PET scans are
used most often to detect cancer and to examine the effects of cancer therapy by
characterizing biochemical changes in the cancer. These scans can be performed
on the whole body. PET scans of the heart can be used to determine blood flow to
the heart muscle and help evaluate signs of coronary artery disease. PET scans
of the heart can also be used to determine if areas of the heart that show
decreased function are alive rather than scarred as a result of a prior heart
attack, called a myocardial infarction. Combined with a myocardial perfusion
study, PET scans allow differentiation of nonfunctioning heart muscle from heart
muscle that would benefit from a procedure, such as angioplasty or coronary
artery bypass surgery, which would reestablish adequate blood flow and improve
heart function. PET scans of the brain are used to evaluate patients who have
memory disorders of an undetermined cause, suspected or proven brain tumors or
seizure disorders that are not responsive to medical therapy and are therefore
candidates for surgery.
