What happened
Researchers found that measuring how quickly the boundary between gray and white matter in the brain degrades over time — rather than taking a single scan — predicts whether someone with mild memory problems will develop Alzheimer's disease. This matters because it's cheaper than current tests, faster to administer, and could help doctors identify who needs early treatment before cognitive damage becomes severe.
Why it matters
For decades, doctors have tried to predict Alzheimer's progression using expensive imaging (PET scans costing $5,000–$7,000) or invasive procedures. A measurement from standard structural MRI that costs a fraction as much and captures change over time could shift how patients are screened and enrolled in prevention trials, removing a major bottleneck in early intervention research.