Routine brain scanning could improve dementia diagnosis for two thirds of patients, ending years of misdiagnosis, a study has found.

Currently the only way to determine whether Alzheimer’s is present is to look at the brain of a patient after death.

For patients who are still alive, doctors usually use special cognitive tests which monitor memory and everyday skills such as washing and dressing, but the results are often be misleading or inaccurate.

Now new findings presented at the Alzheimer’s Association International Conference in London show that Positron Emission Tomography (PET) scans altered the diagnoses for more than two thirds people.

Currently people with early stage Alzheimer’s can wait up to four years to receive a correct diagnosis because PET scans are rarely carried out on the NHS as they cost up to £3,000 a time.

But PET scans show the build-up of sticky amyloid plaques in the brain which prevent neurons from communicating and eventually kill areas, wiping out memories and can help with a definitive diagnosis.