Positron Emission Tomography (PET) scanning is a type of radionuclide scanning in which a radioactive substance is introduced into the body to assess structure and functions of tissues. It was developed in 1970. Unlike other scanning technique like CT scanning, PET does not produce good structural images; instead it gives information about the chemical activity of tissues or organs. It may also be used to assess blood flow.
In this technique, the molecules that are to be taken up by the tissue or organ are labeled with a radioactive substance (radionuclide) before they are introduced into the body. PET uses radionuclides that emit particles called positrons. The radiation produced by the particles is detected by PET scanner. The radiation produced by the particles is detected by PET scanner. The number of positrons emitted by an area of tissue or organ indicates how much radionuclei it has taken up.
· PET is used to study the heart and brain.
· It is used to locate the origin of epileptic activity in the brain.
· It is also used to detect tumours.
· It is also used to study the mental health problems such as depression.