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CN-122029446-A - Metamaterial coil for magnetic resonance tomography apparatus and magnetic resonance tomography apparatus

CN122029446ACN 122029446 ACN122029446 ACN 122029446ACN-122029446-A

Abstract

The invention relates to a metamaterial coil (2) for a magnetic resonance tomography apparatus (1) and to a magnetic resonance tomography apparatus (1), wherein the task of the invention is to provide a metamaterial coil (2) which combines high image quality with a possibility of unimpeded medical intervention on a patient (10). The object is achieved by a metamaterial coil (2), wherein the metamaterial coil (2) has a plane with a free region (12), wherein a plurality of units (13) forming a resonator of the metamaterial coil (2) are arranged around the free region (12) in the plane of the metamaterial coil (2), and wherein an opening (11) is arranged inside the free region (12).

Inventors

  • I. Vogt
  • R. kowal
  • L. Nal

Assignees

  • 奥托·冯·格里克马格德堡大学

Dates

Publication Date
20260512
Application Date
20241016
Priority Date
20231017

Claims (11)

  1. 1. A metamaterial coil (2) for a magnetic resonance tomography apparatus (1) which is wirelessly coupled with the magnetic resonance tomography apparatus (1), characterized in that the metamaterial coil (2) has a plane with a free region (12), wherein a plurality of units (13) forming a resonator of the metamaterial coil (2) are arranged in the plane of the metamaterial coil (2) around the free region (12), and wherein an opening (11) is configured in the free region (12).
  2. 2. Metamaterial coil (2) according to claim 1, wherein the cells (13) are arranged in a strip shape with a straight or curved course, or in a grid shape with a straight or curved course, or circularly, or polygonally, or helically extending.
  3. 3. Metamaterial coil (2) according to claim 1 or 2, wherein an outer ring (15) surrounding the plurality of cells (13) or an inner ring (15 a) surrounding the opening (11) is arranged on a plane of the metamaterial coil (2) as a subsystem of the metamaterial coil (2) for decoupling from the magnetic resonance tomography apparatus (1) during an excitation phase of MRT imaging.
  4. 4. A metamaterial coil (2) according to any one of claims 1 to 3, wherein the cells (13) are implemented in strips and are arranged in two groups (16, 17) each consisting of the same number of strip-shaped cells (13), and the groups (16, 17) are arranged mirror-symmetrically to each other about a first symmetry line (18).
  5. 5. Metamaterial coil (2) according to any one of claims 1 to 4, wherein four strip-like units (13) are arranged in each group (16, 17).
  6. 6. Metamaterial coil (2) according to any one of claims 1 to 5, wherein the opening (11) is a square or circular opening and has a width and a height in the range between 2cm and 20 cm, or a diameter in the range between 2cm and 20 cm, in particular a width and a height of 10 cm or a diameter of 10 cm, respectively.
  7. 7. Metamaterial coil (2) according to any one of claims 1 to 6, wherein the cells (13) of the metamaterial coil (2) are implemented as strips, grids, dipoles, loops or solenoids.
  8. 8. Metamaterial coil (2) according to any one of claims 1 to 7, wherein the metamaterial coil (2) is designed for larmor frequencies of 50kHz to 500MHz, preferably for larmor frequencies in the range of 20 MHz to 25 MHz or 60 MHz to 65 MHz or 120 MHz to 125 MHz or 190 MHz to 220 MHz or 290 MHz to 310MHz or for the range of 390 MHz to 410 MHz.
  9. 9. A magnetic resonance tomography apparatus (1) which is wirelessly coupled with a metamaterial coil (2) according to claims 1 to 8, characterized in that the magnetic resonance tomography apparatus (1) has means (9) for patient positioning, that a patient (10) for performing a surgical intervention is placed on the means (9) for patient positioning, and that the metamaterial coil (2) is arranged on a surface of the patient (10).
  10. 10. The magnetic resonance tomography apparatus (1) as claimed in claim 9, characterized in that at least one additional receiving coil (25) is arranged on the surface of the patient (10) for supplementary irradiation of the patient (10).
  11. 11. The magnetic resonance tomography apparatus (1) according to claim 9 or 10, characterized in that a first metamaterial coil (2) and at least one second metamaterial coil (2) are arranged on the surface of the patient (10).

Description

Metamaterial coil for magnetic resonance tomography apparatus and magnetic resonance tomography apparatus Technical Field The invention relates to a metamaterial coil for a magnetic resonance tomography apparatus, which is wirelessly coupled with the magnetic resonance tomography apparatus. The invention also relates to a magnetic resonance tomography apparatus which is coupled wirelessly to a metamaterial coil. Background The imaging method known from the prior art is the so-called magnetic resonance tomography, abbreviated as MRT or MR, which is used in medical diagnosis and therapy to show the structure and function of a tissue or organ in the body of a patient. Based on the physical principles of nuclear spin resonance, in particular the principles of field gradient NMR, this method is also called nuclear magnetic resonance tomography. Magnetic resonance tomography can produce images or tomographic images of the human or animal body. In this way, for example, the state of the organ can be detected and possible lesions of the organ can be determined. The invention is applied in the field of Magnetic Resonance Tomography (MRT). In order to be able to see the structures inside the body, imaging methods such as magnetic resonance tomography are used. In order to be able to scan also body regions which are difficult to access, the flexible operability of the MRT coils used in magnetic resonance tomography is important. MRT imaging is often used adjunctively for surgical intervention on a patient. Therefore, it is necessary to place the MRT coil such that it is spatially close to the intervention site. Also known in the art are so-called metamaterials as artificially prepared structures whose optical, electrical or magnetic properties do not occur in nature. For example, the permeability to electric and magnetic fields may be different than is common in nature. Metamaterials are specially manufactured, mostly periodic structures in the sub-wavelength range, or units made of materials with electrical or magnetic effects. One particular characteristic of such metamaterials is frequency selective performance. Thus, the metamaterial and its units may be configured such that preferential transmission of electromagnetic waves occurs, for example, within a particular frequency band of the electromagnetic spectrum. To achieve this, the dimensions of the metamaterial unit are matched to the desired wavelength. The use of metamaterials in the antenna field and in the field of signal conductors in MRT devices is known in the prior art. US 2010/0039111 A1 relates to an HF coil or an HF antenna system, which is composed of one or more HF coils or HF antennas, in particular for transmitting HF excitation signals (B 1 -fields) and/or for receiving MR relaxation signals in an MR imaging system. Furthermore, an MR imaging system comprising such an HF antenna system is described. The object to be solved is to provide an HF/MR antenna system or an HF/MR coil which has improved efficiency or sensitivity on one side and is provided with a metallic HF shield on the opposite side. In order to solve this task, it is proposed to combine an HF/MR transmit/receive antenna or coil structure or coil for a magnetic resonance tomography system with a so-called metamaterial, which forms the HF shield of the antenna as a magnetic wall. DE 20 2011 105 135 U1 describes a supermrt antenna arrangement for travelling wave magnetic resonance tomography. The object to be solved is to provide an antenna device for traveling wave magnetic resonance tomography, which has a significantly higher local resolution of only a few centimeters. In order to solve this problem, a supermrt antenna device for traveling wave magnetic resonance tomography is proposed, which has a combination of interaction elements for the modular construction of the supermrt antenna device. A local coil for a magnetic resonance apparatus having a plurality of magnetic resonance antenna elements and a magnetic resonance apparatus having a local coil communication interface are known from DE 10 2013 210 381 B3. The object to be solved is to provide a suitable local coil and a corresponding magnetic resonance system and an alternative method for transmitting signals from and to the local coil, by means of which the known problems of the prior art, such as high costs, high technical outlay and interference fields, are overcome. To solve this task, the local coil has a plurality of magnetic resonance antenna elements, i.e. at least one magnetic resonance antenna element, but typically a plurality. These magnetic resonance antenna elements may be either transmit or receive antenna elements. But preferably it is at least the receiving antenna element. The local coil is provided with a metamaterial signal conductor. The local coil furthermore has an adapter device, i.e. for example a suitable coupling-in and/or coupling-out device, for coupling signals into and/or out of the metamaterial