1. CT Brain Interpretation
Dr. Chew Keng Sheng
Professor/Emergency Physician
FHMS, Universiti Malaysia Sarawak

2. Hounsfield Unit

7. Calcified structures
The occipital lobes and the occipital horns of the lateral ventricles are located posteriorly and contain the choroid plexus, which is often calcified
At the posterior margin of the third ventricle is the pineal gland, which also is often calcified

9. Caudate nucleus
Lentiform nucleus
(Putamen & Globus Pallidus)
Internal capsule
Thalamus

17. Suprasellar Cistern
Also called the “pentagonal cistern” because it has the shape of a five-pointed star
The circle of Willis lies within the suprasellar cistern and is the site of most aneurysmal subarachnoid hemorrhage
The basilar artery can be seen just anterior to the pons
The middle cerebral arteries are often visible in the lateral extensions of the suprasellar cistern extending into the Sylvian fissures.

18.
A hyperdense vessel is defined as a vessel denser than its counterpart. This is seen in 25% of stroke patients. In patients presenting with middle cerebral artery stroke, the hyperdense vessel sign is present 35-50% of the cases

19. Hyperdense MCA sign is due to the presence of acute thrombus
Hyperdense MCA sign is due to the presence of acute thrombus. It is one of the early signs of MCA infarct

23. Sylvian fissure
Third ventricle
Quadrigerminal cistern plate
Cerebellum

24. Sylvian fissure
Supracellar Cistern (Circle of Willis)
Temporal lobe
Temporal horn
Pons

25. Sylvian fissure
Supracellar Cistern (Circle of Willis)
Temporal lobe
Temporal horn
Pons

26. Temporal Horns of Lateral Ventricles
The temporal horns of the lateral ventricles, which normally appear as narrow, barely visible, slits. Enlargement of the temporal horns has a distinctive CT appearance and is a reliable indicator of hydrocephalus

28. Temporal lobe
Pons
Fourth ventricles

29. Useful Tips
CROSS
STAR

30. BEAN

32. Extradural Hematoma Associated with skull fracture
Classic: Middle meningeal artery tear
Lenticular / biconvex shaped
Lucid interval
Can be rapidly fatal
Early evacuation essential

34. Subdural Hematoma Venous tear / brain laceration
Involving the cortical bridging veins
Morbidity / mortality due to underlying brain injury
Rapid surgical evacuation recommended, especially if > 5 mm shift of midline

35. Differentiating EDH from SDH
EDH does NOT cross the sutures.
EDH CAN cross midline
SDH CAN cross the sutures (not bound by the suture lines)
SDH does NOT cross midline (bound by falx cerebri)

36. Features of hydrocephalus
Narrowing of ventricular angle <40o
Dilated third ventricle

37. Features of hydrocephalus
Periventricular perilesional
oedema
Dilated frontal horns of lateral ventricles (“Mickey mouse”)
Rounded third ventricle

38. Features of hydrocephalus
FH/ID ratio >50% (normal FH/ID ratio <40%) where
FH (widest diameter of frontal horn) and
ID (internal diameter from inner table to inner table)
Opening up of the temporal horn of lateral ventricles