Shielding of magnetic resonance imaging apparatus

Patent metadata

Field	Value
Publication number	US-10495706-B2
Application number	US-201816182757-A
Country	US
Kind code	B2
Filing date	Nov 7, 2018
Priority date	Nov 7, 2017
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

Combined MRI and radiotherapy installations require complex Faraday cage structure that encloses the room, the MRI magnets, and the patient volume, but excludes the linear accelerator path and its supply cabling. A problem with this is that the MRI magnets tend to vibrate when in use, and if physically connected to a rigid structure then the vibrations will be passed to that structure also. To alleviate this, we propose that the Faraday cage be made of a mix of prefabricated conductive sections and flexible sections of a conductive sheet. The flexible conductive sheet can be copper or aluminium, in the form of a foil or mesh.

First claim

The invention claimed is:

1. A combined imaging and treatment installation, comprising:
a co-located radiotherapeutic apparatus and magnetic-resonance imaging apparatus,
a first conductive cage, partly enclosing the radiotherapeutic apparatus;
a second conductive cage, partly enclosing the magnetic-resonance imaging apparatus and the first cage;
the first and second conductive cage being made up of rigid sections;
a flexible conductive sheet that connects the first and second conductive cages, thereby to define a Faraday cage enclosing the MRI apparatus.

2. A combined imaging and treatment installation according to claim 1 in which the radiotherapeutic apparatus and magnetic-resonance imaging apparatus are co-located within a single room.

3. A combined imaging and treatment installation according to claim 2 in which the second conductive cage is arranged over or defines at least a part of the wall surface of the room.

4. A combined imaging and treatment installation according to claim 2 in which the flexible conductive sheet includes a portion arranged over at least a part of the floor surface of the room.

5. A combined imaging and treatment installation according to claim 4 in which the portion is covered with floor tiles.

6. A combined imaging and treatment installation according to claim 5 in which the floor tiles are non-conductive.

7. A combined imaging and treatment installation according to claim 2 in which the flexible conductive sheet includes a portion arranged over at least a part of the ceiling surface of the room.

8. A combined imaging and treatment installation according to claim 7 in which the portion is covered with ceiling tiles.

9. A combined imaging and treatment installation according to claim 8 in which the ceiling tiles are non-conductive.

10. A combined imaging and treatment installation according to claim 2 in which the flexible conductive sheet includes at least one portion extending across a part of a wall of the room from the ceiling to the floor.

11. A combined imaging and treatment installation according to claim 2 in which the first conductive cage is formed by structure within the room extending from floor to ceiling, from a first wall of the room, around the radiotherapeutic apparatus, and to a second wall of the room.

12. A combined imaging and treatment installation according to claim 11 in which the first wall and the second wall are the same wall.

13. A combined imaging and treatment installation according to claim 11 in which the radiotherapeutic apparatus comprises a source that is movable along a substantially circular path around an axis, the structure comprises a passageway disposed around the axis and within the path, and the magnetic-resonance imaging apparatus is located substantially within the passageway.

14. A combined imaging and treatment installation according to claim 1 in which the flexible conductive sheet is made up of one or more of copper or aluminium foil or mesh.

Assignees

• Elekta ltd

Inventors

• Mikeska Jurgen Michael
• Hainke Andreas Michael

Classifications

• G01R33/4808

  Multimodal MR, e.g. MR combined with positron emission tomography [PET], MR combined with ultrasound or MR combined with computed tomography [CT] · CPC title

• A61N5/10 Primary

  X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy (A61N5/01 takes precedence) · CPC title

• E04B1/92

  Protection against other undesired influences or dangers (buildings providing protection against external dangers E04H9/00; shielding against dangerous radiation G21F) · CPC title

• G01R33/422 Primary

  of the radio frequency field · CPC title

• A61N2005/1094

  Shielding, protecting against radiation · CPC title