MRI Room Sizes

By Tobias Gilk

Capital improvement projects often suffer from the same symptom… the construction estimates outstrip the planned budget. In order to accommodate the fiscal belt-tightening, designs for new or renovated spaces are often stripped of everything deemed non-essential. When these downgrades fail to make up the shortfall, the designers are often challenged to squeeze every square foot out of a potential design in an attempt to reduce the associated construction costs. While across-the-board space cutting is rarely the most intelligent way to reduce costs, it’s particularly harmful to MRI suites that may have started out too small to begin with!

MRI equipment vendors all provide ready-made templates for the scanner, equipment and control rooms. These are often drawn to indicate the minimum recommended room sizes but, if pushed, often vendors will concede that it’s possible to reduce room width and length, if critical.

First, it’s vital to debunk the notion that the vendor minimum room sizes are appropriate to today’s clinical MRI needs. Minimum room sizes are often shown without any (or at best, inadequate) storage for coils, phantoms, supplies and medications. While the addition of cabinets and casework doesn’t make the walls any closer together, they do consume significant quantities of floor space that were already in short supply.

Vendor minimum rooms are often so tight that anesthesia or biopsy cases become unwieldy. With a couple extra clinical staff, procedure lights, anesthesia machine, biopsy device, medical gas or suction lines, medication pumps, patient monitors or anything else, these rooms begin to feel almost as claustrophobic as the inside of the bore!

Second, we need to evaluate the anticipated life-span of the MRI suite versus the MRI equipment. The bricks and mortar of a building should typically be expected to last at least 50 years, but the average first-use life of an MRI is somewhere on the order of 7 years. This means that your MRI suite could be capable of hosting 7 different magnets during its life span! When a suite is designed and constructed to the bare minimums for the first piece of equipment, those negligible cost savings may come at the expense of siting difficulties for as many as 6 equipment replacements!

While 1.5 Tesla MRIs currently strike the best balance of clinical capability versus capital cost for most providers, nobody who has even casually reviewed the history of MRI technology would think that this is the recipe for future success, too. Though brief, the entire development of MRI technology has followed a constant upward trend in field strength. So the suite built to support today’s 1.5 Tesla magnet will, most likely, be replaced with a 3.0 Tesla MRI in 2015. It is expected that more than half of all MRIs in clinical use in the year 2020 will be more powerful that today’s ubiquitous 1.5 T.

Often, MRI gantry rooms are sized to contain (in plan) the 5 gauss line, without the recognition that stronger magnets are likely to have even larger magnetic fields. The idea that construction of an MRI room can save $10,000 by making it 25 square feet smaller ignores the fact that this ‘minor’ reduction may make siting the next MRI technically impossible, or require hundreds of thousands of dollars in additional costs for magnetic shielding, structural reinforcing, vibration mitigation, etc…

Magnet rooms need to be designed with a prospective view to two critical factors, else risk jeopardizing the entire capital investment. Room designs must anticipate the real space needs for current and future clinical practices. This means space for equipment, staff, storage and yes, even visitors. Rooms must also anticipate that the MRI technology they house will change over time and that the new technology will likely require more space, more cooling, and more power.

MRI technology is following the personal computer example, though at a different pace. MRI technology does typically get more compact and easier to site, but these generalizations break down when considering specific pieces of equipment. If the room you currently have is large enough, has enough cooling, but is not structurally stout enough to accommodate a magnet that weighs twice as much as the previous one, this is a case where 2/3 of success is still failure.

If you have questions about the overall safety and efficiency of your MRI suite, you would be wise to have a MRI Suite Survey which can help you identify safety, throughput and operational improvements.