Newswise — MAYWOOD, IL –  Loyola Medicine is participating in a landmark $100 million study of the effectiveness of using PET scans to detect Alzheimer's disease.

Alzheimer's disease has been linked to clumps of amyloid proteins, which block signals in the brain. PET, which stands for positron emission tomography, can detect amyloid plaques.

In a PET scan, a tracer drug is injected into the patient and the drug is taken up by any amyloid plaques in the brain. Attached to the drug is a slightly radioactive tracer, which emits a small amount of energy in the form of gamma rays. The PET scan detects this energy and a computer produces a detailed image. The tracer drug has been approved by the U.S. Food & Drug Administration.

It is difficult to make a definitive diagnosis of Alzheimer's disease. The study will examine how PET scans affect treatment. Researchers hypothesize that PET scans will decrease uncertainty and increase confidence in the underlying cause of a patient's cognitive impairment. This would lead to earlier counseling and interventions, resulting in improved outcomes.

Researchers will examine whether PET scans affect drug therapy and counseling about safety and future planning, and whether the test improves outcomes by reducing hospital and emergency department admissions. The findings will inform the Centers for Medicare & Medicaid Services in deciding whether to cover PET scans in dementia care.

The multi-center nationwide study will enroll 18,488 Medicare beneficiaries who have been diagnosed with mild cognitive impairment or dementia of unknown cause.

The study is sponsored by the American College of Radiology Imaging Network, in collaboration with the Alzheimer's Association. It is titled, "Imaging Dementia – Evidence for Amyloid Scanning (IDEAS)". Principal investigators at the Loyola site are Moises Gaviria, MD, a specialist in neuropsychiatry, and Robert Wagner, MD, medical director of nuclear medicine.