Neuroradiology and Brain Tumours Flashcards
what can cause a headache due to raised ICP
mass, bleed, hydrocephalus, venous thrombosis, infection, oedema
what is CT good for
bony detail
spatial resolution
good with emergency/ ICU equipment
fast
what is CT bad for
soft tissue
detail
contrast not as good as MRI
high radiation
what is dark and light on CT
white things more dense
darkest thing is air
what is MRI good for
contrast
soft tissue resolution
depiction of anatomy
marrow and cord pathologies
what is MRI bad for
less bony detail
less spatial resolution
not compatible with equipment/ implants
not as quick- need patient cooperation
what are the different types of MRI
T1 and T2
T1
-fat, methemoglobin (subacute haematoma), mineral deposition, melanin, contrast material = bright/ hyperintense
-water, air= dark/ hypointense
GREY MATTER WILL BE DARK
T2 (two W's= water white) -water, air= bright -fat and 4 m's= dark GREY MATTER WILL BE LIGHT
T2 flare
form of T2 (grey matter bright) that removes brightness of CSF in the image to look for oedema in the brain
GREY MATTER BRIGHT, CSF DARK
does white or grey matter have more myelin
white matter- will be dark in T2, bright in T1 MRI
what scan if you suspect an infarct in the brain
MRI (if blood vessel not flowing will show up white)
what scan for a brain haemorrhage
CT sensitive for acute haemorrhage but sensitivity lessens with time
time doesn’t matter in MRI
if haemorrhage look for aneurysm with CT angiography
what vascular abnormality has a popcorn appearance on imaging
cavernoma (cluster of abnormal blood vessels)
what scan is used in acute stroke
CT- shows loss of distinction between grey and white matter
what imaging is used in all strokes
diffusion weight image
what is the hallmark for trauma imaging
CT
what can a haematoma in the brain cause
mid line shift, herniation
what type of dural haematoma will affect the shape of brain more
extra dural- sub dural can spread further across the brain, extra will create a convex shape
when will a tumour enhance with contrast
if vascular in brain only when high grade or if arises from dura (BBB)
what does low density around hydrocephalus on imagine mean
oedema in brain
what does demyelination look like on CT (T2 and flare)
predominantly affects white mater, inflammation around small venules and veins, lesions on the white matter. CT T2 and flare
what is an example of an non infective imflammatory brain condition
demyelination- MS
what are intrinsic or extrinsic brain tumours
within our outside of brain parenchyma
what are the most common presentations of brain tumours
progressive neurological deficit
motor weakness
headache
seizures
how can a tumour increase ICP
mass
oedema mass effect
blockage of CSF flow
haemorrhage
what symptoms does raised ICP cause
headache, vomiting, mental changes, seizures
if uncal herniation can cause blown pupil if compresses on oculomotor nerve
what are the types of brain herniations
cingulate (subflacine) central (trans tentorial) transcalvarial uncal upward cerebellar/ transtentorial downward cerebellar (tonsillar)
what type of headache should make you think of brain tumour
worse in morning- wakes them up
increased with coughing/ leaning forward
may be associated with vomiting or symptoms similar to tension headaches/ migraines
what do you do if there is scary headache symptoms
always do fundoscopyto look for papilloedema
why do tumours cause headaches
raised ICP
invasion/ compression of dural/ blood vessels/ periosteum
double vision
difficulty focusing
extreme hypertension (cushings triad of raised ICP)
psychogenic
what does the parietal lobe do
processes sensory input sensory discrimination body orientation primary somatic area secondary somatic area
what does werknickes area do
language comprehension
what does the occipital lobe to
visual reception area
visual interpretation
what does the cerebellum do
coordination and control of voluntary movement
what does the brainstem do
breathing, digestion, heart control, blood vessel control, alertness
what does the temporal lobe do
auditory reception area
expressed behaviour
receptive speech
memory/ information retrieval
what does the frontal lobe do
premotor cortex- storage of motor patterns
prefrontal area- concentration, elaboration of though, judgement, inhibition, personality, emotional traits
brocas area language production
motor cortex- voluntary motor activity
what symptoms should make you urgently refer a patient on suspicion of a brain tumour
adults- progressive sub acute loss of central neurological function
children- newly abnormal cerebellar or other central neurological function
new onset seizures headaches mental changes cranial nerve palsy unilateral sensioneural deafness
headaches with symptoms of raised ICP
- vomiting
- drowsiness
- posture relates
- pulse synchronous tinnitus
what investigations for suspected brain tumour
CT MRI LP PET lesion biopsy EEG evoked potentials angiograms radionucleotide studies
is papilloedema a late or early sign of a brain tumour
late
what is the commonest brain tumour
mets from other areas
what type of cells do gliomas arise from
astrocytes
what are grade 1 astrocytomas
benign, slow growing- affects children and young adults
what are grade 2 astrocytoma like
not benign
vascular
tend to be in parietal or frontal lobes
present with seizures
what are the poor prognostic factors for
over 50 focal deficit short duration of symptoms raised ICP altered consciousness enhancement on contrast studies
what is the treatment for a grade 2 astrocytoma
want to do surgery as can become malignant
or depending on tumour:
serial imaging +/- chemo, radio/ no Tx
what are grade 3 astrocytomas like
bad- median survival 2 years
what are grade 4 astrocytomas like
really bad- median survival 14 months
what is the most common pituitary tumour
astrocytoma
what is the treatment for grade 4 astrocytomas
Tx not curative unless present v early with a cyst, surgery- cytoreduction, reduce mass effect, post op radiotherapy
can you drive if you have a brain tumour operation
no if seizure risk (all glioblastomas) or if significant visual defect
what are the types of chemotherapy
temozolomide, PCV, carmustine wafers
what are oligodendrogial
tumour of oligodendrocytes (myelin making cells)
affects frontal lobes, may present with seizures - chem sensitive
what does tiptoeing, ataxia and vomiting with headaches in children suggest
BRAIN TUMOUR
what are meningiomas like
extra axial
commoner in females
majority asymptomatic
90% benign
what are the aggressive types of meningiomas
clear cell, choroid, rhabdoid, papillary, radiation induced
what is the Tx for meningiomas
small- leave, pre op embolisation
surgery, radiotherapy
what does recurrence of meningiomas depend on
extent of resection and grade
what are the types of nerve sheath tumours
schwanomas, neurofibromas, malignant peripheral nerve sheath tumours
what are the symptoms of a vestibular schwannoma
hearing loss (unilateral), tinnitus, dysequilibrium
what is the treatment of a vestibular schwannoma
'expectant' hydrocephalus management radiotherpay surgery audiological assessment
are vestibular schannomas malignant
1% are
what are pineal tumours like
present with parinad syndrome, lots of them hormone secreting, often curable with chemo and radio (germ cell tumours)
what do you test in any child with a midline tumour
tumour markers- ALP, HCG, LDH
to see if germ tumour and whether it will be chemo/ radio sensitive
what procedure treats hydrocephalus
VP shunt
what are the symptoms of a pituitary tumour
bitemporal hemianopia, HA, endocrine abnormality
what tests for a pituitary tumour
morning cortisol and prolactin
which pituitary tumours do you surgically remove
in patients with cushings, acromegaly or if going blind (unless prolactinoma)
