A new fMRI acquisition method developed at the University of North Carolina reduces peak scan noise from levels exceeding 120 decibels.

Researchers at the University of North Carolina School of Medicine have developed a new functional brain imaging technique designed to substantially quiet the acoustic noise produced during functional magnetic resonance imaging (fMRI) scans — noise that can reach peak levels of 120 to 138 decibels, roughly equivalent to a jackhammer.

The method, called SORDINO (Steady-state On-the-Ramp Detection of INduction-decay with Oversampling), is an fMRI acquisition sequence — the set of instructions an MRI scanner uses to collect brain measurements such as blood flow and oxygen levels and convert them into images. A paper describing the technique was published in Nature Neuroscience.

The work was led by Yen-Yu Ian Shih, PhD, professor of neurology and associate director of the UNC Biomedical Research Imaging Center (BRIC), who served as senior author of the study.

Reducing Noise and Interference

Conventional fMRI presents challenges beyond patient discomfort. Loud acoustic noise during scanning can cause stress and movement artifacts in research subjects, and it can interfere with implanted devices and other electrical measurements of brain activity. For hearing care professionals, this interference concern is particularly relevant: many patients with cochlear implants or other implanted auditory devices face unique challenges in MRI environments.

In evaluations using mouse models, SORDINO substantially reduced acoustic noise, electromagnetic interference, and stress-related hormones, while producing images with less distortion compared to conventional fMRI. The technique also enabled researchers to study more complex behaviors, including voluntary skilled movements and social interactions between two mice scanned simultaneously.

“SORDINO is something we now use regularly in our lab for a variety of neuroscience research projects,” says Shih, in a release. “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.”

Broader Research Applications

Researchers use fMRI to study how brain activity changes during sleep-wake transitions, social interactions, and sensory-motor behaviors. Though currently applied in small animal models, the technique is intended to accelerate innovations in neurological research and eventually human MRI. Such advances could have downstream relevance for auditory neuroscience and brain-hearing research, areas of growing interest in the hearing care field.

Shih and his team were granted a US patent for the SORDINO method in 2024.

Featured image: The Shih lab team in front of an MRI machine. Photo: Yen-Yu Ian Shih, PhD