Radio Frequency Shielding
MRI equipment generates strong RF interference, which can disturb other electronic equipment in the hospital or affect television and radio reception in the neighborhood.
Conversely, external RF signals may be picked up by the MRI system’s RF coils and adversely influence the accuracy of the imaging data. MRI scan rooms therefore must be efficiently shielded to prevent radiation leaving or entering.
IMEDCO RF Enclosure
Radio Frequency Shielding
The IMEDCO RF enclosure is basically a Faraday cage constructed of panels of high-quality copper foil wrapped round wooden frames, which are clamped together such as to ensure the integrity of the shielding throughout the life of the enclosure.
Electrical cables, medical gas pipes and other supplies are routed out of sight in the wall cavities. This method of construction gives the architect full freedom of design and permits subsequent replacement or modification of the MRI equipment.
If necessary, with the exception of the floor, the enclosure can be dismantled and erected at another location.
All fittings are of non-magnetic materials. Doors, windows and penetrations for services are also shielded or fitted with filters to prevent leakage. RF enclosures are dielectric insulated from the rest of the building.
They are delivered to site in prefabricated modules and assembled by trained IMEDCO personnel.
Alternative RF shielding materials
Aluminium or galvanised steel can be supplied instead of copper. These are chosen mainly for low-field magnets because of their better magnetic shielding characteristics at low frequencies and/or on sites with fluctuating spurious magnetic fields. Copper, on the other hand, is superior for medium and high-field magnets and has an almost unlimited operational life.
The specification including precise dimensions, shape, penetrations, corners etc., must be available well in advance for aluminium and galvanised steel shielding, because of the gauge and design of the panels changes can scarcely be accommodated afterwards.
Features and benefits
- Faraday cage with high quality copper foil ensuring the integrity of the shielding throughout the life of the enclosure
- Full freedom of design for architect enabled by routing supply lines out of sight
- Modular design allows for disassembly and reassembly
- All fittings are of non-magnetic materials
- Doors, windows and penetrations for services are also shielded or fitted with filters to prevent leakage
- Dielectric insulation to the building
- Prefabricated modules are assembled by trained IMEDCO personnel
RF Attenuation and RF Testing
| Field | Frequency | Attenuation |
| Magnetic field: | 15 MHz | 100 dB |
| Electric field: | 10 MHz | 100 dB |
| 30 MHz | 100 dB | |
| Plane Wave: | 30 MHz | 100 dB |
| 100 MHz | 100 dB | |
| 200 MHz | 100 dB |
Test standards:
- IEEE Standard 299-2006 or
- NSA 94-106
Test equipment measuring ranges:
- E field: 10 kHz…30 MHz
- H field: 10 kHz…30 MHz
- Plane wave: 30 MHz…1 GHz
The best MRI results can only be obtained in an environment which is free of electromagnetic interference. IMEDCO has mastered this problem and that is why they have become the preferred supplier all over the world. With an IMEDCO RF enclosure you are assured of unsurpassed shielding characteristics, the basis of consistently high long-term diagnostic quality and all-round operational reliability.
Before handing over the installation to the user, the conformity of the entire enclosure with the requirements of the respective MRI manufacturer is verified by certified personnel using the most modern field measuring instruments and the results are recorded in a test report.
RF Doors
Radio Frequency Shielding
StandardDOOR
FrictionlessDOOR
SlidingDOOR
Double Swing RF Door
To ensure long-term high quality, IMEDCO manufactures its own doors. Apart from being a good RF shield, the door of an MRI room also has to be easy and safe for medical staff to use and look attractive to reassure patients.
IMEDCO RF doors are especially light and have ergonomically designed handles. A high-quality frame provides for ease of opening and good RF contact. Worn contact fingers around the edge of the door can be replaced without difficulty with the door in situ. They are mounted such that damage due to passage through the doorway is scarcely possible. The threshold is designed to permit easy passage with a gurney, wheelchair or trolley.
The standard size is 1.20 m x 2.10 m and the outer surfaces are a white laminate, but other sizes and colors are available on request. Regardless of whether a door is locked or not, it can always be opened from the inside for safety.
Doors available at IMEDCO:
- StandardDOOR
- FrictionlessDOOR
- SlidingDOOR «single & double»
- Double Swing RF Door
RF Windows and PrivacyGLASS
Radio Frequency Shielding
double-glazed with a special tempered safety glass that incorporates two layers of bronze mesh
The bronze mesh is blackened to avoid reflection and the layers are positioned to minimise moiré patterns.
RF windows are double-glazed with a special tempered safety glass that incorporates two layers of bronze mesh as the RF shield. The bronze mesh is blackened to avoid reflection and the layers are positioned to minimise moiré patterns. The transparency of the windows is excellent and they afford an unhindered view of the scan room.
The standard observation window has a viewing area of 1.2 m x 0.9 m. Other sizes are optionally available for observation and daylight windows and skylights.
The intelligent PrivacyGLASS becomes transparent when an electrical voltage is applied, so you have a full view of the patient. If there is no voltage, the glass becomes opaque. The added “switchable glass” is seamlessly integrated into our specifically produced frame to the outer face of the RF window.
You can also expect a further advantage in terms of sound insulation since the glass acts as another sound barrier. In combination with our special SilentSHIELD™ acoustic window frame, a sound reduction index of Rw 55dB can be achieved.
Windows available at IMEDCO:
- Standard RF Window
- PrivacyGLASS
SpotLIGHT « flex »
Spotlighting is indispensable for any kind of procedure on the patient during an MRI examination.
- MRI compatible LED spot lights
- Focused light for injections (4000 K)
- Flexible adjustable
- Energy saving
- Long service life of approx. 25 000 hours
- Therefore, less maintenance costs
- CE and RoHS certified
FixLIGHT « round »
Your MR room will shine in a whole new light with the round, ultra-thin, flush-mounted LED lights from IMEDCO.
- MRI compatible LED lighting (Non-dimmable)
- Modern design
- Easy retrofitting of the conventional IMEDCO lighting
- No need for ramping down the MR-system
- Energy and space efficient
- Long service life of approx. 25 000 hours
- Warm white colour temperature (3 000 K)
DimLIGHT « square&round »
The dimmable LED light panels from IMEDCO bathe every last inch of an MR room in pleasant light.
- Dimmable, MRI compatible LED lighting
- Modern design
- Energy-efficient
- Space-saving
- Long service life of approx. 25 000 hours
- Neutral white colour temperature (4000 K)
- Less radiated heat and therefore lower air conditioning costs
- CE and RoHS certified
RelaxingLIGHT/PANEL
High patient comfort with colour lighting. The LED mood lighting by IMEDCO, creates a relaxed atmosphere in your MR room.
- Dimmable, MRI compatible LED lighting
- Modern design
- Energy-efficient
- Space-saving
- Long service life of approx. 25 000 hours
- Neutral white colour temperature (4000 K)
- Less radiated heat and therefore lower air conditioning costs
- CE and RoHS certified
Thanks to our many years of experience planning and in-stalling over thousands of MRI rooms, we are glad to assist you with not only the implementation and optimal use of the mood lighting, but of course also with the realisation of your entire RF-enclosure.
Lights available at IMEDCO:
RF Feedthroughs
Radio Frequency Shielding
Waveguide penetrations for inserting non-conductive pipes.
Waveguide penetrations for connecting metal pipes.
All air ducts have interposed honeycomb brass waveguides. Which are soldered to provide uninterrupted shielding in the IMEDCO wall or ceiling panels. Wooden flanges dielectrically insulate the filters from the customer’s external air ducts.
Penetration and waveguide for the introduction of non-conducting temporary services (e.g. anesthetic, patient monitoring etc.).
The choice of waveguide depends on the medium (medical gases, liquids etc.) and local regulations.
Waveguide penetrations for connecting metal pipes.
Penetration and waveguide for the introduction of non-conducting temporary services (e.g. anesthetic, patient monitoring etc.).
All power and signal circuits entering the MRI room are equipped with RF filters to prevent unwanted RF from being conducted into the enclosure. Filters are usually fitted in both phase and neutral power lines. To ensure patient safety, only approved types are used having a maximum leakage of 2 x 0.6 mA and conforming to the ENEC IEC / EN 60939 and UL 1283 standards. Electrical filters are available from IMEDCO with a rated current up to 20 A. Other filters for signal and control circuits are also available. A ground terminal is located close to the filters.
IT signals are normally converted to optical signals and transferred via optical fiber cables run in brass conduits.
