Computers can diagnose Alzheimer's disease faster and more accurately than experts, research suggests.
Alzheimer's can be difficult to diagnose
University College London researchers say their work may help ensure patients are diagnosed earlier, increasing the chances of effective treatment.
Their study, published in the journal Brain, found computers can identify brain damage caused by Alzheimer's with an accuracy as high as 96%.
At present a definitive diagnosis is usually only possible after death.
Alzheimer's is caused by the build up in the brain of plaques and tangles of brain tissue filaments, which causes tissue to start wasting away.
It is currently diagnosed using a combination of brain scans, blood tests and patient interviews, but distinguishing the disease from other forms of dementia is difficult, and time consuming, and the accuracy of diagnosis is only about 85%.
The new method works by teaching a standard computer the differences between brain scans from patients with proven Alzheimer's, and people with no signs of the disease.
The two conditions can be distinguished with a high degree of accuracy on a single clinical MRI scan.
Researcher Professor Richard Frackowiak said: "The advantage of using computers is that they prove cheaper, faster and more accurate than the current method of diagnosis.
"The new method makes an objective diagnosis without the need for human intervention.
"This will be particularly attractive for areas of the world where there is a shortage of trained clinicians and when a standardised reliable diagnosis is needed, for example in drug trials."
Professor Frackowiak emphasised that as symptoms only emerge after a considerable amount of damage has already occurred in the brain it is important to make an accurate diagnosis early to improve the chances of effectively preventing further deterioration.
He said: "The next step is to see whether we can use the technique to reliably track progression of the disease in a patient.
"This could prove a powerful and non-invasive tool for screening the efficacy of new drug treatments speedily, without a need for large costly clinical trials."
Dr Susanne Sorensen, of the Alzheimer's Society, said: "Currently, MRI imaging is not routinely used in diagnosing the diseases causing dementia.
"This paper puts a strong case for the wider use of this technique."
Dr Sorensen said it was vital the National Dementia Strategy currently being produced by the government makes early diagnosis a high priority.
Rebecca Wood, of the Alzheimer's Research Trust, said: "This promising computer aided technique could act as a second opinion to increase the accuracy of a doctor?s diagnosis.
"However, this research is in the early stages and further analysis is required to understand the full benefits and accuracy of this technique and to see if it can be used to assess the effectiveness of new drugs."
It is estimated that over 700,000 people in the UK are currently living with dementia, of which Alzheimer's is the most common form.