MRI at Bedside

Fundamental research by Matthew Rosen, director of the Low-Field Imaging Laboratory in the Martinos Center, contributed to the early development of a new portable MRI scanner by Hyperfine Research Inc. The potentially game-changing technology was introduced in October 2019 at the American College of Emergency Physicians meeting in Denver.

Over the past several decades, MRI has emerged as a gold standard in biomedical imaging, 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 advances in the years since, the underlying technology— and its inherent limitations—have remained largely the same. MRI scanners today still depend on hulking superconducting magnets to produce the high magnetic fields needed for imaging. As a result, the scanners are confined to highly specialized MRI suites in hospitals or to large, tractor trailer-based units parked on hospitals’ lawns.

Rosen started thinking about ways to overcome these limitations in the early 2000s, while a postdoctoral fellow in the Harvard-Smithsonian Center for Astrophysics. He dove headlong into the work when he moved the Martinos Center in 2009. Initially, his efforts in this area were aimed at supporting the Department of Defense and combat casualty care to “break the MRI scanner out of its controlled access environment in the radiology suite and reinvent it in a way that could operate in field-forward environments,” he says. This early work inspired efforts in his group to innovate in the area of ultralow-field MRI, where the magnetic field is essentially “turned down” so the scanner is compatible with both mobile operation and undisclosed shrapnel but still could be sensitive enough to make clinically actionable MRI images in short scan times.

Above: Mass General is now using the portable MRI scanner in the clinic. Shown here with the system are the Center’s Matt Rosen and Mass General neurologist Taylor Kimberly. Photo courtesy of Matt Rosen.

Recognizing the potential of portable MRI technology for other point-ofcare locations, Rosen co-founded Hyperfine Research with serial entrepreneur Jonathan Rothberg in 2014. Hyperfine subsequently developed its newly introduced bedside MRI scanner, which flips the current paradigm in magnetic resonance imaging by bringing the imaging to the patient. The scanner is not intended to replace high-field MRI, which provides superior resolution and tissue contrast. Rather, the ultra-low-field MRI technology that drives it will make imaging accessible to clinicians and patients in a number of new scenarios.

The unveiling of the bedside MRI scanner in late 2019 followed a successful study of the technology, funded by the American Heart Association, in the Neuro ICU at Yale New Haven Hospital. (Hyperfine is based in Guilford, Conn., not far from New Haven.) Rosen was one of three co-principal investigators of the study, alongside study lead Kevin Sheth from Yale University Department of Neurology and Taylor Kimberly of the MGH Department of Neurology.

Rosen reflects on the synergistic relationships that make possible the sort of innovation seen with the Hyperfine bedside MRI scanner, as well as on the unique environment in the MGH Martinos Center that inspires such fruitful work in developing biomedical imaging technologies.

“This is a truly great example of how basic physics research can create something amazing with the right commercial partner,” he says. “Rothberg and his incredible team at Hyperfine have succeeded in advancing the science and technology as well as taking things to the next level in form factor, cost and performance. Meanwhile, I have been able to lead my academic group into new interesting areas of physics, such as our work with hyperpolarized nanodiamonds and other molecules, quantitative image acquisition strategies for multiparametric contrasts, and more recently all the work we do with machine learning to completely reframe the way raw data is processed into image data.”

He continues: “Martinos is an incredibly creative place, and very open to the kinds of work that really lead to next-generation successes such as the Hyperfine MRI scanner. It is a wonderful environment and I don’t think this work could have happened without our deep connection to our incredible clinical collaborators.”

Mass General is now using the portable MRI scanner in the clinic. Shown here with the system are the Center’s Matt Rosen and Mass General neurologist Taylor Kimberly.

Photo courtesy of Matt Rosen