4 Acoustic Background and Design Guidelines
The acoustic information is provided for site planning and architectural design activities to
address acoustics to meet local regulations and customer requirements. For more information
about recommended safety procedures regarding patient exposure to MR generated acoustic
levels, see the MR Safety Guide included with the system Users Manual.
4.1 Acoustic Background
A typical MR suite has two types of acoustic noise issues. The first is the acoustics within the
rooms in which the patients and technicians are impacted by the noise of the MR system as the
gradients are pulsed. The second is noise transmitted to other spaces via airborne and
structureborne paths.
4.1.1 Airborne
The airborne transmission path entails the excitation of air within the magnet room; the
resonator module consisting of the magnet, RF coil, and gradient coil generates acoustic noise
similar to an intense loud speaker. The airborne noise passes through walls via any openings,
i.e. small holes, cracks, HVAC ducts, and waveguides, into surrounding spaces within and
possibly beyond the confinements of the building. Acoustic energy can transmit across
distances of significant length.
Examples of airborne acoustics issues may include the following (not limited to only these) :
•
MR Operator exposure at Operator Workstation (i.e. Operator viewing in-line with the patient
inside the magnet may require a higher acoustic attenuation window)
•
Image reading rooms adjacent to Magnet Room, may be separated by hallways
•
Secretarial, offices, meeting rooms, patient rooms (ICU, exam, primary care, etc.)
•
Adjacent residential areas/spaces
•
In-house library facilities
4.1.2 Structureborne
The structureborne transmission path is the result of mechanical excitation of the floor/building
structure causing the building to vibrate. The vibration of the surfaces at surrounding spaces
then radiates as acoustic noise. Acoustic energy can transmit across distances of significant
length.
NOTE:
Less than 5% of installed base sites have experienced structureborne acoustic
issues.
Examples of structureborne acoustics issues may include the following (not limited to only
these):
•
Areas directly above or below the Magnet Room, may not always be an issue
•
Image reading rooms adjacent to Magnet Room, may be separated by hallways
•
Secretarial, offices, meeting rooms, patient rooms (ICU, exam, primary care, etc.)
•
Adjacent residential areas/spaces
SIGNA Voyager Pre-Installation
Direction 5680008–1EN, Revision 2
Chapter 7 Appendix
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