Researchers in Japan have developed a new brain scan which could help doctors accurately diagnose Alzheimer's.
The scan allows doctors to detect a protein called tau which builds up in the brains of Alzheimer's sufferers.
There is currently no fail-safe method to test for the degenerative illness which effects around 500,000 people in Britain.
Until now, it has only been possible to confirm a diagnosis of Alzheimer's by looking at the brain after a person's death, according to Alzheimer's Research UK.
Dr Eric Karran, director of research at Alzheimer's Research UK, heralded the discovery as "promising" but warned "more long-term studies" were needed to see how much the scan could be used to track the progression of the disease.
– Dr Eric Karran, director of research at Alzheimer's Research UK
This promising early study highlights a potential new method for detecting tau - a key player in both Alzheimer's and frontotemporal dementia - in the living brain.
With new drugs in development designed to target tau, scans capable of visualising the protein inside the brain could be important for assessing whether treatments in clinical trials are hitting their target.
If this method is shown to be effective, such a scan could also be a useful aid for providing people with an accurate diagnosis, as well as for monitoring disease progression.