Most magnetic resonance imaging (MRI) machines require large amounts of helium to produce their diagnostic images. But as helium becomes increasingly hard to obtain, with once-plentiful sources in the United States drying up and the world’s most promising new source located behind an international embargo, more and more hospitals are turning to models that use less of the widely known but little understood gas.
Helium may be most familiar through its use in party balloons, but that is only a minor commercial application. Hospitals have been the largest end users of helium in the U.S., making up roughly 20 per cent of the market, says Phil Kornbluth, director of Kornbluth Helium Consulting in Bridgewater, N.J.
Helium is most commonly found as a component of natural gas, from which it is crudely separated at natural gas processing plants before being purified at helium plants. But in January, there was a natural gas leak at one of the largest helium plants in the U.S., the Cliffside Crude Helium Enrichment Unit near Amarillo, Tex.
“If someone had lit a match, the facility wouldn’t be here anymore,” says Rich Gottwald, the president of the Compressed Gas Association, a trade association for industrial gases, including helium. “It was really fortunate that it wasn’t an explosion.”
The Cliffside facility was shut down; approval to restart it only came at the end of May. This also cut off access to the U.S.’s National Helium Reserve, an almost 700 km-long underground pipeline that runs northeast from Amarillo through Oklahoma to Bushton, Kan. Kornbluth likens the National Helium Reserve to an ATM for helium, in which the U.S. government and various private companies can inject or withdraw purified (or “enriched”) helium at meters along the pipeline.
The National Helium Reserve once stored decades’ worth of helium, but today it only has enough to match roughly one year of domestic demand, or a third of a year of global demand.
Canada and the U.S. cannot make up for the helium shortfall simply by producing helium at other natural gas wells because not every well contains helium. The plant had already been taken down for maintenance several times in 2021.
“It didn’t create a full-scale, industry-wide shortage because folks thought it was temporary and also a large new supply from Russia was supposed to start up late last year,” says Kornbluth.
This new supplier was the Amur gas processing plant, operated in Russia’s Far East by Gazprom, Russia’s largest company. Amur started producing helium last September, but was hit by a fire during scheduled maintenance in early October. A further explosion this January again postponed resumption.
This is the fourth time that helium supply has been restricted since 2006, and each time, prices have surged.
The war in Ukraine, and the pull-out of western companies from Russia, likely will push the scheduled restart date from late 2022 to sometime in 2023, Kornbluth says.
“It’s become basically impossible for foreign experts to travel to Amur to assess the damage and help figure out what needs to be repaired,” says Kornbluth. “Equipment from Europe and the U.S. (needs) to be replaced … to get the plant back into operation. That may be impacted or delayed by the sanctions.”
This is the fourth time that helium supply has been restricted since 2006, and each time, prices have surged. Prices doubled between 2011 and 2013; fell by roughly 25 per cent between 2014 and 2017 when there was excess supply; and then doubled again between 2018 and early 2020, when COVID-19 curtailed demand for helium.
MRI machines cannot function without helium. The images show differences in how hydrogen atoms in different molecules and different bodily tissues and environments interact with a magnetic field. A stronger magnetic field produces a sharper image, and the strongest magnets appropriate for MRI machines are superconducting magnets, produced by sending large volumes of current through a material that has lost all of its electric resistance.
But to lose all of its electric resistance, the magnet must be cooled to extremely low temperatures – below at least -255 C, colder than the moon at night. Helium, which has a boiling point of -269 C, is used to reach these temperatures; as liquid helium at these low temperatures evaporates, it sucks heat away from the magnet, bringing down its temperature. Other, more readily-available gases, such as nitrogen and oxygen, have higher boiling points and do not cool the magnets cold enough.
Hospitals have still been able to obtain helium because suppliers prioritize them before party balloon stores. But the rising costs and difficulty of sourcing helium have led to the development of new MRI machines that use significantly less helium.
The Dutch electrical equipment maker Philips has produced a machine that requires seven litres of liquid helium instead of the 1,500 litres required by a traditional MRI machine. Furthermore, these seven litres of helium are sealed within the machine and cannot escape. A traditional MRI machine is not fully sealed and there is always some loss of helium into the atmosphere through evaporation. More than 500 such machines have been sold since 2018, says Arjen Radder, general manager of MRI at Philips, including several in Ontario and Quebec.
Traditional MRI machines are heavy and are thus usually located in the basement or on a reinforced floor of a hospital. They also require pipes venting out of the hospital to ensure that the helium can escape in case all of the liquid quickly evaporates and expands into the gaseous form. These pipes are no longer required with the smaller machines.
U.S. conglomerate General Electric has also done work on low-helium MRI technology, and China’s Wandong Medical Technology claims to have developed a helium-free MRI machine.
However, traditional MRI machines still make up the vast majority of MRI machines sold each year. Donations of old machines to developing countries means that helium will still be needed for medical applications for years to come.
The hunt for new helium sources is on. Some companies are exploring for “green helium,” where the helium underground is typically not mixed with natural gas but with nitrogen (the main component of air); high helium prices mean that this is profitable, even without selling off a stream of natural gas. Extraction of green helium is already taking place in Alberta and Saskatchewan, though it makes up less than 5 per cent of the market.
The worst of the current helium shortage may be already over, says Kornbluth, but the years of plentiful helium supply promised by Gazprom’s Azur plant look to be some way off.