The Nijmegen superscanner will soon make the most accurate images of the brain: what can science do with it?

The Donders Institute will build the world’s most powerful MRI scanner in Nijmegen, together with six other Dutch partners. A superscanner enables unprecedentedly detailed brain images, but can test subjects handle such a strong magnetic field?

It was big news until 8:00 a.m.: Nijmegen is getting the world’s most powerful MRI scanner. The scholarship provider NWO makes available 19 million for this purpose, From the “National Road Map” support program. This jar is for important and expensive research equipment, including parts for space telescopes, for example. This scanner puts Nijmegen in the field Neuroimaging Soon at the center of the world, says research leader David Norris (Donders Institute) proudly. “This will make Nijmegen more attractive to leading international scientists.”

“We’ll soon be able to identify very small brain nuclei as well.”

The device will have a power of at least 14 tesla – never seen before for human searches. Tesla is the physical unit of magnet force (unrelated to make of car). For comparison: the earth’s magnetic field, with which the compass needle interacts, is less than one ten-thousandth of a tesla.

The new Nijmegen scanner will be nearly five times more powerful than the modern 3-Tesla MRIs in many hospitals, and more powerful than any existing scanner in the world used for brain research. The current record holders are Paris and Baltimore, which currently have two 11.7 Tesla MRIs.

Amazing performance

What exactly can we expect from this scanner, which will be launched for the first time in three years, if all goes well? He doesn’t have to think long, Norris says in his office in the Trigon Building. One MRI physics professor appears one by one artist impression on screen, along with all the great performances DYNAMIC Confederation has come to expect (see box). We will soon be able to make much better scans that can discern 0.3mm detail. Current scanners in Nijmegen barely reach 0.8 millimeters. “We will soon be able to identify very small brain nuclei as well.”

It will also be possible to distinguish between the different layers of gray matter (nerve cells in the outermost layer of the brain), says the professor, and how information is exchanged within them. Previously, laboratory animals were mainly used for this purpose. “It is also possible to characterize those layers using today’s powerful Tesla Model 7 scanners, but at a lower resolution.” In addition, the required inspection time is much shorter with the 14-Tesla. This makes it possible to carry out studies that would currently take a long time for test subjects.

But entirely new research possibilities are also being added, such as measuring the amount of neurotransmitters, the messenger substances in our brain. Norris: “We will soon be able to determine some of these details as eighteen times greater than 7 Tesla.” This provides opportunities to better understand what goes wrong in the diseases in which these substances are involved, such as depression and Parkinson’s disease.

This may all sound promising, but this great magnetic force brings with it all kinds of practical challenges. Current superscanners of 10 Tesla or more have all sorts of problems, despite occasionally patching for ten years. Very little real research has been done on humans.

For example, researchers in Baltimore worked for years to fix the 11.7-inch Tesla superscanner after it accidentally overheated during initial tests. MRI scanners are cooled with liquid helium to a fraction above absolute zero (minus 273 degrees), because only then do the wires have superconducting properties. This is necessary to create the magnetic field. The equally powerful scanner in Paris has been under construction for a decade and so far only has test images of it inside the pumpkin Delivered.

The limit has been raised

Do you really want a more powerful MRI machine, if the current overhead scanners already have so many problems? Norris says that’s right. The Nijmegen scanner will be technically very different from the current devices. With the superconducting materials we use traditionally, you could theoretically get to 12 tesla. Present high field Scanners (with high magnetic field strength, ed.) are close to that, which is why they have so many technical problems.

“I expect the first person to come in will vomit.”

In the Nijmegen variant, the theoretical maximum is much larger, at 28 Tesla, and the scanner is not pushed to the limit. The material also needs to be cooled less severely. That is why helium is not needed (sometimes difficult to obtain), but cooling takes place using a vacuum. An additional advantage is that the scanner will be more compact than current ultrascanners, with a wide aperture for test subjects – great for those with claustrophobia.

Fairground attraction

There are also concerns about what this scanner does to test people. “I expect that the first person who enters will come out vomiting,” says John van Opstal, for example, in a firm tone, in his office in the Huygens Building. This, explains the professor of biophysics (also Donders Institute), is because strong magnetic fields stimulate the vestibular system, in a similar way to fairground attraction. “You get the feeling that you’re spinning all the time.” Van Opstal has been conducting research for decades on, among other things, the functioning of the balance organ located in our inner ear.

At relatively low field strengths such as 3 Tesla, the stimulating effect is still small, but it is already noticeable at 7. Van Opstal includes a video in which A close-up view can be seen of a subject in a 7 Tesla MRI. The eye moves back and forth all the time. Such a so-called nystagmus is an automatic eye reaction that occurs when you turn.

Float

Van Opstal: “With 14 Teslas, this would be worse. The effects could be harmful – nobody knows that. For example, hearing stones may be released in the ear stones (part of the balance organ), he says. This leads to a form A form of vertigo that can last for weeks. The question is also whether so-called paramagnetic effects can actually occur – a phenomenon that causes things to levitate. This occurs at points of maximum magnetic strength, such as those in the 37.5-Tesla scanner (not suitable for humans) in the HFML-FELIX, which was used by physicists in Nijmegen in 1997. Frog float. The test subject won’t float in the new scanner, but small objects on the object might, Van Opstal speculates.

“We take safety very seriously”

Norris stresses that he and his colleagues didn’t happen overnight. “We take safety very seriously,” he says. We know from other powerful scanners that short-term effects, including dizziness, can occur. We will study test subjects only after all these aspects have been thoroughly examined. Plus, there will be an independent safety committee that tests everything. And we’re working closely with Paris and other labs to learn from their experiences with superscanners. It also does not expect floating effects. And if it’s really necessary, he says, the magnet’s strength can be reduced. Therefore, investing millions will not waste money anyway, he wants to say.

Dizziness

Radiology professor Thijs van Osch (Leiden University Medical Center) does not foresee any intractable problems either. Van Oesch, who himself participates in the DYNAMIC consortium, has repeatedly investigated the risks of scanning at high field strengths. like him Analyze it in 2013 Experiences of over a hundred people tested with the powerful Leiden 7-Tesla scanner. They weren’t so bad. A third of people experienced dizziness, but especially when they entered the scanner,” he explained over the phone. “You can manipulate that a little bit if you move people really slowly.”

Plus, an equally large group found the Razer’s loud sound uncomfortable (despite the hearing protection). Only 3 percent found the scanning session really annoying overall. Van Osch: “In practice, most people get used to it after about ten minutes. So I don’t expect 14 tesla to suddenly be a problem.

We probably won’t know exactly how the new Donders Institute takeover will turn out in about ten years’ time. Then the scanner will be fully tested and will have to run at full speed brain and medical research, is the plan. Norris laughs: “This will keep me busy until I retire.”