MEP/FP design for MRI suites, part two: design considerations
Within a hospital, needs vary significantly by department and specialty treatment area, a MEP firm needs to understand each area’s unique specifications and requirements involving mechanical, electrical, plumbing, and fire protection (MEP/FP) systems.
MRI equipment must be protected from electrical interference that can upset the magnetic field and the imaging process. Keeping equipment running is critical, and the RTM team knows that the heart of a safe and reliable facility is the primary and secondary power supply [VS1] systems with proper distribution channels.
An MRI scanner produces a radio frequency (RF) signal that must be protected from interference. Alternating current (ac) power has been known to result in RF interference and distortion of images. Because of this, MRI room-lighting fixtures use direct current (dc) power. As in every hospital setting, lighting levels should be carefully reviewed; RTM uses in-house lighting designers to run photometric calculations to assure proper light levels.
RF shields are typically thin sheets of copper foil, aluminum, or galvanized steel that cover floors, ceilings, doors, and windows in an MRI magnet room. Any penetrations into RF-shielded areas (HVAC, power, exhaust, plumbing, and piping) pass through RF filters or wave guides. Since ferromagnetic materials can interfere with MRI operations, all ductwork, hangers, and supports within the RF shield must be nonferrous.
Emergency power and UPS
Individual hospitals, along with the building code, determine the type of emergency power MRI equipment will need in the event of a power outage. Hospitals frequently use uninterrupted power supply (UPS) systems to maintain constant power to equipment during an outage or when transferring from one source to another. The UPS helps maintain power when switching to and from generator-backed power.
Plumbing and fire protection systems
MRI suites require unique plumbing and fire protection systems to meet the facility’s health and safety needs while also accommodating the equipment’s distinct specifications.
Designing plumbing systems around an MRI magnet room without interfering with sensitive equipment is particularly challenging. Water and drain lines must be installed in a way that will not interfere with the RF shield including passing through RF wave guides and dielectric breaks.
All sprinkler system components in MRI rooms must be constructed of nonferrous materials (copper, brass, and stainless steel are common). Careful consideration should be made for piping in adjacent spaces.