Using an MRI system operating at six times the magnetic field of a conventional clinical scanner, researchers at the Duke Center for In Vivo Microscopy have gathered the most detailed magnetic resonance images ever captured of a mammalian brain. And while that may sound fairly wonky, the images – which will go into an online atlas open to researchers around the world – will allow researchers to slice and dice the brain digitally any way they want, helping researchers across disciplines run virtual experiments on the highly-detailed structure.
A typical MRI scan represents brain tissues in cubic units called voxels that can be thought of loosely as a 3-D pixel in a brain image. But since the new atlas images were taken at a resolution 300,000 times higher than those from a conventional MRI scanner, each voxel is much smaller and more detailed, shrinking from about 1-by-1-by-3 millimeters to about 20 microns per side (a micron being a millionth of a meter).
The images were taken of fixed brain tissue still in the craniums of eight different mice to minimize the distortions that can occur when the brain is removed or sliced for typical study. But using the tools in the Waxholm Space brain atlas – so named for the Swedish town where the idea for the atlas took shape – the brain can be digitally sliced at any angle, providing researchers with the ability to use the brain however they like without losing resolution.
Using three different data acquisition protocols while imaging, the team was also able to characterize 37 different brain structures, and by mashing up the data from the eight different mice they were also able to create a model for an average brain and a probabilistic brain. And that’s just the starting point for researchers; as new data is acquired it will be registered to the brain atlas site so other researchers can access it as well, fostering a system of information sharing that is far cleaner and more convenient than mailing mouse brains through the post.