Brain Imaging Flashcards
imaging modalities for the brain
- CT
2. MRI
when is CT used?
first line
fast tolerated
specialist intervention e.g. angiography or venography
when is MRI used?
soft tissues
embolic causes of ischaemic stroke
cardiac embolism (AF, ventricular aneurysm, endocarditis)
paradoxical embolism
atherosclerotic embolism
fat or air embolism
thrombus causes of ischaemic stroke
perforator thrombus (lacunar infarct) acute plaque rupture
why is imaging important in acute stroke?
exclude intracranial haemorrhage
confirm ischaemia
exclude other pathology mimics e.g. tumour
permit rapid treatment
first line imaging in stroke
non-contrast CT
non-contrast CT findings in ischaemic stroke
hyperdense segment of a vessel
loss of grey-white matter differentiation
swelling
late= gliosis, volume loss and hydrocephalus
example of intra-axial haemorrhage?
lobar haemorrhage
examples of extra-axial haemorrhage?
extradural
subdural
SAH
what is a SAH?
blood within the sub-arachnoid space (CSF)
most common cause of SAH?
circle of willis
what to do in the absence of trauma + SAH?
CT cerebral angiography for underlying Berry aneurysm
what cancers commonly metastasize to the brain?
lung breast melanoma renal cell colorectal
what is tonsillar herniation?
descent of the cerebellar tonsils below foramen magnum (coning) which compresses the brainstem against the clivus altering pons and medulla functions (respiratory and cardiac)
