Brain Scans Flashcards
What are the 3 types of brain scans?
PET Scans
fMRI Scans
CT Scans
What type of waves do fMRI scans use?
Magnetic and radio waves through an fMRI machine
What does the head have to be placed in in order for an fMRI scan to take place?
A large electro magnet
What happens when neural activity in the brain increases (fMRI scans)?
Blood flow to that part of the brain also increases
How is oxygen carried to the brain?
Via haemoglobin
What does oxygenated haemoglobin do in relation to magnetic fields?
Repels them
What does de-oxygenated haemoglobim do in relation to magnetic fields?
Follows them
What must patients do when getting an fMRI scan?
Activities that increase blood flow (e.g. forming a fist)
Give an advantage of fMRI scans
Don’t use radiation therefore are less dangerous
Give a disadvantage of fMRI scans
Only shows which part of the brain is active, not what it is doing
What is the process of PET scans?
- A radioactive chemical is injected into the blood
- As it breaks ddown, it releases radioactivity into the blood which is picked up on the scan
If the brain is more active, what will be picked up (PET)?
More radioactivity
What colours will be present on PET scans depending on brain activity?
Red/orange - High levels of activity
Blue/green - Low levels of activity
What substance do PET scans allow us to see?
Glucose - the more brain activity, the more glucose is present
Give 3 advantages of PET scans
- Helps to see where exactly activity is happening
- Simple procedure
- Easy to interpret as it’s colour co-ordinated
