Brain Radiology Flashcards
cause of ischaemic stroke
cardiac embolism paradoxical embolism air embolus fat embolus atherosclerotic thrombus/embolus arterial dissection
what area does ACA supply
inferior temporal lobe and central parasagittal strip
what area does PCA supply
occipital lobe and posterior temporal lobe
what area does MCA supply
large portion of frontal, temporal and parietal lobes
true/false - loss of one ICA compromises brain blood flow
false - it shouldnt theoretically due to the circle of willis but there are exceptions
how may CT immediately following stroke appear
generally will appear normal
may see hyperdense intravascular thrombus
how may CT hours following stroke appear
hypoattentuation of affected area, lost grey/white matter contour, cortex involvement, swelling and loss of gyri/sulci
mass effect
how may CT months following stroke appear
gliosis of affected area
what colour is acute blood on unenhanced CT
white
what is an intra-axial brain bleed
brain bleed within parenchyma of the brain
what is an extra-axial brain bleed
brain bleed outside of brain parenchyma but inside skull
where would a bleed from severe hypertension possibly ocvcur
thalamus
cause of epidural haematoma, radiological features
trauma, skull fracture, often MM artery
biconvex lentiform shape limited by cranial sutures
can lead to mass effect or herniation
sulcal effacement
cause of subdural haematoma, radiological features
NAI, falls in elderly or RTA in young
semilunar shape and crosses sutures
possible mass effect
cause of subarachnoid haemorrhage, radiological features
usually berry aneurism, can be AVM or trauma
high attentuated blood in SA space, suprasellar cistern, sylvian fissures and sulcu
complications of SAH
vasospasm
infarct
hydrocephalus
what colour does blood appear on CT in a subacute brain haemorrhage
isodense with brain parenchyma
what colour does blood appear on CT in a chronic bleed
hypodense to brain parenchyma
following diagnosis of SAH, what test is indicated and why
CT cerebral angiography to look for berry aneurism or AVM
majority of brain masses in adults are due to?
metastatic disease
majority of brain masses in children are due to?
primary lesions
most common sites of mets to brain
lung, breast, melanoma, renal cell, colorectal
how may a metastatic tumour appear on imaging
lots of oedema, mass effect, well enhancing
how may primary tumours appear on imaging
degree of oedema, mass effect and enhancement depends on grading
how can a brain mass be differentiated radiologically from stroke
not wedge shaped, or affecting cortex often
what is tonsilar herniation and why is it an emergency
descent of cerebellar tonsils below foramen magnum, coning
can compress pons and medulla against clivus leading to alteration of life sustaining functions
how can SAH lead to hydrocephalus
blockage of resorption of CSF
where is the conus medullaris generally located
L1
causes of spinal cord compression
Disc protrusion/extrusion, discitis osteomyelitis trauma tumour epidural abscess/haematoma spinal meningioma nerve sheath tumour
investigation of spinal cord compression
MRI
red flags for spinal cord compression
hx cancer
major trauma
thoracic/radicular pain
constant and progressive non mechanical pain
systemic unwell
loss power LL
grossly abnormal neuro signs/symptoms
loss of sensation and saddle anaesthesia
urinary retention, faecal and urinary incontinence
