Medical imaging takes a lead role in Alzheimer's research

Toward the end, she couldn't recognize me. She had become a danger to herself and those around her. I could hold similar conversations with my then-3-year-old daughter and my 84-year-old grandmother, whose brain had been sapped by Alzheimer's disease.

My grandmother was, by no means, grandmotherly. I never once ate a cookie she baked. To say she was a tough bird—no doubt hardened by the Great Depression and her status as the oldest of nine siblings, largely left to care for the others—would be an understatement. She and I didn't get along well, but to see someone suffer from such a thief as Alzheimer's was difficult, nonetheless.

Others I know who have close family members being robbed of their memories, and then of their ability to function, have had a much tougher time.

"By 2050, 1 in 85 persons worldwide will have Alzheimer's disease," Ron Brookmeyer, a researcher at Johns Hopkins University, told reporters at a recent gathering.

As several recent studies using MRI and PET scanning to trace the progression of Alzheimer's show, medical imaging will help catch the thief.

A 5-year, $60 million clinical study, barely under way, has already provided some hope for detecting, preventing, and maybe even curing Alzheimer's.

The Alzheimer's Disease Neuroimaging Initiative (ADNI) studies 800 adults age 55 to 90 in order to identify biological markers of memory decline and Alzheimer's disease. The ADNI research employs serial MRI and PET scanning to track mild cognitive impairment and early progression of Alzheimer's.

"Our goal is to 'see' critical brain changes and to identify biochemical indicators that may be useful in evaluating treatments aimed at slowing memory decline and [Alzheimer's]," explained Michael W. Weiner, MD, of the San Francisco Veterans Affairs Medical Center and the University of California, San Francisco.

Weiner and the Northern California Institute for Research and Education hope to detect brain and biological changes before memory decline and other symptoms appear. That would allow researchers to test the effectiveness of drugs at early onset.

Similar work employing medical imaging has already shown remarkable results in early detection. Researchers from the University of Pennsylvania used a combination of PET and MRI scans to diagnose incipient Alzheimer's disease in 30 volunteers. The group correctly identified all 15 cases of mild cognitive impairment and cleared 15 healthy volunteers.

"This abnormal pattern of brain structure and blood flow detected not only mild cognitive impairment but even earlier ... when they were clinically normal," study leader Christos Davatzikos told Reuters News Service.

Similar success stories have been reported by researchers at the Banner Alzheimer's Institute, Phoenix, Ariz, and Mayo Clinic, Rochester, NY. Using PET scans and MRI, researchers at each facility have been able to compare changes over time. The comparisons have allowed doctors to detect the onset or progression of Alzheimer's with stunning reliability.

These early success stories bode well for a future treatment or cure for Alzheimer's, an end to the thievery of humans' memories. They also bode well for the future of medical imaging in research.

Dan Anderson
Editorial Director