Why the timeline matters — and why it varies
For most facilities, an MRI project is on a clock. A scanner has been ordered with a delivery date, patients are waiting, and every week of delay has a cost. So one of the first questions after "how much will it cost" is "how long will it take?" As with cost, there is no single answer — but the shielding schedule follows a predictable sequence of phases, and knowing them lets you plan realistically and spot where time can be lost.
The shielding work is only one part of the wider MRI project, but it sits on the critical path: the scanner cannot be installed and commissioned until the shielded room is built and tested. Coordinating the shielding schedule with the scanner delivery and the rest of the construction is central to good project planning. This article breaks the shielding timeline into its phases so you know what to expect at each stage.
Phase 1: Design and engineering
Before anything is built, the enclosure has to be engineered for the specific scanner and room. This phase begins with the scanner manufacturer's site-planning drawings, which define the magnet footprint, fringe field, clearances, and penetration locations. The shielding engineer uses these to design the Faraday cage, size any magnetic shielding, and coordinate penetrations with the electrical, mechanical, and plumbing trades.
Design typically takes a few weeks, though it depends heavily on how quickly the scanner drawings and building information are available and how many approvals are needed. This is also the phase where the choice between a modular or site-built enclosure is confirmed, which affects the phases that follow. Time invested here — getting the drawings right and coordinating the trades — is what prevents costly delays during installation.
Phase 2: Fabrication and lead time
Once the design is approved, the shielding materials and components are fabricated or procured. This is largely a lead-time phase rather than on-site work, and it runs in parallel with other construction where possible. The specialized components — the RF shielded door, the shielded window, and the penetration panels — often have the longest lead times, so they are ordered early.
A modular enclosure is prefabricated in panels before it reaches the site, which shifts more of the work into this phase and shortens on-site installation. A site-built approach places more of the work in the installation phase instead. Either way, lead times for the door, window, and filters are a common driver of the overall schedule, which is why an experienced contractor orders long-lead items as soon as the design is locked.
Phase 3: On-site installation
This is the phase most people picture: assembling the shielded enclosure in the room. The walls, floor, and ceiling of the Faraday cage are installed, the shielded door and any window are fitted, and the penetration panels are set in place and connected. For a typical single-scanner room, the shielding installation itself often takes on the order of one to three weeks, depending on room size, whether magnetic shielding is included, and site conditions.
Installation rarely happens in isolation. It has to be sequenced with the other trades — electrical, HVAC, plumbing, and finishes — because each service that enters the room passes through the shielding at a penetration that must be handled correctly. A retrofit in an occupied building can extend this phase due to access constraints, limited working hours, and the need to protect surrounding operations.
Phase 4: Testing and handover
Once the enclosure is complete, it undergoes shielding effectiveness testing to confirm it meets the scanner manufacturer's attenuation specification. The test itself is quick — typically a day — but its result gates everything that follows: the scanner cannot be delivered and commissioned until the room passes. If the enclosure passes on the first test, the schedule moves straight to scanner installation. If it does not, remediation adds time, which is one more reason to choose a contractor who guarantees the tested result.
After a successful test, the room is handed over for scanner delivery, ramp-up, and clinical commissioning by the scanner vendor. The shielding contractor's work is essentially complete at this point, though the enclosure then enters its maintenance lifecycle. Building the testing milestone clearly into the schedule — and protecting it from being squeezed — keeps the whole project on track.
What causes delays, and how to avoid them
Most schedule slips trace back to a handful of causes: scanner site-planning drawings arriving late, which delays design; long-lead components ordered too late; poor coordination between the shielding contractor and the other trades, leading to rework at penetrations; and a failed shielding test that requires remediation. Site surprises during a retrofit — unexpected structure, restricted access, or inadequate floor capacity for magnetic shielding — are another common source of lost time.
The most effective way to protect the schedule is to involve the shielding contractor early, order long-lead items as soon as the design is approved, and coordinate the trades around the enclosure from the start. A realistic timeline built with the contractor at the planning stage, rather than an optimistic one imposed afterward, is what lets the scanner arrive to a room that is ready and tested.
Frequently Asked Questions
How long does it take to install MRI shielding?
The on-site shielding installation for a typical single-scanner room often takes on the order of one to three weeks, but the full timeline is longer once design, component lead times, and testing are included. The total depends on the scanner, room size, whether magnetic shielding is required, and whether it is new construction or a retrofit.
What part of the MRI shielding schedule takes the longest?
Often it is the lead time for specialized components — the RF shielded door, shielded window, and penetration filters — rather than the on-site installation itself. This is why an experienced contractor orders long-lead items as soon as the design is approved, and runs fabrication in parallel with other construction.
Can the shielding work happen while the rest of construction is underway?
Yes, and it should be coordinated that way. Component fabrication runs in parallel with other work, and on-site installation is sequenced with the electrical, HVAC, and plumbing trades because each service enters the room through a shielded penetration. Good coordination is what keeps the shielding off the critical path where possible.