Magnetic resonance imaging system for the head area

Abstract

A magnetic resonance imaging system (1) is described. The magnetic resonance imaging system (1) has a scanning unit (3). The scanning unit (3) comprises a gantry (3b) having a magnet system with a basic field magnet and a patient opening, and a support unit (3a) having a vertical translation mechanism configured to arrange the gantry (3b) in a predetermined height position. Part of the magnetic resonance imaging system (1) is also a patient seat (2), on which a patient (P) can be positioned in an at least semi-upright position during imaging and which is arranged so as to be displaceable in the horizontal direction relative to the gantry (3b). A method for constructing a magnetic resonance imaging system (1) is also described.

Description

[0001] The invention relates to a magnetic resonance imaging system for the head region. Furthermore, the invention relates to a method for constructing a magnetic resonance imaging system.

[0002] Medical imaging systems, especially magnetic resonance imaging systems, can be used for whole-body imaging as well as for imaging specific individual body regions or parts.

[0003] One concept that addresses the most efficient operation of medical imaging systems involves the use of dedicated medical imaging systems with a limited application area. Such a limited application area is determined, for example, by the geometry and dimensions of the interior of a medical imaging system. If a medical imaging system is intended to image only a specific group of body parts, this can be achieved by limiting the dimensions of the patient aperture.

[0004] On the other hand, a specific use, especially of a magnetic resonance imaging system, can also be facilitated by a suitable arrangement of a scanning unit of a magnetic resonance imaging system. Especially for imaging a patient's head or teeth, it may be advantageous to choose a relatively small patient opening and place the patient in a sitting position rather than a lying position, which is usually more comfortable for the patient and also requires less space.

[0005] Today's scanning units in magnetic resonance imaging systems are typically designed to generate a horizontally directed basic magnetic field (also referred to as the B0 field). Solenoid magnets are used for this purpose, creating a circular opening for the patient. The patient is moved into the circular opening on a patient couch and remains in a reclining position during the imaging process. However, the space required for a universal magnetic resonance imaging system is quite large, so such systems are usually only found in larger medical facilities, such as hospitals, or facilities specifically specializing in radiology.

[0006] To reduce X-ray exposure, there is discussion about using magnetic resonance imaging as a replacement for X-ray imaging in dentistry. However, dental practices usually have limited space and lack the financial resources to purchase a universal magnetic resonance imaging system.

[0007] There are now considerations to offer a scaled-down magnetic resonance imaging system specifically designed for dentistry, which is suitable only for imaging the head area or dentition and, due to this specialization, has a comparatively small space requirement and is relatively resource-efficient and thus also cost-effective to manufacture.

[0008] The problem therefore arises of developing a magnetic resonance imaging system dedicated to head imaging that is designed to save space and resources and is therefore also suitable for use in individual medical practices, especially dental practices.

[0009] This object is achieved by a magnetic resonance imaging system according to claim 1 and by a method for constructing a magnetic resonance imaging system according to claim 14.

[0010] The magnetic resonance imaging system according to the invention comprises a scanning unit. The scanning unit comprises a gantry having a magnet system with a basic field magnet and a patient opening. In addition to the basic field magnet, the magnet system preferably comprises a gradient coil, a receiver coil, and a transmission coil (e.g., a body coil integrated into the gantry and / or a local transmission coil positionable on the patient) and a patient opening. The patient opening is also referred to as a patient receiving area, a patient tunnel, or a bore. A portion of a body or a patient's body is received through the gantry. The patient opening is at least partially or completely enclosed by a magnet system along a circumferential direction. The patient opening can be annular, but it can also be designed with a lateral opening.

[0011] Also part of the scanning unit is a support unit, which has a vertical translation mechanism configured to position the gantry at a predetermined height. In particular, the vertical translation mechanism can be designed to position the gantry variably and / or at different heights. In this way, the height of the gantry can advantageously be adjusted to a patient's height or sitting position.

[0012] A height position of the gantry can be characterized by a distance of the gantry to a floor surface on which the magnetic resonance imaging system is placed or installed.

[0013] The magnetic resonance imaging system according to the invention also has a patient seat with an at least semi-upright sitting position. The backrest of the patient seat is thus inclined such that a patient can be positioned at least semi-upright on the patient seat before an imaging session, leaning on the backrest. The patient seat is arranged so as to be displaceable horizontally relative to the gantry. "At least semi-upright sitting" means that the patient assumes a sitting position and not a lying position. A lying position is understood to be a position in which the patient's head is at the same height as the rest of the body. In a sitting position, the patient's head is elevated relative to the rest of the body, and the back is oriented at least diagonally to the floor or even vertically.In order to allow the patient's head to enter the preferably ring-shaped patient opening for imaging, the patient seat can be moved horizontally and the gantry can be moved vertically.

[0014] The orientation of the gantry can be selected such that the longitudinal axis of the gantry runs vertically, but it can also be selected such that the longitudinal axis of the gantry runs deviating from the vertical, in particular diagonally. As explained in more detail later, the magnetic resonance imaging system according to the invention can also have a pivoting mechanism with which it is possible to switch between different orientations of the gantry.

[0015] Advantageously, the patient can sit in an at least partially upright or tilted position during imaging. The height of the gantry can also be adjusted to the height of a seat back or the height of a person before imaging. This not only provides a more comfortable position for the patient, but also reduces the space required for setting up the magnetic resonance imaging system. In particular, the space required for transporting the gantry is also reduced, as it can be quite small in the axial direction and can be moved to the desired examination area before imaging.

[0016] In the method according to the invention for constructing the magnetic resonance imaging system according to the invention, a patient seat is set up, on which a patient can be positioned at least semi-upright prior to imaging. Furthermore, a support unit is set up, which has a vertical translation mechanism configured to arrange a gantry of a scanning unit of the magnetic resonance imaging system at a predetermined height position. The height position of the gantry can be variably adjusted using the vertical translation mechanism. Finally, the gantry is connected to the support unit such that the gantry of the scanning unit is arranged to be displaceable in the vertical direction, so that the patient's head can be inserted into an annular patient opening in the gantry for imaging, or conversely, the gantry can be pushed over the head of the patient sitting below the gantry.The method according to the invention shares the advantages of the magnetic resonance imaging system according to the invention.

[0017] The dependent claims and the following description each contain particularly advantageous embodiments and developments of the invention. In particular, the claims of one claim category can also be developed analogously to the dependent claims of another claim category. Furthermore, within the scope of the invention, the various features of different embodiments and claims can also be combined to form new embodiments.

[0018] In one embodiment of the magnetic resonance imaging system according to the invention, the carrier unit has a pivot mechanism configured to pivot the preferably annular gantry about a horizontal pivot axis. Advantageously, the orientation of the gantry can be adapted to the orientation of the head and upper body of a patient seated on a patient seat. The orientation of the gantry is preferably selected to match the orientation of the backrest of the patient seat. In this position, the patient's head can be pushed into the patient opening of the gantry by moving the patient seat closer to the scanning unit. While the patient's head is surrounded by the gantry in this arrangement, the rest of the patient's body remains outside the gantry.In this variant, the patient's head can be pushed into the patient opening due to the patient's tilted seating position and the tilted arrangement of the gantry, provided the gantry is positioned at the correct height, which corresponds to the patient's head height. To adjust the height of the gantry to the patient's head height, the previously discussed support unit can be used. This unit has a vertical translation mechanism designed to position the gantry at a predetermined height.

[0019] In one variant of the magnetic resonance imaging system according to the invention, the carrier unit has a locking unit designed to lock the gantry in a desired orientation relative to the horizontal pivot axis. The locking unit is preferably designed with a positive locking mechanism for locking and releasing a pivot position of the gantry. Advantageously, a selected orientation of the gantry can be locked and thus maintained for the duration of an imaging session.

[0020] The support unit preferably has a swivel angle limiting unit configured to limit a rotation angle of the gantry relative to the horizontal swivel axis. The swivel angle limiting unit is preferably configured to limit a maximum rotation angle or swivel angle to a predetermined maximum angle. Excessive swiveling or rotating of the gantry, which potentially poses the risk of a collision between the gantry and a patient's head, can advantageously be avoided by limiting the possible swivel angle to safe values.

[0021] The pivot mechanism also preferably has an adjustment mechanism for establishing a mechanically preset pivot angle, which is achieved by a pivoting movement. This presetting allows the gantry to assume a pivot position that corresponds to a standard inclination of a patient seat backrest, so that manual adjustment of the gantry's pivot angle is not necessary in most cases. An adjustment mechanism can comprise a locking element, a stop element, a clamping element, a latching element, a securing element, or the like. The adjustment mechanism can be designed, in particular, to limit a movement, e.g., a rotational movement and / or a translational movement, of the gantry along a movement trajectory or rotational path defined by the pivot mechanism.

[0022] Most preferably, the mechanically preset swivel angle aligns the longitudinal axis of the gantry with the longitudinal axis of the patient's upper body. The patient can advantageously be pushed into the patient opening of the gantry by moving the patient seat backward.

[0023] The pivoting mechanism preferably has a grid that allows pivoting in a plurality of different predetermined angular increments. Advantageously, the orientation of the gantry can be adapted to different inclinations of the patient seat. The predetermined angular increments preferably have a grid of one degree, i.e., a gradation of 1°, 2°, 3°, etc. Alternatively, the grid can also comprise smaller or larger angular increments than 1 degree.

[0024] As a drive, the pivoting mechanism preferably has at least one of the following types of actuation: - manual operation, - an electric actuator, - a hydraulic actuation.

[0025] Manual, purely mechanical operation is generally particularly reliable and low-maintenance and can be manufactured with relatively little effort.

[0026] An electrical actuator allows automatic adjustment of the gantry's inclination without the need for an operator to exert muscle power.

[0027] Hydraulic actuation is particularly advantageous for a heavy gantry, whereby the hydraulic power transmission allows particularly high forces and torques and a high power density, especially compared to the use of an electric motor.

[0028] In one embodiment of the magnetic resonance imaging system according to the invention, the gantry is designed such that, when arranged as intended, it does not exert any torque, purely due to gravity, that would cause the gantry to rotate relative to the horizontal pivot axis of the pivot mechanism of the scanning unit, and thus does not allow the gantry to pivot purely due to gravity. "In arranged as intended" means that the gantry is correctly mounted on the support unit, so that, in particular, the gantry is arranged to be pivotable about a horizontal pivot axis. Furthermore, the support unit is arranged and oriented as intended, so that the aforementioned pivot axis for pivoting the gantry is aligned horizontally. This torque-free arrangement is achieved by distributing the weights of the gantry components in such a way that, without external influence, no torque is exerted on the pivot axis by these weights.The components include, in particular, the RX electronics, the magnetic electronics, etc. This can be achieved by arranging the gantry components with symmetrical weights relative to the gantry's pivot axis or, optionally, by attaching additional counterweights to the gantry. The pivot mechanism thus prevents any pivoting movement driven solely by weight, preventing accidents when tilting or pivoting the gantry or tipping over the system.

[0029] In one variant of the magnetic resonance imaging system according to the invention, the carrier unit is designed to be separable from the gantry. "Separable" here means that the carrier unit and the gantry can be detached from one another, particularly for transport, and transported as individual elements. Due to this separability, the carrier unit and the gantry are preferably reversibly connected to one another. To enable a reversible mechanical connection of the magnetic resonance imaging system, the carrier unit and the gantry preferably have complementary parts of a mechanical connecting element. The mechanical connection is preferably based on a positive and / or non-positive connection of the aforementioned complementary parts. Advantageously, the magnetic resonance imaging system can be transported in individual parts, thus saving space, especially if the gantry is comparatively small in size, adapted to the size of the head.

[0030] The support unit preferably has a large-area base plate (relatively large compared to the cross-section of the support arm unit) and a vertical support arm unit with a small cross-section compared to the area of ​​the base plate. For example, a main surface of the base plate (e.g., a surface of the base plate with the largest dimension) can be many times, in particular more than ten times or more than one hundred times, the cross-sectional area of ​​a vertical support arm unit. Advantageously, the overall system has good stability due to the large-area base plate, whereby the vertical support arm unit can be relatively slim and lightweight and thus, in addition to an elegant appearance, also has a comparatively low transport weight.

[0031] In a preferred embodiment of the magnetic resonance imaging system according to the invention, the vertical translation mechanism has a manual drive, a hydraulic drive, or an electric drive. The translation mechanism has an adjustment or displacement mechanism with which different relative positions of the gantry in the vertical direction relative to the carrier unit can be controlled and adjusted. If the vertical translation mechanism has a manual drive, it preferably has threaded rods with which kinetic energy can be manually introduced. In this case, the kinetic energy can be generated by manually turning the threaded rods. If the vertical translation is controlled by a hydraulic drive, the energy can be transferred by hydraulic pumps. Electrical actuation of the translation mechanism with motor support is also possible, e.g.by means of a linear drive or an electric motor with a rotating drive principle.

[0032] The support unit preferably has a buffer element for vibration decoupling of the gantry from a floor on which the support unit is positioned. Vibrations caused by the magnetic forces can advantageously be dampened, preventing the vibrations from being transmitted to the floor and, in particular, the building in which the magnetic resonance system is installed. Such a buffer preferably comprises one or more springs and / or rubber elements. The vibration decoupling is preferably arranged in the region of the pivot mechanism or the pivot axis of the pivot mechanism in order to also dampen vibrations transmitted to the pivot mechanism.

[0033] In one variant of the magnetic resonance imaging system according to the invention, the gantry is connected to the support unit on both sides via its outer surface and is pivotable relative to the support unit. Advantageously, the gantry is mechanically supported in a stable manner.

[0034] Preferably, the support unit is constructed symmetrically to the sagittal plane of the system. The sagittal plane is defined as a plane extending from top to bottom and from back to front. A sagittal plane divides a body into a right and a left portion. This symmetry allows for particularly good mechanical stability and robustness of the assembly.

[0035] Likewise, the base plate of the carrier unit preferably comprises a plurality of sub-elements so that no continuous base plate needs to be used, thus saving weight and transport size.

[0036] Also preferably, the base plate of the support unit is designed to be separable from the vertical support arm unit of the support unit. In this case, the base plate is preferably designed to be screwed to the support arm unit to provide a stable base for the entire system. Due to the disassembly of the entire system, the magnetic resonance imaging system can be transported more easily, as it takes up less space when disassembled and individual elements are lighter, making them easier to transport individually than the assembled system.

[0037] The base plate of the support unit preferably also includes buffer elements, preferably springs or rubber elements, for vibration decoupling of the magnetic resonance imaging system from the building in which it is installed. This advantageously ensures that vibrations generated by the magnetic fields of the magnets of the magnetic resonance imaging system, in particular by the gradient fields of the gradient magnets, are sufficiently dampened.

[0038] The support unit is preferably made of a weakly magnetic or even non-magnetic material. Advantageously, the support unit does not amplify the magnetic flux of the gantry's magnets and transfer it to the floor of a building.

[0039] Particularly preferably, the carrier unit comprises material of one of the following types: - aluminum, - non-magnetic steel, - Stainless steel.

[0040] Aluminum is a particularly lightweight material for transport.

[0041] Non-magnetic steel is particularly stable and strong, allowing for the construction of a support unit that is particularly resistant to gantry vibrations. Advantageously, non-magnetic steel does not transmit magnetic fields to the outside or amplify them, unlike a support unit made of magnetic material.

[0042] Stainless steel is particularly resistant to corrosion.

[0043] The above properties can also be combined. The carrier unit preferably comprises non-magnetic stainless steel, in particular austenitic or martensitic stainless steel.

[0044] The invention is explained in more detail below with reference to exemplary embodiments in the accompanying figures. They show: Fig. 1 is a schematic side view of a conventional magnetic resonance imaging system, Fig. 2 a plan view of the Fig. 1 illustrated a conventional magnetic resonance imaging system and an adjacent equipment room, Fig. 3 is a side view of a magnetic resonance imaging system according to an embodiment of the invention, Fig. 4 a plan view of the Fig. 3 illustrated magnetic resonance imaging system according to an embodiment of the invention, Fig. 5 is a side view of a magnetic resonance imaging system according to an alternative embodiment of the invention, Fig. 6 a plan view of the Fig. 5 already illustrated magnetic resonance imaging system, Fig. 7 a plan view of a base plate and a side view of a pivoting mechanism of the Fig. 3 and Fig. 4 illustrated magnetic resonance imaging system according to an embodiment of the invention, Fig. 8 is a side view showing an assembly of the Fig. 3 and Fig. 4 and Fig. 7 according to an embodiment of the invention, Fig. 9 is a side view showing an assembly of the Fig. 5 and Fig. 6 according to an alternative embodiment of the invention, Fig. 10 is a flowchart illustrating a method for constructing a magnetic resonance imaging system according to an embodiment of the invention.

[0045] In Fig. Figure 1 illustrates a schematic side view of a conventional magnetic resonance imaging system 1. The conventional magnetic resonance imaging system 1 comprises a patient bed 2 on which a patient can sit in a horizontal lying position. In this lying position, the patient is pushed to the left into a patient opening of a gantry 3b of a scanning unit 3 of the magnetic resonance imaging system 1. The gantry 3b is positioned and supported on the floor by a support unit 3a, also referred to as a base. As shown in Fig. As can be seen in Figure 1, the dimensions in length and height are considerable, so that an appropriately dimensioned room is required for an examination.

[0046] In Fig. 2 is a plan view of the Fig. Figure 1 shows a conventional magnetic resonance imaging system 1 and an adjacent equipment room 4. Equipment room 4 houses all electronic components, RF filters, and power supplies. It is a service area that facilitates the maintenance of all electronic devices used in the room. In total, the area for the magnetic resonance imaging system itself requires approximately 19 m². 2 and equipment room 4 has an area of ​​just under 6 m 2 on.

[0047] Equipment room 4 also houses a gradient power amplifier (GPA) for gradient generation. Furthermore, equipment room 4 houses an electronics cabinet (EPC), referred to as an "Electronics and Power Cabinet." Equipment room 4 also includes a helium compressor (MREF) for magnetic cooling.

[0048] In Fig. 3 shows a side view of a magnetic resonance imaging system 1 according to a first exemplary embodiment of the invention. Unlike the conventional magnetic resonance imaging system 1, the magnetic resonance imaging system 1 according to a first exemplary embodiment of the invention has a patient seat 2 in which a patient can sit in a semi-upright position. To match the patient seat 2, the scanning unit 3 is equipped with a pivotable gantry 3b, wherein the gantry 3b is designed to be pivotable relative to a support unit 3a on which the gantry 3b is mounted. The support unit 3a also has a base plate 3c, which rests on the floor and functions as a device base. If necessary, the gantry 3b is oriented by the pivoting movement such that the orientation of its longitudinal axis conforms to the orientation of the seat back 2a of the patient seat 2. If a patient sits on the patient seat 2, the backrest orThe headrest area 2b of the patient seat 2 is pushed into the patient opening of the gantry 3b. An image of the patient's head area can then be acquired. In contrast to conventional magnetic resonance imaging systems, the patient can assume the usual sitting position, particularly in the field of dentistry, and does not have to change into a lying position. Furthermore, the gantry 3b can be moved more freely than with a conventional arrangement (see ). Fig. 1) are dimensioned accordingly smaller. Overall, this modification significantly reduces the space requirement of the magnetic resonance imaging system 1, as described in Fig. 4 is clear.

[0049] In Fig. 4 is a plan view of the Fig. 3 illustrates the magnetic resonance imaging system 1 according to an embodiment of the invention. As shown in Fig. 4, the space requirement for the examination room is reduced due to the reduced length of the magnetic resonance imaging system 1 and the patient seat 2. The space requirement of the arrangement according to the invention is typically about 8 to 9 m 2 , which is about half the space required compared to the corresponding conventional arrangement (19 m 2 ) means.

[0050] In Fig. 5 shows a side view of a scanning unit 3 of a magnetic resonance imaging system according to an alternative embodiment of the invention. Unlike in the Fig. 3 and Fig. 4 is the embodiment shown in Fig. 5 is not designed to be pivotable. Instead, the height position of the gantry 3b can be adjusted as required. For this purpose, the gantry 3b has guide elements (in Fig. 5 not shown) which can slide up and down along the support rails of the carrier unit 3a.

[0051] Like one in Fig. 6 shown top view of the in Fig. As illustrated in Figure 5, the magnetic resonance imaging system 1 associated with the scanning unit 3 already illustrated, a patient can sit in an upright sitting position on a patient seat with an upright backrest under the gantry 3b. The gantry 3b is then lowered and positioned at the height of the patient's head to image the patient's head area, for example, the jaw area.

[0052] In Fig. Fig. 7 is a plan view of a base plate 3c and a side view of a pivoting mechanism of the scanning unit 3 of the Fig. 3 and Fig. 4 according to a first embodiment of the invention. The base plate 3c has recesses in which the support elements 3g of the support unit 3a can be fixed. An adjustment and pivoting unit is arranged on the support elements 3g, with which the gantry 3b can be pivoted about a transverse axis and displaced in the vertical direction.

[0053] In Fig. 8 is a side view showing an assembly of the Fig. 3 and Fig. 4 and Fig. 7 of a magnetic resonance imaging system 1 according to an embodiment of the invention. In the following, the Fig. The five partial images shown in Figure 8 are explained in order from left to right. The first partial image shows the individual components of the magnetic resonance imaging system 1 according to an exemplary embodiment of the invention, i.e., the gantry 3b, the carrier unit 3a with two carrier elements 3g, and the base plate 3c arranged one above the other.

[0054] The second partial image shows how the support elements 3g of the support unit 3a are fastened to the base plate 3.

[0055] Subsequently, the third partial image shows that the gantry 3b is suspended between the support elements 3g by means of a pivot bearing 3f.

[0056] The fourth image shows how the gantry 3b is moved upwards to a desired height position. The gantry 3b, or rather its suspension, slides upwards, guided by the vertical grooves shown.

[0057] Finally, the gantry 3b is pivoted into a desired pose, as shown in the fifth partial image on the far right, so that a patient who has sat down on a patient seat with an inclined seat backrest can have his head pushed into the patient opening of the gantry 3b.

[0058] In Fig. 9 is a side view showing an assembly of the Fig. 5 and Fig. 6 for a magnetic resonance imaging system according to an alternative embodiment of the invention. The support elements 3g of the support unit 3a of the scanning unit 3 have guide rails 3e on which a holder 3d of the gantry 3b of the scanning unit 3 can slide. The third partial image from the left shows a positioning of the gantry 3b, wherein the gantry 3b is arranged in the region of the guide rails 3e facing the base plates 3c of the scanning unit 3. In this positioning, the scanning unit 3 takes up little space, therefore this position is particularly well suited for transporting the scanning unit 3. As shown in the partial image on the right in Fig. As can be seen in Figure 9, the gantry 3b can be slid into an upper position on the support elements 3g so that a patient can sit upright underneath.

[0059] In Fig.10 shows a flowchart 1000 illustrating a method for constructing a magnetic resonance imaging system 1 according to an embodiment of the invention.

[0060] In step 10.I, a patient seat 2 is set up, on which a patient can be positioned at least semi-upright before imaging.

[0061] In step 10.II, a carrier unit 3a is set up, which has a vertical translation mechanism that is configured to arrange a gantry 3b of a scanning unit 3 of the magnetic resonance imaging system 1 in a predetermined height position.

[0062] In step 10.III, the gantry 3b is connected to the carrier unit 3a in such a way that the gantry 3b of the scanning unit 3 is arranged to be displaceable in the vertical direction, so that the head of the patient P can be pushed into an annular patient opening of the gantry 3b for imaging.

[0063] Finally, it is pointed out once again that the methods and devices described above are merely preferred embodiments of the invention and that the invention can be varied by a person skilled in the art without departing from the scope of the invention, insofar as it is defined by the claims. For the sake of completeness, it is also pointed out that the use of the indefinite articles “a” or “an” does not exclude the possibility that the features in question may be present in multiple units. Likewise, the term “unit” does not exclude the possibility that it consists of several components, which may also be spatially distributed. Regardless of the grammatical gender of a particular term, persons with male, female or other gender identity are included.

Claims

[1] Magnetic resonance imaging system (1), comprising: - a scanning unit (3) comprising: - a gantry (3b) having a magnet system with a basic field magnet and a patient opening, - a support unit (3a) having a vertical translation mechanism adapted to arrange the gantry (3b) in a predetermined height position, - a patient seat (2) on which a patient (P) can be positioned at least semi-upright during imaging and which is arranged to be displaceable in the horizontal direction relative to the gantry (3b). [2] Magnetic resonance imaging system according to claim 1, wherein the carrier unit (3a) has a pivoting mechanism (3f) which is adapted to pivot the gantry (3b) about a horizontal pivot axis. [3] Magnetic resonance imaging system according to claim 2, wherein the carrier unit (3a) has a locking unit which is designed to lock the gantry (3b) in a desired orientation relative to the horizontal pivot axis. [4] Magnetic resonance imaging system according to claim 2 or 3, wherein the carrier unit (3a) has a pivot angle restriction unit which is configured to restrict a rotation angle of the gantry (3b) relative to the horizontal pivot axis. [5] Magnetic resonance imaging system according to one of claims 2 to 4, wherein the pivoting mechanism (3f) has an adjustment mechanism for determining a mechanically preset pivoting angle which is achieved by a pivoting movement. [6] Magnetic resonance imaging system according to claim 5, wherein the mechanically preset pivot angle determines an orientation of the longitudinal axis of the gantry (3b) in the direction of the longitudinal axis of the upper body of the patient (P). [7] Magnetic resonance imaging system according to one of claims 2 to 6, wherein the pivoting mechanism (3f) has a grid which enables pivoting of the gantry (3b) in a plurality of different predetermined angular steps. [8] Magnetic resonance imaging system according to one of claims 2 to 7, wherein the pivoting mechanism (3f) comprises at least one of the following types of operation: - manual operation, - an electric actuator, - a hydraulic actuation. [9] Magnetic resonance imaging system according to one of claims 2 to 8, wherein the gantry (3b) is designed such that, due to gravity alone, in the intended arrangement, it does not exert a torque which causes a rotation of the gantry (3b) relative to the horizontal pivot axis of the pivot mechanism. [10] Magnetic resonance imaging system according to one of the preceding claims, wherein the carrier unit (3a) is designed to be separable from the gantry (3b). [11] Magnetic resonance imaging system according to one of the preceding claims, wherein the support unit (3a) has a large-area base plate (3c) and vertical support elements (3g) with a small cross-section compared to the area of ​​the base plate (3c). [12] Magnetic resonance imaging system according to one of the preceding claims, wherein the vertical translation mechanism comprises at least one of the following drive types: - a manual drive, - a hydraulic drive, - an electric drive. [13] Magnetic resonance imaging system according to one of the preceding claims, wherein the support unit (3a) has a buffer element for vibration decoupling of the gantry (3b) from a floor on which the support unit (3a) is positioned. [14] A method for constructing a magnetic resonance imaging system (1) according to any one of the preceding claims, comprising the steps: - Setting up a patient seat (2) on which a patient (P) can be positioned at least semi-upright before imaging, - setting up a carrier unit (3a) which has a vertical translation mechanism which is designed to arrange a gantry (3b) of a scanning unit (3) of the magnetic resonance imaging system (1) in a predetermined height position, - Connecting the gantry (3b) to the carrier unit (3a) such that the gantry (3b) of the scanning unit (3) is arranged to be displaceable in the vertical direction, so that the head of the patient (P) can be inserted into a patient opening of the gantry (3b) for imaging.

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