- Modern self-contained MRI systems use as little as 1 liter of helium versus 1,000 liters or more in traditional machines, reducing retrofit complexity and long-term operational costs significantly.
- Structural design begins at the floor. Slabs must be evaluated and engineered to carry several tons of static and dynamic loads, maintain a precisely level plane, and integrate vibration-dampening systems as required based on site-specific conditions.
- A minimum floor-to-ceiling clearance of 12 feet is required to accommodate the MRI unit, RF shielding, ductwork, cooling systems, and vibration isolation infrastructure.
- Moving ferromagnetic materials and unmanaged electrical currents adjacent to the MRI can distort images, reduce diagnostic accuracy, and create serious projectile hazards for patients and staff.
As the healthcare landscape evolves and adapts, the demand for advanced proactive screening continues to rise. Magnetic resonance imaging (MRI) technology plays a vital role in helping to detect and monitor conditions such as tumors, cardiovascular diseases, and neurological disorders. However, many existing healthcare facilities were not originally designed to accommodate the sophisticated infrastructure required for MRI equipment.
Successfully integrating MRI technology into an existing building often requires extensive structural modifications and updates to electrical, mechanical, and new shielding systems to meet the machine’s precise operational requirements while creating a safe and efficient environment. Retrofitting these buildings also ensures that advanced imaging capabilities are more readily and safely available.
This article explores the key factors that project teams must consider when retrofitting facilities for MRI technology—from structural and infrastructure upgrades to patient experience and safety measures.
What’s the impact of evolving MRI technology on space planning?
Traditional MRI machines rely heavily on liquid helium to cool the superconducting magnets that generate the strong magnetic fields necessary for imaging. However, this dependence comes with significant challenges, including high operational costs, supply chain uncertainties, and environmental concerns due to the finite nature of helium resources.
A breakthrough happened in 2018 with the introduction of self-contained MRI systems, which have advanced cooling methods that use as little as 1 liter of helium versus 1,000 liters or more in traditional systems. Weighing 1,900 kilograms lighter than a traditional system, the self-contained MRI option is more sustainable, cost-effective, and easier to install and maintain. Their smaller footprint also allows for greater flexibility with site selection and facility design.
An added advantage is the development of self-contained, quenchless MRI machines, which eliminate the need for extensive venting infrastructure, making it easier to retrofit existing buildings without the constraints imposed by traditional helium-based systems. Additionally, helium-free MRI technology is more sustainable and operationally efficient. When a traditional MRI quenches, helium is lost to the atmosphere via the quench pipe. Quenching requires refilling up to 1600 liters of helium, which comes at a cost of more than $100,000. The “helium-free” systems have only 7 liters of helium, which is entirely enclosed in the system and does not need to be refilled.
Site selection and design considerations for MRI machines
There are many variables to consider when deciding whether an existing building may be suitable for hosting MRI.
First, floor construction must be capable of supporting the substantial equipment weight without compromising the structural integrity of the rest of the building. MRI machines are heavy, often weighing several tons, which may require reinforcing the floor with additional concrete thickness or steel beams on elevated floors. Additionally, the floor must be perfectly level to prevent any tilting or shifting of the MRI machine, which could impact image quality.
Vibration isolation is another essential factor, as external vibrations from foot traffic, nearby machinery, or even road traffic can interfere with the MRI’s magnetic field and degrade image clarity. Implementing a vibration-dampening system within the floor construction helps mitigate these issues.
It’s essential to review the existing conditions to determine current structural slab thickness, concrete strength, rebar placement (which may need to be removed depending on proximity to the MRI isocenter), and any underlying supports to ensure the MRI is properly anchored and doesn’t have any magnetic interference due to significant steel embedded in the structure, which could negatively affect image quality and accuracy. Design teams must also carefully coordinate MRI below-slab infrastructure, ensuring that all pathways are identified prior to construction so that trenching can be efficiently minimized.
Floor-to-ceiling clearance—the distance between the floor and lowest object of permanent obstruction in the space—is another critical consideration. MRI machines require substantial vertical space not only for the equipment itself but also for essential infrastructure, including radiofrequency (RF) shielding, fire protection, ductwork, and cooling systems.
A minimum clear height of 12 feet is recommended to ensure sufficient space for the MRI and its supporting systems.
Furthermore, delivering an MRI machine into a building requires a pathway wide enough for the imaging scanner, which typically measures around 7 feet in diameter and can weigh several tons. This often necessitates removable knockout walls or windows to facilitate entry.
Additionally, the pathway must be free of obstacles and sturdy enough to support the heavy equipment, often requiring temporarily reinforced flooring. In some cases, specialized equipment such as cranes or forklifts may be needed to maneuver the MRI machine into place.
Adjacent moving metals and electrical current
Along with reviewing and understanding building conditions, project teams also need to control the presence of moving metals and electrical currents around MRI machines due to the high sensitivity of their magnetic fields. Ferromagnetic materials, such as steel or other alloys containing more than 95 percent iron, and electrical currents can interfere with the magnetic field, causing image distortions, reduced diagnostic accuracy, and potential equipment malfunctions.
To mitigate these risks, the MRI isocenter must be positioned at a safe distance, usually determined by each MRI vendor, from moving metals, and electrical currents must be carefully managed to prevent electromagnetic interference.
Additionally, moving metals can become dangerous projectiles if attracted to the MRI’s magnetic field, posing a serious safety hazard to patients and staff. Stringent protocols must be established to keep the MRI environment free of such materials, ensuring both safety and imaging quality.
Factoring in existing building infrastructure
MRI machines and their backup equipment consume a large amount of power and generate significant heat, necessitating robust electrical and cooling systems. Unless a building or facility has previously housed an MRI, it likely doesn’t have the necessary infrastructure to support the heating, ventilation, and air conditioning (HVAC) and power demands required for operation.
Additionally, most non-healthcare buildings operate within standard business hours, while a new MRI clinic needs HVAC infrastructure operating around the clock. Healthcare clinics must coordinate with building owners to ensure that power and house HVAC systems remain available during extended operating times.
Design teams must also evaluate additional HVAC requirements to maintain consistent temperature and humidity levels, which can fluctuate throughout the day, across seasons, and over time. The system should be flexible and responsive to environmental changes to keep the MRI safely operating, minimizing the need for shutdowns.
Dedicated chillers are also required and must be installed outside the building or in a well-ventilated space. Because chillers are large and noisy, they should be strategically located to minimize acoustical impact to neighboring functions. The distance from the MRI must also be carefully considered to ensure that condensate piping maintains consistent pressure and flow without drop-offs before reaching its point of use.
Soundproofing measures for MRI installations
Acoustic mitigation is essential in MRI installations due to the significant noise levels generated during operation. The rapid switching of gradients within the MRI machine produces loud, repetitive sounds that can reach up to 110 decibels—comparable to a rock concert.
To create a comfortable environment for both patients and staff, soundproofing measures must be implemented. These may include acoustical panels on walls and ceilings, insulated doors, and specialized sound-absorbing materials around the MRI suite.
Effective acoustic mitigation not only enhances patient comfort and reduces anxiety but also helps maintain a calm and focused environment for healthcare professionals, improving the overall MRI experience.
Added value of a modernized MRI suite
MRI clinics play an important role in diagnostic and preventative care, providing advanced imaging capabilities that can help detect and monitor various medical conditions.
To expand access to imaging services, architects and designers can work with healthcare organizations to assess the best path forward to retrofitting existing healthcare facilities with new and evolving technology. Incorporating patient-centered design elements can help reduce anxiety, improve comfort, and create a more positive experience, which can lead to higher patient satisfaction, increased retention, and competitive market expansion.
Scott Lagstrom is healthcare studio principal at Little (Durham, N.C.) and can be reached at [email protected].
