New Delhi: MRI scanners can defeat their own purpose at times. They can be so loud, as much as a power drill or rock concert, that subjects get stressed or move around, making it harder to measure brain signals.
Now, scientists at the University of North Carolina School of Medicine have developed a new functional magnetic resonance imaging (fMRI) technique to make scans a much less cacophonous experience and help researchers get better readings.
The advanced technique, called SORDINO, was detailed in a study published on 9 September in Nature Neuroscience. The acronym stands for Steady-state On-the-Ramp Detection of Induction -decay with oversampling.
“SORDINO is something we now use regularly in our lab for a variety of neuroscience research projects. It has really simplified our day-to-day fMRI experiments,” said Yen-Yu Ian Shih, professor of neurology and associate director of the UNC Biomedical Research Imaging Center, who was the study’s senior author. “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.”
Researchers use fMRI to study how activity across the brain changes during sleep-wake transitions, social interactions and sensory-motor behaviours. This can offer insight into brain function and neurological disorders.
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Noise-sensitive research
Conventional fMRI is particularly difficult when researchers need subjects to stay awake and be still. The scanner’s noise can cause stress and movement and its electromagnetic interference can disrupt implanted devices and electrical measurements of brain activity.
SORDINO tackles both problems by keeping the total magnetic gradient amplitude steady rather than repeatedly switching it. This reduces the acoustic noise produced during scanning.
Researchers compared SORDINO with conventional fMRI in awake mice. They found that it reduced acoustic noise, electromagnetic interference and stress-related hormones, while also producing images with less distortion.
The quieter scans also made it easier to combine fMRI with calcium imaging, which records activity from groups of neurons. Using the two together, the researchers were able to track how activity in individual brain cells related to larger brain networks in awake mice.
The researchers were granted a US patent for the SORDINO method in 2024, according to a UNC release.
(Edited by Asavari Singh)