arranged for placement in the region of the particular body part to be scanned.

[0003] The main MRI scanner typically includes a main magnet, gradient coils, RF transmit coils, and receive coils, all arranged in a main unit with a bore in which the patient is placed during the scan. If present, body-part-specific receive coils are also typically placed in the bore during the scan.

[0004] As is well known, MRI (magnetic resonance imaging) systems are widely used to image subjects and may also be used in combination systems, such as MR-Linac and PET-MR systems. These combine magnetic resonance imaging with other radiation-based techniques, e.g., for therapeutic purposes, e.g., in MR-Linac, or to provide functional imaging, e.g., in PET-MR. In MRI, a magnet generates a large static magnetic field B0, an RF transmit coil generates an alternating magnetic field B1, and receive coils, whether in the main unit or dedicated body-part receive coils, are arranged to collect magnetic resonance signals (i.e., acquire magnetic resonance data). Gradient coils are used to spatially encode the B0 field, enabling tomography.

[0005] When an MRI system is operated using only the receive coils located in the main scanning unit, the resulting resolution and accuracy can in some cases be limited, which leads to the use of separate, sometimes called local, receive coils, such as the body-part-specific coils mentioned above, aimed at improving the imaging of selected locations / body parts.

[0006] However, existing body-part-specific receive coil devices have limitations, including that they may be cumbersome to position around or onto a particular body part, and / or they may provide poor imaging results for the region of interest, and / or they may be incompatible with use with other systems that use radiation sources, such as linear accelerators or positron emission tomography systems.

[0007] It would therefore be desirable to provide an MRI system receive coil arrangement that aims to address at least one of these challenges, as well as an MRI system and combination therapy and / or imaging system that includes such an MRI system receive coil arrangement. Summary of the Invention [Means for solving the problem]

[0008] According to a first aspect of the present invention, there is provided an MRI system receive coil arrangement for use with a main MRI scanning apparatus, comprising at least one primary receive coil having a first size defined by a first impedance at a predetermined frequency and a cross-section defined by the primary receive coil, and at least one auxiliary receive coil having a second size defined by a second impedance at the predetermined frequency and a cross-section defined by the auxiliary receive coil, wherein the first impedance is lower than the second impedance and the first size is greater than the second size.

[0009] This makes it possible to provide a coil system in which the primary receive coil serves to acquire signals from a relatively deep region in the subject being imaged (although still limited to the receive coil system), and the auxiliary receive coil serves to acquire signals from a region relatively close to the position of the auxiliary receive coil.

[0010] Preferably, the receive coil device comprises a plurality of auxiliary receive coils, each of which has an impedance at the predetermined frequency that is higher than a first impedance, and each of which has a size defined by a cross section defined by the respective auxiliary receive coil that is smaller than the first size.

[0011] Because these auxiliary receiving coils have a relatively high impedance, mutual coupling problems between the coils and their surroundings are reduced.

[0012] Although it is generally preferred to provide a single primary receive coil, in some embodiments the receive coil system comprises multiple primary receive coils. In such cases, the multiple primary receive coils are typically maintained in a precise positional relationship with respect to each other to minimize mutual coupling; for example, the multiple primary receive coils may be mounted on a rigid support.

[0013] The receive coil system may be a body-part dedicated receive coil system arranged for use in imaging a predetermined portion of a subject.

[0014] The receive coil device may comprise a support structure that supports at least one of the primary receive coil and the auxiliary coil.

[0015] The support structure may hold at least one of the primary receive coil and the auxiliary coil in a desired shape.

[0016] The support structure may include mounting means for holding at least one of the primary receiving coil and the auxiliary coil in a desired shape.

[0017] The mounting means may comprise a fastening means. The mounting means may comprise one or more grooves or channels.

[0018] The support structure may include at least two portions, a first of the portions supporting the primary receive coil and a second of the portions supporting the auxiliary receive coil.

[0019] At least two portions of the support structure may be movably arranged between an access configuration that allows placement of a subject between the two portions of the support structure and a functional configuration for placing the primary and auxiliary receive coils in desired positions relative to each other for use during imaging operations of the MRI equipment with which the receive coil device is used.

[0020] This may allow portions of the subject to be easily introduced into the receive coil device and / or allow the receive coil device to be easily aligned with the subject, while allowing the coil to be accurately positioned relative to the subject for imaging.

[0021] The at least one auxiliary receive coil may be more flexible than the primary receive coil.

[0022] This can aid in attaching the at least one auxiliary receive coil to the respective support part, which may facilitate using a relatively flexible support part to support the at least one auxiliary receive coil.

[0023] The support portion supporting the at least one auxiliary receive coil may be more flexible than the support portion supporting the primary receive coil.

[0024] One of the at least two support portions may include a base portion for mounting or incorporating into a patient support bed of an MRI machine.

[0025] Another of the at least two support portions may include a cover portion for attachment to the base portion. Hook and loop fastening means may be provided for fastening the cover portion to the base portion.

[0026] The base portion may support a primary receive coil. The cover portion may support an auxiliary receive coil. Preferably, there are a plurality of auxiliary receive coils, each supported by a cover portion.

[0027] The cover portion may include a substrate of plastic material that supports the at least one auxiliary receive coil, and a layer of foam material for covering the at least one auxiliary receive coil.

[0028] The cover portion may include at least one fastening means for holding the at least one auxiliary receive coil in place on the substrate. The fastening means may comprise a screw thread. The at least one auxiliary receive coil may be sewn in place.

[0029] The covering portion may include a plurality of covering portions each for covering a respective portion of interest in the subject, and at least one auxiliary receiving coil in each of the plurality of auxiliary receiving coils provided in each of the covering portions in the plurality of covering portions.

[0030] The receive coil system may be a head and / or face and / or neck and / or shoulder receive coil system.

[0031] The base portion may include at least a portion of a pillow portion for supporting the subject's head. The cover portion may be arranged for placement over the subject's head and / or face and / or neck and / or shoulders. The cover portion may have at least one of a head-covering portion, a face-covering portion, a neck-covering portion, and a shoulder-covering portion.

[0032] At least one auxiliary receiving coil in the plurality of auxiliary receiving coils may be provided in a face covering portion, and / or at least one auxiliary receiving coil in the plurality of auxiliary receiving coils may be provided in a neck covering portion, and / or at least one auxiliary receiving coil in the plurality of auxiliary receiving coils may be provided in a head covering portion, and / or at least one auxiliary receiving coil in the plurality of auxiliary receiving coils may be provided in a shoulder covering portion.

[0033] In one set of embodiments, the receive coil device comprises a plurality of auxiliary receive coils, each supported by a cover portion, the cover portion having a face covering portion and a neck covering portion, and at least one auxiliary receive coil in the plurality of auxiliary receive coils is provided in the face covering portion and / or at least one auxiliary receive coil in the plurality of auxiliary receive coils is provided in the neck covering portion.

[0034] In a subset of such embodiments, the covering portion may further include a head-covering portion, in which case at least one auxiliary receiving coil in the plurality of auxiliary receiving coils may be provided in the head-covering portion.

[0035] In another subset of such embodiments, the cover portion may further include a shoulder covering portion, in which case at least one auxiliary receive coil in the plurality of auxiliary receive coils may be provided in the shoulder covering portion.

[0036] In another set of embodiments, the receive coil device comprises a plurality of auxiliary receive coils, each supported by a cover portion, the cover portion having a face covering portion and a head covering portion, and at least one auxiliary receive coil of the plurality of auxiliary receive coils is provided in the face covering portion and / or at least one auxiliary receive coil of the plurality of auxiliary receive coils is provided in the head covering portion.

[0037] The receive coil system may be arranged so that it can be used in addition to, ie around, a fixed mask or other fixture provided for radiation therapy.

[0038] The cover portion may be arranged to have at least one radiolucent portion.

[0039] The receive coil arrangement may include an electronic component free zone corresponding to a zone through which radiation, for example a radiation therapy beam applied in use or radiation for use in forming an image, may pass in use.

[0040] The receive coil arrangement may be arranged for use in an MRI-assisted radiation therapy method or system, for example as part of an MR-Linac system.

[0041] The receive coil arrangement may be arranged for use in a radiation-based imaging method or system in conjunction with MRI, for example as part of a PET-MR system.

[0042] The receive coil system may comprise at least one tuning capacitor for tuning at least one of the respective receive coils.

[0043] At least one tuning capacitor may be located outside the electronics-free zone.

[0044] The at least one auxiliary receive coil may comprise at least one coaxial cable.

[0045] At least one auxiliary receiving coil may comprise a coaxial cable arranged in a loop, with a gap provided in the outer conductor of the coaxial cable at a position midway around the loop, and the outer conductor of a first end of the coaxial cable may be connected to the outer conductor of a second end of the coaxial cable.

[0046] Each end of one coaxial cable can be connected to a matching board.

[0047] The primary receive coil may include at least one unshielded conductor portion.

[0048] The primary receive coil may include two unshielded conductor portions arranged together in a loop, with a first end of each unshielded conductor portion connected to a matching board and a second end of each unshielded conductor portion connected to a detune board.

[0049] The first support portion may include at least one channel or recess that receives at least a portion of the at least one non-shielded conductor portion.

[0050] The first support portion may include a plate portion and a pair of upright portions protruding from the plate portion, and the first portion of the primary receive coil may be supported by the plate portion, while the second and third portions of the primary receive coil may be supported by the pair of upright portions.

[0051] In one set of embodiments, the plate portion includes a plate channel that receives a first portion of the primary receiving coil, a first of the set of upright portions includes a first upright channel that receives a second portion of the primary coil, and a second of the set of upright portions includes a second upright channel that receives a third portion of the primary coil.

[0052] In one embodiment, the receive coil system comprises one primary receive coil and seven auxiliary receive coils.

[0053] According to another aspect of the present invention, there is provided a cover portion apparatus for use in a receive coil apparatus as defined above, the cover portion apparatus comprising a plurality of auxiliary receive coils of the receive coil apparatus and a cover portion supporting and supporting each of the auxiliary receive coils.

[0054] According to another aspect of the present invention, there is provided an MRI system comprising a main MRI scanner apparatus, a patient support, and an MRI system receive coil apparatus as defined above, mounted on the patient support and electrically connected to the main MRI scanner apparatus.

[0055] The receive coil device may comprise a support structure supporting at least one of the primary receive coil and the auxiliary coil, at least a part of the support structure being attachable to or forming part of a patient support.

[0056] In one set of embodiments, the support structure may include a base portion that supports the primary receive coil and that is attachable to or forms part of a patient support.

[0057] According to another aspect of the present invention, there is provided an MR-Linac system comprising an MRI system as defined above and a medical linear accelerator system.

[0058] According to another aspect of the present invention, there is provided a PET-MR system comprising an MRI system and a positron emission tomography system as defined above.

[0059] It should be noted that, in general terms and with any necessary modifications in wording, all of the additional features defined above according to any aspect of the invention described above are applicable as additional features of all other aspects of the invention defined above, and merely for the sake of brevity, these additional features will not be restated after each aspect of the invention.

[0060] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0061] [Figure 1] FIG. 1 is a diagram illustrating a schematic diagram of an MRI system including a receive coil device. [Figure 2] 2 is a diagrammatic representation of a receive coil arrangement of the type included in the MRI system of FIG. 1 in place on a subject; [Figure 3] 3 is a diagram schematically illustrating a base plate of the receive coil device shown in FIG. 2.

[0023] FIG. [Figure 4] 3 is a diagram schematically illustrating a cover portion of the receive coil device shown in FIG. 2. FIG. [Figure 5] 4 is a more detailed view of the portion of the base plate shown in FIG. 3 that is arranged to receive the primary receive coil. FIG. [Figure 6] FIG. 10 shows a primary receive coil on a base plate with a portion of the base plate removed. [Figure 7] 3 is a diagram illustrating a schematic example of a connection configuration of auxiliary receive coils included in the receive coil device shown in FIG. 2.

[0023] FIG. [Figure 8A] FIG. 3 is a front view of the primary and auxiliary coils of the receive coil system of FIG. 2 when placed around a subject. [Figure 8B] FIG. 3 is a side view of the primary and auxiliary coils of the receive coil system of FIG. 2 when placed around a subject. [Figure 9] FIG. 3 is a schematic diagram showing the connections between the various components in the receive coil system shown in FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0062] 1 shows an MRI system comprising a main scanner assembly 1, a patient support 2 arranged to support a patient while the patient is in the scanner assembly 1, and an MRI system receive coil assembly 3 that is separate from the main scanner assembly and in this example is a body-part dedicated receive coil assembly. More generally, such a receive coil assembly 3 may be referred to as a local receive coil assembly.

[0063] As alluded to above, in some instances, the MRI system is used in combination with other systems, for example to provide an MR-Linac system comprising an MRI system and a medical linear accelerator system, or in another instance to provide a PET-MR system comprising an MRI system and a positron emission tomography system. In such cases, the MRI system shown in Figure 1 may be complemented by a linear accelerator system or a positron emission tomography system S, illustrated in very schematic form in Figure 1 only by dotted lines.

[0064] The main MRI scanner apparatus 1 may be a fully conventional main MRI scanner apparatus comprising a main magnet 11, typically a superconducting electromagnet, an RF transmit coil 12, gradient field coils 13, and a main unit receive coil 14. These components are provided in the body of the MRI scanner apparatus 1, which has a main bore B, and a patient support 2 provided in the main bore B, or more typically, capable of moving into the main bore B, supporting the patient until the patient support 2 reaches an operating position.

[0065] At least in use, a body-part dedicated receive coil arrangement 3 is also provided in this main bore B. If present, at least part of a medical linear accelerator system or a positron emission tomography system S may also be located in this main bore B during operation.

[0066] In addition to being located in the main bore B of the main MRI scanner 1 during operation, the receive coil unit 3 is electrically connected to the main scanner unit 1 so that magnetic resonance signals collected by the receive coil unit 3 can be sent to the main scanner unit 1 for processing.

[0067] The signals collected by the receive coil system 3 may be used alone or in combination with the signals collected by the main unit receive coil 14 in processing and producing images. In some instances, a main MRI scanner system 1 that does not have its own main unit receive coil 14 may be used with a receive coil system 3 of the present type.

[0068] The structure and operation of MRI scanner apparatus is well developed and understood, and the inventive concept relates to a receive coil system 3 for use with such an MRI scanner apparatus. Therefore, it is not necessary to further describe the structure and operation of the MRI scanner apparatus 1, and the remainder of this description relates to the receive coil system 3.

[0069] 2 shows in more detail a schematic representation of the body portion dedicated receive coil device 3. The body portion dedicated receive coil device 3 comprises a cover portion 4 and a base portion 5. The base portion 5 is arranged to be mounted on the patient support 2, or in some embodiments may be made to be an integral part of the patient support 2. On the other hand, the cover portion 4 is removably attached to the base portion 5 so that it can be fitted over a subject and then fixed in place on the base portion 5.

[0070] As can be seen by considering Figures 3, 4, 5 and 6, the body-part dedicated receive coil device 3 comprises a primary receive coil 6 (see Figures 5 and 6) and a plurality of auxiliary receive coils 7 (see Figure 4). The base portion 5 is arranged to support the primary receive coil 6, and the cover portion 4 is arranged to support the auxiliary receive coils 7.

[0071] The base portion 5 includes a plate portion 51 and two upright portions 52. The upright portions 52 can be seen, for example, in Figures 3 and 5. The plate portion 51 has two layers 51a and 51b. The upright portions 52 are supported by an upper layer 51a, as can be seen in Figures 3 and 5. In Figure 6, the upper layer 51a has been lifted off to reveal the lower layer 51b and to better show the primary receive coil 6.

[0072] The base portion 5 is provided with a plurality of channels 52a, 52b for supporting and holding in a predetermined position the primary receive coil 6. A respective channel 52a (only one of which can be seen in the drawing, i.e., FIG. 5) is provided in each of the upright portions 52 for holding a respective portion of the primary receive coil 6 in position on the upright portions 52.

[0073] For example, as can be appreciated by considering Figures 2, 3, 4, and 5 together, in use, this portion of the primary receive coil 6 will be in close proximity to the subject, and in particular the subject's head in the particular embodiment shown. The particular shape and path of coil 6 is selected to provide desired receive characteristics, for example, to maximize penetration depth and ensure relatively constant electromagnetic coupling of energy to the subject's tissue.

[0074] The lower layer 51b of the plate portion 51 includes respective channels 52b for holding other parts of the primary receive coil 6 in defined positions.

[0075] The primary receiving coil 6 has a plurality of unshielded conductors. In this embodiment, two unshielded conductor portions 61 are provided. A first of the two portions extends in the channel 52a of a first of the uprights 52, and a second of the two portions extends in the channel 52a of the other upright 52. First ends of these conductor portions 61 are connected to a detune board 62, while the other ends of each of the two conductor portions 61 are connected to a matching board 63. The detune board 62 and the matching board 63 each include at least one electronic component, such as at least one tuning capacitor in the case of the matching board 63.

[0076] As can be seen in FIG. 6 , the detune board 62 and matching board 63 avoid the central region of the coil 6, i.e., they are away from the upright portion 52 and the portion of the coil 6 that is closest to the target region of interest. This creates an electronics-free zone in the target region of interest. This is particularly important when the body-part-specific receive coil device 3 is used in a combined system of the type described above, where radiation is used in the combined system. The radiation passes through this central region, i.e., the target region of interest of the subject, without being adversely affected by the presence of electronics and / or without the risk of damaging such electronics. This configuration of the primary receive coil 6 thus lends itself to the use of the receive coil device of the present invention in systems such as PET-MR and MR-Linac systems.

[0077] The base portion 5, ie the plate portion 51 and the upright portion 52, are made of a relatively rigid plastic material to hold the primary receive coil 6 in place.

[0078] As alluded to above, this is important because changes to the geometry of the primary receive coil 6 tend to affect tuning and matching, which adversely affects the sensitivity of the primary receive coil 6. The rigid structure and shape and placement of the coil 6 are selected to minimize these effects.

[0079] Each of the auxiliary receiving coils 7 has a different structure from the primary receiving coil 6. While the primary receiving coil 6 is made of an unshielded conductor and has a relatively low impedance, the auxiliary receiving coils 7 are arranged as high-impedance coils. In particular, these coils 7 have a higher impedance than the impedance of the primary receiving coil 6. Furthermore, the size of the auxiliary receiving coils 7 is smaller than that of the primary receiving coil 6; in particular, the area defined by the auxiliary receiving coil 7 is smaller than the area defined by the primary receiving coil 6. This means that the primary receiving coil 6 is more suitable for receiving signals emanating from deep within the subject, whereas the auxiliary receiving coils 7 are more suitable for collecting signals emanating from areas of the subject that are close to the auxiliary receiving coil 7 itself.

[0080] Furthermore, due to the nature of the high impedance coils used for the auxiliary receive coils 7, they have very poor coupling to their surroundings and therefore precise placement is less important, which allows for more precise placement of these auxiliary receive coils 7 relative to the subject and allows these receive coils 7 to conform to the shape required to bring them into close contact with the relevant region of interest in the subject.

[0081] FIG. 7 shows a schematic diagram of the connection configuration of each auxiliary receiving coil 7. Each auxiliary receiving coil 7 is made from a single coaxial cable including a center conductor 71 and an outer shielding conductor 72. In the receiving coil, the center conductor 71 is continuous around the coil, and the ends of the center conductor 71 are connected to respective matching boards 73 (see FIG. 4). On the other hand, the shielding conductor 72 has a gap at a position spaced apart from the end of the inner conductor 71, while the two ends of the shielding 72 near the end of the inner conductor 71 are connected together. Each matching board 73 includes at least one electronic component, such as at least one tuning capacitor.

[0082] Due to the nature of high impedance coils, the total length of each coaxial cable defining the coil is limited to be very close to half a wavelength, thereby limiting the overall size of the auxiliary receive coil 7.

[0083] Each of these auxiliary receive coils 7 is supported by a plastic substrate 41 of the cover portion 4. The auxiliary receive coils 7 may be held in place by stitching, for example using a textile thread. In this embodiment, the substrate 41 is made of a relatively flexible plastic material, and as a whole, this substrate 41 and the cover portion 4 are more flexible than the base portion 5. If the substrate 41 is flexible and the auxiliary coils 7 are flexible, this means that the cover portion 4 can be designed to fit closely to the area of ​​interest, providing that the auxiliary coils 7 can take up the desired position and operate efficiently.

[0084] Thus, in this embodiment, the cover portion 4 is arranged for placement on the patient's head, face, and neck, and accordingly, it comprises the portion of the cover for covering the subject's head, face, and neck when in place.

[0085] The cover part 4 combined with the auxiliary coil 7 may be referred to as a cover part assembly 4, 7. The base part 5 combined with the primary coil 6 may be referred to as a base part assembly 5, 6.

[0086] The position of the primary coil 6 and auxiliary coil 7 relative to the object when the object is placed on the base part 5 and the cover part 4 is in place can best be seen in Figures 8A and 8B.

[0087] In this example, a primary receive coil 6 can be seen placed in the region of the patient's head. The primary coil 6 is very easy to acquire data from deeper within the subject. This receive coil 6 can effectively collect signals emanating from regions within the patient's head and neck.

[0088] On the other hand, the auxiliary coils 7 are placed at different positions across the patient's face and neck. Each auxiliary coil 7 overlaps partially, but for the most part, each auxiliary coil 7 attempts to collect signals from a different region of the subject's face and neck. In this embodiment, there are seven auxiliary coils 7, three of which are arranged for placement across the subject's face, and four of which are arranged for placement across the subject's neck and shoulders. Accordingly, assuming the cover portion 4 is, for example, as illustrated in FIG. 4, four of the auxiliary coils 7 are provided in the portion of the cover covering the neck, and three of the auxiliary coils 7 are provided in the portion of the cover 4 covering the face.

[0089] In this embodiment, the auxiliary coils 7 are arranged to overlap each other by 10 to 15% in order to further reduce coupling due to residual magnetic induction.

[0090] Furthermore, the matching board 73 for the auxiliary coil 7 avoids the central area, i.e. the area of ​​interest in the subject, thus creating an electronics-free zone which provides the above mentioned benefits.

[0091] In practice, the substrate 41, auxiliary coil 7 and matching board 73 of the cover part arrangement 4, 7 are covered by a layer of foam provided on each side of the substrate 41. In this embodiment, the cover part 4 is arranged to be held in place on the base part 5 using hook and loop fasteners 44 provided at appropriate mounting locations.

[0092] It should be noted that the flexible design of the cover 4, as well as allowing the auxiliary coil 7 to be provided in different positions and bent into slightly different shapes, facilitates the provision of a cover portion device 4, 7 that can be used over a mask or other fixture that needs to be used in the combined system. For example, in an MR-Linac system where a patient-specific fixed mask or fixture is provided to properly direct and deliver the radiation used in radiotherapy by the MR-Linac system, a cover portion 4 of the type of the present invention can be used with that existing mask or fixture without the need to modify it.

[0093] Figure 9 is a schematic diagram showing the overall connection configuration of the receive coil system shown in Figures 2 to 8. The low impedance primary coil 6 and high impedance auxiliary coil 7 are connected via appropriate cable traps 8 to a preamplifier board 9, the output of which is fed to a driver and malfunction board 10, which collectively forms the output of the receive coil system 3 for feeding the main MRI scanner system 1.

Claims

1. 1. An MRI system receive coil arrangement for use with a main MRI scanning apparatus, comprising: at least one primary receive coil having a first size defined by a first impedance at a predetermined frequency and a cross section defined by a primary receive coil; and at least one auxiliary receive coil having a second size defined by a second impedance at the predetermined frequency and a cross section defined by an auxiliary receive coil, wherein the first impedance is lower than the second impedance and the first size is greater than the second size; the auxiliary receiving coil comprises at least one coaxial cable, the primary receiving coil includes at least one unshielded conductor portion, and the auxiliary receiving coil is more flexible than the primary receiving coil; the MRI system receive coil assembly comprises a support structure supporting the at least one primary receive coil and the at least one auxiliary receive coil; the support structure includes at least two portions, a first of the at least two portions supporting the at least one primary receive coil and a second of the at least two portions supporting the at least one auxiliary receive coil; 1. An MRI system receive coil assembly, wherein the first of the at least two parts includes a base portion for mounting or incorporating into a patient support bed of an MRI machine, and the second of the at least two parts includes a cover portion for attaching to the base portion.

2. 2. The MRI system receive coil system of claim 1, wherein the MRI system receive coil system comprises a plurality of auxiliary receive coils, each of the auxiliary receive coils having an impedance at the predetermined frequency that is higher than the first impedance, and each of the auxiliary receive coils having a size defined by a cross section defined by the respective auxiliary receive coil that is smaller than the first size.

3. 3. The MRI system receive coil device of claim 1, wherein the at least two portions of the support structure are movably arranged between an access configuration that allows placement of a subject between the two portions of the support structure and a functional configuration for placing the primary and auxiliary receive coils in desired positions relative to each other for use during imaging operations of an MRI machine with which the MRI system receive coil device is used.

4. 4. The MRI system receive coil arrangement of claim 1, wherein the second of the at least two sections supporting the at least one auxiliary receive coil is more flexible than the first of the at least two sections supporting the primary receive coil.

5. 5. The MRI system receive coil device of claim 1, wherein the covering portion includes a plurality of covering portions, each covering a respective portion of interest in the subject, and wherein there are a plurality of auxiliary receive coils, and at least one auxiliary receive coil in each of the plurality of auxiliary receive coils is provided in a respective covering portion in the plurality of covering portions.

6. 6. The MRI system receive coil device according to claim 1, wherein the base portion comprises at least a part of a pillow portion for supporting the subject's head.

7. 7. An MRI system receive coil system according to any one of claims 1 to 6, which is a head and / or face and / or neck and / or shoulder receive coil system.

8. 8. An MRI system receive coil arrangement according to any one of claims 1 to 7, comprising an electronics-free zone corresponding to a zone through which radiation can pass in use.

9. 9. The MRI system receive coil device of claim 1, wherein the at least one auxiliary receive coil comprises a coaxial cable arranged in a loop, a gap being provided in the outer conductor of the coaxial cable at a position midway around the loop, the outer conductor of a first end of the coaxial cable being connected to the outer conductor of a second end of the coaxial cable.

10. 10. An MRI system comprising: a main MRI scanner apparatus; a patient support; and an MRI system receive coil apparatus according to any one of claims 1 to 9, mounted on the patient support and electrically connected to the main MRI scanner apparatus.

11. An MR-Linac system comprising the MRI system of claim 10 and a medical linear accelerator system.

12. A PET-MR system comprising the MRI system of claim 10 and a positron emission tomography system.

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