PET and the brain
Scientists have used PET to investigate what different areas of the brain do, how the brain develops and how drugs affect it. The information gathered from PET scans can be added to MRI images from the same person - this provides a better idea of exactly where the activity is taking place. PET scans can detect changes due to brain damage, epilepsy, Alzheimer disease and brain tumours, often earlier than is possible using other methods. But PET is an expensive and time-consuming technique.