Brain scanning techniques Flashcards
what radioactive material is used in PET scans
fluorodeoxyglucose
PET - how is FDG taken up by the brain
glucose is used for respiration
PET - how does FDG being used for respiration show up on the PET scanner
when the glucose is being used by the brain, this causes the radioactive atoms to start to break down, emitting positrons and producing gamma rays
rays are picked up by the scanner to produce a colour image
PET - what would a high concentration of gamma rays mean
it’s an area of higher brain activity - portrayed with warmer colours
PET - strengths
shows brain in action
provides evidence for the localisation of function
reliable - can be repeated
PET - weaknesses
invasive - unethical
what can people do whilst having a PET scan
complete a task so that the area of the brain used for this task is picked up by the scanner
what do MRI scans use to scan
magnetic and radio waves
MRI - process for the scan
person lies in a large cylinder magnet and radio waves are sent through the body
MRI - what are the scans used for
looking at brain structure, rather than function
MRI - how can blood flow be monitored
through inserting a dye
MRI - strengths
no radiation exposure
excellent quality image produced
not invasive
MRI - weaknesses
person must lie very still
takes a long time
- not accessible to all people as they may not be able to go through the procedure
CAT - procedure
passing of multiple x-rays through the body to create an in depth image
CAT - purpose
produced detailed image of any body part
