WO2013153493A1

WO2013153493A1 - Patient examination table system for use with a magnetic resonance (mr) scanner system

Info

Publication number: WO2013153493A1
Application number: PCT/IB2013/052731
Authority: WO
Inventors: Christoph Leussler; Oliver Lips; Jens FOKKE
Original assignee: Koninklijke Philips N.V.; Philips Deutschland Gmbh
Priority date: 2012-04-10
Filing date: 2013-04-05
Publication date: 2013-10-17

Abstract

A patient examination table system for use with a magnetic resonance (MR) scanner system (46) comprising a main magnet with a bore (50) that provides a region of examination (52) with a longitudinal center axis (54) and at least a first radio frequency (RF) antenna (58, 60, 62), wherein the at least first RF antenna (58, 60, 62), in at least one operating state, is fixedly mounted in the bore (50) of the main magnet, comprising: a patient table top (12) provided for a patient (10) to lie on at least partially within the bore (50) of the main magnet during an MR examination; a mechanical support (16) for supporting the patient table top (12); and at least one adjustable coupling member (42, 44) to adjustably couple the patient table top (12) to the mechanical support (16), wherein the adjustable coupling member (42, 44) enables to adjust a position of the patient table top (12) relative to the first RF antenna (58, 60, 62) in at least one direction of adjustment (40) that is perpendicular to the longitudinal center axis (54), so as to position a portion of interest of the patient's body close to the first RF antenna (58, 60, 62); a method for moving a patient (10) with the patient examination table system; a software module (76) provided to control a position control unit (70), so as to automatically move the patient table top (12) of the examination table system; and an MR scanner system comprising a patient examination table system.

Description

Patient examination table system for use with a magnetic resonance (MR) scanner system

FIELD OF THE INVENTION

The invention pertains to a patient examination table system for use with a magnetic resonance (MR) scanner system, a method for moving a patient with the patient examination table system within a region of examination of the MR scanner system, a software module provided to control a position control unit to execute the method, and an MR scanner system comprising a patient examination table system.

BACKGROUND OF THE INVENTION

In the technical field of magnetic resonance (MR) scanning, in particular with MR scanner systems comprising a main magnet with a bore that provides a region of examination, it is an objective to optimize a signal-to-noise ratio (SNR) of a received signal while keeping a specific absorption rate (SAR) for radio frequency (RF) electromagnetic field applied to a patient below certain limits at the same time.

To this end, it is known to use surface coils inside the MR scanner system to attain a high SNR compared to a body coil. Such surface coils, however, have a downside in reducing an inner bore diameter of the main magnet and thus, reducing a patient's comfort due to the build-up of a coil packaging on the patient. Further, applying surface coils is a time-consuming procedure. Moreover, surface coil arrays are a heat barrier and have to be made electromagnetically transparent during an RF transmit phase.

Further, it has been suggested to provide an RF antenna that can be moved parallel to a longitudinal axis of a patient bed and relative to a main magnet and a patient bed. Such an RF antenna is for instance described in US 7,602,189 B2. Moving the RF antenna relative to the main magnet and gradient coils of the MR scanner system breaks up a carefully designed balance between these objects and requires a re-check after a change of their relative positions.

Therefore, there is a need to avoid the use of surface coil arrays on the patient body and to keep the advantage of a high SNR, while, at the same time, improving patient comfort and workflow. SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a solution with a high SNR of a received MR signal and improved patient comfort and workflow.

In one aspect of the present invention, the object is achieved by a patient examination table system for use with a magnetic resonance (MR) scanner system

comprising a main magnet with a bore that provides a region of examination with a longitudinal center axis and at least a first radio frequency (RF) antenna, wherein the at least first RF antenna, in at least one operating state, is fixedly mounted in the bore of the main magnet, comprising

a patient table top provided for a patient to lie on at least partially within the bore of the main magnet during an MR examination,

a mechanical support for supporting the patient table top, and

at least one adjustable coupling member to adjustably couple the patient table top to the mechanical support, wherein the adjustable coupling member enables to adjust a position of the patient table top relative to the first RF antenna in at least one direction of adjustment that is perpendicular to the longitudinal center axis, so as to position a portion of interest of the patient's body close to the first RF antenna.

The phrase "RF antenna", as used in this application, shall be understood particularly to encompass antennae that are provided to transmit RF electromagnetic fields, antennae that are provided to receive RF electromagnetic fields, as well as antennae that are provided to transmit RF electromagnetic fields at one time of operation and to receive RF electromagnetic fields at another time of operation. RF antennae are preferably designed as a type of coil.

The invention is based on the concept that, fundamentally, the SNR of a received MR signal depends on a distance between an RF antenna and a patient's tissue. The patient examination table system in accordance with the invention can always be positioned in a distance to the RF antenna that are fixedly mounted in the bore of the main magnet to achieve an optimum SNR, thereby compensating a patient's physique. An applied RF power level can be reduced due to an adapted positioning of the patient to the fixed RF antenna. Moreover, the proposed invention allows for a significantly improved workflow by providing the option to scan considerably more patients in the same time period as a desired position of the patient within the region of examination can be readily obtained. Preferably, the adjusted position of the patient table top relative to the first RF antenna is secured by at least one fixing member that can be reversibly set from a position of release to a locking position.

The invention is applicable not only to sole MR scanner systems but also to hybrid systems, in which the MR scanner system is combined with a therapy system or another diagnostic imaging system, such as a hyperthermia therapy system, a LINAC (Linear Accelerator) system or a PET (Positron Emission Tomography) device. Due to the omission of surface coils, it is also applicable to interventional MR scanner systems.

In a further aspect of the invention, the patient examination table system further comprises a mechanical drive provided to co-operate with the at least one coupling member for adjusting the position of the patient table top relative to the first RF antenna, allowing for an easy positioning of the portion of interest of the patient's body within the region of examination.

In a preferred embodiment, the mechanical drive comprises an electromagnetic motor or a pneumatic drive. Thereby, the positioning of the portion of interest of the patient's body within the region of examination can be attained fast and with a high comfort for a physician or an MR scanner system operator.

A high degree of control and precision of positioning the portion of interest of the patient's body within the region of examination can be obtained by furnishing the patient examination table system with at least one distance sensor that is provided to determine a clearance in at least one direction of adjustment that is perpendicular to the longitudinal center axis, between the patient that is lying on the patient table top in an examination position, and an inner wall cover of the bore of the main magnet. Preferably, the at least one distance sensor is selected from a group of sensors formed by capacitive sensors, video devices and ultrasound sensors. In general, also other distance sensors that appear to be suitable to the one of skills in the art may be used for this purpose.

The distance sensor signal may be processed and fed to a display, giving feedback on an actual clearance between the patient and the inner wall cover of the bore of the main magnet to the physician or the MR scanner system operator while positioning the patient.

In another aspect of the invention, the patient examination table system comprises a position control unit that is provided to control the mechanical drive to automatically move the patient table top to a pre-determined distance, in at least one direction of adjustment that is perpendicular to the longitudinal center axis, with regard to the inner wall cover by using a signal from the distance sensor in a closed-loop control. By that, the positioning of the patient within the region of examination to the desired position and distance to the inner wall cover of the bore of the main magnet can be most easily obtained with a high degree of precision and reproducibility.

Preferably, the position control unit provides an output signal that corresponds to the distance in at least one direction of adjustment that is perpendicular to the longitudinal center axis between the patient that is lying on the patient table top in an examination position, and the inner wall cover of the bore of the main magnet, to a control device of the MR scanner system. The output signal can advantageously be used by the MR scanner system to monitor this distance, and also a variation of the distance over time; i.e. a speed, for a beneficial correlation of both distance and speed with an MR scanning sequence.

In another aspect of the present invention, the patient examination table system further comprises at least a second RF antenna that is fixedly arranged at an underside of the patient table top. Thus, during an adjustment of the position of the patient table top in a direction of adjustment that is perpendicular to the longitudinal center axis, the second RF antenna moves in the same manner with the patient table top, so that a distance between the patient and the second RF antenna is maintained during positioning of the patient table top. In a preferred embodiment, the second RF antenna can be designed as an RF receive coil.

It is another object of the invention to provide a method for moving a patient with an embodiment of the patient examination table system to a pre-determined examination position. The method comprises steps of

placing the patient on the patient table top;

placing the mechanical support and the adjustably coupled patient table top at a desired position in the longitudinal direction;

- adjusting a position of the patient table top relative to the first RF antenna in at least one direction of adjustment that is perpendicular to the longitudinal center axis by adjusting the adjustable coupling member, so as to position a portion of interest of the patient's body close to the first RF antenna.

This method is applicable with a patient examination table system comprising a mechanical drive which is manually operated by the MR scanner system operator, and also with a mechanical drive that comprises an electromagnetic motor or a pneumatic drive, and either with or without making use of a distance sensor for determining the clearance between the patient and the inner wall cover of the bore of the main magnet. In yet another embodiment of the method for moving a patient to a predetermined examination position, the method applies to a patient examination table system comprising at least one distance sensor and a position control unit, and comprises the steps of placing the patient on the patient table top;

- placing the mechanical support and the adjustably coupled patient table top at a desired position in the longitudinal direction;

activating the position control unit to automatically move the patient table top to a pre-determined distance with regard to the inner wall cover of the bore of the main magnet, so as to position a portion of interest of the patient's body close to the first RF antenna in at least one direction of adjustment that is perpendicular to the longitudinal center axis. This method allows for a positioning of the patient within the region of examination to the desired position and distance to the inner wall cover of the bore of the main magnet which is most easily obtained with a high degree of precision and reproducibility. The activation of the position control unit is preferably carried out by the physician or the MR scanner system operator as a confirmation of completing an examination preparation check routine.

It is yet another object of the invention to provide a software module comprising a program code that is implementable in and executable by a control device of the MR scanner system. The program code is a conversion of a step of the method for moving a patient with the patient examination table system comprising at least one distance sensor and a position control unit. The program code can be started by an activation of the position control unit by the physician or the MR scanner system operator. The software module is provided to control the moving of the patient table top via the position control unit to a predetermined distance, in at least one direction of adjustment that is perpendicular to the longitudinal center axis, with regard to the inner wall cover by using a signal from the distance sensor in a closed-loop control.

In another embodiment, the control device of the MR scanner system that the program code is implementable in and executable by can also be the position control unit itself.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter. Such embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention.

In the drawings:

Fig. 1 shows a side view of a patient examination table system in accordance with the invention as viewed from the right,

Fig. 2 depicts an arrangement of the patient examination table system pursuant to Fig. 1 with a patient within an examination region of an MR scanner system main magnet bore and a table top in a lower position in a side view as viewed from the front,

Fig. 3 illustrates the patient examination table system pursuant to Fig. 2 with the table top in an adjusted, higher position in the same view,

Fig. 4 shows the arrangement pursuant to Fig. 2 in a side view as viewed from the left, and

Fig. 5 depicts the arrangement pursuant to Fig. 3 in a side view as viewed from the left.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows a side view of an embodiment of a patient examination table system in accordance with the invention as viewed from the right. The patient examination table system comprises a patient table top 12 provided for a patient 10 to lie on and a mechanical support 16 for supporting the patient table top 12 from below. The mechanical support 16 has a base body 22 that is equipped with lockable castors 18, so that the mechanical support 16 can easily be moved on a floor 20 and can readily be locked at a desired location.

The massive base body 22 has an upper portion 24 and a lower portion 26, wherein the upper portion 24 is trans lational shiftable parallel to a direction of extension 14 of the patient table top 12 via an air bearing 28 and two guide plates arranged at the sides of a top part of the lower portion 26 of the base body 22. The air bearing 28 that is connected to a compressed air supply 32 (connection not shown for the sake of clarity) is activated as long as a push-button 34 is pushed by an operator. This action also sets spring-loaded clamps to a release position that are attached at both sides of the lower portion 26 and that engage with grooves that run along the sides to secure the upper portion 24 to the lower portion 26. After release of the push button 34, the air supply 32 stops and the upper portion 24 and the lower portion 26 of the base body 22 lie on top of each other. The spring-loaded clamps engage with the grooves to secure the upper portion 24 to the lower portion 26 of the base body 22. Mechanical stops (not shown) at each end of the lower portion 26 of the base body 22 are provided to limit a movement of the upper portion 24 to each side in the direction of extension 14.

The upper portion 24 of the base body 22 comprises three adjustable first coupling members 42 to adjustably couple the patient table top 12 to the mechanical support 16. The first adjustable coupling members 42 are designed as threaded rods and are made from glass fiber-reinforced epoxy resin. They are rigidly coupled with their upper ends, respectively, to an underside of the patient table top. Lower ends of the first coupling members 42 are guided within corresponding second coupling members 44 designed as threaded holes in discs that are rotatably supported in the upper portion 24 of the base body 22, respectively, and coupled to a gear mechanism that is driven by a pneumatic drive 30 connected to the compressed air supply 32. The pneumatic drive 30 is thus provided to cooperate with the first coupling members 42 via the second coupling members 44 for adjusting the position of the patient table top 12 in a direction of adjustment 40. The pneumatic drive 30 can be activated by push buttons 36, 38 for an up or down movement of the patient table top 12 (electric cables and air supply hoses not shown). Alternatively, the pneumatic drive 30 may be activated using software keys of a wireless control system that is commonly available in a control environment of the MR scanner system 46. The gear mechanism is designed to synchronously rotate the three discs about a vertical axis of rotation, respectively, which coincide with axes of symmetry of the discs.

The patient examination table system is designed for use with a magnetic resonance (MR) scanner system 46 (Figures 4 and 5) comprising a main magnet with a bore 50 that provides a region of examination 52 with a longitudinal center axis 54.

In a side view as viewed from the front, Fig. 2 illustrates a configuration with the patient 10 lying on the patient table top 12 and in full length within the bore 50 of the main magnet. The MR scanner system 46 comprises a transmit body coil as a first radio frequency (RF) antenna 58 that, in the illustrated operational state, is fixedly mounted in the bore 50 of the main magnet along an azimuthal direction in a constant radial distance from the longitudinal center axis 54.

As a second RF antenna 60, a receive coil array of individual coils is integrated in the bore 50 of the main magnet in the azimuthal direction in a distance that is closer to the longitudinal center axis 54. The individual coils of the receive coil array are connected to local fully digital receivers, which are located between rungs of the transmit body coil (not shown). As is known to the one of skills in the art to be beneficial, the first 58 and second RF antennae 60 are shielded from the main magnet and the (not shown) gradient magnet coils by a closed metal foil RF screen 64. Towards the longitudinal center axis 54, the first 58 and second RF antennae 60 are mechanically protected by a coaxial inner wall cover 56 of the bore 50 of the main magnet.

Further, the patient examination table system is equipped with a third RF antenna 62 that is designed as a posterior local RF receiving coil array that is fixedly arranged at the underside of the patient table top 12. During a change of the position of the patient table top 12 in the direction of adjustment 40 that is perpendicular to the longitudinal center axis 54, the third RF antenna 62 moves in the same manner as the patient table top 12, so that a distance between the patient 10 and the third RF antenna 62 is maintained during positioning of the patient table top 12.

Fig. 4 shows a configuration after the patient table top 12 with the patient 10 lying on has been shifted into the region of examination 52 in a movement parallel to the longitudinal center axis 54. The patient 10 can be placed within the region of examination 52 in a head-first position as well as in a feet-first position.

The adjustable coupling members 42, 44 enable to adjust a position of the patient table top 12 relative to the first RF antenna 58 in the direction of adjustment 40 that is perpendicular to the longitudinal center axis 54, so as to position a portion of interest of the patient's body close to the first RF antenna 58.

An ultrasound distance sensor 68 that is attached at a highest position of the inner wall cover 56 is provided to determine a clearance 66 in the direction of adjustment 40 that is perpendicular to the longitudinal center axis 54, between the patient 10 that is lying on the patient table top 12 in an examination position, and the inner wall cover 56 of the bore 50 of the main magnet. A signal from the distance sensor 68 is fed to a display 78, thus giving feedback on an actual clearance between the patient 10 and the inner wall cover 56 of the bore 50 of the main magnet to a physician or an MR scanner system operator while positioning the patient 10.

This can be accomplished by the physician or the MR scanner system operator pressing one of the push buttons 36, 38 for an up or down movement of the patient table top 12 to activate the pneumatic drive 30 (Fig. 1). Again, the pneumatic drive 30 may be activated using software keys of a wireless control system as described earlier. By use of the push buttons 36, 38 and the distance sensor signal as a feedback, the MR scanner system operator can position the portion of interest of the patient's body closer to a pre-determined distance to the first RF antenna 58 which is known to be beneficial regarding a signal-to- noise ratio of a received MR signal. As the patient's body is in an off-axis position with regard to the longitudinal center axis 54, homogeneity of the main magnet magnetic field at the portion of interest might be insufficient. In this case, the magnetic field homogeneity may locally be improved using an active local shim device (not shown) comprising at least one shim coil that can be activated, for instance, via software when the patient table top is in the upper position as shown in Figures 3 and 5. Alternatively, the magnetic field homogeneity may locally be improved by arranging a passive local shim device within the bore of the main magnet, comprising material of a relative magnetic permeability that is larger than 10, preferably larger than 50.

In another embodiment that is illustrated in Fig. 4 and 5 by dashed lines, the patient examination table system comprises a position control unit 70 that is provided to control the pneumatic drive 30 to automatically move the patient table top 12 to the predetermined distance, in the direction of adjustment 40 that is perpendicular to the longitudinal center axis 54, with regard to the inner wall cover 56 by using the signal from the distance sensor 68 in a closed- loop control. A value for the pre-determined distance with regard to the inner wall cover 56 is stored in a memory 74 of the position control unit 70. The position control unit 70 is further designed to provide an output signal 80 that corresponds to the distance in the direction of adjustment 40 that is perpendicular to the longitudinal center axis 54 between the patient 10 that is lying on the patient table top 12 in the examination position, and the inner wall cover 56 of the bore 50 of the main magnet, to a control device 82 of the MR scanner system 46. The output signal 80 is used by the MR scanner system 46 to monitor this distance, and also a variation of the distance over time; i.e. a speed, for a correlation of both distance and speed with an MR scanning sequence.

The positioning of the patient 10 within the region of examination 52 to the desired position and distance to the inner wall cover 56 of the bore 50 of the main magnet can thereby be most easily obtained with a high degree of precision and reproducibility by pressing a button 72 of the position control unit 70 as a confirmation of completing an examination preparation check routine and for activation of the pneumatic drive 30, after the patient 10 has been shifted to an intended location within the region of examination 52. To this end, the position control unit 70 is equipped with a software module 76 provided to control the position control unit 70, so as to automatically move the patient table top 12 of the examination table system as described earlier. The software module 76 comprises a program code that is implementable in and executable by the position control unit 70 as one of a plurality of control devices 82 of the MR scanner system 46.

While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments. Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be construed as limiting the scope.

REFERENCE SYMBOL LIST:

10 patient 72 button (activation)

12 patient table top 74 memory

14 direction of extension 76 software module

16 mechanical support 78 display

18 castor 80 output signal

20 floor 82 control device

22 base body

24 upper portion

26 lower portion

28 air bearing

30 pneumatic drive

32 compressed air supply

34 push-button (table top)

36 push-button (up)

38 push-button (down)

40 direction of adjustment

42 first coupling member

44 second coupling member

46 magnetic resonance scanner

system

50 bore

52 region of examination

54 longitudinal center axis

56 inner wall cover

58 first RF antenna

60 second RF antenna

62 third RF antenna

64 RF screen

66 clearance

Claims

CLAIMS:

1. A patient examination table system for use with a magnetic resonance (MR) scanner system (46) comprising a main magnet with a bore (50) that provides a region of examination (52) with a longitudinal center axis (54) and at least a first radio frequency (RF) antenna (58, 60, 62), wherein the at least first RF antenna (58, 60, 62), in at least one operating state, is fixedly mounted in the bore (50) of the main magnet, comprising:

a patient table top (12) provided for a patient (10) to lie on at least partially within the bore (50) of the main magnet during an MR examination;

a mechanical support (16) for supporting the patient table top (12); and at least one adjustable coupling member (42, 44) to adjustably couple the patient table top (12) to the mechanical support (16), wherein the adjustable coupling member (42, 44) enables to adjust a position of the patient table top (12) relative to the first RF antenna (58, 60, 62) in at least one direction of adjustment (40) that is perpendicular to the longitudinal center axis (54), so as to position a portion of interest of the patient's body close to the first RF antenna (58, 60, 62).

2. The patient examination table system as claimed in claim 1, further comprising

a mechanical drive provided to co-operate with the at least one coupling member (40, 42) for adjusting the position of the patient table top (12) relative to the first RF antenna (58, 60, 62).

3. The patient examination table system as claimed in claim 1, wherein the mechanical drive comprises an electromagnetic motor or a pneumatic drive (30).

4. The patient examination table system as claimed in claim 1, further comprising at least one distance sensor (68), provided to determine a clearance (66) in at least one direction that is perpendicular to the longitudinal center axis (54), between the patient (10) that is lying on the patient table top (12) in an examination position, and an inner wall cover (56) of the bore (50) of the main magnet.

5. The patient examination table system as claimed in claim 4, further comprising a position control unit (70) that is provided to control the mechanical drive to automatically move the patient table top (12) to a pre-determined distance, in at least one direction that is perpendicular to the longitudinal center axis (54), with regard to the inner wall cover (56) by using a signal from the distance sensor (68) in a closed-loop control.

6. The patient examination table system as claimed in claim 5, wherein the position control unit (70) provides an output signal (80) that corresponds to the distance in at least one direction that is perpendicular to the longitudinal center axis (54) between the patient (10) that is lying on the patient table top (12) in an examination position, and the inner wall cover (56) of the bore (50) of the main magnet, to a control device (82) of the MR scanner system (46).

7. The patient examination table system as claimed in one of the preceding claims, further comprising at least a second RF antenna (58, 60, 62) that is fixedly arranged at an underside of the patient table top (12).

8. A method for moving a patient (10) with the patient examination table system as claimed in one of claims 1 to 7 to a pre-determined examination position, comprising the following steps:

placing the patient (10) on the patient table top (12);

placing the mechanical support (16) and the adjustably coupled patient table top (12) at a desired position in the direction of the longitudinal center axis (54);

adjusting a position of the patient table top (12) relative to the first RF antenna (58, 60, 62) in the at least one direction of adjustment (40) that is perpendicular to the longitudinal center axis (54) by adjusting the adjustable coupling member (42, 44), so as to position a portion of interest of the patient's body close to the first RF antenna (58, 60, 62).

9. A method for moving a patient (10) with the patient examination table system as claimed in one of claims 5 to 7 to a pre-determined examination position, the method comprising the following steps:

placing the patient (10) on the patient table top (12); place the mechanical support (16) and the adjustably coupled patient table top (12) at a desired position in the direction of the longitudinal center axis (54);

activate the position control unit (70) to automatically move the patient table top (12) to a pre-determined distance with regard to the inner wall cover (56) of the bore (50) of the main magnet, so as to position a portion of interest of the patient's body close to the first RF antenna (58, 60, 62) in at least one direction that is perpendicular to the longitudinal center axis (54).

10. A software module (76) provided to control a position control unit (70), so as to automatically move the patient table top (12) of the examination table system as claimed in claims 5 or 6,

with a patient (10) lying on the patient table top (12) at least partially within the bore (50) of the main magnet of the MR scanner system (46), to a pre-determined distance with regard to the inner wall cover (56) of the bore (50) of the main magnet,

so as to position a portion of interest of the patient's body close to the first RF antenna (58, 60, 62) in at least one direction that is perpendicular to the longitudinal center axis (54), comprising

a program code that is implementable in and executable by a control device (82) of the MR scanner system (46).

11. An MR scanner system (46), comprising:

a main magnet with a bore (50) that provides a region of examination (52) with a longitudinal center axis (54);

at least a first radio frequency (RF) antenna (58, 60, 62), wherein the at least first RF antenna (58, 60, 62), in at least one operating state, is fixedly mounted in the bore (50) of the main magnet;

a patient examination table system as claimed in one of claims 1 to 7.