In-room imaging and MR planning

Outside the Magnet: Fringe Field

• Magnet is shielded to reduce extent of fringe field 5 G line for an unshielded 7 T is 23m away! • Active & passive shielding is use • Active shielding causes a sharp field gradient Magnitude and variation of field need to be understood

Note: ‘Magnetic Shielding’ is also sometimes used to describe RF shielding (Faraday cage)