Helium-free MRI systems: What does that mean for a radiology decision maker?

Traditional MRI systems rely on large liquid-helium baths to maintain superconductivity, requiring complex infrastructure, quench pipes, and ongoing helium supply management. Modern "dry" or sealed micro-helium MRI magnets replace this approach using conduction cooling and sealed helium volumes of only a few liters. These systems drastically reduce helium dependence, eliminate routine refilling, simplify installation, and lower the lifetime operating costs. The major practical advance came from moving from the open helium baths in the 2010s, which still required quench pipes and other safety features, to sealed systems, rather than from differences in small helium volumes (e.g., 0.7 vs. 7 L or 20 L) marketed by vendors. Smaller volumes marginally affect safety margins and resilience during power interruptions, rather than affecting routine clinical operations. This paper provides a brief introduction to the problem and terminology, and subsequently presents the technological issues related to the volume of sealed micro-helium MRI magnets. It also provides a list of questions to ask about the magnet sub-assembly itself, which enables the calculation of the total cost of ownership. KEY POINTS: Question What does it mean and how relevant is a "helium-free" MRI magnet and the remaining sealed liquid Helium volume? Findings The real operational leap in MRI magnet technology was from hundreds/thousands of liters of liquid helium to single-digit sealed systems; the sub-liter distinction does not really matter. Clinical relevance statement The article argues from a technical and economic perspective. While these sealed systems eliminate helium logistics, come with simpler siting, and reduced infrastructure costs, they raise other procurement questions for suppliers, like quench recovery time and resilience in low-resource settings.