MR systems have a strong magnetic field around the magnet, the so called fringe field. Reduction of this fringe field (e.g. 0.5-mT area) can be required under certain circumstances. A reduction can be achieved with ferromagnetic plates mounted to the parent walls, under the construction floor and above the RF-ceiling. These plates are called passive shielding.
Passive shielding calculations require dedicated Philips Healthcare software. As documented in the Planning Reference Documentation, these calculations must be performed by Philips. It provides the requirements for the thickness and the location of the shielding material which are to be implemented, preferably by Philips’ selected RF cage suppliers.