CT as is very good at showing fresh blood as bright and allows us to rule out a haemorrhage

First imaging modality for anyone suspected of a brain bleed and why?

Because haemorrhagic stroke is managed with no tpa as opposed infarct stroke

Why do we care so much about haemorrhage v infarct and thus use CT?

Whether bleed is extra-axial/parenchymal means it is around the blood and usually comes from large vessel rupture/aneurysm as opposed to intra which is bleed into brain itself usually from small vessel disease/HTN

Difference in location of brain bleeds and how they differ from casue?

Will get bright bleeds often on basal side of brain around circle of willis or inbetween sulci, enough pressure can bleed into brain itself/ventricles

Where/how does blood from subarachnoid bleed typically show on CT? How can it develop?

CT angiogram to find source of bleed/aneurysm, catheter angiogram

Key to follow up once haemorrhage is found?

Trauma as will have bleed at coup and cotra-coup positions

What can create a weird/multi-pattern of subarachnoid bleeds?

Will often see now change mainly just looking for no haemorrhage, bright visible vessel due to occlusion causing backlog

How will a fresh stroke often appear on CT? Although we can get waht?

Occluded MCA

What is going on here?

Flow analysis CT to see movement of fluid sort of like a doppler, will have an area with low flow and a gradient of increasing flow around it

New era method for quickly analysising stroke area on CT?

Angiogram to find occlusion and use stent/clot retrieval, follow up to ensure flow is returned

Key to follow up once stroke is found/suspected post CT? What we do?

Stroke that has begun to infarct and thus have lost grey-white matter differentiation, will get darker and darker until liquefactive necrosis leaves a small dark area

What is going on here? How will it change as it develops?

May get enough edema to cause hydrocephalus and even midline shift that requires craniotomy to reduce pressure

Although the infarcted area eventually shrinsk on CT post infarct how can a currently necrosising area affect the brain?

MRI on DWI that makes edematous change extremely obvious

What is this imaging modality as an alternative to CT for stroke?

Pineal gland and ventricles

Two common areas on CT to appear bright due to calficification not bleeding?

Posterior fossa and basal ganglia esp thalamus just lateral of third ventricle

TWo very common spots for haemorrhagic stroke to occur secondary to HTN?

Minimal hemiplegia more cerebellar ataxia and dysarthria from temporal lobe effects

How do posterior fossa strokes change in presentation?

Bleed into ventricles and thus secondary hydrocephalus

Common problem with lacunar infarcts?

Basilar artery clot

Is this a normal CT, so what is this bright vessel?

Will have a lot of perpindicular (from the ventricles) bright plaques and also some in the spinal cord

How MS/demyelination appears on MRI?

Use a special sequence to see high activity and thus active lesion or contrast enhancing plaques are typically active

Two ways to visualise number of active plaques as opposed to inactive?