Neuro Flashcards
top 2 intradural extramedullary lesions
meningioma, schwannoma
top 2 intradural intramedullary tumors
ependymoma
astrocytoma
(both make up 70% of total spinal cord tumors, E more common in adults, A in children)
classic presentation of intradural intramedullary lesions
insidious, progressive back pain worse with lying down, radicular pain and often neurologic deficits
Intra-dural/intraaxial compartment means what?
everything inside the PIA mater (WM, GM, ependymal lining -> embryonic neuroectoderm)
neuroepithelial tumor categories/subtypes
glial, neuronal, pineal, embryonal
Glial tumor subtypes
astrocytic, oligodendroglial, ependymal, choroid plexus
which is more common in the adult spine - ependymal or astrocytic lesions
ependymal
which is more common in the adult brain - ependymal or astrocytic lesions
astrocytic
WHO ependymal tumors
Grade I: subependymoma/ myxopapillary ependymoma,
Grade II: ependymoma/ ependymoma RELA fusion-positive (grades II and III),
Grade III: anaplastic ependymoma
Classic features of ependymal tumors
well circumscribed, non-infiltrative enhancing mass, centrally located in the spinal cord
- T1 hypo/iso, T2 iso/hyper + heterogenous with cystic/blood products
- +/- syrinx formation (CSF flow disruption)
- very heterogenous - think anaplastic
most common intramedullary tumor in adults
ependymoma
typical location for astrocytoma in spinal cord - central or eccentric ?
eccentric
NF2 common CNS tumor types
ependymomas, schwanommas and meningiomas
- frequently present with multiple lesions, at young ages
myxopapillary ependymoma features
- slow growing variant of SC ependymomas, 13% of all spinal ependymal tumors
- M > F
- T2 hyperintense enhancing mass, often with cyst/syrinx/hemorrhagic changes
- +/- hemosiderin cap
subependymoma features
slow growing glioma
- benign, WHO Gr 1
- middle age + older (slight M>F)
- most common in 4th and lateral ventricles
- very rare in the spine
- T2 hyper, T1 iso/hypo. usually NO enhancement
Astrocytoma grade categories
pilocytic (Gr1), diffuse (Gr2), anaplastic (Gr3), glioblastoma (Gr4)
important prognostic marker for astrocytomas
IDH (isocitrate dehydrogenase)
most common primary intra-axial tumor of SC in kids
pilocytic astrocytoma
intracranial pilocytic astrocytoma features
- young ppl; 75% by 20.
- 2nd MC primary brain tumor in kids (after medulloblastoma)
associated with NF1 (optic path) - 60% cerebellum, 20-30% CN2
- well-circumscribed, variable imaging appearance; 67% - large cystic mass with E+ mural nodule , 16% mixed cystic/solid, 17% solid.
spinal astrocytomas
eccentrically positioned
appearance depends on subtype
- E+ correlates with tumor grade
- Gr3 and 4 => poor prognosis
ganglioglioma
Gr1
- arises MC in the cortex, then GM in hypothalamus/brainstem, rarer in spine
- circumscribed enhancing mass with cystic changes
3rd MC spinal cord tumor
hemangioblastoma
hemangioblastoma
relatively benign non-aggressive tumors of mensenchymal origin
- often VHL mutations (TSG on Cr 3)
- 80% in cerebellum. <20% in spinal cord (3rd most common intramedullary lesion, 2-6%)
hemangioblastoma imaging features
hypervascular enhancing tumor at the pial surface
- ‘cyst with nodule’ in >50%
- T1 variable, T2 iso/hyper, vivid enhancement
- may have ++flow voids, vasogenic edema
intramedullary SC mets
typically enhancing lesions with circumscribed margins and surrounding edema
- lung, breast CA
- very poor prognosis, median 4/12
Cavernous malformation of the SC
low flow capillary malformation with spongy ectatic blood-filled channels.
- anywhere along neuroaxis
- T1/T2 heterogenous hyper with peripheral T2 hypo from hemosiderin
- no sig E+
spinal epidermoid
cystic tumors lined by Sq epithelium derived from ectoderm
- rare to be IM (case reports)
- can be congenital, many acquired (post LP)
- well defined, match CSF ( T1 hypo, T2 hyper, FLAIR hyper, no E+, DWI bright)
commonest causes of multiple dural based masses
meningioma, metastases, neurosarcoid, extramedullary hematopoeisis, LHC (can look like anything)
what is a lipomyelomeningocele?
spinal dysraphism - lipoma + dorsal defect
- elongated SC ends in attachment to lipomatous tissue
+/- syrinx, split cord, segmental anomalies, caudal agenesis
- anorectal/GU malformations in 5-10%
spinal meningioma features
F>M, thoracic spine most common, usually located laterally
T1 iso/hypo, T2 slightly hyper to cord, intense E+, Ca2+ sometimes
spinal schwannoma
associated with NF2, typical location dorsal spinal nerve root, common to extend into foramina
well-circumscribed T1 hypo/T2 hyper to cord, intense E+ but heterogenous in larger lesions
malignant peripheral nerve sheath tumor
rare. 30-60 yo, 50% inn NF1, prior radiation 10%. paraspinal location most common. can mimc benign nerve sheath tumors.
most common cystic IDEM lesion in the lumbar spine
schwannoma
Common IDEM neoplasms
Meningioma
Nerve sheath tumors (Schwannoma, neurofibroma),
paraganglioma,
filum terminale ependymomas,
subarachnoid seeding (usually CNS primary)
anaplastic astrocytoma features
heterogenous T2 hyper. often no E+. elevated Cho, decreased NAA
- diffusely infiltrating malignant mass
DDx diffuse astro, GBM, oligodendroglioma, cerebritis
most common IDEM lesion type?
nerve sheath tumors
types of nerve sheath tumors
schwannoma, neurofibroma, malignant peripheral NST
NF1 characteristic lesion
neurofibroma
meniscus CSF sign
widening of the CSF space at the margins of the lesion => IDEM!!
cystic degeneration of schwannoma - common?
yes
masses extending through neural foramina
schwannoma, neurofibroma, MPNST, lymphoma, mets
intradural-extradural lesion
schwannomas extending rhough neural foramen
NF2 lesion locations in spine
Extradural, intradural extramedullary (NST), IDIM (ependymoma)
neurofibromatosis 1
14% have hamartomas, low grade astrocytomas
20% have IDEX masses (neurofibromas)
neurofibroma imaging features
- similar to Schwannoma,
- ‘target sign’ can sometimes have low T2 centrally, and usually no cystic
- more likely to degenerate to malignancy (2-12%)
NF1 features
enlarged NF, dural ectasia, arachnoid cyst, neurofibromas
meningocele (thoracic)
10% scalloping of post vert body from dural ectasia
spinal meningioma features (clinical)
- 2nd MC IDEM primary
- usuallyT region (80%)»_space; C > lumbar
F>M, 20-60, located dorsal to cord
spinal meningioma imaging
IDEM lesion (meniscus sign)
iso to cord on T1 and T2, avid E+
broad dural base
+/- E+ dural tail, calcs, bone rxn
features of fibrous dysplasia of temporal bone
younger pppl (<30), expansile, mixed lucent and sclerotic/GG matrix density, rarely involves otic capsule
- rarely destructive
osseous temporal bone lesions
FD, Paget’s, otosclerosis, meningioma, osteoma, osteopetrosis, endolymphatic sac tumor, osteogenesis imperfecta
what is a CAPNON?
calcifying pseudoneoplasm of neuraxis
- benign, non-neoplastic fibroosseous mass
intra or extra-axial
- can mimic meningioma
types of otosclerosis
cochlear and fenestral
1st and 2nd most common pediatric brain tumor?
1st: gliomas
2nd: medulloblastoma
Peds: 4th ventricle mass DDx
medulloblastoma (30-40%)
ATRT (<3yo)
brainstem glioma
posterior pilocytic astrocytoma (25-35%)
posterior fossa ependymoma
medulloblastoma features
- usually midline mass along roof 4th V
- mass effect & hydroceph common
- T1 low, T2 iso/hyper to GM, hypercellular tumor (bright DWI), 90% E+
- usually does not extend into basal cisterms
- prognosis depends on genetics/ molecular subgroup (4)
COMMON TO HAVE DROP METS
if intracranial medulloblastoma, image what?
whole neuroaxis
posterior fossa ependymoma features
- glial tumor
- usually midline floor 4th V or lateral recess near obex
- often squeezes out foramen of Luschka/Magendi
- heterogenous masses: necrosis/calcs/hemorrhage/cystic
- T1 iso/hypo, T2 hyper, E+ heterogenous,
IMAGE WHOLE NEUROAXIS
intracranial subependymoma
uncommon, benign, slow growing lesions, usually middle/older age (50+)
- well defined, usually <2cm,
- T1 iso/hypo to WM, T2 hyper, E+ usually NONE/minimal
DDx for a subependymoma
ependymoma (E+)
choroid plexus papilloma (avid E+)
central neurocytoma (uncommon)
subependymal GCA and nodules (TS+ patients)
spinal hemangioblastomas - basic features (location, appearance, rule of 1/3rds?)
- extradural, pial, intradural, intramedullary
- 60% T spine, 30% C spine.
- cauda = usually (>90%) solid. 75% elsewhere mural nodule + cyst
- 1/3 of pts with VHL have spinal HGB, 1/3 of pts with spinal HGB have VHL
DDx multiple enhancing nodules on surface of spinal cord?
subarachnoid seeding of mets, hemangioblastomas, infection, sarcoid
where specifically to look in VHL?
- temporal bone - look for endolymphatic sac tumors
- retinal angiomas
- renal
myxopapillary ependymoma - clinical features
usually IDEM,
- exclusive conus medullaris and filum terminale
- slight M>F
- benign WHO gr 1, slow growing, relatively ASx
- cystic change and E+, & location in FT and central thecal sac are best clues
DDx cystic lesions of the cauda/filum terminale
myxopapillary ependymoma, cystic Schwannoma, filum terminale cyst
can myxopapillary ependymoma erode and invade bone?
yes! often remodel VBodies (scalloping), but can also grow extradurally into the bones
spinal paragangliomas - clinical features
origin of neural crest cells
typical locations - Cauda E or terminal filum
spinal paraganglioma imaging features
T1 iso, T2 hyper, intense E+
50% FLOW VOIDS
rarely cystic change
spinal paraganglioma in lumbar region DDx
myxopapillary ependymoma, schwannoma, meningioma, hemangioblastoma
intradural mets in peds DDx
medulloblastoma, ependymoma, pineal tumors, primitive GCTs, leukemia
intradural mets in adults DDx
lymphoma, melanoma/lung/breast/gastric
where does the vein of Labbe run?
sylvian fissure to transverse sinue.
superficial anastamotic veins (3)
superficial middle cerebral vein, vein of Trolard, vein of Labbe
Lhermitte Duclos aka?
dysplastic cerebellar gangliocytoma
Lhermitte Duclos imaging features
alternating bands of T1 and T2 hyperintense signal. No/minimal enhancement, no DR.
little mass effect for the size of the lesion
Big 3 peds posterior fossa
Pilocytic astrocytoma, medulloblastoma, ependymoma
classic peds pilocytic astrocytoma features
- low grade = low cellularity.
- large cystic component, enhancing nodule
- High T2, low T1, low DWI, external to 4th V, eccentric location
- often cerebellum (60%), 4th V expands around it. 2nd most common is optic nerve pathway
classic peds medulloblastoma
- 2nd MC malignant brain tumor in peds (2nd to astrocytoma)
- hypercellular, intermediate/low T2, HIGH DWI/low ADC, 90% enhance heterogenously
- ROOF 4th V
GET NEUROAXIS IMAGES FOR DROP METS
classic peds ependymoma location
floor of the 4th V
Classic PRES
subcortical and juxtacortical WM T2/FLAIR high SI, classically parietoocciptal region
- generally not a lot of E+ (may be leptomeningeal), not really DR,
- 40% hemorrhagic component
ADEM clinic + imaging features
- acute monophasic inflammation/demyelination of WM
- Typically bilateral, asymmetric iT2 high SI in subcortical WM/thalami/BS.
- E+ -> punctate/rin/arc enhancement (open ring sign along leading edge)
- peripheral DR (not central!)
treatment/prognosis for ADEM
50-60% recover w/in 1/12
sequelae in 20-30%, 10% relapse.
10-20% fulminant course
ADEM vs MS
MS: callososeptal interphase, deep WM spinal cord, brainstem, more focal neurologic, uncommon to have viral/immunization before.
ADEM: more asymmetric subcortical WM
acute hemorrhagic leukoencephalitis (Hurst disease)
fulminant ADEM
PML
multifocal asymmetric WM, subcortical U fiber involvement, immunocompromised
NO ENHANCEMENT, little mass effect.
hypoglycemic encephalopathy
bilateral involvement, cortex (parieto-occipital, insula, neonates - posterior fossa)
Spine MS features
multiple, short segment (<2 VB), T2/FLAIR high SI, mild E+.
McDonald Criteria
- disseminated in space: periventricular, cortical/juxtacortical, infratentorial, SC lesion
- disseminated in time - new lesions, or some lesions with E+ and some not, some with DR+ some note. (ie, different age of lesions)
MIMSE
NF2
- meningioma, schwanoma, ependymoma
Owl’s Eye sign
cord ischemia! central location of abnormal SI
long segment T2 high SI in SC
transverse myelitis
cord edema from compression
intramedullary lesion (astrocytoma)
subacute combined cord degeneration
dorsal columns demonstrate high T2 SI
causes: B12 def, Vit E def, intrathecal MTX toxicity, copper overload, HIV, neurosyphilis
cystic IDEM lesions in spine
arachnoid cyst (matches CSF, no DR)
epidermoid cyst (FLAIR HI, DR+)
spinal neurenteric cyst (ventral)
ventral SC herniation
dural ectasia (Lumbar region, vertebral scalloping)
neurenteric cyst features
developmental abnormality - persistent neuro-enteric canal
IMID, or EMED!
associated with spinal vertebral anomalies (fusion, butterfly)
high protein content in the fluid - not CSF signal
transdural spinal cord herniation
transdural herniation - defect in the thecal sac (most common trauma/DDD related) resulting in SC herniation
best seen on myelograms
spinal arachnoid cyst
IDEM, CSF signal on all sequences. no enhancement
Fatty lesions in the spinal cord DDx
lipoma
lipomyelomeningocele
dermoids
fatty infiltration of the filum
lipoma of the filum terminale association?
tethering of the cord/low-lying cord
fatty infiltration of the filum
not associated with tethering of cord. just fat signal in the filum, will suppress on STIR
dural ectasia - features
de novo or associated with syndromes
expansion of the intraspinal dural spaces, with scalloping of the VB
dural ectasia associated syndromes
NF1, lateral thoracic meningocele, Marfan syndrome, mucopolysaccharidoses
achondroplasia
Spetzler classification of spinal dAVF - # classes?
4
dural AVF
arteriovenous shunts
variable presentation with hemorrhage/venous congestion & HTN
70% of spine vascular malformations
60-70yo. M>F
dural AVF typical features?
typically cord enlargement
flow voids on cord surface
consider angiogram
differential for spinal nerve root enhancement?
infection (WNV, CMV, HZV, lyme disease, TB, fungals)
inflammatory (GBS)
post-op,
subarachnoid seeding (cancer, neurosarcoid)
Differential for spinal vascular malformation?
hemangioma
cavernoma
AVFs
capillary telangiectasia
GBS findings in the spine?
acquired demyelinating polyneuropathy
diffuse NR E+ common
selective anterior NR E+ also possible
neurosarcoid features
CNS involvement in 15% of sarcoid cases
variable T2 SI, but enhances - usually surface of neural element, may be nodular. can also grow into the spinal cord (IM)
DDx: SubA seeding
spinal dAVF vs spinal AVM
both ABN arteriovenous connections
- dAVF : MC spinal vascular anomaly, DURAL vessels. extramedullary location. age 60-70, M>F, RARE
hemorrhage.
- dAVM: AV shunts with a true nidus, 25% of vasc malformations, IM and EM locations, usually younger presentation, more common to hemorrhage, cause myelopathy, arterial steal if high flow
chronic inflammatory demyelinating polyradiculoneuropathy?
autoimmune disorder
- cause of myelopathy and nerve root enlargement (may NOT enhance!)
Rx: steroids and plasmaphoresis
DDx: hereditary neuropathy syndrome (MCT), mucopolysaccharidoses
differential for enlarged nerve roots?
subarachnoid seeding
infections
sarcoid
neurofibromatosis
chronic inflammatory demyelinating polyradiculoneuropathy
intraaxial cyst with mural nodule DDx
hemangioblastoma
pilocytic astrocytoma
ganglioglioma
cystic ependymoma
IDIM differential
astrocytoma
ependymoma
hemangioblastoma
metastasis
ganglioglioma
cord edema
demyelination
syrinx
cavernoma ?
spinal cord hemangioblastoma
solid enhancing nodule with surrounding cystic changes
IDIM location
look for prominent blood vessels on the surface of the SC
spinal cord ganglioglioma
rare, <1% SC tumors in adults, more common in peds (15%)
cervical > thoracic
long segments of cord, eccentric,
T1 mixed, T2 high, patchy enhancement/no enhancement. COMMON Ca2+
DDx astrocytoma, ependhymomas are shorter, transverse myelitis 0 central location and resolves
bright T1 and T2
fat, blood, melanin, enhancement
6 segments of the facial nerve
origin: medulla. exit: bulbopontine sulcus
cisternal seg in CPA cistern
meatal/canalicular seg
labyrinthine seg (IAC seg to geniculate ganglion)
tympanic seg (geniculate to foraminal eminence
mastoid segment (foraminal eminence to stylomastoid foramen)
extra-temporal segment
meningioma vs schwannoma
bone changes/thickening (M>S)
in CP Angle, cystic lesion (S>M)
dural tail (M>S)
calcifications (M>S)
heterogenous enhancement (S>M)
base of tongue lesions
thyroglossal duct cyst (MC congenital neck lesions)- matches fluid.
lingual thyroid (T1/T2 high SI. avid E+)
epidermoid/dermoid cyst (cystic + DR for epidermoid, fat for dermoid)
hemangioma, venolymphatic malformation
tonsillar hypertrophy
facial nerve lesions
normal enhancment of the tympanic/mastoid
Bell palsy/infection/postinfection
nerve sheath tumor
hemangioma
perineural tumor spread (parotid, usually adenoid cystic)
floor of mouth/submandibular cystic masses
SqCC - usually ill defined, enhancing mass
infection/abscess
ranula - mucous retention cyst
venolymphantic malgormation
epidermoid/dermoid
congenital cholesteatomas are the same as (except for location)?
epidermoid cyst!
nasal cavity enhancing mass DDx
peds: juvenile nasopharyngeal angiofibroma (local aggressive, origin in NP adj to sphenopalatine foramen and ptgopatn fossa)
esthesioneuroblastoma - malignant, classic T2 bright dumbell shape
rhabdomyosarc
hemangioma
sinonasal lymphoma
inverted papilloma
CADASIL means?
cerebral AD arteriopathy with subcortical infarcts and leukoencephalopathy
ADEM features
monophasic DMD folloing vax or virus
variable course
large, b/l WM lesions, high T2/FLAIR.
may have open ring/nodular enhancement
NOM (Devic disease)
optic and spinal cord (periaqueductal WM)
relative brain sparing
DDx confluent WM lesion in peds
leukodystrophies (metachromic and adrenoleukodystrophy), sometimes MS, chemo-related change.
ADEM
ring-enhancing brain lesions
metastasis
abscess
GBM
subacute infarct + infection/inflammatory
contusion
demyelination (incomplete ring)
radiation necrosis
confluent periventricular and deepwhite matter lesions in adult
chronic microvascular changes
demyelination
HIV related progressive multifocal leukoencephalopathy (reactivation of JC virus) - characteristically involves subcortical U, typically asymmetric)
neoplastic (gliomatosis cerebri)
treatment-related leukoencephalopathy (chemo/rad)
dandy walker malformation
developmental abnormality of the vermis and 4thC,
- enlarged posterior fossa
- vermis partial or complete agenesis
- hypoplasia of the cerebellar hemispheres
- dilated 4th ventricle in communication with the CSF space
DW variant
normal posterior fossa size
large 4th V
vermial hypoplasia
cerebral cortical calcifications DDx
Sturge weber - bulky, dystrophic ‘tram-track’ + atrophy
tuberous sclerosis
post-ischemic
AVM
post operative
torch infections
Sturge-Weber syndrome
phakomatosis, rare, sporadic, 1/20-50k incidence
facial port wine stain (congenital facial cutaneous capillary malformation), pial angiomas
Filum terminale lesion DDx
myxopapillary ependymoma
lipoma
lipomyelomeningocele
spinal neuroendocrine tumor
nerve sheath tumor
cauda equina neuroendocrine tumors
rare WHO I tumors
hemangiopericytoma = no longer used. use solitary fibrous tumor of the dura
aggressive solitary fibrous tumor of the dura
large, solitary mass, frequently goes through the skull
central neorucytoma
50% of intravent tumors in 25-50 yo.
usually 4thV, but can be lat vent.
WHO II.
lobular, well circumscribed lesion with intratumoral cysts, near septum pellucidum
DDx subependymoma (no enhancement, older), SEGA, intraventricular met, meningioma, choroid plex papilloma (usually 4th vent/posterior horn)
lhermitte duclos
dysplastic cerebellar gangliocytoma
relatively well defined, infiltrative, cerebellar tumor, usually above vermis, benign but unclear if neoplasm or hamartomatous
T1 low, T2 high with septations, little to minimal enhancement
MASS effect!
EAC masses DDx
cerumen impaction
exostoses
keratosis obturans
cholesterol granuloma
cholesteatomas (congenital/epidermoids or acquired)
EAC atresia
fibroangiomas
malignant otitis external
venous malformations/hemangioma
foreign body
cholesterol granuloma vs cholesteatoma
CG is T1 and T2 hyper, not DWI bright
cystic petrous apex lesions
cholesterol granuloma
carotid aneurysm
mucocele
cephalocele
congenital cholesteatoma
petrous apex effusion
solid petrous apex lesions
meningioma
schwannoma
paraganglioma
skull base chordoma/chondrosarc
plasmacytoma
met
suprasellar lesions DDx
if arising from sella - pituitary macroadenoma
meningioma
saccular aneurysm
astrocytoma
craniopharyngioma (papillary solid in adults, adamantinomatous cystic in peds)
germinoma
oligodendroglioma features
intraaxial, WHO 2-3 gliomas, 5-25% of gliomas, 30-40yo.
cortical-based therefore often px as seizures
IDH mutation and 1p19q co deleted
cortex or subcortical WM
low T1, high T2, variable enhnacement, blooming common, typically no DR
heterogenous - Ca2+ hemorrhage, cyst.
DDx: astrocytoma, ganglioglioma, PXA
ganglioglioma
uncommon, low grade, cortical based tumors.
propensity for temporal lobes (70%)
VARIABLE - cystic mass with nodule to solid mass
variable E+ (solid component), ca2+ show blooming
DDx: DNET (bubbly), PXA, oligodendoglioma
subependymal giant cell astrocytomas
WHO 1, seen in TS patients (5-10%), may be asx or px with obstructive hydroceph
intraventricular mass near F of Munro, multilobulated mass, heterogenous T1 and T2 (high T2), marked E+, may ca2+
Ddx: subependymoma (no E+), central neurocytoma (older), choroid plexus tumors, intraventricular meningioma, met
dysembryoplastic neuroepithelial tumor
glioneuronal tumors arising from cortical or subcortical GM
associated with cortical dysplasia. cause of intractable focal seizures
common temporal (65%+), frontal lobe (~20%).
low T1, high T2, bubbly appearance, some suppress on FLAIR. E+ variable (20-30%)
PXA features
cortical tumor, uncommon, peak 20-30s.
usually cortical tumor with cystic component and vivid E+, usually temporal lobe.
may involve overlying meninges
T1 iso/hypo to GM, T2 solid hyper. cystic hyper. E+ in solid component
DDx: ganglioglioma. DNET, oligodendroglioma (Ca2+ common!)
calcified intraaxial cortical mass
oligodendroglioma, sometimes ganglioglioma., DNET, cavernoma, ATRT, CAPNON (mostly extraaxial)
calcified extraaxial
meningioma, skull base chondrosarc, chordoma, intracranial dermoid , adamantinomatous craniopharyngioma
clival chordoma features
chordoma - uncommon malignant tumors originating from primitive notochord remnants, locally aggressive
30-35% of chordomas
posterior midline, indentation of pons
CT: central, circumscribed, destructive lytic lesion with expansile ST mass.
T1 inter/low. T2 very high. hetero E+
clival mass DDx
chondrosarc SB
chordoma
meningioma SB
pit macroadenoma
plasmacytoma
PRES causes and associations
severe HTN/eclampsia, HUS, SLE, TTP, drug tox (chemo, interferon, immunosuppr.) transplants, sepsis, SCD
PRES features
bilateral vasogenic edemia inparietooccipital regions (70-90%) butcan be non-posterior.
cortical/subcortical.
T1 low. T2 high. DWI usually normal. 10-50% hemorrhage. E+ patchy
may have vessel irregularity (constrict/dilation/string of beads)
PRES DDx (cortical/subcortial high T2 signal)
inflammatory amyloid
PML (but spares cortex)
post circ infarct (DR+)
gliomatosis cerebri
gliomatosis cerebri
uncommon growth pattern of diffuse gliomas
Chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS)
uncommon disorder characterized by infiltration of the brain by inflammatory cells.
predilection for pons, fairly characteristic curvilinear regions of enhancement
multiple punctate, patchy and linear regions of E+ relatively confined to the pon
RCVS features
thunderclap HA and reversible vasoconstriction
F>M, 20-50 yo.
T2/FLAIR high signal - cortical or sulcal from SAH. MRA _ vascular narrowings sometimes, DWI - infarcts/
DDx: SAH with vasospasm, primary angiitis, arterial dissection
DDX (broad) for high T2 signal in spinal cord
neoplasm (astro/ependy/HMB/mets/lymphoma(
demyelination (MS, TM, NMO, ADEM)
Vascula: ischemia, AVM, DAVF
Inflam: vasculitis, sarcoid
Infection
short segment demyelination
MS, TM
long segment demyelination
TM, NMO, ischemia
differential for SAH withoutt aneurysm
non-aneurysmal SAH
pseudo-SAH
trauma
causes of non-aneurysmal SAH
perimesencephalic, traumatic, vascular malformation, RCVS, rare inflammatory causes (vasculitis), drug use (cocaine)
aneurysm frequency - ant vs posterior?
90% anterior
(Acom, Pcom, MCA bif, carotid terminus)
10% posterior circ (basilar tip, cerebellar arteries)
densely calcificed parenchymal CNS lesion DDx
oligodendroglioma
ganglioglioma
DNET
ATRT
cavernous hemangioma
typical location for ganglioglioma?
temporal lobe
primary CNS lymphoma
1-2% intracranial tumors. most NHL. prediliection for meninges/ependyma/deep BG/periventricular region/CC.
solid E+, low T1 and T2 signal, surrounding edema
classic appearance of Sjogren’s on US
multiple small cystic spaces throughout the gland, gland atrophy
Salivary gland tumor DDx
Pleomorphic adenoma)
Warthin tumor (2nd MC, b/l in 10%)
Adenoid cystic (MC in SMG)
mucoepidermoid (50% in MSG, 40% parotid)
Acinar cell CA
undifferentiated
mets
hemangiomas
Systemic dz affecting salivary glands
HIV - lymphoepithelial cysts
sarcoid (gland calcs)
Sjogren’s disease
Lymphoma
inflammatory/infectious
