LOS ANGELES, Jan. 11 -- UCLA scientists have created the first technique to image the earliest evidence of Alzheimer's disease in the living brain -- before the disorder begins attacking brain cells. Reported in the January issue of the American Journal of Geriatric Psychiatry, the technique will allow doctors to monitor the disease as it unfolds, speeding diagnosis, intervention and new therapies for the disorder, which afflicts 10 percent of people over 65. UCLA researchers combined a new chemical marker called FDDNP with positron emission tomography (PET) to see for the first time the brain lesions indicative of Alzheimer's disease in living patients. "We have developed the first tracer molecule that visually zeroes in on the brain lesions caused by Alzheimer's disease," said principal investigator Dr. Jorge R. Barrio, UCLA professor of medical and molecular pharmacology. "This noninvasive method will help us monitor new vaccines and drugs designed to prevent and treat the brain damage caused by Alzheimer's disease," said co-author Gary Small, Parlow-Solomon professor of aging and UCLA professor of psychiatry and biobehavioral sciences. Physicians regard these brain lesions, called amyloid plaques and tangles, as the definitive hallmarks of Alzheimer's disease. Experts suspect that the lesions' growth disrupts cell function and kills off brain cells, leading to disorientation and progressive memory loss. Barrio and Small discovered that PET scans of patients injected with FDDNP showed the presence of early brain lesions — before the plaques are believed to destroy brain cells. If experts' hypotheses about the lesions' role prove accurate, UCLA's technique could identify when medical intervention may still stave off or prevent the onset of disease.