The modules made of magnetic steel are mainly used in so-called ‘Open’ MRI-Systems which operate on the basis of a permanent magnet. However, in certain exceptional cases the use of magnetic steel is also used for the enclosures of a superconductive MRI-System.
Depending on the size of the RF room two different thicknesses of steel are used 2mm and 1.5mm. For modules made from folded sheet steel, these are prefabricated in the factory to a consistently high quality, each module having a very high dimensional accuracy with tight tolerances. This is essential to meet the future specifications for the shielding effectiveness that will be required by manufacturers of MRI-Systems.
The modules are screwed together with a special contact material inserted between all the mating surfaces; this forms a 100% homogeneous RF seal. All other components fitted to the shielding, such as, honeycomb vents for connection the air conditioning system, medical gas tube penetrations, quench pipe and RF window will also use this special contact material to maintain the shielding integrity.