A large majority of the nation's top neurologists say they would use a recently approved amyloid detection brain scan to evaluate their patients for Alzheimer's disease if the scan was paid for by health insurance, according to a survey recently published in the Journal of Alzheimer's Disease.

The U.S. Food and Drug Administration in April approved a special dye used in the brain scan, a dye that can show amyloid plaque in the human brain. Amyloid is a physical marker of Alzheimer's, so the test can provide further evidence that a person's dementia symptoms are likely Alzheimer's.

But the test is not conclusive. A negative result likely means the person doesn't have Alzheimer's. But a positive result does not necessarily mean the person has or will develop Alzheimer's, since some people with amyloid plaque never develop the disease.

So the results of the survey of leading neurologists might be surprising: more than 83 percent of the neurologists surveyed said they would use the scan to evaluate their patients for Alzheimer's.

There is currently one large hurdle in the use of the brain scans, however. Medicare and most insurance plans don't pay for the scans — which generally cost more than $3,000. So their use for the general population has been limited in the months since the FDA approval.

“As with all new medical technologies, cost will undoubtedly be an important factor in initial uptake of amyloid imaging,” said Eran Klein, M.D., Ph.D., lead author of the article and an assistant professor of neurology at Oregon Health & Science University. “Nonetheless, it is clear from our survey that experts in the field of dementia currently see clinical value in testing for brain amyloid and plan to add it to their tools for understanding and diagnosing Alzheimer’s dementia.”

The survey was conducted shortly before the April 2012 approval of the special brain imaging dye. It was conducted among neurologists who practiced at U.S. medical schools and specialized in dementia.

Beyond overall use of the scans, the survey found that:

• 92 percent of neurologists believed patients should be counseled on the meaning of the imaging results before the scan.
• Roughly equal percentages of neurologists planned to use the scan either to bolster or rule out a diagnosis of Alzheimer's. About 77 percent of the neurologists planned to use the scan to bolster a diagnosis; 73 percent planned to use the scan to rule out Alzheimer's.
• Younger neurologists were more likely to use the scans than older neurologists. All of the neurologists with fewer than five years experience in practice — 19 of 19 — said they planned to use the amyloid imaging scan. Seventy percent of the neurologists with 20 years or more in practice planned to use the scans.