CT Brain
CT
Contrast generally unnecessary, prefer non contrast MRA
for ?Abscess if unable to have MRI
Angiogram
Venogram ?thrombosis
Blood Can Be Very Bad
Look at Blood > Cisterns > Brain > Ventricles > Bones
Blood is:
hyperdense (white) early (<4d) - due to global in blood
isodense (same as brain) mid (4d-2w) - as globin is broken down peripherally to centrally clot
Hypodense (dark) late (>2w) -
i.e.
rebleed will look white next to black
hyperacute bleed isodense (not clotted) +/- hyperdense (clotted)
Bleed usually visual early (unless clotting disorder) v ischaemia (12-24hours)
Intracranial haemorrhage
Extra-axial
- Extradural aka epidural (lens) usually meningeal arteries
- Subdural (crescent) bridging cortical veins between dura and arachnoid
- Subarachnoid (blood in cisterns)
Intra-axial
- intracerebral (lobar, basal ganglia, pontine, cerebellar)
- intraventricular
IVH
Grade I – confined to the germinal matrix
Grade II – <50% of lateral ventricle
Grade III – >50% of lateral ventricle
Grade IV – with infarction of adjacent periventricular white matter (periventricular leukomalacia)
Germinal matrix is site of neuronal and glial cell production, migrates to cortex
Located in shallow groove in frontal horn of lateral ventricles between caudate and thalamus
Germinal matrix gone by 37/40
Contrast generally unnecessary, prefer non contrast MRA
for ?Abscess if unable to have MRI
Angiogram
Venogram ?thrombosis
Blood Can Be Very Bad
Look at Blood > Cisterns > Brain > Ventricles > Bones
Blood is:
hyperdense (white) early (<4d) - due to global in blood
isodense (same as brain) mid (4d-2w) - as globin is broken down peripherally to centrally clot
Hypodense (dark) late (>2w) -
i.e.
rebleed will look white next to black
hyperacute bleed isodense (not clotted) +/- hyperdense (clotted)
Bleed usually visual early (unless clotting disorder) v ischaemia (12-24hours)
Intracranial haemorrhage
Extra-axial
- Extradural aka epidural (lens) usually meningeal arteries
- Subdural (crescent) bridging cortical veins between dura and arachnoid
- Subarachnoid (blood in cisterns)
Intra-axial
- intracerebral (lobar, basal ganglia, pontine, cerebellar)
- intraventricular
IVH
Grade I – confined to the germinal matrix
Grade II – <50% of lateral ventricle
Grade III – >50% of lateral ventricle
Grade IV – with infarction of adjacent periventricular white matter (periventricular leukomalacia)
- motor tracts pass through this area > one of the causes of CP
Germinal matrix is site of neuronal and glial cell production, migrates to cortex
Located in shallow groove in frontal horn of lateral ventricles between caudate and thalamus
Germinal matrix gone by 37/40