Enhanced magnetic strength technique developed for more precise imaging of myelin sheath in MS

Researchers have devised a novel method for more accurately mapping the myelin sheath, the protective layer surrounding nerve fibres that deteriorates in multiple sclerosis (MS), during imaging scans of patients.

Although further refinement is required, the technique has so far had promising outcomes, according to the scientists. They suggest that once optimised it could enhance the precision of MS diagnoses and enable better tracking of myelin damage and repair in patients with MS.

MS arises from inflammation in the brain, resulting in harm to the myelin sheath, which disrupts nerve signalling and manifests as disease symptoms. Over decades, medicines have primarily relied on magnetic resonance imaging (MRI) to monitor myelin damage in patients.

MRI functions by utilising powerful magnets to produce a signal from hydrogen atoms. Typically, an MRI detects signals from hydrogen atoms in water molecules. Since myelin consists of fats and proteins rather than water, conventional MRI methods indirectly estimate myelin levels by measuring water content surrounding the myelin layers.

Given that myelin’s hydrogen atoms emit much shorter signals than those in water, traditional MRI scanners struggle to capture these fleeting signals effectively. Markus Weiger, PhD, co-author of the study at ETH Zurich in Switzerland, explained, “Put simply, the hydrogen atoms in myelin tissue move less freely than those in myelin water. That means they generate much briefer signals, which disappear again after a few microseconds. And bearing in mind a microsecond is a millionth of a second, that’s a very short time indeed.”

To overcome this challenge, the researchers developed a specialised MRI scanner with enhanced magnet strength tailored for analysing the head region, enabling quicker signal detection.

Emily Baadsvik, a researcher at ETH Zurich and the study’s lead author, elaborated, “The greater the change in magnetic field strength generated by the three scanner coils, the faster information about the position of hydrogen atoms can be recorded.”

Despite the innovation, the system has limitations, such as lengthy scan durations of approximately an hour and a half, which may test the patience of cooperative volunteers.

Nonetheless, proof-of-concept experiments demonstrated the system’s capability to accurately visualise the myelin sheath in healthy adults with sub-two-millimetre resolution.

The researchers intend to further refine the technology and evaluate its efficacy in MS patients, with the ultimate goal of collaborating with industry partners to facilitate its clinical implementation.

“We’ve shown that our process works,” Weiger affirmed. “Now it’s up to industry partners to implement it and bring it to market.”

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