Functional magnetic resonance imaging, or fMRI, gives researchers a powerful way to study brain activity. But the scans can be incredibly noisy for patients and research subjects, with peak sound levels reaching 120 to 138 decibels - about as loud as a jackhammer.
Yen-Yu Ian Shih, PhD, professor of neurology and associate director of the UNC Biomedical Research Imaging Center (BRIC) at the UNC School of Medicine, is working to address that challenge. Shih and his research team have developed a new functional brain imaging technique that quiets fMRI scans, resulting in clearer, more accurate images.
Yen-Yu Ian Shih, PhD
"SORDINO is something we now use regularly in our lab for a variety of neuroscience research projects," said Shih, who was senior author of the study. "It has really simplified our day-to-day fMRI experiments. We hope SORDINO will help other researchers overcome some of the technical barriers that have long complicated fMRI studies and eventually bring similar advances to human MRI."
Initially used to map brain activity in small animal models, SORDINO may also be used to accelerate innovations in neurological research and human MRI. A paper describing the SORDINO method and its research benefits was published in Nature Neuroscience.
Researchers use fMRI to study how activity across the brain changes during sleep-wake transitions, social interactions, and sensory-motor behaviors. Often conducted in small animal models, this research provides important insight into human brain function and neurological disorders.
Conventional fMRI, however, presents challenges for both noise-sensitive research subjects and research outcomes. Loud acoustic noise can cause stress and movement, and it can interfere with implanted devices and other electrical measurements of brain activity.
SORDINO, which stands for Steady-state On-the-Ramp Detection of INduction-decay with Oversampling, is an fMRI acquisition sequence. It acts as the set of instructions an MRI scanner uses to collect brain measurements, such as blood flow and oxygen levels, and translates them into images.
To evaluate SORDINO, researchers compared the method with conventional fMRI in mouse models. They found that SORDINO substantially reduced acoustic noise, electromagnetic interference and stress-related hormones, while producing images with less distortion. The improvements enabled researchers to use SORDINO-powered fMRI to study complex behaviors, including voluntary skilled movements and social interactions between two mice scanned at the same time. Shih and his team were granted a U.S. patent for the SORDINO method in 2024.
UNC researchers interested in exploring SORDINO for new MRI research projects are encouraged to contact Shih or visit https://camri.unc.edu. Researchers outside UNC may request the SORDINO sequence through a material transfer agreement (MTA) at https://camri.org/sordino/.
This work was primarily supported by the National Institute of Biomedical Imaging and Bioengineering (R01EB033790) and the W. M. Keck Foundation. The Carolina animal MRI research infrastructure was supported in part by the UNC School of Medicine Office of Research, the Core Facility Advocacy Committee (CFAC), the National Institute of Mental Health (S10MH124745), and the NIH Office of the Director (S10OD026796). Shih is also a member of the UNC Bowles Center for Alcohol Studies (P60AA011605) and the UNC Intellectual and Developmental Disabilities Research Center (P50HD103573).
