Advancements to functional imaging technique result in ultra-high resolution capture of human cortical columns

Despite numerous advances in fMRI technology, most components are optimized for the entire body. This makes safe, ultra-high resolution (UHR) imaging of columnar organization throughout the cortex of the human brain nearly impossible. At the University of California, Berkeley, Dr. David Feinberg and colleagues applied updates to magnetic gradients, receiver arrays, and pulse sequences of simultaneous multi-slice echo planar imaging fMRI to achieve UHR imaging of human ocular dominance columns. Focusing particularly on a prototype receiver array (8 channels with 4 cm diameter coils), the group systematically describes the changes necessary to achieve the higher signal-to-noise ratio required to attain ~0.5 mm imaging resolution in 3 dimensions. Finally, the researchers display their updated UHR system compared to commercially available technology when mapping ocular dominance columns in three subjects shown visual stimuli in the scanner. The group notes their findings are part of a growing set of 3D imaging studies, moving to leverage fMRI to understand neural circuitry by revealing activity of distinct cell populations in different cortical layers. They postulate that this 3D imaging technique could eventually progress from 0.5 mm to 300-400 µm resolution fMRI of the entire human brain.