New brain atlas offers unprecedented detail in MRI scans
5 November 2025
A new AI-assisted brain atlas helps visualise the human brain in unprecedented detail, representing a major step forward for neuroscience and neuroimaging.
NextBrain is an atlas of the entire adult human brain that can be used to analyse MRI scans of living patients in a matter of minutes and at a level of detail not possible until now.
It was developed by academics at University College London, along with the University of Girona, Cardiff University, and Massachusetts Institute of Technology . Their work is published in the journal Nature.
The creators of the atlas, which is freely available, hope it will ultimately help to accelerate discovery in brain science and its translation into better diagnosis and treatment of conditions such as Alzheimer’s.
The brain is an incredibly complex structure – with existing atlases identifying major structures in MRI scans, but finer sub-regions remaining hard to detect. These smaller sub-regions can be altered in neurological disease or conditions, like Alzheimer's disease, so it’s important that we can detect these distinctions.
AI assists atlas’ development
The atlas took the research team six years to build, using post-mortem tissue from five human brains from donors . The brains were dissected and sectioned into 10,000 pieces, stained to identify brain structures, photographed under a microscope, then reassembled into a 3D digital model.
“Before we began the process, we conducted MRI scans of the brains, so we would know how to put them back together. Similar to a jigsaw puzzle,” added Matteo.
AI was used to help align the microscopic images and the MRI scans, accounting for the differences between the two techniques and ensuring that the pieces did not overlap or have gaps in between them.
A total of 333 brain regions were then labelled on the digital 3D models of each of the five brains, a process accelerated by AI. Done manually, it would’ve taken decades.
NextBrain is the culmination of years of effort to bridge the gap between microscope imaging and MRI. By combining high-resolution tissue data with advanced AI techniques, we’ve created a tool that allows researchers to analyse brain scans in a level of detail that was previously unattainable. This opens up new possibilities for studying neurodegenerative diseases and ageing.
The resulting atlas, which is an ‘average’ of the five brain models, is generalisable to all adult humans – meaning it can be used to automatically infer detail from MRI scans of living or deceased subjects.
Testing NextBrain’s accuracy
NextBrain was successfully tested on thousands of MRI datasets, demonstrating the ability to reliably identify brain regions across diverse imaging conditions and scanner types. In one experiment, the team used the atlas to automatically label brain regions in a publicly available ultra-high-resolution MRI scan, which closely matched the manually labelled regions, even for small areas such as subregions of the hippocampus.
In another experiment, the researchers applied NextBrain to over 3,000 MRI scans of living individuals to investigate age-related changes in brain volume. The atlas enabled detailed analysis of ageing patterns, which were more detailed than existing tools.
Dr Zane Jaunmuktane, University College London Queen Square Institute of Neurology and the Queen Square Brain Bank for Neurological Disorders, said: “Our goal by building this atlas was to enable researchers to identify hundreds of brain regions in living patients quickly and consistently, while maintaining the fine-grained anatomical accuracy of microscope data. The level of anatomical detail in NextBrain is remarkable, and its public availability means that researchers worldwide can benefit from it immediately."
The NextBrain atlas provides an unparalleled map of the brain’s cellular architecture. The foundation built into the atlas now enables rapid, accurate and accessible analysis of brain images in living individuals, opening the door to detecting the earliest signs of neurological diseases such as Alzheimer’s, long before symptoms appear, and advancing our ability to understand, monitor and ultimately prevent these devastating diseases.
All underlying data, tools, and annotations used in NextBrain have been released openly through the FreeSurfer neuroimaging platform, along with visualisation tools and educational resources. The study was supported by the European Research Council, Alzheimer’s Society, the Lundbeck Foundation, and the National Institutes of Health (US).
