Neuroimaging

Question 1

What are the indications for imaging?

Answer 1

headache/raised ICP
seizures
weakness/stroke 
trauma
loss of conciousness
post op

Question 2

What are the benefits of a CT for imaging the head?

Answer 2

good bone detail - good for fractures

quick

Question 3

What are the downsides of CT for imaging the head?

Answer 3

poor soft tissue detail

causes radiation

Question 4

What shows up as bright (hyperdense on CT)?

Answer 4

bone

Question 5

What shows up as dark (hypodense on CT)?

Answer 5

air

Question 6

What are the benefits of MRI imagine for the head?

Answer 6

good soft tissue detail
can see bone marrow and spinal cord
multiplanar capabilties

Question 7

What are the downsides of MRI imagine for the head?

Answer 7

takes a long time - not good for emergencies
not compatible with pacemakers
patient must be cooperative

Question 8

What are the two different MRI sequences?

Answer 8

T1 and T2

Question 9

Describe how T1 sequence shows fat and water?

Answer 9

fat = bright
water = dark

Question 10

Describe how T2 sequence shows fat and water?

Answer 10

fat = dark
water = bright

Question 11

What is a FLAIR sequence?

Answer 11

type of T2 where the water is surpressed

Question 12

For how long are CTs sensitive to blood?

Answer 12

first few hours - then MUST DO A MRI

Question 13

What is a cavernoma?

Answer 13

cluster of abnormal blood vessels

POPCORN APPEARANCE

Question 14

What is an aucoustic schwannoma?

Answer 14

outside the BBB, ICE CREAM APPEARANCE

Question 15

What is a Chairi malformation?

Answer 15

brain tissue extends into the spinal cord

Question 16

What is a polymicrogyria?

Answer 16

too many small gyria

Question 17

What is an arachnoid cyst?

Answer 17

filled with CSF

Question 18

What is cortical dysplasia?

Answer 18

top layer of the brain has not formed properly

causes epilepsy