Preparing a Room for MRI Installation

Start from the manufacturer's site planning guide

Every MRI model has a site planning document from its manufacturer specifying minimum room dimensions, weights, clearances, service requirements and tolerances. That document, for the exact model and configuration being installed, is the authority. Everything below explains what those requirements mean in practice and where projects typically run into trouble.

The rooms an MRI installation needs

• Examination room — houses the magnet and patient table, entirely inside the RF shield.
• Control room — operator console, with an RF window giving direct sight of the patient.
• Technical / equipment room — cabinets, amplifiers, filter cabinet, often the chiller interface. Generates heat and noise, so it needs its own cooling.
• Patient preparation and changing areas, and a screening point where ferromagnetic items are removed.

Note that the finished internal dimension of the examination room is smaller than the raw structural opening, because the RF shield and the interior cladding are built inside it. Plan from the finished internal dimension required by the manufacturer, then work outwards.

Floor loading and structure

A superconducting magnet is heavy and its weight is concentrated. A 1.5 T magnet commonly falls in the range of several tonnes, and 3 T systems are heavier; the manufacturer's figure for the specific model is what the structural engineer needs. Two separate checks are required:

• Static load in position — the slab must carry the magnet where it will stand, permanently.
• Dynamic load along the route — every floor, ramp and lift the magnet crosses on the way in must carry it in motion, often with load-spreading plates.

Above ground floor, this is a structural engineering exercise, not an assumption.

Access route

Confirm the full route from the delivery vehicle to the final position before committing: door and corridor widths, turning radii, ceiling heights, lift dimensions and capacity, ramp gradients. Where the route is inadequate, the usual solution is a temporary wall or roof opening with a crane lift — which must be planned, permitted and priced early, and reinstated afterwards to an agreed standard.

Quench pipe

A superconducting magnet must be able to vent helium safely to outside air in the event of a quench. The quench pipe is a dedicated duct from the magnet to an external discharge point, sized and routed to the manufacturer's specification, with a minimum of bends, adequate support, and a terminal position where discharged helium cannot re-enter the building, reach a window or air intake, or endanger anyone at ground level.

The quench pipe route is one of the most common reasons a candidate room is rejected. Establish it during feasibility, not during construction.

HVAC and environmental control

The examination room requires controlled temperature and humidity within the manufacturer's stated band, stable enough to hold through the working day, with adequate air changes for patient comfort. The technical room requires cooling sized for the continuous heat output of the cabinets — typically the larger cooling load of the two. Ventilation ducts crossing the RF shield pass through honeycomb waveguide vents. Many installations also require oxygen monitoring in the examination room as part of the cryogen safety strategy.

Electrical supply

Requirements are model-specific, but generally include a dedicated supply of the specified rating and quality, defined earthing arrangements, and separation of the imaging supply from noisy loads. Consider whether an uninterruptible supply is needed for the cold head and monitoring — losing cold-head power for an extended period risks helium boil-off. All power entering the shielded room passes through the filter panel; lighting inside the room must be selected as MRI-suitable so that drivers do not inject RF noise.

Chilled water and cooling for the magnet system

Most systems need a chilled-water circuit for the gradient and RF chain and, on many platforms, for the cold-head compressor. Establish whether the chiller is included with the equipment or is site infrastructure, where it will be located, how pipework reaches the technical room, and what redundancy exists. Chiller failure takes a scanner out of service quickly.

The 5 gauss line, zoning and safety

The static magnetic field extends beyond the magnet as a fringe field. The 0.5 mT (5 gauss) contour is the conventional boundary for controlled access, because above that level implanted devices such as pacemakers may be affected. On modern actively shielded magnets this contour is compact — commonly a few metres from isocentre, depending on the model — but its position must be plotted from the manufacturer's field maps against the actual floor plan, including the rooms above and below.

Nothing that stores magnetic media, or that houses people with implants, should fall inside it. Access control, signage and a defined zoning scheme with a screening point are part of the room design, not an afterthought. Ferromagnetic material inside the examination room — fixings, ceiling grids, furniture, cleaning equipment, oxygen cylinders — is a projectile hazard and must be excluded by specification and by procedure.

Interior finishes

Wall cladding, suspended ceiling, lighting and flooring are installed inside the shielded shell. All must be non-ferromagnetic, cleanable to healthcare standards, and installed without compromising the shield. Fixings into shielded surfaces must be agreed with the shielding contractor — an unplanned screw through a copper panel undoes a tested enclosure.

A workable sequence

1. Feasibility: room candidates assessed against access, structure and quench route
2. Equipment selected; manufacturer site planning guide obtained
3. Design: layout, structural check, services design, shielding design, field plot and zoning
4. Civil and structural works
5. RF shield installation and shielding-effectiveness test
6. Services: HVAC, electrical through the filter panel, chilled water, quench pipe
7. Interior finishes
8. Equipment delivery, installation, ramp-up, shimming and commissioning
9. Acceptance testing, staff training, clinical handover

Quick summary

• Work from the manufacturer's site planning guide for the exact model
• Check floor loading both in position and along the whole route in
• Establish the quench pipe route during feasibility — it disqualifies rooms
• Size technical-room cooling for continuous cabinet heat load
• Plot the 5 gauss line on the real plan, including floors above and below
• Finish and test the shield before the magnet arrives

Frequently asked questions

Related guides

Published 2026-08-12 by Radiology Invest Group, Bucharest, Romania. General information for planning purposes; always confirm requirements against the equipment manufacturer's documentation and the applicable authority at your destination.