System and methods for grounding patients during magnetic resonance imaging

Abstract

A magnetic resonance imaging (MRI) system, comprising a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, electromagnetic shielding provided to attenuate at least some electromagnetic noise in an operating environment of the MRI system, and an electrical conductor coupled to the electromagnetic shielding and configured to electrically couple to a patient during imaging of the patient by the MRI system. The magnetics system may include at least one permanent B0 magnet configured to produce a B0 magnetic field for an imaging region of the MRI system. The B0 magnetic field strength may be less than or equal to approximately 0.2 T.

What is claimed is: 
     
         1 . A magnetic resonance (MR) imaging system, comprising:
 a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, the magnetic fields comprising a B 0  magnetic field having a field strength between 50 mT and 0.2 T; and   a grounded electrical conductor configured to ground a patient during imaging of the patient by the MR imaging system.   
     
     
         2 . The MR imaging system of  claim 1 , further comprising electromagnetic shielding, wherein the electromagnetic shielding is grounded, and wherein the grounded electrical conductor is grounded through the electromagnetic shielding. 
     
     
         3 . The MR imaging system of  claim 2 , wherein the grounded electrical conductor comprises an electrically conductive sheet. 
     
     
         4 . The MR imaging system of  claim 3 , further comprising a surface for supporting the patient during imaging, wherein at least a part of the electrically conductive sheet is disposed on the surface. 
     
     
         5 . The MR imaging system of  claim 2 , wherein the grounded electrical conductor comprises an electrically conductive pad. 
     
     
         6 . The MR imaging system of  claim 2 , wherein the grounded electrical conductor comprises a first wire coupled to a first electrical connector configured to be attached to a patient. 
     
     
         7 . The MR imaging system of  claim 6 , wherein the first electrical connector comprises a clip. 
     
     
         8 . The MR imaging system of  claim 7 , further comprising a second wire coupled to a second electrical connector configured to be attached to a patient. 
     
     
         9 . The MR imaging system of  claim 6 , wherein the grounded electrical conductor further comprises a second electrical connector configured to be removably attached to a complementary socket. 
     
     
         10 . The MR imaging system of  claim 6 , further comprising a surge protection circuit electrically coupled between the first wire and the electromagnetic shielding. 
     
     
         11 . The MR imaging system of  claim 1 , wherein the magnetics system comprises:
 at least one permanent B 0  magnet to produce a magnetic field to contribute to the B 0  magnetic field for the MR imaging system;   a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals; and   at least one radio frequency coil configured to, when operated, transmit radio frequency signals to a field of view of the MR imaging system and to receive magnetic resonance signals emitted from the field of view.   
     
     
         12 . A magnetic resonance (MR) imaging system, comprising:
 a magnetics system having a plurality of magnetics components configured to produce magnetic fields for performing magnetic resonance imaging, the plurality of magnetics components comprising a plurality of gradient coils configured to, when operated, generate magnetic fields to provide spatial encoding of emitted magnetic resonance signals;   a grounded electrically conductive pad configured to ground a patient during imaging of the patient by the MR imaging system; and   electromagnetic shielding between the plurality of gradient coils and the electrically conductive pad, wherein the electromagnetic shielding is grounded, and wherein the electrically conductive pad is grounded through the electromagnetic shielding.   
     
     
         13 . The MR imaging system of  claim 12 , wherein the plurality of magnetics components are configured to produce a B 0  magnetic field having a field strength between 50 mT and 0.2 T. 
     
     
         14 . The MR imaging system of  claim 13 , wherein a first portion of the electromagnetic shielding is positioned between the plurality of gradient coils and an imaging region of the magnetic resonance imaging system. 
     
     
         15 . The MR imaging system of  claim 14 , wherein the first portion of the electromagnetic shielding comprises a frequency selective mesh. 
     
     
         16 . The MR imaging system of  claim 15 , wherein the frequency selective mesh is configured to pass substantially all electromagnetic signals having a frequency between 1 KHz and 10 KHz and reflect back substantially all electromagnetic signals having a frequency at or above 2.76 MHz. 
     
     
         17 . The MR imaging system of  claim 16 , wherein the frequency selective mesh comprises a copper mesh having a density between 50 and 150 lines per inch. 
     
     
         18 . The MR imaging system of  claim 13 , wherein the magnetics system further comprises:
 at least one permanent B 0  magnet to produce a magnetic field to contribute to the B 0  magnetic field for the MR imaging system; and   at least one radio frequency coil configured to, when operated, transmit radio frequency signals to a field of view of the MR imaging system and to receive magnetic resonance signals emitted from the field of view.   
     
     
         19 . The MR imaging system of  claim 18 , further comprising a base supporting the magnetics system, electrically conductive pad, and the electromagnetic shielding, the base comprising a conveyance mechanism that allows the MR imaging system to be transported to different locations. 
     
     
         20 . The MR imaging system of  claim 12 , wherein the electromagnetic shielding is grounded through a power connection of the MR imaging system.