DE102012206922A1 - Receiving coil system for recording electromagnetic signals in MRI scanner that is utilized for imaging body portion of patient, has retention device comprising bracket, where patient desk is attached to bracket for positioning of coils - Google Patents

Abstract

The invention relates to a receiving coil system (2) for a magnetic resonance tomograph (4) having a number of receiving coils (20) and a holding device (18) which comprises a bracket (18) which is fastened to a patient table (12) for adaptable positioning the receiving coils (20).

Description

The invention relates to a magnetic resonance tomograph with a number of receiving coils and the receiving coils themselves.

In a magnetic resonance tomograph so-called surface coils are often used as receiving coils for the recording of electromagnetic signals, which are positioned in close proximity to the body portion of a patient to be examined. In this case, different surface coils are provided for different examinations and for different body regions to be examined, which are structurally adapted to the respective intended use. However, the surface coils are less part of the magnetic resonance tomograph, but rather accessories for the magnetic resonance tomograph, wherein a corresponding surface coil for use relative to the patient to be examined positioned and also with the magnetic resonance tomograph signal technology and / or supply technology must be connected. If a corresponding surface coil is not in use, it is not connected to the magnetic resonance tomograph and is stored at a storage location.

As a result, an operator of the magnetic resonance tomograph must select and position a suitable receiving coil for each examination and connect it to the magnetic resonance tomograph, which is sometimes associated with a relatively high expenditure of time and effort. In addition, for a magnetic resonance tomograph, for example, for cost reasons, often only a relatively small selection of receiving coils available, so that for some patients and / or some investigations only conditionally adapted receiving coils must be used. As a result, then, for example, the quality of the images is impaired, increases the duration of the examination and / or the patient responds to the receiver coil used with claustrophobic anxiety attacks.

Proceeding from this, the object of the invention is to specify an improved magnetic resonance tomograph and improved receiver coils.

The object with respect to the receiver coils is achieved by a receiver coil system having the features of claim 1. The dependent claims include in part advantageous and in part self-inventive developments of this invention.

The receiving coil system is provided for a magnetic resonance tomograph and comprises a number of receiving coils and a holding device with a bracket, which is attached to a patient table, so that with the help of the holding device an adjustable positioning of the receiving coils is made possible. Thus, instead of providing individual receiving coils as accessories for a magnetic resonance tomograph, a receiving coil system tuned to the magnetic resonance tomograph is used instead, which at least with the aid of the holding device to the respective patient, ie the extent of the body of the patient, and the respective examination, in particular the body region to be examined , can be adjusted.

The adaptation is done not only in favor of the shortest possible duration of investigation and / or the highest possible quality of the image data generated, but the operator of the magnetic resonance tomograph is also able, by adjusting the positioning of the receiving coils used for the investigation, the examination for the patient more pleasant and more comfortable. For example, if a patient is prone to claustrophobia, the receiving coil system allows the operator to position the receiving coils used so that the patient feels less constrained, which typically results in sacrificing the quality of the generated image data and / or prolonging the examination time However, this avoids anxiety attacks in the patient, which usually necessitate a termination of the examination or lead to the fact that the generated image data are useless due to the physical reaction of the patient.

In this case, a variant of the receiving coil system in which the patient table comprises a lying board on which the patient is positioned for the examination, and in which the lying board together with the bracket can be moved, is preferred. Magnetic resonance tomographs with a patient table, in which the patient table, or at least a part of the table on which the patient is positioned, can be moved, are known in principle to those skilled in the art and are currently being used. This is intended to facilitate the positioning of the patient on the patient table, which is why the patient table is as accessible as possible before the examination. For the examination, the patient table, or at least the movable part of the patient table, and then together with the patient are moved to the assembly of the magnetic resonance tomograph, with the aid of which the electromagnetic field is generated for the examination. In the position in which the examination then takes place, the patient table and the patient are then typically at least partially surrounded by the corresponding assembly, so that in this situation there is no good accessibility to the patient Patients and is given to the patient table. In the case of the receiver coil system presented here, the holding device, in particular the bracket, with the lying board and the patient is moved with the movable part of the patient table, in this case the lying board, whereby the receiver coils provided for the examination are in an easily accessible position of the lying bed can be positioned relative to the patient and then let proceed with the lying board, without changing their position relative to the patient.

A variant of the receiver coil system is expedient in which the bracket is pivotable between an insertion position and a parking position, whereby, for example, the positioning of the patient on the patient table is facilitated.

According to a further advantageous variant of the receiver coil system, the bracket has a number of joints for adjusting the bracket shape. It is provided in particular with the help of these joints, the contours or silhouette of the patient viewed in the longitudinal direction of the track trace so that the bracket, for example, for a Ganzkörpercan across the entire length of the body away a constant distance to the surface of the good Body of the patient has. If one then positions receiver coils along the bracket, these receiver coils are each arranged at a comparable distance from the patient due to the adapted bracket shape.

Also preferred is an embodiment of the receiver coil system, wherein the bracket is adapted for the transmission of electromagnetic signals. This makes it possible to provide the receiving coils with electrical energy when needed and / or forwarded to the receiving coils electromagnetic signals as measurement signals on the bracket and finally the magnetic resonance tomograph, more precisely a dedicated control and signal processing unit supply. In this way, cable connections, as are customary in receiver coils and in particular in surface coils according to the prior art, can be avoided in the area in which as much free space as possible is needed for positioning the patient and for positioning the receiver coils.

In an advantageous development, at least one receiver coil of the receiver coil system can be adapted. However, this adaptability of this receiver coil is not restricted to a simple possibility for regulating the distance between the bracket and the design of the receiver coil provided as an inductance for the metrological detection of electromagnetic signals, but this design should preferably also be adaptable to the surface shape of the patient's body region. which should be examined with the help of the corresponding receiver coil.

In addition, a variant of the receiver coil system in which the receiver coils have a guide element and in which the guide elements can be positioned along the bracket and in particular can be displaced is advantageous. The aim is to ensure the highest possible flexibility of the receiver coil system and at the same time allow the operator to position and adapt the receiver coil system as simple as possible to the respective patient and the respective examination. This can be achieved, for example, by virtue of the fact that each receiver coil has a simple guide element adapted to the cross-sectional shape of the bracket so that the operator hangs the receiver coils of the receiver coil system respectively selected for the respective examination against the bracket, whereby the corresponding receiver coils are held in such a way by positive locking on the bracket be that further a shift of these receiving coils along the bracket without much effort is possible. Subsequently, the operator moves the corresponding receiving coils along the bracket and thus expediently along the longitudinal direction of the body of the patient in a favorable area for the investigation.

In an advantageous embodiment, each receiving coil preferably in addition to the guide element has a fixing element for fixing the receiving coil on the bracket as required. With the help of the fixing element, the receiving coil is fixed in the desired position, so that an undesired change in the position of the receiving coil is prevented. Recapturing the example described above, therefore, each receiving coil provided for the examination is hung by the operator on the bracket, then moved along the bracket to the desired position and finally fixed in this position.

Furthermore, a receiver coil variant is advantageous in which at least one receiver coil has distance sensors with the aid of which the distance between the receiver coil and the patient can be detected metrologically. These then serve to assist the operator in positioning the receiver coil relative to the patient's body.

In addition, a variant of the receiving coil system is expedient, are provided in the different receiving coils.

A further advantage is a variant of the receiver coil system in which at least one receiver coil is set up for automated adaptation. This coil then directs automatically and preferably fully automatically on the basis of predetermined distance parameters relative to the body of the patient. This can increase the ease of use for the operator and reduce the probability of operator error.

Furthermore, a variant of the receiver coil system is preferred in which the patient table has holders and more preferably holding pens for receiving the guide elements as holders for the receiver coils. Receiving coils not required for the respective examination are then positioned in the corresponding holders or suspended in the holding pens. The receiver coils of the receiver coil system can be accommodated in this way very space-saving and are always ready for the operator when they are needed. A separate storage or even a separate storage room are not necessary. In addition, the proximity of the storage location of the receiving coils to the location of use reduces the likelihood that the receiving coils will be damaged during shipment, for example by the operator abutting with the corresponding receiving coil somewhere or by it falling out of his hand.

The stated object of specifying an improved magnetic resonance tomograph is achieved according to the invention by a magnetic resonance tomograph having the features of claim 14.

The magnetic resonance tomograph is equipped with a receiver coil system according to one of the previously described variants, and is preferably set up such that an automated adaptation of the receiver coil system to the respective patient and the respective examination can be carried out. For a corresponding automated adaptation, distance sensors and a control and evaluation unit are provided, for example, so that the corresponding receiver coils are aligned relative to the body of the patient on the basis of the sensor data and predetermined distance parameters. Alternatively, it is provided as a setpoint for an automated adjustment to specify a value or range of values for the signal-to-noise ratio (SNR) of the measurement signals detected by means of the receiver coils. Here, a value between 20 and 30 has proved to be favorable.

Embodiments of the invention will be explained in more detail with reference to a schematic drawing. Show:

1 in a perspective view a magnetic resonance tomograph with a patient,

2 in a second perspective view of the magnetic resonance tomograph,

3 - 6 four perspective views of a bracket of the magnetic resonance tomograph,

7 - 8th two alternative variants of a receiving coil for the magnetic resonance tomograph,

9 - 10 two alternative variants of the temple,

11 a perspective view of the magnetic resonance tomograph with a further alternative strap variant,

12 in a truncated perspective view a relative to the patient positioned and alternative receiving coil,

13 - 18 various sectional views of different body regions of the patient and receiving coils adapted thereto,

19 a perspective view of the magnetic resonance tomograph with holders for the receiving coil,

20 - 21 two representations of the magnetic resonance tomograph with selected "region of interest",

22 an image sequence for illustrating the procedure for positioning the receiving coils,

23 an enlarged view of a lying-bed with incorporated holding pens,

24 an enlarged view of the lying bed with the bracket in a parking position,

25 a further enlarged view of the lying bed with the bracket in an intermediate position,

26 a further enlarged view of the lying bed with the bracket in an insertion position,

27 a further enlarged view of the lying board with aligned on the body of the patient receiving coil,

28 - 30 three illustrations for adjusting the distance between the receiving coil and the patient's body and

31 - 32 two pictures of a receiver coil with distance sensors.

Corresponding parts are provided in all figures with the same reference numerals.

The variants described below of a receiving coil system presented here 2 are all for a magnetic resonance tomograph 4 provided with the help of imaging medical examinations on a patient 6 can be made according to a known principle.

The magnetic resonance tomograph 4 includes, as in 1 indicated, a hollow cylindrical base unit 8th , in the interior, also tunnels 10 called in operation for the examination of the patient 6 used electromagnetic field is generated. Next is a patient table 12 with a lying-board 14 provided, the patient table outside the base unit 8th is positioned and where the lying board 14 in the tunnel 10 is movable.

Over one end on the bed 14 arranged hinge joint 16 is a strap 18 with cuboid cross section on the bed 14 pivotally attached so that this is the lying board 14 in a longitudinal direction parallel to the central longitudinal axis of the approximately cylindrical tunnel 10 aligned, spanned. Here is the hanger 18 between a parking position, in 2 is shown, and a deployment position, in 1 can be seen, swiveling, the couch 14 together with the hanger 18 regardless of the position of the bracket 18 in the tunnel 10 is movable.

Part of the receiver coil system 2 are still receiving coils 20 , with the aid of which electromagnetic signals can be detected metrologically. The in the receiving coils 20 Coupled electromagnetic signals are via an electrical contact between each receiving coil 20 and the hanger 18 passed on to the same, then over the hanger 18 forwarded and finally to a non-illustrated, as in the base unit 8th integrated, control and evaluation transferred, so that by means of the receiving coils 20 recorded measurement signals processed by the control and evaluation and can be used to generate image data.

For transmitting the corresponding electrical signals from the receiving coils 20 to the temple 18 are in accordance with embodiment of 3 to 5 provided electrical connectors, wherein at each receiving coil 20 a plug 22 is attached and being in the hanger 18 contact bars 24 are incorporated, which serve as a socket for the plug 22 act. Accordingly, the plug can be 22 each receiving coil 20 at any position along the contact rails 24 for producing an electrical contact for the signal transmission in the contact rails 24 plug in and subsequently along the contact rails 24 in the direction of displacement 26 move. As a result, in turn, the receiving coils can be 20 for examination at any position along the temple 18 position and thus favorable relative to the patient 6 align. Alternatively, as in 6 indicated, for each plug 22 an insert element provided as a socket, which with the contact rails 24 connected and slidable along this.

Are all intended for the investigation receiving coils 20 favorable relative to the patient 6 aligned, so does the lying-board 14 together with the patient 6 , the temple 18 and the receiver coils attached thereto 20 in the tunnel 10 procedure, whereby the relative positioning of the receiver coils 20 to the patient 6 meanwhile not changed. The receiver coils 20 So be outside the tunnel 10 where accessibility to the patient 6 to the bed 14 , to the temple 18 and to the receiving coils 20 favorable for an operator, advantageously positioned.

The receiver coil system presented here 2 should not only allow easy handling, but also a good adaptability to the particular patient 6 and ensure their intended investigation. This is achieved on the one hand by the fact that, depending on the examination, a different number of receiving coils 20 is provided, and in that each used receiver coil 20 regardless of the rest relative to the patient 6 Align and / or adapt to the physique. The positionability and adaptability of the receiver coil system 2 can be realized by different, also combinable and preferably simple mechanical adjustment mechanisms.

In 7 and 8th For example, there are two receiving coils 20 pictured, which is a C-shaped guide element 28 have, through which the corresponding receiving coil 20 to an in 9 Pictured variant of the temple 18 hang with a circular cross-section and then along the bracket 18 can be moved. This will cause any positioning along the bracket 18 allows. In the 8th illustrated embodiment variant of the receiver coils 20 is also with a telescopic arm 30 provided so that in this a height adjustment or distance regulation relative to the bracket 18 can be made.

Additional flexibility in positioning the receiver coils 20 is in a variant of the bracket 18 given in 10 is shown. Here are along the strap 18 several joints 32 placed so that the bow shape of the bracket 18 change and in particular to the silhouette of the patient 6 to align. For positioning the receiver coils 20 in this case are the sections of the temple 18 between the joints 32 intended. A similar design of the temple 18 is beyond in 11 to see, for stability reasons, however deviating additionally a crossbar 34 and in three places with the lying-board 14 connected is.

Additional flexibility for the positioning of the receiver coils 20 can also win by the fact that between the parking position and the deployment position additional intermediate positions for the bracket 18 allows, as in 12 is indicated. This variant is particularly favorable if an examination is somewhat laterally on the body of the patient 6 should be performed, eg when an arm or a leg is to be examined.

To adapt the receiver coil system 2 especially to the physique of the patient 6 and / or to the respectively to be examined body region comprises the receiving coil system 2 differently shaped and configured receiving coils 20 and / or the receiver coil system 2 includes customizable receiver coils 20 that like in 12 to 18 represented, deformable and thus are adaptable to the body region to be examined.

To improve the ease of use are also brackets 36 provided, as in 20 in the lower part of the patient table 12 are placed and of which the receiving coils 20 unless they are in use. In this way, the receiving coils can be 20 save space and safely, while being always within reach so that the operator can easily reach them to use them when needed. The operator then dials as in 21 indicated, depending on the region of interest 38 (in short: ROI), that is, depending on the selected examination region, the appropriate number and / or the appropriately shaped receiving coils 20 and positioned this favorable relative to the patient 6 ,

In the embodiment, which in 20 and 21 is shown, it is at the receiving coil 20 around identically formed receiver coils 20 with which the patient is 6 cover strip-shaped. One each receiving coil 20 is constructed of a plurality of tissue-like configured coils which are embedded in a constructed of fiber material and thereby partially overlap in favor of a good signal-to-noise ratio.

Another variant of the receiver coil system 2 is in the cropping and enlargements 22 to 27 shown. In the process, the image sequence built up from five subsequent images is displayed 22 the typical workstation when positioning the receiver coils 20 for the intended examination exemplifies. First, the patient 6 on the couch 14 positioned and meanwhile there are the receiver coils 20 represented by an imaged receiving coil 20 , in a standby position, in which the C-shaped guide element 28 in a T-shaped holding bay 40 on the side of the bed 14 is mounted. In the following each intended for the investigation receiving coil 20 by means of a horizontal sliding movement from the holding bay 40 to the temple 18 postponed until the guide element 28 the receiver coil 20 the temple 18 embraces with its C-shape. The coat hanger 18 is meanwhile in the parking position and is at the side of the bed 14 positioned so close to the guide element 28 during the shift always either by the holding bay 40 , through the hanger 18 or held by both in its vertical position. In this way it can be ensured that the operator has the receiving coil 20 meanwhile, it can not accidentally fall off. As a result, the hanger becomes 18 pivoted from the parking position to the operating position and the receiving coil 20 is then by means of the guide element 28 along the temple 18 until shifted to the desired position of the receiver coil 20 in the longitudinal direction of the patient 6 is reached. Finally, the bobbin provided as inductance for the metrological detection of the electromagnetic signals of the receiving coil 20 to the surface of the patient's body 6 moved to between the bobbin and the surface of the patient's body 6 a favorable distance d is given.

In the exemplary embodiment, the distance d stands for the smallest given distance between the bobbin and the surface of the patient's body 6 , For this smallest given distance d, a predetermined value which is favorable for the signal-to-noise ratio is predetermined. The currently given smallest distance d is achieved by means of distance sensors positioned on the bobbin 42 represented in 31 and 32 , determined. The operator then moves the bobbin relative to the surface of the patient's body 6 until the metrologically detected current smallest given distance d corresponds to the predetermined target value. Alternatively, an automatic with a control unit is provided, with the aid of which the adjustment described above takes place fully automatically on the basis of the predetermined desired value.

The invention is not limited to the embodiment described above. Rather, other variants of the invention can be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, all the individual features described in connection with the exemplary embodiment can also be combined with each other in other ways, without departing from the subject matter of the invention.

LIST OF REFERENCE NUMBERS

2

Receiver coil system

4

MRI Scanner

6

patient

8th

base unit

10

tunnel

12

patient table

14

Prone board

16

hinge

18

hanger

20

receiving coil

22

plug

24

contact bar

26

displacement direction

28

guide element

30

telescopic arm

32

joint

34

locking latch

36

bracket

38

Region Of Interest

40

holding book

42

distance sensor

d

distance

Claims (15)

Receiving coil system ( 2 ) for a magnetic resonance tomograph ( 4 ) with a number of receiving coils ( 20 ) and a holding device ( 18 ), which is a bracket ( 18 ) which is attached to a patient table ( 12 ), for adaptable positioning of the receiving coils ( 20 ). Receiving coil system ( 2 ) according to claim 1, wherein the patient table ( 12 ) a lying-board ( 14 ) and wherein the lying board ( 14 ) together with the bracket ( 18 ) is movable. Receiving coil system ( 2 ) according to claim 1 or 2, wherein the bracket ( 18 ) is pivotable between a use position and a parking position ( 16 ). Receiving coil system ( 2 ) according to one of claims 1 to 3, wherein the bracket ( 18 ) a number of joints ( 32 ) has to adapt the bow shape. Receiving coil system ( 2 ) according to one of claims 1 to 4, wherein the bracket ( 18 ) is arranged for the transmission of electromagnetic signals ( 24 ). Receiving coil system ( 2 ) according to one of claims 1 to 5, wherein at least one receiving coil ( 20 ) is customizable ( 30 ). Receiving coil system ( 2 ) according to one of claims 1 to 6, wherein the receiving coils ( 20 ) a guide element ( 28 ) and wherein the guide elements ( 28 ) along the bracket ( 18 ) are positionable and in particular displaceable. Receiving coil system ( 2 ) according to one of claims 1 to 7, wherein each receiving coil ( 20 ) has a fixing element for fixing the receiving coil as required ( 20 ) on the bracket ( 18 ). Receiving coil system ( 2 ) according to one of claims 1 to 8, wherein at least one receiving coil ( 20 ) Distance sensors ( 42 ) having. Receiving coil system ( 2 ) according to one of claims 1 to 9, wherein different receiving coils ( 20 ) are provided. Receiving coil system ( 2 ) according to one of claims 1 to 10, wherein at least one receiving coil ( 20 ) is set up for an automated adjustment ( 42 ). Receiving coil system ( 2 ) according to one of claims 1 to 11, wherein the patient table ( 12 ) Brackets ( 40 ) for the receiving coils ( 20 ) having. Receiving coil system ( 2 ) according to claim 8 and 12, wherein the patient table ( 12 ) as brackets ( 40 ) for the receiving coils ( 20 ) Holding bays ( 40 ) for receiving the guide elements ( 28 ) having. Magnetic resonance tomograph ( 4 ) with a receiver coil system ( 2 ) according to one of the preceding claims. Magnetic resonance tomograph ( 4 ) according to claim 14, wherein the receiver coil system ( 2 ) is set up for an automated adjustment ( 42 ).

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