Analysis of stray field of actively shielded MRI magnet

摘要

Stray field outside of magnetic resonance imaging (MRI) magnet must be confined to five gauss in a limited region. It's hard to high field MRI system. In the paper, calculation of magnetic field of MRI magnet is studied Approximate expression of stray field outside of MRI magnet is deduced Influence of shielding coil position on stray field is analyzed and an expression determining shielding coil position is given to cancel stray field of negative five orders.