Scanning techniques to identify brain functioning Flashcards
what do PET Scans do?
they measure metabolic activity in the brain and record what parts are more active
how is a PET scan carried out?
a radio tracer is injected into the patient
the most active parts of the brain absorb the most radio tracer
this data is sent to a computer and different areas appear as different colours
what are 2 advantages of a PET scan
they show the brain in action
they help show localisation of function
what are 3 disadvantages of a PET scan
expensive
results can be hard to interpret
injecting substances raises ethical issues
what do CT Scans do
they use x rays to give us an image of the brain
how is a CT scan carried out?
a large number of X-Rays is taken, different pictures of the brain is taken and put together to produce a detailed image
what are 2 advantages of a CT scan
High image quality compared to x-rays
useful in showing abnormal structures
what are 2 disadvantages of a CT scan
high radiation exposure
only give structural information, none about brain activity
what do FMRI Scans do
similar to PET but measure changes in brain blood oxygen level rather than using a radio tracer
how is an FMRI scan carried out?
when an area in the brain is more active it uses more oxygen
this is picked up by radio signals which send data to a computer
what are 2 advantages of an FMRI scan
- Show brain activity
- no radio tracer
- high resolution
what are 2 disadvantages of an FMRI scan
expensive
there’s 5s lag between brain activity and image on screen
you need to stay still, difficult for children
