The comparative software called PredictAD contrasts patient's measurements with those of other patients kept in large databases, then visualises the status of the patient with an index and graphics.
The support system and imaging methods were developed by VTT Technical Research Centre in Finland and Imperial College London, 'Gizmag' reported.
Researchers used material compiled in the US by the Alzheimer's Disease Neuroimaging Initiative based on the records of 288 patients with memory problems.
Nearly half of them were diagnosed with Alzheimer's disease on average 21 months after the initial measurements, which is about the same as the current European average of 20 months.
Researchers concluded that half of the patients could have been diagnosed with the disease around a year earlier, or nine months after the initial measurements. They say the accuracy of the predictions was comparable to clinical diagnosis.
There are several advantages of an early diagnosis of Alzheimer's. It can delay institutionalisation and slow down the progress of the disease.
It is also advantageous from the clinical trials perspective because if patients caught early can be included in the trials, treatment is likely to be more effective.
Working towards the same goal, researchers at Lancaster University in the UK recently developed an eye test method to detect early signs of Alzheimer's.
An estimated 35.6 people live with dementia worldwide, and that number is expected to rise to 65.7 million by 2030, according to 2010 figures.
The study findings were published in the Journal of Alzheimer's Disease.