- PET Scan
- is a way of seeing a picture of a working brain. It can also show any malfunction, therefore helping identify damage or tumours.
- (1) patients are injected with glucose or water that has been labelled with a radioactive tracer while they lie with their head inside the scanner.
- (2) once the substance reaches the brain, the brain cells start to uptake the oxygen in the water or glucose, and the tracer begins to decay.
- (3) when the tracer decays, it emits positrons, and the more glucose or oxygen the cells in the brain use up, the more positrons there will be emitted in that area of the brain.
- (4) when the positrons are emitted, they collide with electrons and form gamma rays which are detected by the scanner to produce an image of the activity in areas of the brain.