NEURO/SPINE Flashcards
Acute spinal cord ischaemia clinical
Anterior
- bilateral
- paralysis below level
- pain and temperature loss
- sparing of proprioception and vibration
- anterior horn; sensation preserved
- cervical/man in barrel; bilateral arms, normal face and legs
Posterior
- unilateral
- complete sensory loss at level
- proprioception and vibration loss below
- minimal motor sx
Acute spinal cord ischaemia imaging
MRI
- T2 in cord, pattern based on artery
- restricted diffusion
Spinal subarachnoid haemorrhage (usually due to avm) also known as
Coup de poignard of Michon (poignon = french for dagger)
Spinal epidural haemorrhage aetiology
spontaneous (most common)
trauma
iatrogenic
AVM
tumours
pregnancy
Spinal AVM clinical
25% spinal vascular malformations
Clinically variable;
- foix alajouanine syndrome (progressive myelopathy)
- coup de poignard of Michon (stab in back)
Spinal AVM imaging
T1
- signal voids
- dilated perimedullary vessels, indent/scallop cord
T2
- signal voids
- increased cord signal due to oedema or myelomalacia
Spinal AVM classification
Intramedullary or extramedullary
four angio subtypes
1: single coiled vessel
2: intramedullary glmus AVM
3: juvenile
4: intradural perimedullary
Spinal AVF clinical
70% of all spinal vascular malformations
Cause venous congestion, vague sx
- motor; gait disturb and reduced power
- paraesthesia
- radicular pain
- later; incontinence, ED
Spinal AVF imaging
MRI
- tortuous enlarged vessel flow voids
- spinal cord oedema; usually centromedullary and multisegmental
- low T2 rim and peripheral of oedema, deoxy blood product
DSA
Spinal AVF classification
1: dural AVF
2: intramedullary glomus AVM
3: intramedullary juvenile AVM
4; perimedullary AVF
5: extradural AVF
Spinal cord cavernoma clinical
peak during fourth decade
blood filled endothelial lined spaces lined by thickened hyalinsed walls that lack elastic fibres and smooth muscle
typically thoracic
variable clinical course
Spinal cord cavernoma imaging
CT occult
DSA occult
MRI
minimal cord expansion unless recent hamorrhage
heterogenous, popcorn
bloom on GE
minimal enhancement
Cerebrovascular malformations classification
High flow
- AVM
- DAVF
- proliferative angiopathy
- pial AVF
Low flow
- Cavernoma
- Capillary telengiectasia
- DVA
- venous varix
- sinus pericranii
- mixed
Cerebral cavernoma/cavernous venous malformation clinical/path
40-60
can be single or multiple (?familial ?radiation)
incidental or presenting with haemorrhage
path; mulberry like cluster of hyalinsed dilated thin walled capilllaries with surrounding haemosiderin. No normal intersecting brain. Occ assoc with a DVA
Cerebral cavernoma/cavernous venous malformation imaging
difficult on ct, do not enhance
can be hyperdense if large or speckle calc
MRI
popcorn, rim of signal loss
T1; variable, fluid fluid levels
T2; hypointense rim, FF lvels, variable signal
SWI; blooming
C+ no ehnacment
ddx
amyloid
hypertensice
dai
vasculitis
hamorrhagic mets
parry romberg
mets/primary
calcified lesions (neurocyterocosis)
Cerebral cavernoma/cavernous venous malformation classification
Zabramski
1; subacute harmorrhage
2; classic popcorn
3; chronic haemorrhage
4; multiple punctate microhaemorrhage
Parry Romberg syndrome
Progressive facial hemiatrophy. rare phakamatosis.
IPSILATERAL: leptomeningeal enhancement, paracnchymal atrophy, microhaemorrhage, clacifications, aneurysms
Perimesencephalic haemorrhage is
SAH around midbrain cisterns. 95% cause not found ?venous SAH. Better outcomes than if aneurysm, AVM AVF or trauma
Hypertensive microangiopathy is
sustained elevated blood pressure leading to lipohyalinosis and charcot boiuchard aneurysms prone to rupture
Hypertensive microangiopathy imaging
microhaemorrhages affecting the basal ganglia, pons and cerebellar hemispheres
Hypertensive microangiopathy ddx
cerebral amyloid (more peripheral)
multiple familial cavernous malformation syndrome
neurocystericosis
calcified treated mets
Cerebral AVM is
intracranial high flow vascular malformation composed of enlarged feeding arteries, nidus closely associated with parenchyma and draining veins
Cerebral AVM syndromes
typically single but when multiple ?syndromes;
Osler weber rendu HHT
Wyburn mason syndrome CAMS
Cerebral AVM imaging
CTA bag of worms
DSA
MRI
Cerebral AVM grading
Perioperative morbidity. Spetzler Martin
Size: <3, 3-6, >6
Eloquence of brain
Veins: superficial or deep
Cerebrofacial arteriovenous metameric syndrome encompasses
Sturge Weber and Wyburn Mason syndrome. Intracranial and maxillofacial components required.
Three types based on location
1: medial prosencephalic - nose and hypothalamus
2: lateral prosencephalic - occipital, chiasm, optic tract, thalamus, retina, maxiall
3: rhombencephalic = cerebrallum, pons, mandible
Wyburn Mason syndrome is
rare, non hereditary neurocutaneous disorder. Unilateral vascular malformations incolving the brain, orbits and facial structures.
Features:
facial vascular naevus
visual pathway/orbital ACM
intracranial AVM, commonly midbrain
Dural AVFs are
high flow vascular malformations that share AV shunting from dural vessels.
Dural AVF imaging
CTA: abnormal enlarged cortical veins, enlarged transosseous vessels, abnormal dural venous sinuses
MRI: same. watch out forsuperiorly flowing venous blood as arterialised in the left jugular.
DSA
Dural AVF classification
Borden or Cognard. Single most important feature is presence of retrograde leptomeningeal venous drainage.
Borden
1: drain into meningeal veins, spinal epidural veins or dural venous sinus. normal antegrade flow.
- cognard 1 and 2a
2: drain into meningeal veins, epidural veins or dural venous sinus. Retrograde flow into subarachnoid veins.
- cognard 2b and 2a+b
3: direct drainage to subarachnoid veins or isolated segment of venous sinus
- cognard 3, 4, 5
Capillary telangiectasia are
small low flow vascular lesions of the brain. dilated capillaries interspersed with normal brain parenchyma.
Capillary telangiectasia imaging
commonly in hte brainstem, especially the pons. usually solitary. can be assoc with OWR syndrome. usually only seen on MR
T2 subtle high signal
FLAIR subtle high signal
SWI low signal
C+ faint stippled enhancement
Developmental venous anomalies are
congenital malformations of veins which drian normal brain. Characterised by a caput medusae sign of veins draining into a single larger collecting vein (palm tree).
DVA imaging
commonly frontoparietal, cerebellar
usually solitary except in blue rubber bleb naevus syndrome
assoc with cavernomas
CT; curvilinear enhancing structure. can have dystropic calcification.
DSA caput medusae appearance
MRI; postcon t1 and SWI
Cerebral varix is
an uncommon vascular malfomation, usually found in combination with another vascular malformation. Focal dilation of a single vein with no neural tissue or vessel anomalies
Sinus pericranii is
a cranial venous anomaly where there is abnormal communication between intracranial dural sinuses and extracranial venous structures usually via an emissary transosseous vein
Caroticocavernous fistulas are
abnormal communications between the carotid circulation and cavernous sinus. Can be direct or indirect.
Caroticocavernous fistula classification
Barrow classification
A: direct
B: indirect with ICA branches
C: indirect with ECA branches
D: B+C
Caroticocavernous fistula causes
Direct
- trauma
- aneurysm
- CTD
Indirect
- probably secondary to cavernous thrombosis with revascularisation.
- maybe pregnancy, surgery, sinusitis
Caroticocavernous fistula imaging
orbital congestion
- proptosis and exopthalmos
- retrobulbar fat stranding
- enlarged EO muscles
venous engorgement
- enlarged SOV
- bulging cavernous sinus
- asymmetric enhancement
Dehiscent ICA - snowman
haemorrhage
Reversible cerebral vasoconstriction syndrome is
a group of conditions characterised by thunderclap headache and reversible vasoconstriction of the cerebral arteries
Reversible cerebral vasoconstriction syndrome associated conditions/risk factors
Pregnancy
Drugs (lots)
migraines
hypercalc
phaeos
carcinoid bronchial
idiopathic
Reversible cerebral vasoconstriction syndrome imaging
vascular narrowings and/or
- convexity SAH
- lobar hamorrhage
- watershed infarct
- vasogenic oedema
smooth tapered narrowings invovling large to medium sized arteries followed by abnormally dilated segments. beaded or sausage shaped.
Reversible cerebral vasoconstriction syndrome differentials
SAH with vasospasm
Vasculitis
Arterial dissection
untreated fungal/bacterial meningitis
Central nervous system vasculitis are
a heterogenous group of inflammatory diseases affecting the walls of blood vessels in the brain, cord and meninges. Can be primary or secondary
Primary - confined to the CNS, primary angiitis
Secondary - in the context of a systemic process
Central nervous system vasculitis imaging
variable and non specific. infarctions are most common, 53%.
focal or multifocal segmental narrowing
T2 FLAIR high intensity white matter (non spec). meningeal enhancement and ICH can be seen.
Cerebral amyloid angiopathy is
a disorder caused by the accumulation of cerebral amyloid in the tunica media and adventitia of leptomeningeal and cortical vessels causing fragility.
Cerebral amyloid angiopathy forms
Sproadic
- incidental, prominent in autopsy of elderly and alzheimers patients
- not assoc with systemic amyloidoses
Familial
- rare
- usually autosomal dominant
- lots of types includ; AB peptide with precursor protein APP, ACys peptide with precursor protein cystatin c
Assoc; alzheimers, downs, chronic traumatic encephalopathy
Cerebral amyloid angiopathy presentation
Cortical vessels
- lobar/cerebellar haemorrhage
- cognitive impairment
Leptomeningeal vessel involvement
- convexity SAH
Other
- inflammatory type; rapid cognitive decline
- amyloidoma
Cerebral amyloid angiopathy imaging
Haemorrhage
- ICH; corticosubcortical, lobar. tends to spare BG and pons
- microhaemorrhage; tends to spare BG and pons
- convexity SAH
- superficial siderosis
Ischaemia
- ischaemic leukoencephalopathy
- microinfarcts and lobar lacunes
Others
- dilated perivascular spaces of the centrum semiovale
- cortical atrophy
Cerebral amyloid angiopathy ddx
Hypertensive microangiopathy
Multiple cavernoma
Haemorrhage mets
DAI
Neurocystericosis
Fat embolism syndrome
Radiation induced vasculopathy
Cerebral amyloidoma is
a rare manifestation of cerebral amyloid deposition, appearing as a solid enhancing mass.
Cerebral amyloidoma imaging
Nodular solid masses with vivid contrast enhancement centred within the white matter and often abutting the ventricles. Mantle of vasogenic oedema.
CT: hyperattenuating typically. enhancing.
MR
T1 and T2 variable
Vivid enhnacement, can have peripheral radial enhancement
microhaemorrhages
Sturge Weber syndrome is
a phakomatosis characterised by facial port wine stains and pial angiomas
Sturge Weber syndrome path
sporadic, no hereditary component. associated gene GNAQ 9q21.
leptomeningeal haemangioma results in a vascular steal affecting the cortex and white matter producing ischaemia
Sturge Weber syndrome imaging
XR - gyral calcification
CT - subcortical and cortical calc (tram track). calvarial and regional sinus enlargement. dyke davidoff masson appearance. orbital choroidal haemangiomas. ipsilateral cavernous and choroidal enlargement.
MR
T1: volume loss
C+: leptomeningeal enhancement
T2: low signal white matter subjacent
SWI: calcification
Spectro: decreased NAA
Sturge Weber syndrome ddx
AVM
Torch infections
neurocystericosis
PHACE syndrome
health cortical infarct
radiotherapy
gobbi syndrome
PHACE syndrome
aka cutaneous hamangioma vascular complex syndrome
phakamatosis
comprised of:
P: posterior fossa malformation
H: haemangiomas
A: arterial anomalies
C: coaractation of the aorta/cardiac anomalies
E: eye anomalies
Gobbi syndrome aka CEC syndrome
coliac, epilepsy, cerebral calcifications
bilateral occipital calc. no atrophy.
Superficial siderosis is
a rare condition which results from deposition of haemosiderin along the leptomeninges with eventual neurological dysfunction.
classically presents with gradual bilateral sensorineural hearing loss, cerebellar dysfx and pyraimydal signs
Superficial siderosis imaging
MR
pial and ependymal surfaces coated with low signal haemosiderin, particularly brainstem and cerebllum
should image whole axis to look for causative lesion, if presnet
CADASIL is
cerebral autosomal dominant arteriopathy with subcortical infarcts and lekuencephalopathy
AD microvasculopathy characterised by recurrent lacunar and subcortical white matter ischaemic strokes and vascular dementia in young and middle aged patients without known vascular risk factors.
CADASIL path
chromosome 19p13.12
NOTCH 3 gene
small vessel and arteriole stenosis secondary to fibrotic thickneing of the basement membrane.
CADASIL imaging
CT non spec wm hypoattenuation
MR
confluent white matter hyperintensities
lesions can be seen in pons, BG, thalami
initial course anterior temporal lobe and external capsule. can be diffuse subcortical
sparing occipital, orbitofrontal white matter, cortex and subcortical U fibres
CADASIL ddx
hypercoaguable state
MELAS
subcortical arteriosclerotic encephalopathy SAE
Susac syndrome
CNS vasculitis
CARASIL
Susac syndrome quick hitter
retinocochleocerebral vasculopathy. middle aged women. triad of subacute encephalopathy, bilateral sensorineural hearing loss, branch retinal arterial occlusion.
imaging
- small rounded T2 hyperintense snowball lesion, with one in the CC.
- CC predilection; central fibres of the body and splenium without abutting the callosal undersurface
- leptomeningeal enhancement
- punched out T1 holes when chronic
retinal/vestibulocochlear involvement clinically
Remote cerebellar haemorrhage is
benign complication of craniotomy, spinal surgery, LP and shunt insertion. may be secondary to post surgical CSF hypovolaemia, tends to be self limiting.
layering of blood over the superior folia - Zebra sign
Brain abscess imaging features
CT
- outer hypo inner hyperdense rime (double rim)
- uniform hyperdense ring
- central low attenuation
- vasogenic oedema
- ventriculitis
- obstructive hydro
MRI
T1
- low intensity centrally and peripherally
- ring enhancement
T2/FLAIR
- central high intensity
- peripheral high intensity vasogenic
- capsule may have intermediate to low thin irm
DWI
- high DWI centrally
SWI
- low intensity rim; typically smooth and complete
- dual rim sign
Perfusion
- CBV reduced in surrounding oedema
Spectro
- elevated peaks corresponding to lipids/lactate, succinate, acetate, amino acids
Brain abscess differentials
Mets or GBM
- abscesses have smooth wall, satellite lesions,low intensity capsule, reduced perfusion, restriction
Subacute iunfarct, haemorrhage, contusion
Demyelinating lesion
Radiation necrosis
Ventriculitis is
inflammation/infection of the ependymal lining of the ventricles. most often due to meningitis
Ventriculitis imaging
US
- periventricular echogenicity and irregularity of the surface
- choroid plexus irregularity
- intraventricular debris
CT
- hyperdense layering material
- hydrocephalus
- periventricular low density
- thin uniform ependymal enhancement post con
MR
- debris layering
- intensely restricuted diffusion of the debris
- periventricular oedema
- ependymal enhancement
Subdural empyema is
intracranial infection with a suppurative collection b/w the dura and the arachnoid. Commonly seen as a complication of sinusitis, otitis, mastoiditis or surgical intervention.
Subdural empyema imaging
CT
- resemble subdural haematomas
- crescentic, although can seem biconvex
- enhancing surrounding membrane
MR
- same as CT but better
- better for complications like cerebritis, abscess and venous thrombosis.
Intracranial epidural abscess is
a pyogenic collection within the epidural space. sinusitis again most common. strep, h influ, staph.
Intracranial epidural abscess imaging
CT
- less good than MR
- similar to EDH
- peripheral enhancement post con
MR
- T1 hyper
- C+ peripheral enhancement
- T2/FLAIR iso to hyper
- PD same
- DWI restricted
Child/Adult HSV encephalitis is
most common cause of fatal sporadic fulminant necrotising viral encephalitis. Typically HSV1.
Child/Adult HSV encephalitis imaging
General
- typically bilateral, asymmetric
- limbic, medial temporal, indular cortices and inferolateral frontal
- BG spared
CT
- low density in thje anterior and medial temporal lobe and island of reil (insular cortex)
- enhancement rare in first week, then patchy
MR
T1: usually low, unless haemorrhage
C+: enhancement absent early, variable late (gyral, lepto, ring, diffuse)
T2: hyperintensity of white matter and cortex
DWI: restricted due to cytotoxic oedema, less than infarct
SWI: blooming in haemorrhagic
Child/Adult HSV encephalitis differentials
Limbic encephalitis
Gliomatosis
Status epilepticus
MCA infarct
Trauma
Ohter viral encephalitis.
- EBV
- HHV 6
- VZV
- Flu a
- Rabies
Neurosyphlis
Neurocysticercosis is
a CNS infection caused by the pork tapeworm taenia solium which is endemic in low income countries
Neurocysticercosis stages
Escobars pathological stages
- Vesicular - viable, no host reaction
- Colloidal vesicular - cyst fluid becomes turbid. l;eaky oedema.
- granular nodular - oedema decreases as cyst retracts, enhancement persists
- nodular calcified - calcified cyst
Neurocysticercosis locations
SAS - lack a scolex
Parenchyma, most common, GW junction
Basal cisterns “grape like” lack scolex
Ventricles, most common 4th
Spinal
Neurocysticercosis imaging
Vesicular
- cyst with a dot
- CSF density/intensity
- eccentric hyperintense scolex T1
- minimal enhancement/oedema
Colloidal vesicular
- cyst fluid turbid, T1 hyper, CT attenuating
- oedema
- peripheral enhancement
- scolex initially, shrinks down
Granular nodular
- oedema decreases
- retracts to small enhancing nodule
- less enhancement, but persits
Nodular calcified
- end stage quiescent calcified nodule
- no oedema or enhancement
- T2 and * signal dropout
Neurotoxoplasmosis is
an opportunistic infection caused by toxoplasma gondii. Typically in patients with HIVAIDS and most common cause of abscess in these
Neurotoxoplasmosis imaging
Multiple lesions with a predilection for the BG, thalami and CM junction.
CT
- multiple hypodense regions
- BG and CM junction
- variable size
- thin nodular or ring enhancement
- dot like calcification in treated
MR
T1: iso to hypo
T2:
- variable intensity. hyperintense necrotising, iso organising abscess
- concentric alternating zone of hypo hyper iso signal
- perilesional oedema
C+: ring or nodular enhancement
Spectro: incr lactate and lipids. Red cho/cr/naa
PET cold
Neurotoxoplasmosis vs CNS lymphoma
Lymphoma
- subependymal
- solitary
- solid enhancement usually
- haemorrhage uncommon
- more diffusion retriction
- increased choline
- increased rCBV
- high signal thallium
Toxoplasmosis
- BG and CMJ
- multiple
- ring or nodular enhancement
- haemorrhage may be seen
- more facilitated diffusion
- decreased choline
- decreased rCBV
- low signal thallium
CMV encephalitis is
CNS infection, almost always profoundly immunocompromised. Affects entire neural axis.
CMV encephalitis imaging
meningoencephalitis and ventriculitis/ependymitis
MRI
- non spec increased WM T2 signal, periventricular
- no enhancement, unless ventriculitis
- no mass affect
CMV encephalitis ddx
HIV encephalitis
PML
CNS lymphoma
Neurotoxoplasmosis ddx
CNS lymphoma
Cerebral mets
Other infection- TB, crypto, bacterial, neurocysticercosis
CNS cryptococcosis is
most common fungal infection and second most common opportunistic infection of the CNS. Predominantly AIDS, but if competent than history of birds. Can be meningeal, parenchymal or perivascular space predominant
CNS cryptococcosis imaging
range of appearance influenced by degree of immunocompromise and therapy. more effective therapy has enhancement.
range includes
- hydrocephalus
- dilated perivascular spaces coalescing
- leptomeningeal/pachymeningeal enhancement
- cryptococcomas
- miliary nodules
- choroid plexus plexitis
perivascular/BG pattern is common, but also white matter, brainstem, cerebellum
MRI
Meningeal
- leptomeningeal/pachymeningeal enhancement
- FLAIR C+ enhancement
Cryptococcomas
- T1 low
- T2/FLAIR high
- C+ variable
- DWI variable
Perivascular
- T1 low to intermediate
- T2 high
- FLAIR variable
- DWI variable
CNS aspergillosis is
one of the most common fungal CNS infections, resulting from angioinvasive infection from aspergillus spp. Typically AIDS, steroid use, neutropaenia or GVHD
CNS aspergillosis imaging
Variable but three main patterns;
- brain abscess; often multiple, rando distribution
- cerebral infarctions, more likely perforators
- invasive paranasal rhinosinusitis
MR
Abscess
- often multiple, rando distribution
- ring enhancing with high DWI
- DWI can be variable
- may also have peripheral low T2 signal, low GRE (perilesional hamorrhage or iron in fungi) without inner high signal rim (absent dual rim)
Infarction
- multiple, random
- haemorrhage/mycotic aneurysms can be present
Rhinosinusitis
- paranasal disease, invasive features
- OM
- dural enhancement and subdural empyema
Other
- can have a granulomatous mass lesion
- hypo to iso T1
- hypo T2
Progressive multifocal leukoencephalopathy is
a demyelinating disease resulting from reactivation fo the JC virus infecting oligodendrocytes in patients with compromised immune systems.
Typically AIDS CD4 50-100.
Non HIV
- post transplant
- leukaemia
- solid malig
- isolated CD4 lymphocytopaenia
- MABs
Can also be encountered in immune reconstitution inflammatory syndrome.
Progressive multifocal leukoencephalopathy imaging
CT
- asymm focal zones of low attenuation involving periventricular and subcortical white matter. HIV more symmetrical
MR
- Typically multifocal, asymmetric, periventricular, subcortical
- little to no mass effect or enhancement
- subcortical U fibres
- parieto occipital predilection
T1
- hypo
T2
- hyper
- multiple punctate T2 lesions (milky way sign)
- barbell sign; PO region crossing splenium
C+
- typically no enhancement
- can be seen in IRIS, natalizumab
DWI
- patchy leading edge restriction
Spectro
- reduced NAA, lactate presence, incr choline/lipids
MRP
- increased leading edge
Progressive multifocal leukoencephalopathy ddx
MS (more well defined, periventricular)
HIV encephalopathy (more diffuse, atrophic, symmetric, no U fibres)
PRES (different hx, grey and white matter)
ADEM (hx, grey and white matter, enhances)
Progressive multifocal leukoencephalopathy signs
milky way
- punctate T2 foci around primary lesion
barbell
- extending across splenium
Creutzfeldt Jakob disease is
a transmissable spongiform encephalopathy resulting in rapidly progressive dementia and death. Sporadic, but familial and acquired occasionally. Typically hyperintense DWI in cerebral grey matter - cortex, striatum, thalamus.
Creutzfeldt Jakob disease types
Sporadic
Variant
Familial
Iatrogenic
Creutzfeldt Jakob disease variants
Sporadic - rapidly progressive dementia and other features of neuropsychiatic decline
Heidenhain - isolated visual
Brownell oppenheimer - cerebellar ataxia
Vairant - psychiatric symptoms
Creutzfeldt Jakob disease markers
EEG findings
S100
CSF 14 3 3 protein
CSF RT QulC seeding assay
Creutzfeldt Jakob disease affected regions (good luck idiot)
Sporadic distribution: cortex and deep grey matter. from most to least;
- insula, cingulate, superior frontal
- striatum (caudate and putamen)
- precuneus, cuneus, paracentral lobule, medial frontal, occipital, angular/supramarginal, superior parietal, inferior frontal
- thalamus
- post central, pre centra, medial and superior temporal
Usually bilateral.
Heidenhain - parietooccipital
Bronwell Oppenheimer - cerebellum, BG
Variant - hockey stuck/pulvinar (although more commonly seen in sporadic due to overall greater prevalence)
Creutzfeldt Jakob disease imaging and ddx
MRI
DWI: hyperintensity
ADC: variable, depends on timging
FLAIR/T2: hyperintense, more subtle
T1: high signal globus pallidus
C+ no enhancement
DDX
- autoimmune encephalitis
- hypoxic injury
- osmotic demyelination
- hepatic encephalopathy
- hypoglycaemic encephalopathy
- mitochondrial disease
Autoimmune encephalitis is
antibody mediate brain inflammatory process, typically involving the limbic system. Broadly divided into
- paraneoplastic
- non neoplastic
Autoimmune encephalitis causes
tumouts
- small cell
- testicular
- thymic
- breast
- ovarian
- haemotological
- GI
- neuroblastoma
non paraneoplastic
- VGKC antibody
- anti NMDA receptor
- systemic autoimmune conditions
Autoimmune encephalitis imaging
most common location limbic system
cortical thickening and increased T2/FLAIR
bilateral is most common
basal ganglia are frequently involved
patchy enhancement can be seen
restriction and haemorrhage uncommon
Primary ameorbic meningoencephalitis is
rare, usually fatal CNS infection of naegleria fowleria. non specific imaging features in keeping with a haemorrhagic meningoencephalitis
Rocky mountain spotted fever is
an infectious disease caused by Rickettsia rickettsii transmitted by tick bites
Lyme disease is
caused by borrelia burgdorferi. non specific features including periventricular subcortical T2 hyperintensity, nerve root enhancement (esp facial), meningeal enhancement
Immune reconstitution inflammatory syndrome is
paradoxical deterioration following abrupt improvement in immune function. Classiccally seen in HIV patients on ART, but also mabs in MS
Immune reconstitution inflammatory syndrome imaging
underlying pathogen or may mimic woresening of underlying condition or be atrypical. typically enhancing masses gain mass effect rapidly. enhancement is variable and may be bizarre
mycobacterial TB
- new lns may be necrotic, pulmonary nodules or new abscesses
PML
- new enhancement and mass effect in exisiting white matter lesions
pulmonary kaposi sarcoma
- similar but increasing in extent
HHV 6 encephalitis is
rare CNS infection in immunosuppressed patients, esp following haematopoietic cell trnasplant who develop limbic encephalitis syndrome with MRI signal intensity abnormalities of the medial temporal lobe
Subacute sclerosing panencephalitis is
also known as Dawsons disease. rare, chronic progressive fatal encephalitis. persistent measles infection immune resistant.
Subacute sclerosing panencephalitis imaging
T2/FLAIR: high in parietal and temporal lobes
C+ enhancement early
lateral more extensive, atrophic
Rasmussen encephalitis is
a chronic inflammatory disease of unknown origin affecting one hemisphere
Rasmussen encephalitis imaging and ddx
MRI
unilateral cortical atrophy with exvacuo dilatation starting in caudate
T2 hyperintense
DWI restricted can be seen
no enhancement\
DDX
Dyke Davidoff Massson
Sturge Weber
unilateral megaencephaly
hemiconvulsion hemiplegia epilepsy syndrome
CLIPPERS is
chronic lymphocytic inflammation with pontine perivascular enhancement response to steroids
predilection for the pons. characteristic curvilinear regions of enhancement.
Rasmussen encephalitis imaging
multiple punctate patchy and linear regions of contrast enhancement confined to the pons. can also be in the cerebellar peduncles, cerebellar hemispheres and cervical cord/ reatively little oedema. SWI signal loss.
Multiple sclerosis classification
Variants:
Classic (Charcot)
Tumefactive
Marburg (acute malignant)
Schilder type
Balo concentric sclerosis
Patterns:
Relapsing remirrting
Secondary progressive
Primary progressive
Progressive with relapses
Benign
Multiple sclerosis imaging
Plaques in the CNS system, typically ovoid and perivenular
MRI
T1
- iso to hypointense
- callososeptal interface many small lesions (venus necklace)
T2
- hyper
- acute have oedema
SWI
- central vein
FLAIR
- hyperintense
- epndymal dot dash sign
- perpindicular to lat ventricles (dawsons fingers)
C+
- active enhance
- usually incomplete, open ring of enhancement at the periphery
DWI
- active may be high or low ADC
- typically open ring
Multiple sclerosis complications
PML
PML IRIS
CNS lymphoma
Multiple sclerosis ddx
Intracranial
- CNS fungal infection
- mucopolysaccharidosis
- Marchiafava Bignami disease
- Susac syndrome
- antiphospholipid syndrome
- CLIPPERS
Spine
- Transverse myelitis
- infection
- tumours
Tumefactive MS is
an MS variant where patients develop large aggressive demyelinating lesions
Marburg variant MS is
Extensive and fulminant acute demyelination. Typically youynger patients, die within a year. Extensive confluent areas of tumefactive demyelination are seen with mass effect, defined rings and incomplete rim enhancement.
Schilder type MS is
an extremely rare, progressive demyelinating process that begins in childhood.
Balo concentric sclerosis is
a rare and severe monophasic demyelinating disease. Considered an MS variant. Rounded lesion with alternating layers of high and low signal intensity “bullseye” “onion bulb”.
Balo concentric sclerosis imaging
Alternating bands of demyelinated and myelinated white matter, seen as concentric rings.
T1: irregular, concentric rings of iso to low signal
T2: irregular concentric rings of iso to hyper
C+ usually periphal enhnacement in the area of active demyelination
DWI: some restriction in outer ring
Neuromyelitis optica (NMO) and NMO spectrum disorder (NMOSD) is
severe demyelinating disease caused by autoantibody to aquaporin 4 water channel. classic triad of optic neuritis, longitudinally extensive myelitis and postive anti AQP4. Previously known as Devic disease.
Neuromyelitis optica imaging
Orbits
- swollen/hyperintense/enhancing CN2
- bilateral involvement, to optic chiasm
- atrophy in chronic
Brain
- periventricular (no dawsons fingers)
- periaqueductal GM
- hypothalamus/medial thalamus
- dorsal pons/medulla
- CC
- deep punctate white matter lesions
- corticospinal trtact invovlement
- larger >3cm hemispheric lesions (radially orientated, little mass effect)
- fever juxtacortical lesions
- larger, more confluent, more CC
Spine
- at least three levels (long extensive)
- ring enhancing, or patchy enhancement
- prefers central cord
Neuromyelitis optica ddx
cerebral
- MS
- Susac
- Neuro Behcet
- Primary angiitis of the CNS
- ADEM
- ALS
Optic neuritis
Spinal
- NMO
- MS (confluent lesions)
- anti MOG encepha
- Systemic (neurosarcoid, sjogrens, SLE, behcet)
- other causes transverse myelitis
- vascular (AVF, infarct)
Acute disseminated encephalomyelitis ADEM is
a monophasic acute inflammation and demyelination of white matter following viral infection or vaccination,
ADEM imaging
Vary from small punctate to tumefactive
Callososeptal interface involvment is less typical
Bilateral but asymmetrical
Can sometimes involve subcortical grey matter and brainstem unlike MS
Acute haemorrhagic leukoencephalitis is
also known as Hurst or Weston Hurst syndrome. Very rare form of demyelinating disease. Acute rapidly progressive fulminant inflammation of the white matter. Typically young adults (ADEM kids).
Large tumefactive lesions, sparing the cortex. Assoc punctate haemorrhage. POssible BG/thalami involvement.
Acute necrotising encephalopathy is
a rare encephalopathy with bilateral brain lesions, involving the thalami, putamina, internal/external capsule, cerebellar white matter and tegmentum.
Typicall bilateral and symmetrical thalamic involvement. Canhave restricted diff, haemorrhage, cavitation and enhancement.
Vascular dementia is
second most common after alzheimers. seen in atherosclerosis and htn. MRI more sensitive to white matter change, changes of amyloid and chronic htn encephalopathy.
patterns of vascular damage
- binswanger (small vessel)
- cerebral infarct
- lacunar infarctr
- hjaemorrhage
Binswanger disease is
a slowly progressive non hereidtary white matter vascular dementia.
subcortical and periventricular hjypertinscve T2/FLAIR
usually small lesions
moderate diffuse atrophy
ddx
CADASIL (hereditary, genetic, anterior temporal and superior frontal)
CNS vasculitis
Alzheimers imaging
most common degenerative disease. most common cerebral amyloid deposition disease.
characteristic volume loss
1. mesial temporal lobe
- particularly hippocampus, entorhinal cortex and perirhinal cortex
2. temporoparietal cortical atrophy
NM
SPECT/PET to see hypoperfusion/metabolism om a biparietal bitemporal distribution with amyloid/tau agents in the grey matter and medial temporal lobes respectively
PRES three main patterns
Holohemispheric at watershed zones
Superior frontal sulcus
Parieto occipital dominance
PRES is
an acute hypertensive encephalopathy secondary to inability of the posterior circulation to autoregulate in response to bp changes. Hyperperfusion with disruption in the BBB resulting in vasogenic oedema.
PRES aetiology
Severe HTN
Haemolytic uraemic syndrome
TTP
SLE
Drugs
BM t/p
PRES imaging
Bilateral vasogenic oedema, typically parietooccipital
Can also be non posterior; frontal, inferior temporal, cerebellar, central. Can be unilateral.
MRI
T1 hypo
C+ patchy, variable
T2 hyper
DWI vaRIABLE
SWI may have haemorrhage
PRES differential
inflammatory cerebral amyloid angiopathy
PML
hypoglycaemia
posterior infarct
hypertensive brainstem encephalopathy
gliomatosis
Hypertensive brainstem encephalopathy is
severe htn, brainstem vasogenic oedema and various neurology. Can be isolated or with PRES.
Hypertensive brainstem encephalopathy imaging and differentials
CT: diffuse hypoattenuation, mostly at the pons
MRI: increased FLAIR/T2 brainstem, lack of diffusion restriction
ddx
- PRES
- osmotic demyelination
- infarct
- neoplasia
Hypoglycaemic encephalopathy is
brain injury from severe/prolonged hypoglycaemia. Typically affects posterior internal capsule, cerebral cortex, hippocampus and basal ganglia.
Hypoglycaemic encephalopathy imaging
Typically bilateral
characteristically
- posterior limb internal capsule
- cerebral cortex (PO and insula)
- hippocampus and basal ganglia
- cerebellum, brainstem, thalami (spared in adults, present in neonates)
- splenium of CC (boomerang)
Osmotic demyelination syndrome is
seen in the setting of osmotic changes typically with rapid correction hyponatremia
Osmotic demyelination syndrome imaging
T2 bright
DWI bright
T1 hypo
piglet sign
trident sign
Status epilepticus imaging
Increased T2/FLAIR, increased DWI.
Variable distribution
- cerebral cortex and subcorticla WM
- hippocampi and mesial temporal lobes
- thalamus, pulvinar region
- cerebellum
Carbon monoxide poisoning imaging
Bilateral with globus pallidus most commonly affected
CT
GP low attenuation
Can have diffuse white matter hypoattenuation
MRI
T1 low, can have areas of haemorrhage
T2/FLAIR high
C+ can have peripheral enhancement
DWI: increased restriction
Carbon monoxide differentials
Mitochondrial encephalopathies
- leigh
- kearns sayre
Other toxic encephalopathies
- cyanide
- methanol
- organophsophate
Other causes of anoxia
Metabolic
- Wilsons
Prion
- CJD
Hepatic encephalopathy imaging
T2/FLAIR
- mild; symmetric high in insula, thalamus, posterior internal capsule, cingulate
- severe; diffuse cortical.
perirolandic/occpital spared.
DWI
- similar to t2
SWI
- 50% have microhaemorrhage
Fahr syndrome is
abnormal vascular calcium deposition in the basal ganglia, cerebellar dentate nuclei, white matter, with subsequent atrophgy. Can be primary or secondary.
Fahr syndrome secondary causes
Endocrinopathies
- hypoparathyroidism/hyper
Vasculitis
Mitochondrial disorders
Infection
- brucellosis
- EBV
-HIV
Inherited
- neuroferritonpathy
- other conditions
Radiation
Chemo
CO poisoning
Fahr disease imaging
Symmetrical calcification of the causate, lentiform, thalamus and dentate nuclei
Globus first
Subcortical white matter later
Non ketotic hyperglycaemic hemichorea is
A rare complication of non ketotic hyperglycaemia, causing hemichorea hemiballismus syndrome
Non ketotic hyperglycaemic hemichorea imaging
typically unilateral, contralateral to symptoms.
causes abnormality in the striatum (caudateand putamen)
T1 hyper
T2 variable, generally low
SWi increased
DWI high
Non ketotic hyperglycaemic hemichorea differential
Other BG T1 high
- calcium
- wilson and non wilson hepatic
- NHH
- haemorrhage
- japanese encephalitis
Wernickes encephalopathy is
a form of thiamine deficiency typically seen in alcoholics. Can also be seen in starvation, TPN, post bariatic surg, hyperemesis
Wernickes encephalopathy imaging
T2/FLAIR: symetrically increased in
- mam bodies
- dorsomedial thalami
- tectal plate
- periaqueductal grey matter
- peri third ventricle
C+: enhancey same, particularly mam bodies
DWI: same but retricted
Wernickes encephalopathy ddx
Leighs disease (no mamm bodies)
Metronidazole induced encephalopathy (dentate, splenium, cranial nerve nuclei)
Artery of percheron/central venous infarcts
Vitamin B12 deficiency imaging
subacute combined degeneration of the cord
- bilateral symmetrical high signal in the dorsal columns
- iinverted V sign
- start upper thoracic, ascend or descend
- can get lateral tract involvement
Uraemic encephalopathy is
an acquired toxic syndrome in patients with chronic kidney disease.
Uraemic encephalopathy imaging
Cytotoxic oedema in the subcortical grey and white matter, midbrain and mesial temporal lobes.
minimal nehnacement. variable restriction.
lentiform fork sign; white matter surrounding the basal ganglia hypoertintense
Wilson disease CNS imaging
Frequently affects BG (especially putamen), midbrain, pons, thalamus. Bilateral and symmetric.
CT: atrophy
MRI
T2 high signal; putamen, tegmentum midbrain (giant panda), pons (panda cub/double panda).
T1: hypo intense, contrast to acquired non wilson hepatocerebral degeneration atrtreibuted to manganese deposition.
Storage disorders classification
Share the accumulation of a metbolite within various cells due to dysfunction of specific enzymes or transport proteins, resulting in cellular or organ dysfunction. Majority are autosomal recessive. Broadly divided to the type of of metabolic defect.
Carbohydrate metabolism
- carbo intolerance
- glycogen storage disorders
Lysosomal storage disorders
- leukodystrokphies
- mucopolysaccharidoses
- glycogenoses, mucoliposes, sphingolipodoses
- gaucher most common
Mitochondrial
Peroxisomal
Protein
Purine/pyrimidine
Glycogen storage disease are
characterised by a defect in synthesis, metabolism or storage of glycogen
many types, 1-12
1: von gierke
2: pompe
Can be grouped into myopathic, hepatic and miscellaneous forms depending on predominant organ. Hepatomegaly most common.
Mucopolysaccharidoses are
a group of hereditary disorders, type of lysosomal storage disorder. Excessive accumulation of mucopolysaccharides secondary to deficiencies in specific enzymes responsible for degradation of mucopolysaccharides (or glycosaminoglycans).
Types 1-9
1H Hurler syndrome
2: Hunter syndrome
4: Morquio
Whatre the common leukodystrophies
Alexander disease
Canavan disease
Krabbe disease
Metachromatic leukodystrophy
X linked adrenoleukodystrophy
Megalencephalic leukoencephalopathy with subcortical cysts
Pelizaeus Merzbacher
Vanishing white matter disease
Alexander disease is
a rare, fatal leukodystrophy. Usually infantile but can be juvenile/adult.
Alexander disease imaging
Frontal region, extends posteriorly
Subcortical U spared intially, involved late
End stage cystic leukomalacia
Caudate - globus - thalamus - brainstem
Periventricular rim
Canavan disease is
a leukodystrophy characterised by megaencephaly, severe deficits and blindness. Deficiency in enzyme for NAA, leading to accumulation in the brain, CSF, plasma and urine.
Canavan imaging
Megaencephaly
Diffuse, bilateral
Involves subcortical U fibres
mainly subcortical white matter, extending periventricular
Involves the globi pallidi and tyhalami
Generally spares the CC, caudate, putamen and internal capsule
Markedly elevated NAA on spectro
Krabbe disease is
an autosomal recessive lysosomal storage disorder resulting in damage to cells involved in myelin turnover. Typically infantile and rapidly progressive but can be late onset.
Krabbe disease imaging
Changes involve the corticospinal tracts.
CT
Hyperdense areas involving the thalami, cerebellum, caudate, posterior internal capsule and brainstem
Lateral hypoattenuating centrum semiovale. Evetually, atrophy
MRI
T2: high signal periventricular white matter and deep grey matter. Subcortical U fibre may be spared until late. Tigroid pattern can be seen.
C+: no enhancement
Enchnacing/enlarging peripheral nerves can be seen
Metachromatic leukodystrophy is
the most common hereditary leukodystrophy and a lysosomal storage disorder. Characteristic imaging features invluding periatrial and frontal horn wm and periventricular perivenular sparing “tigroid”
Metachromatic leukodystrophy imaging
Bilateral symmetrical confluent areas of periventricular deep white matter signal change.
Typically around the atria and frontal horns, sparing the sub cortical u fibres. Butterfly pattern.
Tigroid pattern on axial or leopard on saggital representing sparing along the venules.
Tigroid pattern
Krabbe
Metachromatic
Pelizaeus Merzbacher
X linked adrenoleukodystrophy is
an inherited metabolic peroxisomal disorder characterised by oxidation of very long fatty acids resulting in severe inflammatory demyelination of the periventricular deep white matter. Posterior predominant change and early involvement of the splenium.
X linked adrenoleukodystrophy imaging
Location - five distinct patterns
1. PO deep white matter and splenium
2. frontal lobe or genu CC
3. frontopontine or corticospinal projection fibres
4. cerebellar white matter
5. combined PO and frontal
Tends to be subcortical u fibre sparing
Three zones: central gliosis, intermediate inflammation, peripher active demyelination
T1: central hypointense
C+ peripherally enhancing
T2: centra hyper, intermediate iso, peripheral hyper
Megalencephalic leukoencephalopathy with subcortical cysts is
a rare inherited autosomal recessive disease characterised by diffuse subcortical leukoencephalopathy with cystic white matter degeneration.
Megalencephalic leukoencephalopathy with subcortical cysts imaging
Megalencephaly
Diffuse bilateral and symmetric T2 hyper and T1 hypo of the cerebral white matter
Have have restriction
Subcortical U fibres invovled
Sparing of deep and cerebellar
Bilateral subcortical cysts anterior temporal and frontoparietal
Eventually atrophyu
Pelizaeus Merzbacher disease is
an x linked leukodystrophy with arrest of myeline development
Pelizaeus Merzbacher imaging
T1 lack of myelination, low signal regions involving internal capsule, corona radiate and optic radiation
T2 diffuse or patchy, tigroid, atrophy
Vanishing white matter disease is
a rare genetic leukoencephalopathy, extensive white matter involvement with cavitatory changes.
Vanishing white matter disease imaging
Diffuse white matter T2 high signal, eventually replaced by CSF intensity fluid (suppresses on FLAIR).
Primary mitochondrial disorders are
a clinically heterogenous group of conditions caused by vairants in mitochondrial DNA or nuclear DNA
Include:
Leigh syndrome
Kearns Sayre syndrome
MELAS
MERFF
Gnerally have bilateral deep grey matter involvement and peripheral white matter delayed myelination in children. Elevated lactate on MRS.
Leigh disease imaging
T2 high signal in
- brainstem
- periaqueductal gm
- putamen
- remainder of the corpus striatum
T1 low
DWI can restric acutely
ddx
Wernicke (involves mamillary, enhances, hamoerrhagic change)
Other mitochondrial disorders
Acute necrotising encephalitis of childhood
Kearns Sayre syndrome imaging
Basal ganglia siderocalcific deposits and subcortical calcifications
MELAS is
mitochondrial encephalomyopathy with lactic acidosis and stroke like episodes. Mitochondrial d/o. Manifests as multifocal stroke like cortical lesions in different stages “shifting spread”, crossing vascular territories. Predilection for posterior parietal and occipital.
MELAS imaging
CT
multiple infarcts, multiple territories
BG calc
MR
Acute and chronic infarcts
elevated lactate on spectro
parieto occipital and parieto temporal most common
Marchiafava Bignami disease is
a rare CNS disorder seen in the context of alcoholism and malnutrition. Classically involved necrosis and demyelination of the corpus callosum.
Marchiafava Bignami disease imaging and ddx
Typically begins in the corpus callosum and later involves the genu and splenium.
Classically involves the central layers with sparing of the dorsal/ventral extremes “sandwich sign” on saggital
CT hypoattenuating
MR
T1 hypointense acute
T2 hyperintense acute, hypointense subacute (haemosidering), ears of a lynx sign (frontal horns)
ddx
- MS
- transient lesions of the splenium of the CC
- DAI
Meningiomas WHO 2021 subtypes (there are 15 lol)
angiomatous
atypical
anaplastic
chordoid
clear cell
fibrous
lymphoplasmacytic rich
meinigothelial
metaplastic
microcystic
papillary
psammomatous
rhabdoid
secretory
transitional
Meningioma imaging
CT
can be slightly hyperattenuating to brain
can have calc
majority have homogenous enhancement
can be heterogenous
hyperostosis, typically BOS
reactive vs direct invasion vs primary intraosseous
MRI
variable intensity, typically
iso T1 with homogenous enhancement post con
iso to gm t2
can restrict
signs
- csf cleft
- dural tail
-suinburt or spoke wheel vessels
- white matter buckling
- arterial narrowing
variable vasogenic oedema
Meningioma differentials
Dural masses
- solitary fibrous tumours of dura
- dural mets
location
- CP angle; schwannoma
- pituitary; macroadenoma, cranipharyngioma
- bos; pachymeningitis, EMH, chondrosarc, chordoma
Burnt out meningiomas are
completely calcified.ossified. typically indolent. likely to be psammomatous meningioma.
Cystic meningioma is
applied to both meningiomas with intratumoural degenerative cyst formation as well as those with peritumoural arachnoid cysts or reactive intraparenchymal cysts.
Five subtypes
- intratumoural, central
- intratumoural, peripheral
- cyst wall nest of tumour cells
- cysts in adjacent brain
- adjacent arachnoid cysts
Intraosseous meningioma imaging
2/3 blastic 1/3 lytic
CT
- commoner sclerotic type shows diffuse sclerosis with bony expansion
MR
- T1 iso, expanded bony component hypo
- T2 iso to grey matter
- uniform enhancement
Intraosseous meningioma ddx
BLASTIC
Pagets
FD
Osteoma
Osteosarcoma
Mets
LYTIC
plasmacytoma
lytic
En plaque meningioma
diffuse and extensive dural invovlement usually with extracranial extension
Intraventricular meningioma imaging and ddx
Location
- mostly trigone
- 15% third ventricle
- 5% fourth ventricle
Iso to grey matter pre and homogenous contrast enhancement post.
ddx
- glial tumour; ependymoma, astrocytoma
- choroid plexus mets; RCC, melanoma
- choroid plexus papilloma
- CNS lymphoma
- central neurocytoma
Optic nerve sheath meningioma imaging
Morphology
- tubular
- exophytic
- fusiform
CT
- iso to nerve
- enhancing relative to nerve “TRAM TRACK” sign
- coronal “DOUGHNUT”
MR
- T1 hypo to nerve
- T2 hyper to nerve
- homogenous enhancement
ddx
- optic nerve flioma
- orbital pseudotumour
- orbital lymphoma
- orbital mets
- sarcoid
Primary CNS lymphoma subtypes
immunocompetent
immunodeficient assocaited
- aids related
- ebv positive
- lymphmatoid granulamatosis
- primary CNS post transplant lymphoproliferative
intravascular
MALT of dura
Primary CNS lymphoma imaging
typically ct hyper, avidly enhancing, t1 hypo, t2 iso to hypo with restricted diffusion diffusion. subependymal and crossing the CC
- predominantly seen in untreated, non immunocompromised
immunocompromised; more heterogeous, central non enhancement and haemorrhage. may have peripheral rim enhancement.
typically supratentorial, solitary or multiple
usually contact subarachnoid/ependymal surfaces
can cross the cc
pronounced enhancement
limited mass effet and vasogenic oedema
NOTCH sign deep depression at the margin
Primary CNS lymphoma ddx
Secondary CNS lymphoma
Cerebral toxoplasmosis
- toxo no subependymal spread
- more likely BG, CMJ
- toxo not pet/thallium avid
butterfly glioma
- more haemorrhage
tumefactive MS/ADEM
cerebral abscess
- central restriction, thinner peripheral enhancement
neurosarcoid
Intravascular lymphoma is
a rare variant of extranodal dlbcl that affects small and medium sized vessels
Intravascular lymphoma imaging
T2/FLAIR high signal in a dynamic pattern
DWI retriction in a dynamic pattern
C+ mass like enhancement in proximity to t2 or DWI changes
MALT lymphoma dura imaging
share imaging features with other small round blue cell tumours and other dural masses. extra axial lobulated mass, either solitary or multiple
ct
slightly hyperdense
enhance
mri
T1 iso to grey
C+ homogeneous enhancement
T2 iso to gry
DWI retricts
MALT lymphoma dura ddx
meningioma
mets
Erdheim chest
Rosai dorfman
Adamantinomatous craniopharyngioma imaging
Primarily suprasellar
Intrasellar component in 25%
Lobulated contour
Calcification is common 90%
CT
large dominant cysts
solid component enhances
calcification stypically stippled and peripheral
MRI
Cysts
- T1 iso to hyper
- T2 variable
Solid
- enhances
- variable T2
Calcification
Adamantinomatous craniopharyngioma ddx
Rathke cleft cyst
- no solid/enhancing
- calc rare
- unilocular
- mostly intrasellar
Pit macroadenoma
- usually intrasellar epicentre
- calcification often absent
Apoplexy
- clinical pres more acute
Teratoma
- presence of fat
Papillary craniopharyngioma imaging
primarily suprasellar with a small intrasellar component in the minority of cases
CT
cysts not a significant feature
solid part enhances
calcification uncommon
MRI
cysts: when present, variable but typically low T1
Solid; T1 iso, T2 variable, enhances
Papillary craniopharyngioma ddx
pituitary macroadenoma
pituicytoma
chordoid glioma
meningioma
Pilocytic astrocytoma are
who grade 1 astrocytic gliomas in young people
majority cerebellum, can be optic pathway or spinal
strong assoc with NF1
Pilocytic astrocytoma location
cerebellum 60%
optic pathway 30%
brainstem/hemispheres/ventricles/spinal
Pilocytic astrocytoma imaging
General
- large cystic with enhancing mural nodule
- heterogenous with mixed solid/cystic/necrotic
- completely solid
- usually enhancement present
- can have calcs
- haemorrhage is an uncommon complication
MRI
T1
- iso to hypo solid part
- cystic fluid signal
C+
- vivd
- wall enhances half the time
T2
- solid hyper to brain
- cystic high
SWI
- calc or haemorrhage
Pilocytic astrocytoma ddx
High grade astrocytoma with piloid features
- NF1
Haemangioblastoma
- usually adults
- children VHL
- no calc
- smaller mural nodule with angiographic blush
Medulloblastoma
- typically midline
- usually younger 2-6yo
ATRT
- larger, heterogenous
Ependymoma
- fourth ventricle
- large cyst less common
Ganglioglioma
PXA
haemorrhage
Optic nerve gliomas are
relatively uncommon tumours usually seen in NF1 and predominantly pilocytic astrocytomas. Typically enlarged, low T1 high central T2, variable enhancement.
Spinal pilocytic astrocytoma imaging
Thoracic > cervical > lumbar
Eccentric location in the cord, typically dorsal
Fusiform enlargement
Well defined and displace cord
Assoc cysts and syringomyelia
Hamorrhage uncommon
Vasogenic oedema rarely present
T1 iso to hypo
T2 hyper
C+ mild variable enhancement
Spinal pilocytic astrocytoma ddx
Astrocytoma
- similar
- also nf1
ependymoma
- enhance strongly
- central position
- hamoerrhage common
ganglioglioma
- calcification
- mixed t1
paraganglioma
- inferior to conus
- flow voids along surface and within tumour
- cap sign from haemorrhage
mets
- more oedema
Medulloblastoma subtypes (fuck you)
Medulloblastoma WNT activated
Medulloblastoma SHH activated
- TP 53 wildtype
- TP 53 mutant
- subgroups 1-4
Non WHT/non SHH
- group 3
- group 4
Epidemiology
- WNT; children and adults
- SHH wild; infants and adults
- SHH activated; children
- gr 3; infants and children
- gr 4; typically children
Location location location
Cerebellar peduncle/foramen of luschka
- WNT
Cerebellar hemisphere
- SHH
Midline
- 3, 4 or SHH
- 3 infants, prominent enhancement, ill defined margins
- 4 children, well defined, minimal enhancement
- SHH adults, variable defined/enhancing
Spectro
Gr3/4
- taurine peak
- high cr
SHH
- little or no taurine
- low creatine
Proggy
- WNT v good
- SHH good
- gr3 poor
- gr 4 intermediate
Medulloblastoma imaging
Strongly influenced by subtpye
But small round blue cell tumour
Typically cerebellum, majority vermis. protrude into fourth from roof. cerebellar peduncle WNT.
CT
- obstructive hydrocephalus
- dense, cysts/necrosis, calcs
- prominent enhancement
MRI
T1 hypo
C+ typically enhance heterogenously
T2/FLAIR iso to hyper, heteorgenous, oedema
DWI; restrict
Medulloblastoma ddx
Ependymoma
- floor 4th, toothpaste
ATRT
- very young children, aggressive
Pilocytic astro
- cystic
brainstem glioma
Choroid plexus papilloma
adult
- mets
- haemangioblastoma
-cpp
- epndymoma
Atypical teratoid/rhabdoid tumour imaging
Location
- cerebellum/brainstem
- cerebral hemi
- pineal
- septum pellucidum
- hypothalamus
CTs
Iso to GM
deterogenous enhancement
calc is common
obstructive hydro
MRI
necrosis, cysts, haemorrhage
T1: iso to hyper
T2: generally hyper
C+ heterogenous
DWI restrict
ATRT ddx
Embryonal tumour with multilayered rosettes
Medulloblastoma
Intracranial teratoma
Embryonal tumour with multilayered rosettes (ETMR) are
rare small round blue cell tumours
one of the most aggressive tumours in children
Embryonal tumour with multilayered rosettes imaging
large, demaracted, solid, patchy enhancement, oedema, signifincant mass effect
minority have cystic comonents and microcalc
t1 hypo
t2 hyper
c+ patchy or no
Astrocytoma IDH mutant tumours are
WHO grade 2, 3 and 4. diffuse infiltrating astrocytic tumours.
IDH mutation and absence of 1p19q deletion.
Astrocytoma IDH mutant tumours imaging
Low grade infiltrating astrocytomas, iso or hypodense without any enhancement. Can have cystic components.
T1; iso to hypo
T2/FLAIR
- mass like hyperintense that suppresses on FLAIR
- white matter distribution
- can have microcystic changes at periphery
DWI: facilitated diffusion. lower adc values suggest higher grade.
C+: no enhancement in lower grades, solid enhancement/necrosis suggests higher
Perfusion; elevated in higher grade
Astrocytoma IDH mutant tumours ddx
GBM
infarct
cerebritis, encephalitis
cortical based tumour
Oligodendrogliomas are
intracranial tumours characterised by IDH mutation and 1p19q codeletion. present as masses involving the cortex or subcortical grey matter with low attenuation on CT, hypointensity on T1, and hyperintensity on T2. Can be heterogenous due to calc, cysts and haemorrhage
Oligodendrogliomas imaging
CT
70-90% calc
can have central, peripheral or ribbon calc
variable enhacement
MR
T1 hypo
T2 hyper, but for calc
SWI; calc seen as blooming
DWI; variable enhancement, not indicative of grade
DWI no restriction
perfusion; chicken wire increased vasc
Oligodendroglioma ddx
astrocytoma
- t2/flair mismatch
- more well defined margins
- no calc
ganglioglioma
PXA
CAPNON (entirely calc)
Glioblastoma IDH wild type tumours are
diffuse astrocytic tumours that are IDH wild type. most common adult primary brain tumour. typically heterogenous, irregular peripheral enhancement, central necrosis, vasogenic oedema.
three variants
- giant cell glioblastoma
- gliosarcoma
- epithelioid glioblastoma
Glioblastoma imaging
large at diagnosis
thick irregular enhancing margins
central necrotic core
may have haemorrhage
vasogenic type oedema, actually infiltration
multifocal 20% with connections
multicentric; no connection
CT
irregular thick margins
slightly hyperattenuating
marked mass effect
vasogenic oedema
haemorrhage/calc occasionally
intense irregular heterogenous marginal enhancement
MRI
T1
- hypo to iso
- central heterogenous
C+
- peripheral and irregular
T2/FLAIR
- hyperintense
- vasogenic oedema
- flow voids
SWI
- low intensity rim, incomplete and irregular
- absent dual rim sign
DWI
- solid usually restricts
- necrotic/cyst facilitated
Perfusion
- rCBV elevated
Glioblastoma ddx
astrocytoma IDH mutant 4
- generally younger
mets
- usually grey white matter junction
- rCBV in oedema reduced
CNS lymphoma
- central necrosis in aids
abscess
- should have dual rim sign
- central restricted diff
tumefactive demyelination
- open ring pattern enhancement
- younger
subacute infarct
- hx
- low rcbv
toxo
Pleomorphic xanthoastrocytomas are
astrocytic tumour in young patients who gr 2 or 3.
most often cortical, cystic component with vivid enhancement. temporal lobe common. minimal oedema. can have overlying scalloping and dural tail. calcs rare.
Pleomorphic xanthoastrocytoma imaging
solid enhancing nodule with peripheral cystic component
may have a dural tail (reactive)
MR
T1
- cystic low, solid hypo to gm
- leptomeningeal involvement in 70%
C+
- solid enahnces vividly
T2
- solid hyper
- cystic high signal
- not quite as suppressed on FLAIR as CSF
- little vasogenic oedema
Pleomorphic xanthoastrocytoma ddx
Ganglioganglioma
- more calc
- no dural tail
DNET
- enhancement uncommon
- bubbly
Oligodendroglioma
- calc
Diffuse midline glioma H3 K27 altered is
a specific entity that represents the majority of diffuse intrrinsic pontine gliomas. Aggressive tumours with poor prognosis, who grade4. Typically young children and in the pons.
Diffuse midline glioma H3 K27 imaging
located in the pons
pons enlarged with basilar displaced anteriorly
floor of the fourth ventricle flat
can be exophytic
CT
hypodense, minimal enhancement
MRI
T1 low
T2 heterogenously incr
C+ usually minimal
DWI mild restriction, usually normal
Focal brainstem glioma is
a relatively uncommon brainstem glioma, carries a more favourable prognosis than diffuse brainstem glioma. Majority low grade, pilocytic astro, can be ganggliogliomas or oligodendrogliomas. higher grade can be GBM
Tectal gliomas are
brainstem gliomas, typically low grade astros. Assoc with NF1. Obstructive hydro or parinaud syndrome
Tectal gliomas imaging
CT
homogeneous expansion of the tectal plate
minimal enhancement
can have central calc
MRI
T1 iso to hypo GM
T2 hyper to grey
C+ no enhancement
Tectal gliomas ddx
aquaduct stenosis
pineal parenchymal tumours
germ cell tumours
meningioma
mets
malformation
Subependymomas are
slow growing and non invasive WHO grade 1 lesions
Subependymomas imaging
Most commonly seen in the 4th ventricle
Followed by lateral ventricles
Third ventricle and spinal cord rare
Typically small, 1-2cm
CT
hypodense/isodense
intravenciular
non enhancing
may have cystic or calcific components
MRI
T1 iso to hypo, generally homogeneous when small
T2 hyper, heterogenous when large, no oedema
C+ no enhancement generally
Subependymoma ddx
Ependymoma
- children, younger adults
- heterogenous enhancement
Choroid plexus papilloma
- vividly enhancing
- children, young adults
- in adults, fourth ventricle
Central neurocytoma
- typically younger patients
SEGA
- TS
Calcified glial tumours
Old elephants age gracefully (and Eat PNETS)
Oligodendoglioma
Ependymoma
Astrocytoma
Glioblastoma
EMTR/PNET
Supratentorial ependymomas are
an uncommon type, with distinct molecular features to posterior fossa and spinal.
Molecular subtypes
= ZFTA fusion positive
= YAP1 fusion positive
Supratentorial ependymoma imaging
heterogenous parenchymal masses
calcification, cystioc components, solid enhancing components
surrounding oedema
predilection for frontoparietal, but can be anywhere
CT
coarse calcs are common
cystic areas are comon
solid part iso to hypo
can have haemorrhage
periwinkle sign
MRI
T1; iso to hypo
T2; hyper
SWI: foci of blooming from haemorrhage/calc
C+ heterogenous enhancement
DWI can restrict
Supratentorial ependymoma ddx
Parenchymal
- diffuse astro, oligo, gbm
- ETMR
- pilocytic astrocytoma
- met
Intraventricular
- central neurocytoma
- choroid plexus papilloma
- SEGA
- subependymoma
Posterior fossa ependymomas are
the most common type, typically occuyring in children. divided on the basis of DNA methylation profiling into A and B groups.
A infants and young children
B adolescents and adults
Posterior fossa ependymoma imaging
PFA; lateral recess of fourth ventricle
PFB midline floor of fourth ventricle near the obex
Extend through foramina, plastic appearance
Hterogenous, necrosis/calc/cystic/haemorrhage
Can have intraparenhcymal lesiosn in the cerebellum
CT
coarse calc
cystic areas
iso to hypo
heterogenous enhancement
variable haemorrhage
MR
T1; iso to hypo
T2; hyper
SWI; foci of blooming
C+ heterogenous enhancement
DWI can have restriction
Posterior fossa ependymoma ddx
Medulloblastoma
- less calc
- more homogeneous
- vermis
- less plastic
Suybependymoma
- usually non enhancing
Choroid plexus papilloma
- children trigone usually
- adults fourth ventricle
- homogeneous enhance
- lacks adjacent oedema
- carcinoma can be heterogenous andinvasive
Choroid plexus met
Dysembryoplastic neuroepithelial tumours (DNET) are
benign who 1 slow growing glioneuronal tumours arising from cortical or deep grey matter. Arise from secondary germinal layers, typically cortical. Frequently assoc with cortical dysplasia. Cause intractable focal seizures.
Specific glioneuronal element SGNE is characteristic. Simple, complex or non spec microscopically
Dysembryoplastic neuroepithelial tumours (DNET) imaging
Location
- temporal lobe 2/3
- frontal 1/5
- caudate
- cerebellum
- pons
predominantly cortical, well circumscribed
CT
low density
no or minimal enhancement
may scallop/remodal skull
calc in 1/3
MR
T1 hypo
C+ variable enhancement in 20%
T2 high signal, bubbly. minimal oedema
FLAIR mixed intensity, bright rim sign, partial bubble suppression
SWI: calc
DWI no restriction
Dysembryoplastic neuroepithelial tumours (DNET) DDX
Ganglioglioma
- non bubble
- more enhancement
PXA
- more enhancement
- dural tail
Low grade astro
- IDH
Oligo
- IDH and 1q19p codeletion
Desmoplastic infantile astro/gang
- young
- dural involvement prominent
- large/multiple lesions
Multinodular and vacuolating neuronal tumours (juxtacortical)
Temporal lobe jenny diffs
Tumours
- ganglioglioma
- DNET
- Pilocytic astro
- diffuse astro
oligodendroglioma
- Pleomorphic xanthoastrocytoma
Cysts
- neuroepithelial
- choroid fissure
Other
- herpes simplex
- limbic encephalitis
- mesial temporal scleoriss
Gangliogliomas are
uncommon usually low grade tumours. can have epilepsy. commonly in the temporal lobes. variable appearance; cytic wih a nodule, solid mass expanding the gyris. variable enhancement
Ganglioglioma imaging
Variable. Can be solid or cystic with a nodule. Infiltrating is uncommon and suggests higher grade
CT
- iso or hypo
- calc 35%
- bony remodelling
- enchnaing 50%
MRI
T1; solid iso to hypo
C+ solid variable enhancement
T2; hyper, variable cystic signal.
Peritumoural oedema is uncommon
SWI; blooming with calc
Ganglioglioma ddx
DNET
- bubbly
PXA
- dural tail
- more enhancy
oligo
- calcs more common
DIG
- young children
- prominent dural invovelemtn
Choroid plexus papillomas are
benign who 1 neuroepithelial intraventricular tumours, more common in paedis. Usually lateral ventricle in kids and fourth ventricle in adults. Solid vascular tumour with vivid frond like enhancement.
Choroid plexus papilloma imaging
CT
Well defined lobulated mass
mildly hyperdense
cauliflower appearance
homogenerously enhance
fine speckled calc 25%
MRI
frond like morphology
assoc hydrocephalus
T1; iso to hypo
T2 iso to hyper, flow voids can be seen
C+ marked
Choroid plexus papilloma ddx
Atypical choroid plexus papilloma
Choroid plexus carcinoma
- usually young children
- heterogenous enhancement
- parenchymal invasion
Choroid mets
Posterio fossa
- medulloblastoma
- AT RT
- ependymoma
Adults
Ependymoma
intraventricular meningioma
subependymoma
central neurocytoma
Choroid plexus carcinomas are
malignant neoplasms, who 3. Predominantly in children 0-5. assoc with liframeni and aicardia
Choroid plexus carcinoma imaging
Markedly enhancing intraventricular tumours, typically in the trigone and invading brain parenchyma.
CT
heterogenous
iso to hyper
calc in 25%
prominent enhancement but heterogenous
MRI
T1 iso to hypo
T2iso to hypo with hyper necrotic areas
GRE blooming foci
C+ marked heterogenous enhancement
Choroid plexus carcinoma ddx
Papilloma and atypical p[apiloma
- homogenous
- lack of necrosis
- lack of invasion
- younger
Central neurocytoma
- older
- usually body lat ventricle abutting the septum pellucidum
Intraventricular meningioma
- more homogeneous
Choroid plexus mets
Pineocytomas are
relatively benign who 1 pineal parenchymal tumours. mostly in adults 20-60. can get hydro or parinaud syndrome
Pineocytoma imaging
slow growing well circumscribed
solid, sometimes focal cystic change
CT
intermediate density
calcifications dispersed peripherally
[
MR
T1 hypo to iso
T2 solid iso, areas of cysts
C+ solid enhances vividly
Pineocytoma ddx
Pineal cyst
Other pineal parenchymal tumours
- pineal parecnhymal with indermediate differentiation
- pineoblastoma
- papillary pineal tumour
Germ cell tumour
- germinoma
- embryonal
- choriocarcinoma
- teratoma
Atrocytoma
Mets
Pineoblastomas are
like small round blue cell tumours located in the pineal region. Highest grade amongst pineal parenchymal tumorus who 4. Typically found in young children. Associated with retinoblastomas. Associated with DICER1.
Pineoblastomas imaging
Large, poorly defined masses, with frequent CSF seeding atpresentation. Directly involve brain structures.
CT
slightly hyperdense
peripherally dispersed or exploded calcification, similar to pineocytoma
MRI
Sizeable, typically >4cm
Irredular
invasion into brain
T1 iso to hypoi
T2 iso, cystic, necrotic
C+ heterogenous
DWI restricted
whole neural axis imaging is needed for CSF seeding
Pineoblastoma ddx
Other pineal parecnhymasl
- pineocytoma
- intermediate diff pineal parenchymal
-0 papillary
Germ cell tumours
- germinoma
- embryonal
- chorio
- teratoma
Pineal cyst
- thin wall
Astrocytoma
Mets
Medulloblastoma
Intracranial germ cell tumours are divided into
Germinomas
Embryonal carcinomas
Yolk sac tumours
Teratomas
- immature
- mature
- malig transformation
Mixed
Intracranial germ cell tumour locations
Tend to cluster in the midline
Predilection for pineal and suprasellar regions.
Also;
- floor of the third
- basal ganglia
- thalamus
- fourth
Germinoma imaging
Engulf normal pineal tissue with assoc central calcification.
Cystic components in 45%
CT
high cellularity, hyperdense
bright enhancement
presence of calc in young child <6.5
MR
ovoid/lobulated, enfulfing the pineal
T1 iso to hyper
T2
- iso to hyper
- cyst formation
- areas of haemorrhage
- predilection for invading parenchyma
- central calcification
C+ vivid and homogenous
Intracranial teratoma imaging
Intra or extra axial
- intra; antenatal. typically larger
- extra; adulthood, pineal/suprasellar
CT
majority have some fat and calc, usually solid/clumpy
cyystic and solid components usually
solid bits variably enhance
MR
T1
- hyper fat/proteinaceous
- intermediate soft tissue
- hypo calc and blood
C+ solid parts enhance
T2 mixed/heterogenous
Intracranial germ cell tumours markers
YS; AFP
chorio; HCG
teratoma and embryonal; variable
germinoma; not AFP/HCG
Haemangioblastomas are
tumours of vascular origin which occur sporadically and in VHL.
typically sharply demarcated, homogenous, cyst with an enhancing mural nodule. flow voids.
assoc
phaeos
rcc’s
VHL
polycythemia
Haemangioblastoma imaging
intracranial
- 95% posterio fossa
- 5% supratent, usually optic radiation
spinal 3-13%
homogenous well defined masses. cyst with mural nodules. non enhcaing walls, nodule vivid enhancement. prominent serpentine flow voids. can be totes solid.
CT
nodule iso to brain
homogenous enhancement
cyst walls dont enhance
no calc
MR
T1; hypo to iso
C+ nodule enhances
T2 bright, flow voids
Haemangioblastoma ddx
Brain mets
AStrocytoma
- PA in kids
- GBM in adults
Ependymoma
Vascular lesions
- AVM
- cavernoma with subacute bleed
- subacute infarct
Medulloblastoma
Pituitary microadenoma imaging
Bulkiness of the gland ipsilateral
Subtle remodelling of the floor
Deviation of the infundibulum
T1 iso
C+ delayed nehancement relative to gland on dynamic
can be hypoenhancing to hypernehcning on delayed
T2 variable
Inferior petrosal sinus sampling; normal mr
- confrim presence in setting of cushings
- lateralise to aid surgical exploration
Pituitary macroadenoma imaging
> 10mm
usually extend superiorly, can compress chiasm
snowman appearance by indentation of diaphragm sellae
enlarged pituitary fossa, thinning and remodelling
CT
- can be heterogenous due to haemorrhage, cystic, necrosis
MR
T1: typically iso, can be heterogenous
C+ solid components enhance
T2 typically iso, can be heterogenous
SWI can have harmorrhage
<90 deg encasement ICA unlikely involvement
>270 deg encasement very likely involvement
knosp classification
Knosp classification:
three lines
- medial tangent
- intercarotid line
- lateral tangent
four grades
0: medial to medial line
1: bw medial and inter
2: between inter and lateral
3: lateral to lateral
- 3a: superior cavernous sinus compartment
- 3b: inferior cavernous sinus compartment
4: complete encasement
Pituitary macroadenoma ddx
mets
- known ca
- less well defined, bony destc
pituitary carcinoma
- rare, but indistinguishable
meningioma
- dural tail, more enhancing
craniopharyngioma
- more likely to be cystic/calc
lymphocytic hypophysitis
- post partum
Hyperprolactinaemia ddx
Stalk effect
- interruption of dopamine from hypothalamus to ant pit, reduces inhibition
- impingement/interruption
- increased intrasellar pressure due to a mass
- congenital ectpic posteiror pit/pituitary stalk interruption
Medications
- dopamine antagnoists; haloperidol, chlorpromazine
Prolactin secretion
- sectroy pit macroadenomas
Ectopic posterior pituitary is
disruption of normal embryogenesis of the psoterior pituitary, common cause of pit dwarfism. also hyperprolactinaemia.
when assoc with a thin or absent infundibulum and hypoplastic anterior pituitary then pituitary stalk interruption syndrome
Ectopic posterior pituitary imaging
Absent posterior bright spot
High T1 signal at the median eminence (floor of 3rd)
ddx
- fat (lipoma, dermoid, teratoma), chemical shift/FS
- craniopharyng (adamantinomatous), larger, calc
- thrombosed aneurysm
Pituitary stalk interruption/transection is
syndrome characterised by an absent or hypoplastic anterior pit, thin or absent infundibulum and ectopic posterior pituitary
Acromegaly is
excessive GH in skeletally mature patients, usually from an adenoma. In skeletally immature, its giganticism.
Acromegaly imaging
Skull
- calvarial thickening
- frontal bossing
- enlarged paransal sinuses
- enlarged sella
- prognathism/protruding mandible
- gaps in teeth
Spine
- vert fractures
- can also have dish appearance, scalloping, increased vert hegiht
joints
- OA
Hands
- spade terminal tufts
Pituitary apoplexy is
an acute clinical condition caused by haemorrhagic or non haemorrhagic necrosis of the pituitary gland. Variable presentation, typically headaches, visual distuirbances, ophthalmoplegia and AMS. Existing pit macroadenoma commonly present.
Pituitary apoplexy RFs
medical treatment of a macroadenoma
prior radiation
pregnancy (sheehan)
cerebral angiography
trauma/surgery
anticoags
changes in icp
Pituitary apoplexys imaging
Enlarged pit gland with or without bleeding
Haemorrhage in 85%
CT
may show frank haemorrhage
may have fluid debris level
can be insensitive
MR
mass
T1 variable, hyper if haemorrhagic
T2 variable
C+ variable, usually peripheral and may be hard to see
DWI restricted in solid infarcted components
Pituitary apoplexy ddx
pit masses with high t1
necrotic/haemorrhagic macroadenoma
- not acute
adamantinomatous cranio
- calc 90%
- usually children
- not acute
rathke cleft cyst
- asx, spherical
dermoid/teratoma
- fat component
- if ruptures, locules of fat elsewhere
Sheehan syndrome is
a rare cause of apoplexy and hypopituitism. Occurs in post partum females who experience large volume harmorrhage and hypovolaemic shock
Diabetes insipidus - whatisdus? and causes?
deficiency or resistance to vasopressin resulting in polyuria and polydipsia
central causes
- trauma
- nsx
- malignancy (craniopharyn, germinoma, mets)
- autoimmune (lymphotic)
- inflamm (sarcoid, LCH, IgG4)
- infection/tb
- preggo
peripheral
- congenital renal insens
- lithium
- metabolic hypok hypercalc
- CKD
SIADH what is it and causes
excessive ADH resulting in dilutional hyponatremia
etiology
- malignant tumours
- lung diseases
- cns diseases
- drugs
IgG4 hypophysitis is
a rare cause of pituitary inflammation by a rare manifestation of systemic igg4 related disease. Clinical ft relate to part involved - can be anterior, posterior or pan. lymphoplasmacytic infiltrate rich in igg4 postivie plasma cells.
IgG4 hypophysitis imaging
non spec enlargement of the pit gland with or without infundibulum involvement. May enhance post con.
Other H/N manifestations of igg4 may be seen including igg4 related hypertrophic pachymeningitis.
Lymphocytic hypophysitis is
an uncommon non neoplastic inflammatory condition that affects the pituitary gland.
Closelt realted to orbital pseudotumour and tolosa hunt syndrome.
frequently in pregnancy/post partum women.
Lymphocytic hypophysitis imaging
CT
enhancing soft tissue mass extending to suprasella
MR
appears as a pituitary region mass
T1: iso, with slight heterogeneity. may have an absent bright spot.
C+ variable homogeneous enhancement. infundibulum may be thickened. can have a dural tail.
T2: parasellar region hypointensity
Rathke cleft cysts are
non neoplastic sellar/suprasellar cysts arising from the embryologic remnants of rathke pouch in the pituitary gland. common and usually incidental.
Rathke cleft cyst imaging
well defined non enhancing midline cyst within the sella arising between the anterior and intermediate lobes of the pituitary. 60% suprasellar extension.
XR
can cause sellar enlargement
CT
non clacified, uncommon cuvilinear clac in wall
homogeneous low attenuation
non enhancing
MR
T1 50/50 hypo/hypo intense
T2 70/30 hyper/hypo intense
C+ no enhancement, may have a rim of enhancing compressed pit
Small non enhancing intracystic nodule, pathognomic. hyperintense to fluid on t1 and hypo on t2.
Hypothalamic hamartomas are
also known as tuber cinereum hamartomas. they are benign non neoplastic heterotopias that typically occur in the region of the hypothalamus arising from the tuber cinereum, between teh mamm bodies and the optic chiasm. gelastic seizures classic history but also precocious puberty.
Hypothalamic hamartoma imaging
can be sessile or pedunculated
iso attenuating/intense to cortex without enhancement
Pituicytomas are
rare indolent tumours only found in the neurohypophysis and infundibulum of the pituitary gland.
Pituicytomas imaging
CT
homogensouly enhancing
pit fossa/suprasella
MR
T1 iso, absent bright spot
C+ bright enhancement
T2 heterogenous, hypo to iso
SATCHMOE
Sarcoid
Aneurysm
Teratoma/TB
Craniopharyngioma, cleft cyst, chordoma
Hypothalamic hamartoma, hamartoma of tuber cinereum, histiocytosis (LCH, IGG, Lympho)
Meningioma, mets
Optic nerve glioma
Eosinophilic granuloma, epidermoid
Neurosarcoid imaging
five compartments
- skull vault
- pachymeningeal
- pituitary/hypothalamic
- cranial nerve
- parenchymal
CT
can appear hyperdense
enhance, less dramatically
MR
T1 iso to hypo
T2 variable, usually hyper
C+ homogensou enhancement
Craniosynostosis - types
brachycephaly - bicoronal and or bilambdoid
scaphocephaly/doliocephaly - sagittal
plagiocephaly - unilateral coronal and lambdoid
- frontal or occipital
trigonocephaly - metopic
Oxycephaly/turricephaly - sagittal, coronal, lambdoid
cloverleaf - intrauterine sag, coronal, lambdoid
harlequin eye - ipsilateral coronal
Skull vault haemangioma imaging
expansile bone lesion
thin borders
sunburst pattern or trabecular thickening
Skull pagets imaging
Osteoporosis circumscripta
Cotton wool appearance
Diploic widening
Tam o shanter - platybasia and basilar invagination
Chordomas are
uncommon malignant tumours originating from embryonic remnants of the primitive notochord. can be conventional, chondroid or dededifferentiated
most commonly sacrococcygeal, then sphenooccipital then vertebral.
Chordoma imaging
CT
central
well circumscribed
destrtive lytic lesion
exp[ansile soft tissue mass
irregular intratumoural calc
enhancing
MRI
T1 intermediate to low
T2 high
C+ heterogenous, with honeycomb appearance
SWI variable blooming
“Thumbing the pons” sign
chondrosarcoma base of skull imaging
CT tumour, rings and arcs calc
MR
T1 low
T2 high
SWI lwo for clacs
C+ heterogenous
Ecchordosis physaliphora is
a congenital benign hamartomatous lesion derived from notochord remnants, usually in the retroclival prepontine region can can be anywhere to sacrum
Ecchordosis physaliphora imaging
CT - bony clival defect, benign looking. near csf density. can see an osseous stalk at the base
MR
T1 hypo
T2 hyper
C+ varibable, typically non
Dysgenesis corpus callosum associations
aneuploidy
non aneuploidy syndromes
other cns
- hydrocephalus
- lipoma
- chiari 2
- DWS
- holoprosencephaly
inborn errors of metabolism
Dysgenesis corpus callosum imaging
antenatal
- dilated/displaced third ventricle
- colpocephaly
- racing car sign
- absent septum pellucidum
MR
- racing care
- colpocephaly
- dilated high riding third ventricle
- bundles of probst
- radial gyri, absent cingulate
- hypoplastic fornices/hippocampi
Chiari malformation quick breakdown
Chiari 1
- peg like cerebellar tonsils
Chiari 1.5
- tonsils and brainstem
Chiari 2
- medulla, fourth ventricle, cerebellar vermis
- assoc myelomeningocoele
Chiari 3
- similar to 2 but high cervical or occipital encephalocoele
Chiari 4
- severe cerebellar hypoplasia without displacement
Chiari 5
- absent cerebellum
- occipital herniation
Lissencephaly pachygyria spectrum is
a basket term for congenital cortical malformations characterised by absent or minimal sulcation.
- agyria no gyri
- pachygyra broad gyri
- lissencephaly smooth brain surface
Can be further divided to type 1 (classic) and type 2 (cobblestone)
Type 1 Lissencephaly (classic) imaging
grossly abnormal outline of the brain, hourglass or figure 8
cortex is thickened
subcortical band heterotopia is strongly associated
can have
- enlarged ventricles
- flattening anterior corpus callosum
- cavum septum pellucidum et vergae
Type 2 Lissencephaly (cobblestone) is
reduction in normal sulcation, associated with bumpy or pebbly cortical surface. While type 1 is neuronal undermigration, type 2 is due to overmigration.
Heterogenous group of disorders, with similar morphology changes and congenital muscular dystrophy. Three most common;
- Walker Warburg
- Fukuyama congenital muscular dystrophy
- muscle eye brain disease
Type 2 Lissencephaly imaging
Lack or normal sulcation
- small sylvian fissure
- hour glass or figure 8
Multinodular corttical surface, particularly anteriorly
Additional
- hypomyelination
- hydrocephalus
- posterior cephalocoele
- abnormal brainstem
- abnormal cerebellum
- abnormal globes
Grey matter heterotopia is
a group of conditions characterised by interruption of normal neuronal migration from near the ventricle to the cortex
Grey matter heterotopia types
Nodular
- subependymal
- subcortical
Diffuse
- band
- lissencephaly
- laminar
Grey matter heterotopia associ
agenesis CC
pachygyria
schizencepahly
polymicrogyria
chiari 2
polymicrogyria is
a malformation of cortical development, cahracteised by abnormalities of both migration and organisation. strong assoc with schizencepahly.
Polymicrogyria imaging
Predilection for perisylvian region. bilateral 60%.
MR
abnormal morphology
subjacent abnormal white matter with T2 hyperintensity
Schizencephaly is (incl types and assoc)
a cortical malformation that manifests as a grey matter lined cleft extending from the ependyma to the pia.
can be open or closed
assoc
- septo optic dysplasia
- GM heterotopia
- absent septum pellucidum
- dysgenesis of the CC
Holoprosencephaly is
a congenital brain malformation resulting from incomplete separation of the two hemispheres.
three subtypes
- alobar
- semilobar
- lobar
other entities in the spectrum
- syntelencephaly
- septo optic dysplasia
- central incisor syndrome
Alobar holo imaging
single monoventricle
absent midline structures
- septum pellucidum
- cc
- interhemispheric dissure and falx
- olfactory tract
dorsal cyst
absent or fused optic nerves
abnormal arrangement of artereies
craniofacial ft
- proboscis
- cyclopia
- mononostil
- hypotelorism
- cebocepahly
dx
- semilobar
- hydranencephaly
- severe hydro
Semilobar holo imaging
absence of the septum pellucidum
monoventrcile, partially developed occipitala nd temporal horns
rudimentary falx
incomplete interhemispheric fissure
partial or complete thalamic fusion
hypoplasia cc
Lobar holo imaging
fusion of the frontal horns
wide communication to third ventricle
partial fusion of the fornices and anterior frontal lobes
absence of the septum pellucidum
hypoplastic cc
anteriroly displaced ACA, may be azygous
Septo optic dysplasia is
a condition characterised by hpoplasia of the optic nerves and absence of the septum pellucidum. 2/3 also have hypothalamic/pit dysfunction. part of the holoprosencepahly spectrum.
assoc
- schizencephaly
- rhomboencephalosynapsis
- chiari 2
- aqueductal stenosis
Septo optic dysplasia imaging
absent septum
hypoplastic pit stalk
hypoplastic optic nerves and globes
point down appearance of the lateral ventricualr frontal horns on coronal
Syntelencephaly is
also known as middle interhemispheric variant, a mild subtype of holoprosencephaly characterised by an abnnormal midline connection of the cerebral hemispheres between the posterior frontal and parietal regions.
Syntelencepahly imaging
vertically orientated sylvian fissures, connected across midline
cortical dysplasia
subcortical heterotpoic grey matter
dorsal cyst
hypoplasia/aplasia of the CC body
interhemispheric fissure present
absent septum pellucidum
separate frontal and occpital lobes
Focal cortical dysplasia imaging
MR
cortical thickening
blurring of the GWMJ
T2/FLAIR hyperintensity in the grey/white matter
transmantle sign
abnormal sulcual or gyral pattern
segemntal and or lobar hypoplasia
Focal cortical dysplasia classification
BLUMCKE
- focal cortical dysplasia with abnormal lamination
a; radial lamination
b tangential 6 layer lamination
c; radial and tangential lamination
Type 1
- usually temporal, blurring of GWMJ, prominent atrophy, increased t2/flair
2 FCD with dysmorphic neurones
a; without balloon cells
b; with balloon cells
type 2
- commonly frontal, abnormal gyri and sulci, marked blurring, cortical thickening, moderately increased signal, transmantle sign
- architectural distortion of cortical layer
a; temporal lobe with hippocampal atropgy
b; abjacent to tumour
c; adjacent ot vascular malformation
d; abjacent to other lesions of early childhood
Classic dandy walker malformation is
triad of
- hypoplastic vermis and cephalad rotation of the vermian remnant
- cystic dilatation of the fourth ventricle
- enlarged posterior fossa with torcula lambdoid inversion
Dandy walker variant is
a less severe posterior fossa anomaly than the classic, charactersed as partial vermian hypoplasia with partial obstruction of the fourth ventricle. usually no enlargement of the posterior fossa.
Blakes pouch cyst is
a cystic appearing structure that represents posterior ballooning of the inferior medullary velum into the cisterna magna below and psoterior to the vermis that communicates with an open fourth ventricle. It is caused by failure of regression of the blakes pouch secondary to non perforation of the foramen of magendie
Blake pouch cyst imaging
infravermian cyst that communicates with the fourth ventricle
no vermian hypoplasia or rotation
usually hydrocephalus
elevation of the tentorium but normally positioned torcula
mega cisterna magna is
normal variant charactereised by focal enlaregement of the SAS in the inferior and posteiror portions of the posterior cranial fossa
Megalencephaly is
a disorder characterised by an abnormally large brain, primarily a prolferative disorder of embryonic origin. can be all or part, bilateral or unilateral. often assoc with polymicrogyria or agyria.
assoc
- achondroplasia
- beckwith Wiedemann syndrome
- NF1
- TS
- Klipper trenaunay syndrome
- epidermal naevus syndrome
imaging
- thick cortex
- ipsilateral ventricular dilatation
Hemimegaencephaly is (and assoc)
rare congenital disorder of cortical formation with hamartomatous overgrowth of all or part of a cebral hemisphere.
Assoc:
isolated
syndrome
- epidermal naevus
- klippel trenanay
- mccune albright
- proteus
- nf1
- ts
- cloves
total (involving brainstema and cerebellym
Hemiemegalencephaly imaging
increased lat ventricle size
shallow sulci
enlarged gyri
enlarged/thickened calvarial vault
contralateral displacement of the falx
white matter calc
DVAs
can have:
polymicrogyria/lissencephaly
GMH
DDX
- enlarged hemisphere (gliomatosis)
- small hemisphere [rasmussen (no clavarial cahnges), DDM (calvarial changes), Sturge weber]
- other neuronal migration anomalies with overgrowth
Brain cysts breakdown
Parenchymal
- porencephalic (surrounding gliosis, usually comminicates with ventricle)
- perivascular
- neuroglial
- neurocystericosis
Intraventricular
- ependymal
- intraventricular simple/arachnoid
- colloid (formane of monroe)
- choroid plexus/xantholmatous
Subarachnoid
- arachnoid cyst
- epidermoid (restricting)
- choroid fissure
Intracranial epidermoid cysts are
uncommon congenital lesions resulting from inclusion of ectodermal elements during neural tube closure
Intracranial epidermoid cysts imaging
location
- intradural 90%; CP angle, supra sellar, fourth ventricle
- extradural 10%
CT
- similar to CSF
- calcification can be seen
- can be hyperdense due to haemorrhage, saponification or high protein (white epidermoid)
- non enhancing
MR
T1: usually iso to CS, can be high for white
C+ can have peripheral enhancment
T2: usually iso to CSF, can be hypo if white
FLAIR: heterogenous/dirty
DWI: restricting
engulf arteries
Porencephalic cysts are
focal cystic areas of encephalomalacia that communicate with the ventricular system and or suybarachnoid space
Intracranial dermoid cysts are
uncommon lesions, thought of along a spectrum from epidermoid cysts (containing only desquamated squamous epithelium)_ and teratomas (containing any kind of tissue from all three layers).
Thought to occur as a developmental anomaly in which embryonic ectoderm is trapped in the closing neural tube.
Lined by stratified squamous epithelium like epidermoids, but contain epidermal appendages as well, such as hair, sweat glands and sebaceous glands. the latter secrete the sebum that gives their appearance.
Intracranial dermoid imaging
Typically midline. Locations
- sellar/suprasella
- parasella
- frontonasal
- posterior fossa/vermis
CT
- low attenuating well defined
- may have calc at rim
- enhancement uncommon, if present usually rim
- can rupture with IV FF levels of fat in sulci
MR - more variable than a lipoma
T1: typically hyper due to cholesterol
C+ typically not enhancing, although if ruptures that pial enhancement
T2: variable
Scoliosis is (and causes)
lateral curvature with a cobb angle >10
can be levo (left) or dextro (right)
Terminology
- apex: furthest vertebral body or space from centre/greatest rotation
- end: vertebra most tilted toward each other
- neutral: no rotation, not closer to apex than end
- stable: first below the lowest curve thats midline
Etiology
Neuromusular
- CP
- chiari
- friedreich
- syringomyelia/diastematomyelia
- tethered cord, dysraphism
- musuclar dystrophies
- connective tissue
Congenital
- segmental/fusion
- skeletal dysplasia
Tumours
- bone
- soft tissues
Infection
Kyphosis and causes
sagittal curvature of the spine
increased in
- scheuermann disease
- spondyloarthropathies
- OP
- fractures
Decreased in
- straight back syndrome
Spinal dysraphism classification
Open: cord and covering communicate with the outside, nothing covers teh sac
- myelomeningocoele (98%)
- myelocoel
- hemimyelomeningo
- hemimyelo
Closed: cords is covered by other normal mesenchymal elements. can be with or without a subcutaneous mass.
Closed, with subcutaneous mass
- Lipoma with dural defect (lipomyelomeningo, lipomeylo)
- terminal myelocystocoele
- meningocoele
- limited dorsal myeloschisis
Closed, without subcut mass
- posterior spina bfida
- intradural lipoma
- filar lipoma
- tight filum terminale
- persistent terminal ventricle
- disorders of midline notochordal integration (dorsal dermal sinus, neurenteric cyst, split cord malformations)
- disorders of notochordal formation (spinal regression, segmental spinal dysgenesis)
Scheuermanns disease imaging
Sorensen criteria
- thoracic spine kyphosis >40 or
- thoracolumbar kyphosis >30
and
- at least 3 vertebrae wedging >5
Assoc
- schmorls nodes
- limbus vertebrae
- scoliosis
- spondylolisthesis
Basilar invagination is (and causes)
congenital or acquired craniocervical junction abnormality wherte teh tip of the odontoid goes above the FM. often assoc with platybasia. Stenosis of the foramen magnum and compression of the medullar.
Congenital
- OI
- Klippel feil
- achondroplasia
- chiari 1 and 2
- cleidocranial dysostosis
Acquired
- RA
- Pagets
- Hyperparathyroidism
- osteomalacia/rickets
Pagets
Fibrous dysplasia
Rheumatoid/rickets
Osteogenesis imperfect, osteomalacia
Achondroplasia
Chiaris, cleidocranial
Hyperparathyroidism
Klippel feil is (and assoc)
complex heterogenous entity resulting in cervical vertebral fusion.
original classification
1. fusion of cervical and upper thoracic vert
2. fusion of two or three with assoc hemivert, occipitoatlantal fusion or other abnormality
3. cervical fusion with lower thoacic or lumbar fusion
assoc
- sprengel deformity
- wildervanck syndrome
- duane syndrome
- arach anomalies
- scoliosis
- renal anomalies
Congenital lumbar spinal stenosis is
stenosis affecting younger patients, typically with short pedicles. assoc with achondroplasia.
Achondroplasia is
a congenital genetic disorder resulting in rhizomelic dwarfism. most common skeletal dysplasia. sporadic or AD. mutation in FGFR3 causing abnormal cartilage formation in bones formed by endochondral ossification
Achondroplasia imaging (US, cranial, spinal, chest, pelivs/hips, limbs)
US
short femur length
trident hand
frontal bossing
depressed nasal bridge
Cranial
- large vault, small base
- frontal bossing
- narrowed FM
- hydrocephalus
- elevated brainstem
Spinal
- scalloping
- progessive pedicle shortening
- gibbus
- laminar thickening
- widenening of discs
Chest
- anterior flaring of ribs
- anteroposterior narrowing
Pelivs/Hips
- horizontal acetabulum
- trigent acetabulum
- champagne glass pelvis
- tombstone iliac wings
- short sacroiliac notches
Limbs
- metaphyseal flaring
- rhizomelic hosrtening
- bowing mesial segment
- trident hand
- chevron sign
- short metacarpal/metatarsals
Sacrococcygeal teratoma is
a teratoma in the SC region, common in fetus and neonate. Assoc with meylomeningocoele and vert anomalies. elvated afp and bhcg. classified into benign and malignant.
complications
- high output heart failure
- GU/GI obstruction
- nerve compression
- anaemia
- dystocia
- rupture
Sacrococcygeal teratoma imaging
XR
large mass over lower pelivs
may show calcs
US
can be cystic or solid. Marked vascularity.
MR
variable depending on consituetion of the lesion
T1 fat high, calc low
T2 fluid hihg, clac low
GRE calc
C+ enhancing solid bits
ddx
- sacral chordom
- terminal myelocystocoele
- sacral meningocoele
- sacral haemangioma
- low lying neuroblastoma
- low lying rhabdomyosarcoma
Caudal regression syndrome is
spectrum of structural defects of the caudal region. results from an insult in early pregnancy.
Caudal regression imaging
XR
l/s vertebral dysgenesis
usually below L1, often just sacrum
truncated blunt cord above expected level
severe canal narrowing
Ante US
blunt sharp cord
conus way above expected level
absent hypoplastic sacrum
shield sign opposed iliac bones
crossed leg position
MR
similar to US
canal stenosis
wedge sahped cord terminus
Pars defects are
defect in pars interarticularis. Can be developmental or acquired. Acquired can be from repeated microtrauma or high energy trauma. Usually L5 or sometimes L4. Can be unilateral or bilateral.
Pars defects imaging
Assoc
- spondylolisthesis
- spina bfida
- scoliosis
XR
- scotty dog sign
- inverted napolean hat
Hollenberg classification (MR pars defect)
0 normal
1 stress rxn
2 incomplete fracture
3 complete fracture with oedema
4 chronic fracture no oedema
Synovial cysts are
cystic formations connected to the facet joint containing synovial fluid. can cause radiculopathy. predominantly lumbar, predilection L4/5
Synovial cyst imaging
CT
- calc cystic lesions adjacent to facet
- adjacent facet arthropathy
- presence of gas
MR
- difficult to distinguish from ganglion cyst without intraarticular injection
- gas is pathognomonic
- complex fluid
- neural cysts will intimate with a nerve
Disc herniation types
protrusion
- base wider than herniation
- confined to disc level
- outer annular fibres intact
Extrusion
- base narrower than dome
- may extend above or below
- complete annular tear
- disc can sequester
PLL ossification assoc
asians
dish
ank spond
ossification lig flavum
Kummell disease i
osteonecrosis of the vertebral body.
RF: osteoporosis, steroids, alcoholism, radiation
Kummell disease imaging
XR
- collapse
- invertebral vacuum cleft and fluid
MR
- intervertebral vacuum cleft
- intravertebral dluid high t2
Bertolotti syndrome is
controversial but essentially a L/S transitional vertbra and back pain
Baarstrup is
interpsinous bursitis and other degenerative changes between adjacent spinous processes
Bone marrow infiltration causes
Diffuse
- multiple myeloma
- mastocytosis
- myelofibrosis
- leukaemia
Focal
- mets
- lymphoma
Mnemonic MMLMML
- mets
- myeloma
- lymphoma
- myelofibrosis
- mastocytosis
- leukaemia
Mastocytosis is
excessive accumulation of mast cells in one or more organs.
Mastocytosis imaging
Skeletal
- lytic/sclerotic/mixed bone invovlmenet
- typically diffuse
Abdo
- PUD
- small bowel thickneing
- omental and mesenteric thickening
- hepatosplenomegaly
- ascites
- lymphadenopathy
chest
- pumonary nodules, rare
Primary myelofibrosis is
replacement of bone marrow with collagenous connective tissue and progressive fibrosis characterised by
- EMH
- progressive splenomegaly
- anaemia
- variable no granulocytes and platelets
Primary myelofibrosis imaging
lymph nodes
MSK
- osteoscelrosis, diffuse
- can give superscan
abdo
- hepatosplenomegaly
- portal hypertension
cv
- failure
Temporal lobe lesions ddx
PGPDM
PXA
Ganglio
Pilocytic astro
DNET
MVNT
swallow tail sign
normal axial hyperintensity in substantia nigra on T2*/SWI. Loss of sign may inidicate parksinsons, or LBD
