Sunday, December 24, 2023

Next-Generation fMRI Improves Spatial Resolution 10-Fold to image sub-microliter

Good news! Amazing stuff! This seems to be a very significant improvement over existing fMRI!

"Researchers have developed a series of technological improvements that dramatically increase the spatial resolution of an fMRI (functional magnetic resonance imaging) machine. The improvements allow an fMRI to image voxels—the 3D equivalent of pixels—that are less than half a millimeter on each side. In doing so, they have passed an important threshold relative to the structure of the human brain, to roughly match the scale of functional clusters of neurons.
The NexGen 7T scanner is a ten-fold improvement in resolutionover 7T MRI machines that are currently available to researchers. ...
But with higher, sub-microliter resolution, neuroscientists should get a detailed look at the functional organization of groups of neurons in the cerebral cortex ..."

"An intense international effort to improve the resolution of magnetic resonance imaging (MRI) for studying the human brain has culminated in an ultra-high resolution 7 Tesla scanner that records up to 10 times more detail than current 7T scanners and over 50 times more detail than current 3T scanners, the mainstay of most hospitals. ...
This could lead to better ways of diagnosing brain disorders, perhaps by identifying new biomarkers that would allow diagnosis of mental disorders earlier or, more specifically, in order to choose the best therapy. ..."

From the abstract:
"To increase granularity in human neuroimaging science, we designed and built a next-generation 7 Tesla magnetic resonance imaging scanner to reach ultra-high resolution by implementing several advances in hardware. To improve spatial encoding and increase the image signal-to-noise ratio, we developed a head-only asymmetric gradient coil (200 mT m−1, 900 T m−1s−1) with an additional third layer of windings. We integrated a 128-channel receiver system with 64- and 96-channel receiver coil arrays to boost signal in the cerebral cortex while reducing g-factor noise to enable higher accelerations. A 16-channel transmit system reduced power deposition and improved image uniformity. The scanner routinely performs functional imaging studies at 0.35–0.45 mm isotropic spatial resolution to reveal cortical layer functional activity, achieves high angular resolution in diffusion imaging and reduces acquisition time for both functional and structural imaging."

Next-Gen fMRI Improves Spatial Resolution 10-Fold - IEEE Spectrum A suite of improvements enables the NexGen 7T to image sub-microliter neuron clusters


Next-generation MRI scanner designed for ultra-high-resolution human brain imaging at 7 Tesla (open access)

The NexGen 7T MRI (left) has a higher resolution than a conventional 7T scanner (middle) and standard 3T hospital scanner (right). 


With ultra-high resolution functional MRI, it is possible to differentiate active groups of neurons (blue arrows, which show double stripes of activity) in superficial layers as well as the deepest layers of the brain's cortex. The NexGen 7T can detect activity in the thinnest human brain cortex, which is between 1.5 and 2 millimeters thick. 


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