MRI Room RF Shielding: Protecting Image Quality
Why an RF cage is needed in MRI rooms, the details of doors and windows, and the acceptance measurements, explained for hospital teams.
3 min readOctober 16, 2026
Long Recordings, Long Risks
A sleep study lasts all night, recording brain, muscle, eye and heart signals for hours. Interference that would go unnoticed in a short EEG recording repeats many times over an eight-hour recording and makes analysis harder.
On top of that, the patient moves during sleep, electrodes shift and cables end up in different positions. This multiplies the paths by which outside noise can enter the recording.
Where Does the Noise Come From?
The most common source is 50 Hz mains noise. Wiring in the walls, bedside lighting, electric bed motors and charging adapters bring this noise close to the patient. A lift in the corridor or nearby imaging equipment can add further sources.
Radio-frequency noise comes from phones, Wi-Fi access points and patient monitors. Although not directly visible, these signals can be rectified at amplifier inputs and cause low-frequency distortion in the recording.
Simple Measures
The first step is to reduce unnecessary electrical devices in the room and ground the rest properly. Choosing interference-free LED or DC-powered lighting, cutting power to the bed motor during recording and routing cables neatly make a big difference.
Using a fiber or isolated link between the patient-side amplifier of the recorder and the computer also reduces noise paths.
When Is a Shielded Room Needed?
If noise persists despite simple measures, or the lab performs sensitive research measurements, a shielded room is the permanent solution. It cuts out outside noise and keeps measurement conditions the same every night.
Our EEG shielded room solutions are built to look like an ordinary bedroom without compromising patient comfort. For the basics, see our article on why EEG rooms are shielded.
Frequently Asked Questions
Will a shielded sleep room bother the patient?
No. The shielding stays inside the walls; the room is furnished like an ordinary bedroom, with ventilation and lighting planned for comfort.
Can the patient use a phone in the room?
There's no network in a shielded room. A call and intercom system is planned for patient communication.
Can an existing sleep room be shielded?
In most cases, yes. Room dimensions and door position are assessed during the survey.
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