Low-Cost, High-Performance MRI Opens New Opportunities For Brain Imaging

Gary Boas
October 15, 2015
The groundbreaking MRI technology is described in a new study from the Martinos Center. Shown here with the technology are Matthew Rosen (center), senior author of the study and Director of the Center’s Low-Field Imaging Laboratory, and (clockwise from left to right) lead author Mathieu Sarracanie, Cris LaPierre and Najat Salameh.

Recent years have seen tremendous advances in the development and application of magnetic resonance imaging (MRI), allowing imaging of structures and even processes in the human body that would have been unimaginable 30 years ago, when the first generation of commercial MRI scanners was introduced.

But for all the gains in imaging quality and speed, the underlying technology—and its inherent limitations—remain largely the same. MRI scanners still depend on huge superconducting magnets to produce the high magnetic fields that are needed for imaging. As a result, scanners are confined to MRI suites in hospitals or to large, tractor trailer-based units, preventing their use in an array of new mobile applications.

Now a team of investigators at the Martinos Center for Biomedical Imaging at the Massachusetts General Hospital has reported an approach to low-cost, high-performance MRI that would allow researchers and physicians to overcome these limitations. They describe the approach in a Nature Scientific Reports paper published online today.

“We envision a paradigm shift in MRI, where mobile low-cost devices enabled by ultra-low magnetic field technology become ubiquitous, and offer new ways to practice medicine, in previously unreachable places,” said Mathieu Sarracanie, a research fellow in the Low-Field Imaging Laboratory in the Martinos Center and lead author of the newly published results.

The technology described in the paper operates at a magnetic field strength of 6.5 millitesla—more than 450 times lower than with clinical MRI scanners. The authors of the study, including Sarracanie, Cristen LaPierre, Najat Salameh, David Waddington, Thomas Witzel and Matthew Rosen, achieved high-performance MRI at this ultra-low field strength through innovative engineering, acquisition strategies, and signal processing. In the paper, they report 3D MRI of the living human brain with heretofore unattainable speed and resolution in the ultra-low-field MRI regime.

This creates a number of new opportunities for MRI. Not least: Without the need for massive, cryogen-cooled superconducting magnets, the scanners can be sited and operated in a range of unconventional environments. For example, ultra-low-field scanners operating with this new technology could complement traditional MRI by relieving hospital congestion and reducing triage delays in the neuro-intensive care unit.

Also, mobile standalone scanners could be implemented in resource-poor environments and in situations where MRI systems are not traditionally available—for example, during military conflicts, natural disasters or sports events.

“This novel non-cryogenic ultra-low field MRI technology will be smaller, lighter, less expensive, more robust and more transportable than conventional MRI systems,” said Matthew Rosen, Director of the Low-Field Imaging Laboratory, an Assistant Professor of Radiology at Harvard Medical School and the senior author of the work, “allowing for operation in, for example, battlefield hospitals—near to where injuries are most likely to occur—and enabling assessment of brain injury within the first hours of the primary injury.”

Importantly, the ultra-low-field technology is also considerably less expensive than traditional MRI. Conventional scanners can cost upwards of $1.5 million for the high-field (1.5-Tesla) devices most commonly used today. The scanner described in the Nature Scientific Reports paper, in contrast, could cost less than $50,000.


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