Emergency CT brain

Question 1

Most important imaging done in head trauma

Answer 1

Non-contrasted CT brain

Question 2

7 key levels in CT brain

Answer 2

1. Upper cortex
2. Lateral ventricle
3. Basal ganglia and thalamus
4. Quadrigeminal cistern
5. Midbrain
6. Suprasellar cistern at level of pons
7. Base of skull
   - use bone window to look for fractures in trauma

Question 3

Lateral ventricles

Answer 3

boomerang

Question 4

Basal ganglia and thalamus

Answer 4

pizza slice

Question 5

Quadrigeminal cistern

Answer 5

smiley face

Question 6

Midbrain

Answer 6

Heart

Question 7

Suprasellar cistern at level of pons

Answer 7

5 pointed star

Question 8

Terminology: Hypodense lesions

Answer 8

“Less white” than brain tissue
- ISCHEMIA

Question 9

Terminology: Hyperdense lesions

Answer 9

“Whiter” than brain tissue
- BLEED, calcification
- Bleed (hyperdense lesion) often have surrounding area of edema (appears black)
- Density of whiteness in bleed is less than that of calcification

Question 10

Describe extra-dural haemorrhage (EDH)

Answer 10

Hyperdense lesion on the left/right
Biconvex in shape

Question 11

Describe sub-dural haemorrhage (SDH)

Answer 11

Hyperdense lesion on the left/right
Crescent in shape

Question 12

Describe sub-arachnoid haemorrhage (SAH)

Answer 12

Presence of hyperdensity at suprasellar cistern

Question 13

Signs of acute infarct

Answer 13

1. Dense middle cerebral artery sign (white)
2. Obscuration of lentiform nucleus
3. Insular ribbon sign
4. Loss of grey-white differentiation
5. Mass effect:
   - Compression of adjacent ventricles
   - Effacement of sulci
   - Midline shift
6. Haemorrhagic transformation of ischemic stroke

Question 14

Signs of chronic infarct

Answer 14

1. Hypodense lesions (very black)
2. Volume loss
   - Adjacent ventricle becomes bigger
   - Adjacent sulci becomes more prominent
   - Loss of brain tissue (encephalomalacia)