T8L8 Studying the brain

Question 1

Describe how CT works

Answer 1

Uses X-rays to create a 3D image made of many 2D images
Shown as various shades of grey depending on how much radiation is absorbed

Question 2

Explain how fMRI works

Answer 2

works in the same way as MRI, tracking oxygen uptake while a person carries out an activity to show which parts of the brain are active

this is because in active parts of the brain there is an increase in oxyhaemoglobin so there is less absorption

Question 3

Explain how PET works

Answer 3

Special dye containing radio tracer is injected
Scanner detects the emission of positrons/ gamma rays

Question 4

Give advantages of CT

Answer 4

Produces 2D/3D images
Cheap
Quick

Question 5

Give disadvantages of CT

Answer 5

Only identifies large structures
Exposes patient to radiation which could cause mutations
Still image only
Lower resolution

Question 6

Give advantages of MRI

Answer 6

High resolution
Safer than CT
Identifies location, type and size of tumour
3D image

Question 7

Give disadvantages of MRI

Answer 7

Noisy
Patient must stay still
Not suitable for patients with metal implants
More expensive

Question 8

Give advantages of fMRI

Answer 8

Brain activity can be directly viewed over time
High resolution
Safer than CT

Question 9

Give disadvantages of fMRI

Answer 9

Noisy
Must stay still
More expensive

Question 10

Give advantages of PET

Answer 10

3D image
Shows metabolically active areas
High resolution

Question 11

Give disadvantages of PET

Answer 11

Exposure to radiation that could cause mutations
Very expensive

Question 12

Describe how MRI works

Answer 12

Uses a magnetic field & radio waves to detect soft tissues

Hydrogen atoms - easily attracted towards a magnetic field
Radio waves change alignment of H atoms.
Energy from radio waves released when hydrogen atoms return to their original alignment.