BOSTON (CNN) -- Doctors may soon be able to use high-tech brain scanning devices to determine if people with memory problems are at risk of developing Alzheimer's disease.

Researchers at Harvard's Brigham and Women's Hospital in Boston say the scans, known as single photon emission computed tomography scans, or SPECT, will measure blood flow to the brain in an attempt to detect those at risk of developing the disease.

According to a study published in the latest issue of the journal Neurology, a review of the SPECT scans of 136 patients showed reduced blood flow readings in four areas of the brain.

Three of those areas in the brain are related to memory.

Researchers say those areas may be the first affected in early Alzheimer's disease. They hope the findings will help lead to earlier diagnosis and better treatment of the disease, which at present can neither be halted nor reversed.

Alzheimer's is a degenerative disease of the brain in which memory loss is the most prominent early symptom. It usually begins when people are in their 70s and 80s and is considered well-advanced in two or three years.

About 4 million Americans suffer from Alzheimer's disease, and experts say that if a breakthrough is not found before baby boomers reach the age of highest risk, 14 million could be afflicted by the year 2050.