A study published in Science Advances found the answer to creating high-quality images with low-cost MRI scanners and could revolutionize diagnosis.
An average MRI scanner can cost $3 million or more. Rural hospitals with small patient populations usually can’t afford them. Physicist Matthew Rosen, Ph.D. at the MGH Martinos Center for Biomedical Imaging has long wished to create more affordable MRI scanners. “The focus of my lab is to deconstruct the MRI scanner,” Rosen said.
Rosen said an MRI scanner’s cost is mostly due to its superconducting magnet. Stronger magnets mean more expensive MRI scanners. An average MRI generates a magnetic field of 1.5 Tesla (T) and MRIs increasingly hit 3 T. Newer “low-field” MRIs operate at 0.064 T and cost from $50,000 to $100,000.
Rosen is frequently asked by radiologists if a contrast agent is available which can improve the images of low-field MRIs. Doctors sometimes inject patients with a gadolinium-based contrast agent before doing an MRI because it can enhance the image quality. Concerns about gadolinium deposition disease now exist about this practice, though.
Rosen said 1,000 times the amount approved by the U.S. Food and Drug Administration (FDA) would be necessary for gadolinium contrast agent to be used with a low-field MRI.
Physicists David Waddington, Ph.D. and Zdenka Kuncic, Ph.D. from the University of Sydney suggested testing a low-field MRI contrast agent based on superparamagnetic iron oxide nanoparticles (SPIONs). SPIONs are FDA approved for anemia treatment, but Waddington says they also “essentially amplify low magnetic fields,” noting they are 3,000 times more magnetic than gadolinium contrast agents.
The study involved rats being scanned with a low-field MRI, injected with SPIONs and scanned again. Organs glowed brightly after SPION administration in the post-injection images.
The FDA has not yet approved SPIONs for use in contrast agents but doctors can currently use them “off label” with low-field MRIs. Waddington and Rosen think SPIONs and affordable low-field MRIs can bring high quality imaging to doctors’ offices, intensive care units and emergency rooms where it was previously unavailable due to the high cost of a typical MRI scanner.
Kuncic and Waddington are also looking into using coated SPIONs to use MRIs to detect cancerous tumors.
Some patients given contrast agents with gadolinium in them have reported symptoms including a burning sensation in tissues, skin thickening, bone pain, skin discoloration and mental confusion. The suite of symptoms has been dubbed “gadolinium deposition disease.”