The present invention provides a kind of medical device( 100 )Including magnetic resonance imaging system( 110 )It obtains MR data and volume is imaged( 122 )At least partly cover object of interest( 120 ),Wherein( 110 ) ( 112 )Magnetic resonance imaging system includes that main magnet generates magnetic field,In the imaging volume( 122 ),Device( 150 )The particle bunch of the particle beams with the particle beams( 152 ) ( 100 )0 charged particle,Including rack( 100 )1 is configured to around rotation axis(R values),It is arranged in main magnet( 100 )2 longitudinal direction,Wherein rack( 100 )3 include at least one for guiding particle beams bending magnet( 100 )4 ( 100 )5 arrive( 100 )In 6 irradiation volume imaging volumes( 100 )7,Active compensation coil( 100 )8,It is arranged at least substantially surround the imaging volume( 100 )9 and control unit,For controlling the active compensation coil( 110 )0 ( 110 )At least one bending magnet of stray magnetic field caused by 1 counteracting( 110 )Main magnet in 2 imaging volumes is at least in longitudinal direction( 110 )3 ( 110 )4. The present invention also provides one kind to be used for above-mentioned shielding method Medical Devices (100).
