Brain Masterclass Flashcards
first line imaging in the brain?
CT
contrast enhanced vs non contrast enhanced CT in brain?
grey and white matter better differentiated in contrast enhanced
suprasellar cisteren?
star shaped dark area which sits more forward in brain CT
where the circle of willis sits
quadrigeminal cistern?
half circle shaped dark area in middle of brain
sits behind brainstem and suprasellar cistern
learn midline slice MRI>
... featues - thalamus - midbrain - pons - medulla - caudate nucleus - cingulate gyrus - frontal lobe - parietal lobe - occipital lobe - anterior and posterior lobe of cerebellum
difference between cerebrum and cerebellum
gyri are finer in cerebellum (foliae)
T1 weighted?
fluid is black
better for seeing anatomy
T2 weighted?
fluid is white
better for seeing pathology
purely frontal lobe stroke?
executive function
visual disturbance and vertigo are features of a stroke where?
posterior circulation
occipital lobe or cerebellum
main 3 causes of ischaemic stroke?
embolism
thrombosis (plaque rupture etc)
vertebral artery dissection
common source of stroke in cerebellar circulation?
vertebral > basillar > posterior inferior cerebellar areries
why is imaging used in stroke even it is a clinical diagnosis?
management
- different is ischaemic or haemorrhagic etc
window for thrombolysis in ischaemic stroke?
6 hours
is contrast used in CT for stroke?
no
is thrombolysis given is established stroke is found (7 hours - 1 day+)?
no
early findings on CT?
hyperdense segment of a vessel and matching features
finding s within first few hours?
loss of grey white matter differentiation
hypoattenuation of deep nuclei
cortical hypodensity with associated parenchymal swelling with resultant grey matter engulfmant
within a few more hours what is seen?
hypoattenuation and swelling become more marked resulting in a significant mass effect
larger dark area
with even more time?
gliosis occurs appearing as a region of low density with volume loss
darker, slighly smaller and more defined area than earlier hypoattenuation
acute blood and clots appears like what on CT?
white
2 types of intracranial haemorrhage?
intra-axial - intra-parenchymal - e.g burst lobe/lobar haemorrhage - often causes midline shift extra-axial - outside of brain tissue - extra-dural haemorrhage - subdural haemorrhage - subarachnoid haemorrhage
classic place for hypertensive bleed?
basal ganglia
thalamus
etc
main signs of subarachnoid haemorrhage?
white star shaped area in middle of brain
blood may collect around circle of willis, in sulci or in ventricles
what is done if subarachnoid blood is found in absence fo trauma?
CT angiogram to look for berry aneurysm
complications of subarachnoid haemorrhage which usually cause death rather than the haemorrhage itself?
hydrocephalus
vasospasm
infarction
sign of early hydrocephalus?
enlarged temporal horns
first test for brain mass?
CT
which type of tumour will enhance the most?
higher grade
how can oedema (e.g from a brain tumour) be differentiated from blood from haemorrhage/
oedema doesn’t go all the way out to periphery (wedge shaped)
which type of brain tumour generally has lots of oedema?
metastatic
how does coning cause death?
compresses clivus against pons and medulla disrupting cardio and resp centres
level of conus medullaris?
L1
in thecal sac
presentation of spinal cord compression?
back pain with red flags - malignancy history - major trauma - thoracic/radicular pain - constant, progressive, non-mechanical pain - systemically unwell loss of power and sensation in lower limbs urinary retention
investigations in spinal cord compression?
urgent MRI
CT can show fractures or gross malalignment but wont show cord
signs of extra-dural haemorrhage on imaging?
biconvex lens shape
often overlying temporoparietal region
bound by fissures in brain
features of sub-dural haemorrhage on imaging?
often from shaking baby or falls in elderly
wont cross the midline
semilunar shape on CT
subacute = isodense (looks same as brain)
chronic = hypodense (darker)
