Neuroimaging

Question 1

first and second line imaging for brain?

Answer 1

1st = CT (with or without contrast)
2nd = MRI (with or without contrast)
- not used in pacemakers or any implanted cardio device)

Question 2

how do the following appear on CT?

• air
• fat
• soft tissue, muscle and fluid (not blood)
• bone, metal, flowing blood and contrast

Answer 2

air = black
fat = dark grey/black (slightly more dense than air)
soft tissue etc = light grey
bone etc = white

Question 3

grey/white matter differentiation is better seen on CT or MRI?

Answer 3

MRI

Question 4

main difference between T1 and T2 weighted MRI?

Answer 4

T1 = fluid and CSF appear dark providing better resolution and imaging of structure
T2 = fluid and CSF appear light, highlighting pathology better

Question 5

what might cause a loss of differentiation between grey and white matter?

Answer 5

ischaemic tissue
gliosis
oedema