DE102019213406B4 - Coil device with integrated sensors for magnetic resonance imaging and magnetic resonance system - Google Patents

Abstract

Coil device (9) for magnetic resonance imaging, having a cage coil (10) with a plurality of electrical conductors (14) which are distributed in the circumferential direction of the cage coil (10) and are connected to one another by at least one ring structure (15) of the cage coil (10). , wherein at least one of the conductors (14, 16) is designed at least in sections as a hollow rod (16), and- a sensor system (13) arranged in or on the hollow rod (16), with a connecting line for connecting the sensor system (13) from this is guided through the hollow rod (16) along a longitudinal extension direction of the latter to a connection point arranged on the outside of the cage coil (10), characterized in that the plurality of electrical conductors (14) distributed in the circumferential direction of the cage coil (10) run parallel to one another, and that the hollow rod (16) is lengthened in the longitudinal direction compared to the other conductors of the cage coil (10) running parallel thereto, so that the hollow rod (16) has a section (20) protruding outwards beyond an end ring structure (15) of the cage coil (10), the connecting line (19) being routed through this section (20).

Description

The invention relates to a coil device for magnetic resonance imaging and a magnetic resonance system with such a coil device.

Although magnetic resonance imaging is now an established imaging method in medical technology, there is still interest and a need for further developments and improvements, since these can directly benefit the patient's well-being. In the course of development and with advances in data processing, the interest in additional data and corresponding sensors is also increasing. Due to the often very limited space available in conventional magnetic resonance systems and the relatively strong electromagnetic fields that occur during operation, in combination with increased measurement sensitivity compared to previous systems, the problem arises that the accommodation and use of additional sensors in magnetic resonance systems has only been possible to a very limited extent and practicable was then also associated with considerable effort. For example, metallic components of a sensor system arranged in a measurement area of a magnetic resonance system, as well as their connection and supply cables, can lead to interactions with the magnetic resonance measurement system and thus ultimately to interference or image artifacts in the resulting MR images.

Against this background, free positioning of additional sensors is often not practicable, which ultimately limits the diagnostic options in magnetic resonance imaging.

Previous approaches to solutions include, for example, the use of complex electromagnetically shielded cables for a power supply, a large number of complex iterative simulations and tests to optimize cable routing, optical data transmission via fiber optic cables and, if necessary, the installation of the respective sensors within a tube of the respective magnetic resonance system intended for patient admission. However, the process, material and cost expenditure associated with these approaches, as well as the achievable results, are often unsatisfactory.

From the pamphlet U.S. 2008/0 272 786 A1 a receiving antenna for a magnetic resonance signal is known, which has a plurality of electrical conductors. At least one of the electrical conductors is a substantially hollow conductor. At least one electrical component is placed inside the hollow conductor to protect it from interference from a magnetic resonance signal.

The publication “MRC / MRC SYSTEMS GmbH: MRI compatible video cameras. Release date 03/03/2018. (URL: https://web.archive.org/web/20180403213627/http://www.mrcsyst ems.de/en/products/mr-compatible-cameras)" describes video cameras that have been developed for use in magnetic resonance tomographs . The cameras do not show any interactions with the magnetic resonance imaging.

The object of the present invention is to create improved examination options for magnetic resonance imaging. According to the invention, this object is achieved by the subject matter of the independent patent claims. Advantageous refinements and developments of the present invention are specified in the dependent patent claims, in the description and in the figures.

A coil device according to the invention is provided for magnetic resonance imaging and is designed accordingly. The coil device can therefore be used, for example, in or as part of a magnetic resonance system or in connection with or in combination with a magnetic resonance system for magnetic resonance imaging. In particular, the coil device can be embodied as an HF coil (HF: high frequency), ie for generating a high-frequency electromagnetic field, or can comprise such an HF coil. The coil device according to the invention has an (HF) squirrel-cage coil with a plurality of electrical conductors which are distributed in the circumferential direction of the squirrel-cage coil, i.e. over its at least essentially cylindrical or polygonal lateral surface, and in particular extend at least essentially parallel to one another. These conductors are connected to one another by at least one annular structure of the cage coil, which in particular runs transversely thereto. The cage coil can preferably have, for example, two end or front-side ring structures of this type, between which the conductors extend. In a manner known per se from conventional birdcage coils, the at least one ring structure can have electrical or electronic elements, such as capacitive components or components, by which the electrical conductors are electrically isolated from one another, and/or the like.

The squirrel-cage coil can be designed as a so-called body coil, which can be or can be integrated into a magnetic resonance system and there then has a cylindrical or tubular receiving space for the objects to be examined may surround patients. The cage coil can then have a diameter of approximately 50 cm to 80 cm, for example, and a length of at least 1 m, for example. The squirrel-cage coil or the coil device can also be designed as a smaller movable or mobile unit in comparison. Such a mobile unit can be provided, for example, for examining individual parts of the body or extremities, for example a head, an arm or a leg, of a patient.

According to the invention, it is provided that at least one of the conductors is designed as a hollow rod, at least in sections. In other words, this conductor designed as a hollow rod has an interior space that extends at least in a partial section of the hollow rod along its longitudinal direction in the hollow rod and is surrounded in the circumferential direction by a conductive material of the conductor. At least one end face of the hollow rod can be open, so that the interior is accessible from outside the hollow rod. The at least one electrical conductor can therefore be designed as a tube.

A shape or a cross section of the hollow rod can in principle be chosen at will. The hollow rod can, for example, have an oval or round cross section, that is to say it can be at least essentially cylindrical in shape. However, the hollow rod can also have, for example, a rectangular, regular or irregular polygonal cross section or a freely shaped cross section. The selection of the cross-section of the hollow bar can depend on the electromagnetic requirements for the cage coil and its application or environmental conditions in individual cases.

The coil device according to the invention also has a sensor system arranged in or on the hollow rod, with a connection line for connecting the sensor system being routed from this along the longitudinal direction of the hollow rod through the latter to a connection point or contact point arranged on the outside of the cage coil. This connection or contact point can be located on the cage coil or on another part of the coil device and/or, for example, be an end of the connecting line that is led out of the hollow bar and the cage coil.

The connection line can be designed to supply the sensor system with energy and/or for electrical or optical data transmission from the sensor system. The connection line can be a single line or a single cable, but it can also include a number of individual lines or individual cables.

The interior of the hollow rod represents an electromagnetically shielded area. The routing of the connecting cable through the hollow rod can therefore advantageously lead to or contribute to electromagnetically shielding the connecting cable and thereby prevent interactions or interference between the connecting cable or the sensor system on the one hand and other components, in particular a measuring device or a measuring system for magnetic resonance imaging, on the other hand to be avoided or minimized.

A further advantage of routing the connecting line through the hollow rod is that in this way space or installation space can be saved and thus a particularly compact design of the coil device or the corresponding magnetic resonance system can be implemented overall. The same applies to the sensor system itself, since at least parts of the sensor system can also be arranged in the hollow rod, ie in its at least partially electrically shielded interior. If the sensor system is arranged entirely or partially outside of this interior space, advantages can still result, since, for example, the connection line can be routed directly in the area of the sensor system through a wall of the hollow rod or an opening in the wall of the hollow rod to the sensor system. This also enables a particularly compact and space-saving arrangement, simplifies electromagnetic shielding and thus the avoidance of interactions or interference and can enable a mechanically particularly safe and robust arrangement, since, for example, the risk can be avoided that the connecting cable can be damaged by an object to be examined, for example a Patient that is introduced into a receiving space surrounded by the cage coil, can be damaged or torn off.

Overall, the present invention creates the possibility of a technically simplified and less fault-prone electrical connection of sensors in or on the cage coil or in the area of a recording tube of a magnetic resonance system, ie the recording area provided for recording a respective patient. This can advantageously result in cost and effort savings in the development and production and also in the operation of systems for magnetic resonance imaging.

In addition, because of the reduced interactions or interference compared to conventional solutions, an improved image quality of the respective magnetic resonance images can be achieved with the same number of sensors. In addition, the present invention makes it possible arranging and operating more and/or other sensors in a magnetic resonance system without significant negative effects on the MR imaging, which does not appear to be practicable with the magnetic resonance systems that are customary today. The present invention thus advantageously results in new possible applications, through which ultimately the magnetic resonance imaging and thus the diagnosis or examination possibilities can be improved.

It is also advantageous that new design degrees of freedom can result from the presently proposed solution. For example, previous monolithic sensor systems, which include both an actual sensor and associated electronics and data processing equipment, can be divided into cost-intensive and inexpensive components. Inexpensive components, such as a respective sensor, such as a CCD chip or the like, can then always be permanently installed in or on the coil device, while cost-intensive components, such as associated electronics, data processing and/or software, can be outsourced and only can be provided or used as needed. This modular structure with spatial separation of the components of the sensor system is only made possible by the improved routing of the connecting line according to the invention.

A particular advantage of this splitting up of the components and the fixed installation of the inexpensive components in or on the coil device is that in this way an improved electromagnetic shielding of the components installed permanently in or on the coil device can already be provided at the factory or by the manufacturer and is therefore particularly compact and reliable can be reached. In addition, these components can be calibrated in a particularly precise, reliable and permanently stable manner, for example with regard to their alignment or arrangement relative to other components or predetermined reference points of the coil device. As a result, a corresponding alignment and calibration effort during operation of the coil device or the corresponding magnetic resonance system and an associated error susceptibility or error probability can be reduced, which can ultimately benefit the quality of the respective examination results.

Finally, the present invention advantageously also offers the possibility of arranging the sensor system to be better hidden, ie not visible or less easily visible to a patient arranged in the recording room or in the cage coil, ie to integrate it into the coil device or the speaking magnetic resonance system. This can advantageously contribute to the patient being examined feeling more comfortable during the examination and thus being more relaxed and calmer, which can ultimately contribute to improved acceptance of examinations using magnetic resonance imaging and to improved image quality.

Compared to the other conductors of the cage coil running parallel thereto, the hollow rod of the coil device according to the invention is lengthened in the longitudinal direction of the hollow rod—and thus in the longitudinal direction of the cage coil—so that the hollow rod has a section that protrudes outwards beyond a front-side or end-side ring structure of the cage coil. The hollow rod or this section of the hollow rod thus protrudes beyond a main body or a remainder of the cage coil. The connection line is routed through this section. In other words, at least part of this protruding section is hollow and accommodates at least part of the connection line.

If the components or elements of at least the main body of the cage coil or the coil device are arranged in a housing or a casting compound, the section of the hollow rod mentioned can protrude from this housing or this casting compound or can be arranged in a corresponding extension of the housing or at least partially into the or one potting compound be poured.

By extending the hollow rod beyond a length of the remaining parallel conductors, the connection line can advantageously be routed in a particularly reliably shielded manner to a greater distance from the main body or the other components of the cage coil or the coil device, in particular to the receiving space surrounded by it. This can result in interactions or interference, which can emanate, for example, from the connection point, an end point of the hollow rod or a point at which the connecting line is routed out of the hollow rod, or corresponding undesirable influences on the image quality of the respective MR images and/or on the Measured values supplied by sensors can be further reduced. Particularly advantageously, the hollow rod can be designed in one piece over its entire length or at least from its distal end of the extension to the sensor system, as a result of which particularly good and reliable electromagnetic shielding of the connecting line can be implemented.

In an advantageous embodiment of the present invention, the connection line is designed as a twisted Pair cable formed. In other words, the connection line has at least one twisted pair of wires. This configuration of the connecting line can advantageously be used to correct or compensate for or minimize interference or disruptive influences on the sensor system induced by a gradient activity of the magnetic resonance system. As a result, an improved image quality can be achieved on the part of the magnetic resonance imaging and measured values with fewer interferences can be achieved on the part of the sensor system arranged in or on the cage coil.

In an advantageous development of the present invention, the length of the section of the hollow rod protruding longitudinally beyond the ring structure on the end face is designed as a function of a predetermined typical frequency of an electromagnetic field generated by the coil device when it is operated. The length of this section is designed in such a way that the length of the section is not equal to an integer multiple of half a wavelength of the electromagnetic field of the typical predetermined frequency in order to minimize the power radiated via this section of the hollow rod.

The specified typical frequency can be, for example, a design or operating frequency or a frequency at which the radiation generated by the cage coil has its highest intensity or its power maximum.

The corresponding length or design of the hollow rod can preferably apply not only to a single frequency, but to a frequency range that includes a corresponding intensity or power peak in the radiation spectrum of the cage coil.

The frequency-dependent design of the hollow rod proposed here can advantageously minimize an influence of the extended section on a function or HF characteristic of the cage coil or a corresponding HF circuit of the coil device or the magnetic resonance system. Due to the minimization of the radiated power achieved in this way, a deterioration in the image quality of the respective MR images can ultimately be avoided at least essentially without additional loading of electrical components of the coil device or the magnetic resonance system, for example an amplifier.

In a further advantageous embodiment of the present invention, the sensor system comprises at least one camera, that is to say an optical sensor, for example a CCD chip, optionally including associated optics. In this case, this camera is directed in the direction of the recording space surrounded by the cage coil in order to enable imaging of a respective examination object that may be arranged therein. Due to the possibilities described for the compact, space-saving arrangement and connection of the sensor system, the camera can advantageously be arranged at least almost anywhere along the longitudinal direction of the cage coil, in particular without or with only an insignificant reduction in a usable volume or diameter of the examination object that can be used for arranging the examination object recording room. These options, which cannot be implemented in practice with previous solutions, can enable, for example, a particularly precise, more reliable and effective movement compensation when reconstructing respective MR images using image data of the respective examination object recorded by the camera.

In addition or as an alternative to the camera, the sensor system can include at least one microphone, a shock or vibration sensor, a temperature sensor and/or the like.

In a further advantageous embodiment of the present invention, the sensor system accordingly has a plurality of individual sensors which are arranged distributed over a longitudinal extension direction of the cage coil or the hollow rod or a plurality of correspondingly equipped hollow rods. The direction of longitudinal extent of the cage coil corresponds to the direction of longitudinal extent of the conductors or, in the case of an at least essentially cylindrical shape or basic shape of the cage coil, to a direction of a central longitudinal axis or cylinder axis of the corresponding cylinder. The direction of longitudinal extent can therefore be, for example, at least essentially perpendicular to a main plane of extent of the at least one ring structure. The plurality of individual sensors can be connected or linked here in the manner described by the or a respective connection line that runs inside the hollow rod or the corresponding hollow rods. If the individual sensors are arranged on different parallel conductors, several of these conductors can be designed entirely or partially as a hollow rod. If a plurality of individual sensors are arranged in a hollow rod, these can be linked or connected by means of a respective separate connection line or by the same connection line.

The multiple individual sensors can be completely or partially the same or similar or under be different For example, one or more cameras, microphones, shock or vibration sensors, temperature sensors and/or the like can be present as part of the sensor system.

The fact that the sensor system has several individual sensors has the advantage that more detailed data or knowledge can be obtained, depending on the type of individual sensors, for example about the recording room, the respective examination object arranged therein, an operating state or an operating characteristic of the coil device or the magnetic resonance system and/or the like . The spatially distributed arrangement of the individual sensors enables a particularly detailed measurement or data acquisition. Depending on the type of individual sensors, this can enable, for example, improved movement correction, more precise planning or control of a respective examination, improved monitoring of the coil device or the magnetic resonance system and/or the like.

In a further advantageous embodiment of the present invention, the sensor system is arranged in a housing that at least partially shields the sensor system electromagnetically. Parts of the conductor, which is designed at least in sections as a hollow rod and are arranged on opposite sides of the housing, are connected to one another through the housing in a high-frequency conducting manner. The housing can thus interrupt the conductor when viewed as a component, ie it can be inserted between the two parts of the conductor. The housing can also be integrated into the conductor, for example in the form of a thickening of the hollow rod. The two parts of the conductor which are arranged on different sides of the housing can therefore be connected to one another both in a high-frequency conducting manner and mechanically, either directly or through the housing. In this case, the two parts of the conductor can be formed as individual components or together as a one-piece component.

The housing can be designed in one piece or in multiple parts, for example having a high-frequency conducting outer part, ie an outer housing, and an inner part, ie an inner housing. In this case, for example, the outer housing can function as a Faraday cage, while the inner housing can be designed to be electrically insulating, for example. The inner housing can then be used to accommodate or hold the sensor system, which in this way can be or can be electrically insulated in a particularly simple and effective manner from the high-frequency conducting outer housing or the hollow rod or conductor.

Due to the fact that in the present case the housing is integrated into the cross section of the conductor, that is to say it is not only fastened to a side wall of the conductor from the outside, a particularly space-saving arrangement is advantageously made possible. Due to the high-frequency conducting design of the housing, this can take over the function of the conductor in sections, which means that the housing is therefore multifunctional. This can advantageously save not only in installation space, but also in material and possibly costs. Any asymmetry of the cage coil caused by the housing can be compensated for by a corresponding compensating design or design of the remaining conductors, so that the housing does not have to have a significant influence on the function of the cage coil. This can be implemented cost-effectively, for example, using simulation and design techniques that are known per se. Depending on the size of the sensors and the conductors, however, all conductors can also be of the same or uniform design, at least in terms of their external shape, in order to avoid asymmetry in the cage coil and thus, in a particularly simple manner, to ensure the homogeneity of the electromagnetic field generated by the cage coil, at least in one ensure the central area of the recording room.

In an advantageous development of the present invention, the housing has an opening which faces the receiving space surrounded by the cage coil. As described, this recording space is the volume in which, for example, during operation or use of the coil device in a magnetic resonance system, a patient to be examined or to be imaged using magnetic resonance technology is arranged. The sensor system is aligned with the opening in order to detect or record the recording space through this—or during operation or during an examination, an examination object arranged therein or signals or radiation emitted by it. With this configuration, the size of the opening can advantageously be adapted to the respective sensor system and thus be of a minimal size, so that the sensor system can effectively detect the receiving space, but at the same time it is surrounded as much as possible by the housing, i.e. it is electromagnetically shielded by it in the best possible way .

The opening can preferably be designed as a window, which can be closed with a transparent material, for example. In this way, the sensor system can detect the recording space through the window, but is at the same time protected from mechanical interference or damage and the entry of dust or dirt, resulting in consistency and reliability of the function or the function ing of the sensors can be improved. Due to the integrated arrangement of the sensor system, the transparent material of the window can optionally serve as an optical element, for example be shaped as a lens. This can advantageously result in further savings in terms of components and installation space.

If several individual sensors are present as described, then several openings in the housing and/or several respective housings can be present accordingly, for example.

In addition to the sensors, other electrical or electronic components can also be arranged in or on the cage coil in a corresponding manner. These additional electrical or electronic components can thus also be fully or partially integrated into the or a corresponding hollow rod and/or connected by the or a connecting line routed through the or a corresponding hollow rod. At least one light source can be provided as such an additional component, for example, by means of which a respective examination object arranged in the recording space can be irradiated or illuminated. On the one hand, this can promote the well-being of the examination object, ie, for example, a patient, but, on the other hand, it can also support the sensor system, ie, for example, facilitate or improve imaging or recording of the examination object using the sensor system. A spectrum of the light source or radiation emitted by it does not have to be limited to the optical or visible range, but can additionally or alternatively include other spectral ranges, for example infrared.

A further aspect of the present invention is a magnetic resonance system that has a magnetic structure for generating magnetic fields for magnetic resonance imaging in a recording space surrounded by the magnetic structure. The magnet structure is or comprises a coil device according to the invention. The magnetic resonance system according to the invention can therefore in particular be the magnetic resonance system mentioned in connection with the coil device according to the invention. Accordingly, the magnetic resonance system according to the invention can have some or all of the properties and/or components or assemblies mentioned in connection with the coil device according to the invention.

In an advantageous development of the present invention, the magnetic resonance system has a data processing device which is connected to the sensor system by means of the connection line and is designed to receive and process raw data signals sent by the sensor system via the connection line. The data processing device is arranged outside the cage coil or outside the coil device, in particular outside the magnet structure. The arrangement proposed here makes it possible to avoid undesired interference or interaction between the data processing device and the magnetic structure in a particularly simple and effective manner. In addition, the data processing device can advantageously be made larger and more powerful than would be practicable in a spatial combination with the sensor system, ie an arrangement of the data processing device in the immediate spatial vicinity of the sensor system. As a result, advantageously improved options and/or a higher speed in data processing can be achieved.

The sensor system is advantageously designed here to transmit only raw data to the data processing device, which in the sense of the present invention can be at least essentially unprocessed sensor data or measurement signals. For example, analog measurement or output signals generated by the sensor system or a sensor of the sensor system can be transmitted in analog form via the connection line to the data processing device. As a result, signal processing or signal conversion, that is to say corresponding components and corresponding installation space, can advantageously be saved on the part of the sensors. However, at least partial conversion or processing of the measurement signals by the sensor system is also possible, with components and/or installation space being able to be saved to varying degrees depending on the configuration compared to conventional solutions, for example depending on the respective requirements or conditions in the individual case.

The magnetic resonance system can particularly preferably have a control device that is designed and set up to control the magnetic resonance system or the magnet structure as a function of measurement, raw data or other output signals sent by the sensor system and/or as a function of data processing results generated therefrom by the data processing device . For example, the sensor system can detect or generate a movement, a state, a kind or a type of the respective examination object or corresponding measurement signals or sensor data characteristic of this. Based on this, the magnetic resonance system or the magnet structure can then automatically, preferably dyna mixed during the magnetic resonance measurement or magnetic resonance imaging. For example, the timing of an MR sequence can be set or adjusted depending on the movement or type of the examination object, individual measurements or recordings or parts of an MR sequence can be automatically repeated if the range of motion detected is above a predefined threshold value, and/or the like . Likewise, for example, before the start of the MR measurement or MR imaging, it can be determined as the type of examination object, for example whether the patient is calm or restless or active or the like. Depending on this kind or this type or this characteristic of the patient, a specific one of a number of predefined MR sequences or a specific one of a number of predefined parameter sets for the MR system can then be selected or suggested to the respective operating personnel. The sensor data required for such measures can only be obtained in a practicable manner by the present invention.

Said control device can be part of the data processing device, for example. The control device and/or the data processing device can have a process, ie for example a microchip, a microcontroller, a hardware circuit or the like, and a data memory connected thereto. An operating program can be stored on the data memory, which encodes corresponding commands or control instructions for the control device, the data processing device and/or the magnetic resonance system and can be executed by the processor, in particular automatically.

The invention also includes developments of the various aspects of the invention, ie in particular the coil device according to the invention and the magnetic resonance system according to the invention, which have features that are only described in connection with one or some of these aspects of the invention. In order to avoid unnecessary redundancy, the corresponding developments of the present invention are not described again separately here for all aspects of the present invention.

The invention also includes the combinations of features of the described embodiments.

• 1 eine schematische Darstellung einer Magnetresonanzanlage;
• 2 eine schematische ausschnittweise Perspektivansicht einer Spuleneinrichtung der Magnetresonanzanlage; und
• 3 eine schematische ausschnittweise Perspektivansicht einer alternativen Ausgestaltung der Spuleneinrichtung.

Exemplary embodiments of the invention are described below. For this shows:

• 1 a schematic representation of a magnetic resonance system;
• 2 a schematic partial perspective view of a coil device of the magnetic resonance system; and
• 3 a schematic partial perspective view of an alternative embodiment of the coil device.

The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual features of the invention that are to be considered independently of one another and that each also develop the invention independently of one another. Therefore, the disclosure is also intended to encompass combinations of the features of the embodiments other than those illustrated. Furthermore, the described embodiments can also be supplemented by further features of the invention that have already been described.

In the figures, the same reference symbols designate elements that have the same function or correspond to one another.

1 shows a schematic representation of a magnetic resonance system, which is referred to here as MR system 1 for short. The MR system 1 has an examination or recording room 2 in which, in the present case, a patient 3 to be examined or imaged is arranged. In order to record MR data (MR: magnetic resonance) of the patient 3, the MR system 1 has a magnet structure 4, which is indicated only schematically here and which completely or partially surrounds the recording space 2 at least essentially in a ring shape. In the present case, the magnet structure 4 is connected to a data processing device 5 of the MR system 1 . The data processing device 5 is designed and set up to process magnetic resonance data recorded or measured by means of the magnet structure 4, for example in order to generate an MR image of the patient 3 therefrom. Likewise, the data processing device 5 can be designed to control the magnet structure 4 . For this purpose, the data processing device 5 in the present case has a processor 6 and a data memory 7 connected to it. To control or operate the magnet structure 4, the MR system 1 can also have other components not shown here in detail, such as a signal or pulse generator, an HF amplifier, corresponding electrical lines and/or the like. Furthermore, a display 8 is shown schematically here, which is connected to the data processing device 5 and via which MR images generated, for example, can be output.

Additional sensors that differ from the actual magnet structure 4 or are not based on magnetic resonance technology can be useful for increasingly complex and improved examination options within the framework of magnetic resonance imaging. Up to now, such sensors have been arranged, for example, in the narrowly limited receiving space 2 that can only be produced sufficiently large with considerable effort. So-called in-bore sensors of this type have hitherto typically been equipped with local electronics and data processing, including an optical signal converter, in order to optically route data or signals from the sensor out of the recording space 2 . Overall, such solutions are associated with considerable expense and an undesirable restriction of the volume available for the patient 3 in the receiving space 2, as well as other disadvantages.

In order to avoid these disadvantages, the magnet structure 4 in the present case has a coil device 9 with a cage coil 10 surrounding the receiving space 2 (see FIG 2 , 3 ) on. In the present case, housings 11 are integrated into the cage coil 10 and each have an opening 12 towards the receiving space 2 . In each case a sensor system 13 is arranged in the housings 11, which in the present case can comprise a camera, for example. The patient 3 can be imaged or detected through the respective opening 12 by means of the respective sensor system 13 , in particular also while MR data of the patient 3 are recorded by means of the magnet structure 4 .

The cage coil 10 has, as shown schematically in 2 is shown, several parallel conductor bars 14, of which only some are marked here for the sake of clarity. The parallel conductor bars 14 are held or connected to one another by ring structures 15 on the face side. In the present case, at least one of the conductor bars 14 is designed as a hollow bar 16 . The housing 11 is integrated into this hollow rod 16 so that a first part 17 and a second part 18 of the hollow rod 16 extend on two opposite sides of the housing 11 . The first part 17 and the second part 18 of the hollow rod 16 are connected to one another through the housing 11 in a high-frequency manner.

An interior of the housing 11 is connected to an inner cavity of the hollow rod 16. A connecting line 19 for connecting or supplying the sensor 13 is routed through the hollow rod 16 from the sensor 13 or the housing 11 to the cage coil 10. The connecting line 19 can be designed both for the electrical supply of the sensor system 13 and for data and/or signal transport to and from the sensor system 13, for example from or to the data processing device 5.

The connection line 19 can be divided into several partial strands. For example, a partial strand of connecting line 19 intended for data or signal transmission can be routed at least in sections through a different hollow rod 16 than a partial strand of connecting line 19 intended for supplying power or energy to sensor system 13. In this way, the various partial strands of connecting line 19 can be separated effectively be isolated in order to avoid or reduce interference, for example crosstalk or the like.

3 shows a schematic perspective view of a detail of the coil device 9 or the cage coil 10 in a further embodiment. In the embodiment shown here, the hollow rod 16, in which the connection line 19 is routed, is lengthened in the longitudinal direction beyond one of the ring structures 15. In a corresponding extension 20 of the hollow rod 16 the connection line 19 is guided electromagnetically shielded to a greater distance from the part of the receiving space 2 surrounded by the cage coil 10 than would be possible without the extension 20 . A connection or contact point at which the connection line 19 leaves the cage coil 10 or the coil device 19 can be arranged, for example, at an end of the extension 20 facing away from the housing 11 or the ring structures 15 . Here, for example, contact can be made with the data processing device 5 .

The different in 2 respectively 3 The details shown can be transferred mutually and individually between the different configurations of the coil device 9 or the cage coil 10 . For example, in the in 3 shown embodiment, the hollow rod 16 can be divided into two or in the 2 the embodiment shown, the hollow rod 16 can be extended beyond the ring structure 15 on the end face.

The at least one hollow rod 16 is designed as an electrical conductor here, as described, so that its interior is an at least essentially HF field-free space. Conventional electrical supply and/or discharge lines can thus be routed at least essentially without interference through the hollow rod 16, i.e. in the HF field-free space, so that the connection line 19 advantageously does not have to be in the form of a fiber optic cable or the like. A radio frequency connection or contacting the cage coil 10 can be designed and positioned as in conventional cage coils or magnetic resonance systems, so that advantageously no new design has to be developed for this aspect if the coil device 9 or cage coil 10 proposed here is used.

In order to detect specific areas of the recording space 2 or of the patient 3 by means of the sensor system 13, the sensor system 13 or its housing 11 can be arranged on or in different conductor bars 14 depending on the alignment or orientation of the cage coil 10, or the cage coil 10 can be rotated accordingly . Further sensors 13 can also be arranged on or in some or all of the remaining conductor bars 14 . The recording space 2 or the patient 3 can then advantageously be recorded simultaneously from different viewing angles. If the sensor systems 13 include a plurality of cameras or optical sensors, a stereoscopic or 3D image of the patient 3 can advantageously be recorded in this way, for example in order to obtain a three-dimensional movement profile of the patient 3 during the recording of the MR data--e.g. for a motion-compensated MR Image reconstruction - to generate.

However, in addition to or as an alternative to the at least one camera, the sensor systems 13 can be or include further and/or other sensors or sensor types. For example, at least one vibration sensor can be arranged in or on the or a hollow rod 16 . Such a vibration sensor can be arranged in a closed housing 11 which therefore does not have to have an opening 12 towards the receiving space 2 . Such a vibration sensor can, for example, measure vibrations or shocks of the MR system 1 or specifically of the cage coil 10 . A maintenance interval or maintenance time for predictive maintenance of the MR system 1 can, for example, be determined on the basis of the measured vibrations. With the structure proposed here, a corresponding vibration sensor—just like other types of sensors—can be flexibly positioned in comparison to conventional magnetic resonance systems without disrupting or influencing the magnetic resonance imaging, also on or in components or locations that previously appeared unsuitable for this or were inaccessible.

Overall, the examples described show how an intelligent cage coil arrangement for magnetic resonance imaging can be implemented by means of a corresponding built-in sensor device in order to create improved examination options.

Claims (9)

Coil device (9) for magnetic resonance imaging, having - a cage coil (10) with a plurality of electrical conductors (14) which are distributed in the circumferential direction of the cage coil (10) and are connected to one another by at least one ring structure (15) of the cage coil (10). , wherein at least one of the conductors (14, 16) is designed at least in sections as a hollow rod (16), and - a sensor system (13) arranged in or on the hollow rod (16), with a connecting line for connecting the sensor system (13) from this is guided through the hollow rod (16) along a longitudinal extension direction of the latter to a connection point arranged on the outside of the cage coil (10), characterized in that the plurality of electrical conductors (14) distributed in the circumferential direction of the cage coil (10) run parallel to one another, and that the hollow bar (16) is lengthened in the longitudinal direction in comparison to the other conductors of the cage coil (10) running parallel thereto t, so that the hollow rod (16) has a section (20) protruding outwards over an end ring structure (15) of the cage coil (10), the connecting line (19) being routed through this section (20). After coil device (9). claim 1 , characterized in that the connection line (19) is designed as a twisted pair cable. After coil device (9). claim 1 , characterized in that a length of the section (20) of the hollow rod (16) protruding longitudinally beyond the ring structure (15) on the end face is designed as a function of a predetermined typical frequency of an electromagnetic field generated by the coil device (9) when it is operated, that the length is not equal to an integer multiple of half a wavelength of the electromagnetic field of the specified typical frequency, in order to minimize the power radiated via this section (20) of the hollow rod (16). Coil device (9) according to one of the preceding claims, characterized in that the sensor system (13) comprises a camera (13) which is directed in the direction of a receiving space (2) surrounded by the cage coil (10) for imaging a respective one possibly arranged therein object of investigation (3) . Coil device (9) according to one of the preceding claims, characterized in that that the sensor system (13) has a plurality of individual sensors which are arranged distributed over a longitudinal extension direction of the cage coil (10). Coil device (9) according to one of the preceding claims, characterized in that the sensor system (13) is arranged in a housing (11) which at least partially shields the sensor system (13) electromagnetically, with parts arranged on both sides of the housing (11). (17, 18) of the conductor designed as a hollow rod (16) are connected to one another through the housing (11) in a high-frequency conducting manner. After coil device (9). claim 6 , characterized in that the housing (11) has an opening (12) which is surrounded by a cage coil (10) receiving space (2) facing, and the sensor (13) is aligned with the opening (12) to through to detect this through the receiving space (2). Magnetic resonance system (1), having a magnetic structure (4) for generating magnetic fields for magnetic resonance imaging in a recording space (2) surrounded by the magnetic structure (4), wherein the magnetic structure (4) comprises a coil device (9) according to one of the preceding claims. Magnetic resonance system (1) after claim 8 , characterized in that the magnetic resonance system (1) has a data processing device (5) which is connected to the sensor system (13) by means of the connection line (19) and for receiving and processing by the sensor system (13) via the connection line (19). Raw data signals is formed, wherein the data processing device (5) outside of the cage coil (10) is arranged.

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