Forty years in the making: Advanced MRI scan reveals brain images 64 million times sharper

The 40 years in making of sharper MRI

MRI is a well-known medical imaging technology used for disease detection, diagnosis, and treatment monitoring. Doctors and scientists can scan and image almost any part of the body, including the brain and joints, using this technology. 

The new landmark advancement of high-level resolution will allow experts to see and examine biological structures in microscopic detail, which could be especially useful to advance research on brain disorders. 

“It is something that is truly enabling. We can start looking at neurodegenerative diseases in an entirely different way,” said G. Allan Johnson, the lead author of the new paper from the Duke Institute, in a statement. 

When compared to a typical clinical MRI for humans, the generated scans of a mouse brain were significantly crisper. The official statement emphasizes “a single voxel of the new images – think of it as a cubic pixel – measures just five microns. That’s 64 million times smaller than a clinical MRI voxel.”

The high-resolution MRI would make it possible to visualize the connectivity of the entire brain in unprecedented detail. Not only that, but it has the potential to better understand several other brain disorders, including Alzheimer's, Huntington's, and others. In fact, the team has already considered using the newly generated mouse MRI to better understand brain changes caused by age, diet, and neurodegenerative diseases in humans. 

However, it was not easy to develop such a refined and advanced version of MRI technology. Years of trial and error went into it. The team used specialized elements like a powerful magnet, a unique set of gradient coils, as well as an advanced computer with performance equivalent to nearly 800 laptops. This MRI also uses the power of light sheet microscopy to obtain detailed images.

All of these high-tech innovations combined resulted in a dynamically sharper image and made "MRI an even higher-powered microscope."

The details of new MRI work have been reported in the journal Proceedings of the National Academy of Sciences. 

Study Abstract:

We have developed workflows to align 3D magnetic resonance histology (MRH) of the mouse brain with light sheet microscopy (LSM) and 3D delineations of the same specimen. We start with MRH of the brain in the skull with gradient echo and diffusion tensor imaging (DTI) at 15 μm isotropic resolution which is ~ 1,000 times higher than that of most preclinical MRI. Connectomes are generated with superresolution tract density images of ~5 μm. Brains are cleared, stained for selected proteins, and imaged by LSM at 1.8 μm/pixel. LSM data are registered into the reference MRH space with labels derived from the ABA common coordinate framework. The result is a high-dimensional integrated volume with registration (HiDiver) with alignment precision better than 50 µm. Throughput is sufficiently high that HiDiver is being used in quantitative studies of the impact of gene variants and aging on mouse brain cytoarchitecture and connectomics.