Positron emission tomography (PET) opens a window on human
health and behavior with its ability to visualize biochemical
activity in the living body. The technique relies on short-
lived, radioactive chemicals that emit bursts of energy as they
decay. Scientists use these chemicals to harmlessly tag
substances and trace their effect in the body through PET scan
images. USING PET SCANS TO MONITOR CANCER CELLS' ACTIVITY AND
PREDICT WHO WILL DEVELOP ALZHEIMER'S, OTHER DISEASES DALLAS,
March 29 -- When normal cells start to become cancerous, they
develop an enormous appetite for glucose (the basic energy
substrate of the body), says Michael Phelps, Ph.D., of the UCLA
School of Medicine. After injection with a glucose analog tagged
with fluorine-18, a radiotracer, a patient can be examined by a
whole body PET scan to determine whether a tumor is malignant
(high glucose metabolism) or benign, or whether the cancer has
spread to any other organ systems of the body, he said here
today at a national meeting of the Amer