PET Imaging Can Identify Alzheimer Disease
Imaging can differentiate between healthy people and various levels of cognitive impairment
WEDNESDAY, Dec. 20 (HealthDay News) -- Positron-emission tomography (PET) imaging using a particular ligand can differentiate between healthy patients, those with mild cognitive impairment and those with Alzheimer disease, according to the results of a study published in the Dec. 21 issue of the New England Journal of Medicine.
Gary W. Small, M.D., and colleagues from the University of California Los Angeles performed PET imaging in 83 volunteers with self-reported memory problems using a small molecule called 2-(1-(6-(2-F-18 fluoroethyl)(methyl)amino-2-naphthyl)ethylidene)malononitrile, or FDDNP, which binds to plaques and tangles in vitro, and 2-deoxy-2-F-18 fluoro-D-glucose (FDG).
Seventy-two volunteers also underwent magnetic resonance imaging. Cognitive testing showed that 25 volunteers had Alzheimer disease, 28 had mild cognitive impairment and 30 had no cognitive impairment.
The researchers found significantly higher global FDDNP binding (average of four brain regions) in volunteers with Alzheimer disease, followed by less binding in those with mild cognitive impairment, and even less in healthy controls. FDDNP binding correlated better with diagnosis than FDG binding or magnetic resonance imaging, according to the study.
"FDDNP-PET scanning can differentiate persons with mild cognitive impairment from those with Alzheimer disease and those with no cognitive impairment," Small and colleagues conclude. "This technique is potentially useful as a non-invasive method to determine regional cerebral patterns of amyloid plaques and tau neurofibrillary tangles."
UCLA owns a U.S. patent, Methods for Labeling Beta-Amyloid Plaques and Neurofibrillary Tangles, that uses the approach described in this article.