Reading CT Scan Brain Part 2

Hydrocephalus
- dilatation of ventricle

Chronic hydrocephalus with normal pressure
- patient came with blindness but no headache

Acute hydrocephalus

5 things

1) Frontal horn of lateral ventricle became rounded

2) third ventricle became rounded

3) Temporal horn became big and visible

4) CSF sip out - went to the brain parenchyma
- periventricular hyperlucency

5) No sulci visible in top slice
- brain became tight
- sylvian fissure obliterated

Ventriculomegaly
- dilated ventricle without increased ICP

Hydrocephalus
- dilated ventricle with increased ICP

Normal pressure hydrocephalus
patient presented with incontinence, difficulty in micturition, dementia and difficulty in walking

Communicating hydrocephalus
- all ventricle dilated

Contrast CT Scan - not indicated in trauma

1) because it is neurotoxic - blood brain barrier already damage, CT scan with contrast will cause more harm to the brain
2) Blood already hyperdense, contrast also hyperdense

Tumour

Why tumour enhancing with contrast
- contrast indicate breach in enhancement of blood brain barrier
- it is not only because of the vascularity

describe whether the tumour is intraaxial or extraaxial

Intra-axial
arising from the brain

Extra-axial
from outside the brain , arise from the dura

example
glioma - intraaxial
meningioma -extraaxial

Ischaemic infarct

ischaemic, infarct, oedema, inflammed, more water, look like black

oedema
- finger like projection
- going along the white matter
- travel along neuron
- more prominent in white than grey matter

Territorial- area that is supplied by the blood vessel
MCA
PCA
ACA

Cystic lesion

Arachnoid cyst

- congenital
- temporal lobe not formed and space taken by CSF

Hydatid cyst

not an abscess
no ring enhancement

Abscess
- ring enhancement lesion because of the vascularity (capsule)
- inside ( central) is hypodense because of the abscess

Subdural empyema
- central : hypodense
- edges along the dura enhance because of vascularity

Encephalomalacia
- scarring of the brain parenchyma
- pulling effect
- no midline shift or mass effect