Neuro / H+N Flashcards
1
Q
Cholesteatoma features
A
*Acquired - more common- majority= PARS FLACCIDA on Prussaks space (lateral to ossicles- long head of incus most commonly involved), mallulus head displaced medially, semi circular canal fistulation- monnoly lateral part
PARS TENSA= medial to ossicles
*Congenital - TM intact
MRI: iso/low T1/ high T2, high DWI, NO ENHANCEMENT
CF Cholestrol granuloma- high T1 (blood), NO restricted diffusion
2
Q
Duplication cysts
A
Oesophageal- VB anonmalies esophageal atresia
3
Q
Acromegaly features
A
- pituitary adenoma (remodeal sella)- enhannces less
-ENLARGEMENT OF SINUSES/ MASTOID AIR CELLS, posterior VB scalloping, spade like terminal tufts, beak like osteophytes MC heads, calcified IV dics and joint cartilage, joint space widening, DECREASED INTERPEDICULAR DISTANCE, increased heel pad thickness
4
Q
Causes of increased interpedicular distance
A
NF1, ank spond, Ehlers Danlos, Marfan
5
Q
Haemochromatosis features
A
- Hook like osteophytes of metacarpal heads *CAN AFFECT ALL OF THEM CF CPPD (2nd + 3rd)
6
Q
Amyloid features
A
- similar to RA
- in shoulder- soft tissue nodules and atrophy of muscles, intra articular cartilage destruction
7
Q
Alkaptonuria
A
- calcified IV discs at every level _ disc space narrowing
8
Q
Sarcoidosis features
A
- lace like pattern in middle and distal phalanges
9
Q
Features of mega cisterna magna
A
- can be associated with CMV, trisomy 18
- normal posterior fossa but increased retrocerebllar CSF space
10
Q
Enlarged cystic posterior fossa ddx
A
- Mega cisterna magna- enlarged CSF space, no other abnormality
- Blake pouch- sac like cystic protrusion through formamen of magendie, dilated 4h V, hydrocephalus, displaces normal cerebellum anteriorly + superiorly
- DWV- hypoplastic vermis + cerebellar hemishperes, dilated 4th ventricle, NORMAL POSTERIOR FOSSA + TORCULA
- DWM- hypoplastic vermis, ENLARGED POSTERIOR FOSSA + torcula higher, dilated 4th ventricle, hydrocephalus common
11
Q
Intradural, extramedullary lesions
A
- Schwanomma: C or L spine, dumbell appearance, dub=mbell, high T2, can have cystic appearance, encapsulated + can be separated from rest of roots
- Neurofibroma- unencpasulated, can’t be separated from roots
- Meningioma: thoracic spine, dural tail + broad based attachment, homogenous enhancement *NF2
Paragangliona: CE region, avidly enhance + flow voids, often bleed
12
Q
What is Osler Weber Rendu?
A
-hereditary hemorrhagic telangectasia
- telangectasia + epistaxis + fam history
> pulmonary AVMs can haemorrhage
13
Q
CT Head within 1 hour
A
- GCS <13 initial assessment or <15 2 hours after
- skull base fracture
- pist traumatic seziure
- vomiting
focal neurology
14
Q
Subdural vs extradural
A
EXTRADURAL
> between skull + dura
> does not cross sutures,
> arterial MMA, lucid interval
SUBDURAL
> dura + arachnoid
> can cross sutures but not dural attachments
*SSS bounded by a dural lining
15
Q
Le Fort fractures
A
I= Anterolateral Margin of the Nasal Fossa
II= Inferior Orbital Rim and Orbital Floor
III= Zygomatic Arch and Lateral Orbital RimWall
16
Q
Discitis
A
- strep viridans: IVDU, immunocompromised
-sickle cell> salmonella - TB- gibbus deformity, skip lesions, lower thoracic/ upper lumbar spine, abscess, IV DISC HEIGHT PRESERVED
17
Q
Subacute sclerosing panencephalitis
A
- assymetric subcortical + deep WM change + volume loss, temporoparietal lesions
18
Q
CADASIL
A
- young patient with stroke/ TIA symptoms
- ANTERIOR TEMPORAL LOBE + EXTERNAL CAPSULE, subcortical white matter hyperintensities
MELAS- stroke like symptoms with lactic acidosis, encephalopathy + seizures
- PARIETAL + OCCIPITAL LOBES
19
Q
Mandibular lesions/ cysts
A
- Dentigerous cyst- unilocular, crown of unerupted/ impacted tooth
- Radicular/ periapical cyst- COMMONEST unilocular, root of tooth
- Amelloblastoma- bubbly appearance, can look aggressive, root resorption, uni/multilocular, solid cystic, ramus/ body of mandible, mandibular expansion, extensive tooth resorption ENHANCES AVIDLY CF ondontogenic keratocyst
-Odontogenic keratocusy- uni/multilocular, solid, body/ ramus of mandible, no significant expnasion- GORLIN GORTZ
Odotoma- dense + lucent rom, common, can have fluffy calc
20
Q
Hemangiopericytoma vs meningioma
A
hemangiopericytoma: bone destruction/ erosion + flow voids
21
Q
Floor of skull base enhancement
A
TB: basal cisterns involved- pachymeningeal enhancement + hydrocephalus, CN palsies 3,4,6, fever
Neurosarcoid: CN palsies 2 and 7,
leptomeningeal enhancement, can cause DI, SIADH
Cryptococcus- AIDS, gelatinous non enhancing cysts in dilated perivascular spaces, ring enhancing lesions in basal ganglia
22
Q
Neuro vascular lesions
A
- Cavernoma- blooming (T2*), calc, popcorn appearance with central enhancement, peripheral low signal (hemosiderin), enhancement only seen after long delay, increased bleeding risk if associated with DVA, resected when symptomatic, not seen on angiographhy
- DVA: radially orientated + caput medusa, DO NOT TOUCH
- Capillary telangectasia: faint, brush stroke like lesion in pons/ midbrain, no oedema/ mass effect, blooming, not seen on angiography
- AVM: nidus, supratentorial, serpentine vessels/ flow voids, adjacent to area of gliosis/ dystrophic calc. RF for bleeding: intra-nidal aneurysm, venous ectasia, venous stenosis, deep venous drainage, and posterior fossa location.
Spetzler-Martin scale - evaluates surgical risk for resection - large AVM (>6 cm) draining to a deep venous sinus system in eloquent cortex = highest risk
Dural AV fistula: transverse/ sigmoid sinus= commonest location, look for enlarged tortous vessels in SA space, need angio for diagnosis, can cause tinnitus, acquired- dural sinus thrombosis
23
Q
Stroke MRI
A
Hyperacute 0-6 hours: normal T2, increased DWI, low ADC
Acute 6-72hrs: high T2 + DWI, low ADC
Subacute 1.5d - 5d: high DWI + T2, ADC resolving
Late subacute 5d-14d: high T2 + DWI, ADC pseudonormalising
Chronic: high T2, DWI iso, High ADC
24
Q
Blood on MRI
A
Hyperacute: 0-6hrs= iso T1, iso/hyperT2
Acute: 6-72 hrs= iso/ low T1 (DEOXY) , hypo T2
Subacute: 3-7 days, high T1 (MT-BG), low t2
Late: 7d-1 month= high T1 + T2
Chronic: low T1, Low t2
25
Subacute sclerosing panencephalitis
- measles
- subcortical and deep white matter, Cerebral oedema, temporoparietal region
26
Lymphoma
I- SINGLE NDAL GROUP
2 MULITPLE GROUPS, SAME SIDE DIAPHRAGM
3 BOTH SIDES DIAPHRAGM
4 EXTRANODAL DISEASE- LIVER, MARROW
27
Rathke cleft cyst
midline, seen in region of pituitary
intracystic nodule + peripheral rim enhancement
28
Susac syndrome
encephalopathy + retinal artery occlusions + sensorineural hearing loss
high T2 signal CC - body + splenium
29
Neurosarcoid
► CN Palsies II and VII
■ Meningeal disease: plaque-like dural thickening + masses that mimic meningioma ► BG meningeal enhancement
► subependymal granulomatous infiltration that can rarely cause hydrocephalus
■ Small enhancing granulomas: superficial brain parenchyma bordering the basal cisterns (non-enhancing lesions within the periventricular white matter can mimic MS)
■ Other MRI findings: T2WI: high SI non-enhancing lesions in the periventricular white matter and brainstem that can mimic MS lesions ► optic nerve enhancement ► intramedullary spinal cord lesions
Can look like TB but with parenchymal involvement
30
Eye tumours
Pseudotumour- low T1/T2, often involves lateral rectus, PAINFUL
Lymphoma- extra ocular, mold to globe, commonly involve lacrimal gland, low ADC, hyperintense, PAINLESS
Mets: scirrhous breast cancer- enopthalmoc
kids: neuroblastoma, periobrital ecchymoses- MIBG
Rhabdomyosarcoma= commonest extraconal tumour in kids, superior orbit- high T2/ low/ intermediate T1, musce intensity
31
Spinal cord hemangioblastoma
- cervical/ thoracic spine
- superficial, posterior, exophytic
- enhancing nodule with flow voids, solid cystic
- cord expansion
- haemosiderin cap
- VHL
32
Spinal cord astrocytoma
- commoner in kids
- NF1
- ill-defined (infiltrative) margins, patchy or irregular enhancement. can have cystic components, syrinx may be present. Hemorrhage uncommon.
- Eccentrically placed low T1, high T2
- thoracic cord >cervical
●● Cord expansion
33
Spinal cord ependymoma
- adults
- c spine
-well-defined margins, intense, heterogeneous enhancement. Cystic components, syrinx may be present. Hemorrhage = common, hemosiderin cap sign
Extends over large area >4 VB, CENTRAL
Posterior scalloping
34
Lemierre disease
Jugular vein thrombosis + septic emboli -after ENT infection or recent ENT surgery.
35
LCH
- irregular shapped nodules/ cyst
- upper/ mid zones
- spares costophrenic angles
- smoking, young adults
36
LAM
- TS
- chylorthorax
- regular shaped cysts
37
Birt hogg dube
- LOWER ZONE CYST- LAM
-Association with renal findings (bilateral oncocytomas, and chromophobe RCCs).
- Bilateral AMLs
38
LIP
Sjogrens/ HIV
- GG and deep parenchymal, perivascular cysts
39
Asbestosis
- UIP + parietal pleural thickening
=- pleural effusion = earliest sign
- pleural plaques that calcify
> diaphragmtic plaques = pathognomic
- lower lobe predominant disease
40
Vein of Galen malformation
left > right shunt, heart failure
anechoic structure in region of 3rd ventricle
41
Toxo vs lymhpoma
DWI: Lymphoma restricts more
Perfusion: Lymphoma= higher rCBV
Spectroscopy: Lymphoma = elevated choline
FDG PET: Lymphoma = higher glucose metabolism
Thallium SPECT: Lymphoma more avidly takes up thallium
TOXO favours basal ganglia + can hemorrhage
Treated lymphoma will have calc, lymphoma is sub ependymal/ periventricular
42
Marchiafava- Bignami
alcohol excess
necrosis of CC- body > genu
High signal in CENTRAL corpus callosum on T2 / high FLAIR
43
Wernickes encpehalopathy
High FLAIR/ restricted diffusion/ contrast enhancement in
medial thalami, mammillary bodies, hypothalamus, tectal plate and periaqueductal gray matter.
44
Hepatic encephalopathy
symmetric hyperintensity on T1- globi pallidi and substantia nigrae
45
Hypoglycemia
High FLAIR + restricted diffusion - gray matter in parieto-occipital / temporal
relative sparing of thalami white matter and cerebellum.
46
Diabetic striaopathy
unilateral hyperintensity of the striatum on T1-weighted imaging
47
Ethanol poisioning
Restricted diffusion acute phase
Hemorrhagic necrosis of PUTAMEN + relative sparing of globi pallidi
Reduced NAA, elevated lactate
Subcortical white matter necrosis
Optic nerve atrophy
48
CO poisoning
Bilateral, symmetric, necrosis of the globi pallidi - hyperintensity on FLAIR with hypointense rim, restricted diffusion
49
Osmotic demyelination
CENTRAL PONS - high T2
thalami, basal ganglia, and hemispheric white matter,
50
Chronic alcohol use
Brain Atrophy. Particularly the cerebellum and especially the cerebellar vermis
51
PRES
Asymmetric cortical and subcortical white matter edema *PARIETO OCCIPITAL* - superior frontal sulcus is also common
NO restricted diffusion
52
MRI Cardiac enhancement patterns
Transmural- infarct, severe myocarditis, sarcoidosis
Mesocardial - dilated cardiomyopathy, myocarditis, sarcoidosis, Chagas disease, hypertrophic cardiomyopathy
Subepicardial- myocarditis, sarcoidosis, Chagas disease
Circumferential subendocardial - amyloidosis, systemic sclerosis, cardiac transplantation, hypereosinophilic syndrome
53
Ventricular aneurysms
True- occlusion of the LAD, anterolateral or apical wall of LV
* XR = abnormal contour along the midportion of the left cardiac border near the apex
Pesudo- occlusion of circumflex or RCA, inferior, inferolateral or posterior wall of LV.
* XR= retrocardiac density on frontal view and an abnormal posterior contour on the lateral radiograph.
54
Arrythmogenic cardiomyopathy
presence of RV dyskinesia or akinesia and either an increased RV volume or reduced RV ejection fraction.
55
MEN
MEN 1
Pancreatic tumours Parathyroid adenoma Pituitary adenoma
MEN 2A
Parathyroid adenoma
Medullary thyroid carcinoma Pheochromocytoma ‘
MEN 2B
Medullary thyroid carcinoma Pheochromocytoma
Mucosal neuromas of the gastrointestinaltract
Prognathism Marfanoid
Cutaneous neuromas
56
Thyroid cancer
COLD on radio iodine scan
Papillary- COMMONEST- cervical nodes spread, best prognosis. can be CALC/ cystic/ haemorrhagic nodes, RESPONDS TO I-131
Follicular- takes up iodine, spread via the bloodstream - lungs, bones, liver, REPONDS TO 1-131
Medullary- calcification10% ▸ 123I-MIBG + octreotide, takes up thallium ▸ calcitonin elevated, haematogenous spread to liver, lungs, bones. MEN II
Anaplastic- older, punctate calc, worst prognosis
NHL▸RF: Hashimoto’s ▸ rapidly enlarging solitary nodule (80%) or as multiple nodules
57
Hashimotos
Diffusely micronodular gland / heterogeneous coarsened gland
Isthmus =thickened.
End stage = atrophic
increased risk lymphoma
58
Graves disease
diffuse enlargement of the gland, coarsened echotexture, hypervascularity - hyroid inferno sign
59
Subacute thyroiditis
HYPERTHYROID> HYPOTHYROID
Painful, swollen gland
Ill-defined, patchy areas of decreased echogenicity, normal/ decreased vascularity
60
Multinodular gland
Middle aged- eldely women, HYPERTHYROID
Enlarged with innumerable mixed cystic and solid nodules.
61
Adrenoleukodystrophy
X linked
POSTERIOR- occipitoparietal
extends across splenium of CC
AUDITORY + VISUAL PATHWAY involvement
*leading edge of enhancement
62
Canavan
ELEVATED NAA
“Subcortical Predominance”- spares caudate, CC and internal capsule
restricted diffusion, no enhancement
*big head*
63
Alexander disease
Anterior distribution-progresses posteriorly to involve BG
> cerebellum and middle cerebellar peduncles
Enhances
*Big head*
Alexander= ANTERIOR
64
Krabbe
Periventricular white matter with parieto- occipital predominance- involves centrum semiovale, BG + thalamai
Optic nerve hypertrophy
Small head
krabbeeee
centrum semiovaleeee
optic nerve hypertophyyy
65
Metachromatic
Commonest leukodystrophy
Frontal Predominance
Periventricular and Deep White Matter - Tigroid Pattern
SUBCORTICAL U FIBRES SPARED
Commonest= at the front
66
Pelizaus Merchbacher
BIZARRE NAME- BIZARRE TOTAL LACK OF NORMAL MYELINATION
Extension to U fibers.
“tigroid”
No enhancement/ restricteddiffusion.
Decreased NAA
Normal sized head
67
Mucocele
Non aerated, EXPANDED sinus, peripheral enhancement
68
Mucous retention cyst
Partially aerated sinus (maxillary)
intermediate T1 / high T2
69
Antrochoanal polyp
Fills Maxillary sinus, protrude into nasal cavity via widened maxillary ostium,
Low T1 / High T2 peripheral enhancement
Smooth expansion of sinus
70
Sinonasal papilloma
- CEREBRIFORM ENHANCEMENT, heterogenous avid
- Inverted and oncocytic papillomas have malignant potential, typically transforming to SCC
Classic location = LATERAL wall nasal cavity - most frequently related to the middle turbinate.
Hyperostosis
71
Oligodendroglioma
ADULTS
- frontal lobe, calc, expands the cortex
72
DNET
Kids
Temporal lobe
High T2 Signal, BRIGHT FLAIR RIM
“Bubbly” Temporal Lobe
MINIMAL MASS EFFECT, no enhancement/ oedema
± calvarial erosion/remodelling
73
PXA
PEDS (10-20)
Will Enhance
Dural Tail*** leptomeningeal involvement
Cyst with Nodule Temporal Lobe
more likely to bleed than ganglio
74
Ganglio
Any Age
Can Enhance
NOT Bubbly
Can look like Anything - solid cystic with enhancing nodule +/- some calc
Temporal Lobe
+/- focal cortical dysplasia
75
Salivary gland tumours
Pleomorphic adenoma- high t2 and low rim, superficial lobe
Warthins- solid cystic, bilateral, smoker, takes up pertechnetate
Mucoepidermoid= commonest salivary glandd malignancy,
Heterogeneous, enhancing mass with cystic areas
●● Spreads along the VII nerve
MRI= Low T1, heterogeneous T2
●● Early involvement of nodes—jugulodigastric (level II) first
Adenoid cystic > small, unecasulated, minor salivary glands HIGHEST RISK OF PERINEURAL SPREAD
76
PML
Hypointense T1
Involves U fibres
Asymmetric white matter lesions
no mass effect/ enhancement
77
HIV encephalopathy
Bilateral + symmetric WM changes
Spares U fibres
Cerebral atrophy- frontal
78
Huntingtons
Caudate lobe atrophy
Enlarged frontal horns lateral ventricles
Decreased uptake BG on SPECT
79
MSA
● Severe brainstem + cerebellar atrophy (Shrunken Flat Pons)
> high signal in the pons ‘hot cross bun’
● Low T2 signal basal ganglia (iron deposition)
Shrunken Flat Pons & an enlarged 4th vent.
80
PSP
Micky Mouse Sign: Tegmentum Atrophy with Sparing of the Tectum & Peduncles.
Hummingbird Sign: Midbrain volume loss with a concave upper surface + relative sparing of the Pons.
●Atrophy of the midbrain, GP and frontal lobes
● Dilatation of 3rd ventricle, enlargement of interpeduncular cistern
81
Leigh disease
Progressive neurodegenratiob
T2/FLAIR bright lesions in the Brainstem, Basal Ganglia , and Cerebral Peduncles.
Restrict, but do NOT enhance
Characteristically> periacqueductal grey matter
82
Choroid plexus papilloma
TRIGONE Hydrocephalus, homogenous avid enhancement, small calc
Cauliflower appearance
LOW T1/T2
KIDS= SUPRATENTORIAL- trigone lateral ventricle
ADULTS= 3rd ventricle
DSA- enlarged choroidal arteries
Carcinoma- commoner in kids
83
Central neurocytoma
ADULTS, SEPTUM PELLUCIDUM (anterior lateral ventricle near FOM)
●Solid cystic mass - bubbly
● Calcification = common
● Mild to moderate enhancement
●Hydrocephalus + IV hemorrhage
MRI
● Isointense T1, iso-/hyper-intense T2 with cystic regions
● Prominent flow voids
84
Subependymoma
ADULTS. Well-circumscribed IV mass
Foramen of Monro and 4th ventricle
> HYDROCEPHALUS.
> NON ENHANCING, minimal oedema
> High t2
85
Xanthogranuloma
Choroid plexus mass= commonest in adults
Atria of lateral ventricles
RESTRICTED DIFFUSION
DO NOT COMPLETELY SUPRRESS ON FLAIR
86
Chordoid glioma
ANTERIOR 3RD VENTRICLE
circumscribed, ovoid, homogeneously enhancing mass that is hyperattenuating,
slightly hyperintense on T2
87
Colloid cyst
commonest mass FOM
circumscribed, nonenhancing lesion, anterior roof of 3rd ventricle.
* The machine oil-like contents= hyperintense CT and low T2
CAN HAVE CENTRAL NODULE
88
Hemorrhagic brain mets
-RCC
-Chorio
- Papillary thyroid
- Melanoma
89
Craniopahryngioma
Kids: Solid- cystic, can have high T1 (protein) and high T2, CALC
Adults: solid, enhancing, spherical, non-calcified mass
90
Hypothalamic Hamartoma
- TUBER CINEUREUM> between pituitary stalk + mmillary body *Floor of 3rd ventricle*
- hypointense on T1 and T2
- non enhancing
- gelastic seizures
91
Germinoma
MIDLINE PINEAL REGION > SUPRASELLAR
Parinaud syndrome + precocious puberty, hydrocephalus
homogeneous, intensely enhancing Low T2, dark ADC > hypercellularity
TEENAGE BOYS
Engulfs pineal gland > central calc
Iso to grey matter
> need MRI whole spine for leptomeningeal deposits
*Teratoma- fat*
92
Pineoblastoma
YOUNG CHILDREN
●● Slightly hyperdense mass
●● Avid contrast enhancement
●● ‘Exploded’ calcification/peripheral calcification similar to pineocytoma
93
Pineocytoma
YOUNG ADULTS
● Well-demarcated, calcified, slow-growing tumour
● Peripheral calcification
94
Polymicrogyria
TOO MANY GYRI, TOO FEW SULCI
cortex appears thick with irregularly bumpy surface/ fine undulating + resolve multiple small individual gyri *perisylvian fissure*
TORCH - esp CMV
95
Lissencephaly
- SMOOTH THICKENED CORTEX
No gyri
DILATED OCCIPITAL HORNS OF LATERAL VENTRICLES
4 layers instead of 6
Variants= Double Cortex
96
Schizenencphaly
Open/ closed lip
Lined by grey matter
Assoc: septo optic dysplasia
> agenesis of septum pellucidum, optic nerve hypoplasia + pituitary gland abnormalities
97
Porencephaly
Lined with white matter
98
Holoprosencephaly
*ABSENT SEPTUM PELLUCIDUM*
ALOBAR- single monoventricle. Midline structures (e.g. falx and third ventricle) absent, thalami - fused.
SEMILOBAR- anterior hemispheres fail to separate
LOBAR- only most frontal area does not separate, anterior CC absent
99
VHL
- Haemangioblastoma
- RCC (CLEAR CELL)
- Pancreatic tumours (serous cystadenoma and pancreatic neuroendocrine tumors)
- Phaechromocytoma
- Renal + pancreatic cysts
100
Absence of CC features
- Dilated occipital horns lateral ventricles
- Widely separated ventricular frontal horns - parallel configuration of lateral ventricles
- A midline interhemispheric cyst= representing superior herniation of the third ventricle.
101
Graves disease
HYPERTHYROIDISM
Diffuse increased uptake on I 123 / tch99m
US: enlarged, hypervascular, coarse echotexture
thyroid inferno sign
102
Hashimoto
HYPOTHYROIDISM (initially hyper)
diffusely micronodular / heterogeneous coarsened- becomes hypoechoic + avascular
Thickened isthmus, becomes atrophic
TRACER: inhomogeneous gland, focal cold areas.
Can look like Graves initially
103
Subacute thyroiditis
PAINFUL, following viral infection
Ill-defined, patchy areas decreased echogenicity
Vascularity is normal or decreased.
Tarcer: LOW uptake
104
Toxic multi nodular goitre
Middle aged- elderly, HYPERTHYROIDISM
US: enlarged, innumerable mixed cystic and solid nodules.
Heterogeneous, with uptake that is only moderately elevated.
HOT nodules in a COLD gland
105
Branchial cleft cyst
1st-
Along anterior surface of SCM, just deep to the platysma
between EAC and submandibular region >parotid gland
2nd *common*
Anterior surface SCM, lateral to carotid space,
posterior to SM gland
Angle of mandible- displaces SCM posteriorly, carotid and IJV medially and submandibular gland anteriorly.
106
Hand-Schuller-Christian
systemic form LCH
- Mulitple bone involvement + DI + proptosis + lytic bone lesions
107
CJD
progressive dementia, myoclonic jerks and sharp wave electroencephalogram activity.
● High T2 CAUDATE + PUTAMEN AND THALAMI—bilateral.
● Symmetrical high T2 ofPULVINEAR NUCLEUS of the posterior thalami
● Hyperintensity in cerebral cortex on DWI and T2
● Restricted diffusion on DWI (considered most sensitive sign).
cjd = 3 things
caudtae, putamen, thalami
108
LBD
Parkinsons plus- visual hallucaintion
● Similar AD
● Affects the parietal and occipital lobes and the cerebellum.
Normal hippocmapi
FDG PET: Preservation of mid posterior cingulate gyrus
Low in lateral occipital cortex
109
Picks Disease
Severe symmetric atrophy of frontal lobes (milder volume loss temporal
FDG Pattern: Low uptake in the frontal and anterior temporal lobes.
110
Radiation necrosis
> peripherally enhancing, centrally necrotic lesion, rim enhancinging
> mineralizing microangiopathy >6 months, calc in basal ganglia or dentate nuclei. kids ++
> Radiation vasculitis - focal narrowed segments- distal ICAs can result in a moyamoya phenomenon.
> capillary telangiectasis or cavernous malformations
111
Pesudoprogression
- transient contrast enhancement and edema on imaging
RAISED LIPIDS, ELEVATED LACTATE, LOW CHOLINE
CF TRUE TUMOUR PROGRESSION- more restriction, higher rCBV, raised choline, increased thallium, decreased NAA,
- crosses midline
112
Thymic hyperplasia
signal drop out on OUT OF PHASE > chemical shift artefact
113
Thymolipoma
Linear strands of fat + soft tissue
NO CALC CF TERATOMA
114
MS Best sequences
Superior fossa= FLAIR
Posterior fossa= T2
115
Alzheimers disease
decreased uptake PRECUNEUS, posterior cingukate gyrus, posterior parietotemporal lobe
116
GBM
IDH Wildtype- elderly
Hetergenous, oedema, necrosis, restricted diffusion, increased rCBV
Crosses CC
Pons, increased FLAIR, no restricted diffusion, CN VI + VII palsy
Gliomatosis cerebri >3 lobes
Can be multifocal/ multicentric
IDH mutant=
1p19q non-co-deleted = low grade astro. T2 hyperintense with T2/ FLAIR MISMATCH
Co deleted= oligo
117
Cowden syndrome
Lhermitte Duclos, thyroid goitres + skin lesions + GI polyps
118
ATRT
Looks like medulloblastoma but YOUNGER < 3yo
Cerebellum but can be supratentorial
LARGE
●CP angle (medulloblastoma= midline)
● Hyperdense, heterogeneous enhancement
● Heterogeneous with haemorrhagic foci +/- calc
● May restrict on DWI
119
Lingual thyroid commonest location?
Base of tongue
120
Chiari II features
- large foramen magnum
- myelomeningocele
- flattening of cerebellar hemispheres
- beaking of tectum
Assoc: CC dysgenesis, sulcation abnormalities, MYELOMENINGOCELE, synringomyelia
121
TORCH
CMV = commonest, periventricular calc, loss of periventricular white matter causes microcephaly and ventriculomegaly.
Toxo= microcephaly, Scattered white matter calcification, especially affecting the basal ganglia and cortex, Dilated ventricles and cortical loss
Rubella= Calcified basal ganglia and corte, Reduced white matter volume
122
CO poisoning
High T2 in globus pallidus + restricted diffusion
123
Homonymous hemainopia
Contralteral visual cortex
124
Limbic encephalitis
Autoimmune
Group 1 > paraneoplastic
NSCLSL (anti Hu), neuroblastoma, testicular GCT, breast cancer, thymoma, HL, ovarian teratoma.
Group 2> autoimmune/ post viral. Kids and middle aged woman
NMDAr
inferior temporal lobe, cingulate gyrus
125
Sturge Weber
Developemental delay +_ seizures
Port wine stain (opthalmic division trigeminal nerve)
Leptomeningeal angiomas (parieto occipital lobe)
● Gyral/subcortical white matter calcification
● Choroid plexus enlargement- same side as port wine stain
● Long term—cortical atrophy
● Choroidal angioma (eye)
126
Rhabdomyosarcoma
Rhabdomyosarcoma= commonest extraconal tumour in kids, superior orbit
Muscle denity, moderate enhancement
Invades adjacent bone
127
Cryptococcus
CD4 <100
Basal meningitis hydrocephalus + pesudocysts + dilated periventricular spaces
Ring enhancement
128
TMJ dysfuction
Anterior disc displacement in a closed mouth that reduces on opening
129
Capillary telangectasia
Brainstem/ pons
NO mass effect/ oedema
Faint brush like strokes
130
MR spectroscopy
choline= tumour activity
Lipid= necrosis
NAA= normal neuronal tissue
Think tumour if Increased Choline: NAA/ increased choline:Cr
131
Cavernous hemangioma
INTRACONAL
Commonest adult mass
Well-defined mass, iso T1 high T2, slowly fills in
132
Neurocysticercosis
TAPEWORM, IMMUNOCPMPROMISED
1) Viable/vesicular: CSF cysts, without enhancement, eccentric “dot” = scolex.
2) Colloidal: Ring-enhancing lesions, increased diffusivity.
3) Nodular/granular: Edema decreases as cyst involutes, wall thickens.
4) Calcified: Small parenchymal calcifications
Can have hydrocephalus
133
Toxoplasmosis
CD4 <100
● Multiple <2–cm rim enhancing lesions - basal ganglia, CM junction and thalamus
Chornic basilar meningitis- HYDROCEPPHALUS
Can be ion the ventricles> choroid plexus
● Marked vasogenic oedema and mass effect
● High T2 and restrict
● Can be hemorrhagic
Common in AIDS/ immunocompromised, THALLIUM -VE
134
SOF contents
CN III, IV, CN V1, CN VI
Superior ophthalmic vein
Superior branch of inferior ophthalmic vein drains into the superior ophthalmic vein or cavernous sinus.
135
Cavernous sinus contents
CN III, IV, CN V1, CNV2, CN VI
136
Inferior orbital fissure contents
Zygomatic nerve (from CN V2) - cheek and temple sensation
Infraorbital nerve (from CN V2) sensation to inferior eyelid, medial cheek,
upper lip, and lateral nose.
Inferior branch of inferior ophthalmic vein
137
Bilateral choanal atresia
Emergency, posterior nasal cavity
Assoc: CHARGE
bony type= most common
Distress when feeding, cyanosis that improves with crying, can't pas NG
Assoc: Di GEORGE, Malrotation, feotal alcohol syndrome
138
Parkinsons DAT scan
Decreased uptake in
Loss of dopamine activity in the STRIATUM
(loss of comma)
139
Causes of MACROCEPHALY
NF1
Achondroplasia
Alexanders
Canavans
140
Causes of J shaped sella
Optic nerve glioma
NF
Anchondroplasia
MPS
141
JFA
Arises from sphenopalatine foramen
Widening of pterygopalatine formamen
Erosion of medial pterygoid plate
142
Spinal Meningioma
Assoc: older woman, previous radiation, NF2
Intensely enhancing mass + dural tail. Calcification = uncommon.
THORACIC SPINE
143
Tuberculoma
CT = rounded, central calc, CM junction
Central T2 hypointensity on T2-weighted image (cf pyogenic abscess).
Cystic tuberculoma> can mimic pyogenic abscess. RESTRICTED DIFFUSION
144
CMV
CD4 <50
Ventriculitis- subependymal FLAIR hyperintensity, enhancement throughout ventricular system.
145
Dural AVF brain
Hemorrhage near cavernous sinus or posterior fossa
Enlarged meningeal artery or cortical vein
drains to transverse./ sigmoid sinus
Rx if Cognard IIB- V
Type IIB: Reflux into cortical veins:
Type III: Direct cortical venous drainage:
Type IV: Direct cortical venous drainage with venous ectasia:
Type V: Spinal venous drainage. May cause myelopathy.
146
Persistent hyperplastic primary vitreous
Unilateral microphthalmia
Increased attenuation of vitreous
Martini glass sign - Y-shaped soft tissue stalk along the hyaloid (Cloquet) canal of the posterior segment
Small optic nerve
Flattened lens
147
Coat disease
Boys, Idiopathic
Retinal telangiectasias + exudates > retinal detachment.
High protein fluid
148
Retinoapthy of premturity
BILATERAL SMALL GLOBES
Retinal neovasculairty
Increased attenuation> hemorrhage/ neovascularity.
149
Persistent stapedial artery assoc:
Petrous part of ICA
Aplastic foramen spinosum
150
Tornwaldts cyst
MIDLINE NASOPHARYNX between longus colli
Young adults
High T1/2, non enhancing
151
Malignant OE
Soft tissue in EAC
LOW T1/T2= granulation tissue
Assoc: VST
152
Ranula
Arises from SUBLINGUAL GLAND
153
Carotid-cavernous sinus fistula
Enlarged superior opthalmic vein + prominent cavernous sinus
154
Medulloblastoma
Arises from ROOF 4th Ventricle
155
SEGA
GIANT ASTROCYTOMA
TS
Lateral ventricle near FOM, hydrocephalus, calc, marked enhancement
>1cm
MRI
●● Well-defined mass
●● High signal on T2
●● Uniform enhancement
156
Commonest posterior fossa tumours in kids/ young adults
BEAM
Brainstem glioma (diffuse). Ependymoma.
Astrocytoma (pilocytic). Medulloblastoma.
157
Pilocystic astrocytoma
YOUNG ADULTS
Well-circumscribed unilocular cyst
Commonly posterior fossa can be midline or lateral
Enhancing solid mural nodule
●● Commonly calcify.
●● The wall of the cyst does not usually enhance.
●Hydrocephalus.
SUPRATENTORLA- involves optic nerve pathway/ HYPITHALAMUS > NF1
158
Haemangioblastoma
Posterior fossa> PARAVERMIAN. NOT STRICTLY MIDLINE
●● Enhancing solid nodule post-contrast with associated cysts (40% are just solid)
●DO NOT CALCIFY
●● Surrounding oedema
Assoc: polycythemia
159
Arachnoid cyst
LOW signal on DWI, no restriction
160
Mesial temporal sclerosis
Atrophy of hippocampus + amygdala + mamillary bodies
Increased T2 signal
161
Disc protrusions with neurology
L2/3
> Lateral recess stenosis - affects exiting L3
> foraminal stenosis affects L2
C5/6
> Foraminal stenosis affects C6
Exiting nerve root at C7/T1= C8
162
Vertebral artery dissection location
C6 (entry to foramen
transversarium)
C1 (entry to foramen magnum).
163
Horners syndrome
Ipsilateral ptosis, miosis, and anhidrosis.
164
Ivory osteoma assoc
Obstruction of frontal + ethmoid sinus> leads to mucocele formation
165
Graenigo's syndrome
Petrous apex abscess> irritates CN V+ VI
Otitis media, retro orbital pain, CN VI palsy
166
Keratosis obturans
Assoc: chronic sinusitis + bronchiectasis
167
Occipital encphaloceles assoc
Chiari
Dandy Walker
168
Uncal hernation risk
IPSILATERAL PCA
169
IIH
Diffuse dural thickening + enhancement, subdural collections, increased pituitary enhancement
Tonsilar herniation
170
Venous infarction location
Sagittal sinus= Bilateral parasagittal
Transverse/sigmoid sinus= Temporal lobe
Deep veins/straight sinus or vein of Galen= Bilateral basal ganglia
171
Aneurysmal bleed locations
* ACOM: septum pellucidum (frontal lobe), interhemispheric fissue, inferior frontal lobe
AICA: anterolateral cerebellum + middle cerebellar peduncles
* Distal ACA: pericallosal branches
* MCA: Sylvian fissure, anterior frontal lobe
* PCA: isolated CNIII (due to pulsatile pressure on nerve)
PCom: Sylvian fissure + medial temporal lobe
Posterior fossa:
* Basilar artery: Interpeduncular fossa, brainstem or thalamus
* PICA: Ventricles (via 4th ventricle), foramen magnum
172
Ataxic telangectasia
CEREBELLAR VERMIAN ATROPHY
Compensatory dilation 4th ventricle
cerebral infracts + hemorrhage
PULMONARY INFECTIONS + IMMUNODEFICIENCY
173
Wilsons disease
● Increased T2 signal in BG (tegmentum)
● Red nuclei and substantia nigra = spared = ‘face of giant panda’ sign
174
Tethered cord
Cord lies below L2
Bladder/ bowel dysfunction, lower limb neurology
Assoc: spinal lipoma, diastematomyelia, thickened filum terminale, Chiari , syrinx, myelomeningocele and dermal sinus, imperforate anus
175
Epidermoid cyst
High DWI, HIGH FLAIR
176
Pagets disease
●Polyostotic, asymmetrical
● Flame/grass-shaped metadiaphyseal lucencies in active phase, skull= ‘osteoporosis circumscripta’.
●Bone expansion, thickening of the cortex, coarse trabecular pattern.
● Cotton wool sclerosis in the skull.
●● Picture frame appearance
●● Ivory vertebra
●● Coarsening vertical trabeculations
●Bone scan= markedly increased uptake all phases
●● Uptake at the margins- osteoporosis circumscripta.
●● Decreased uptake of technetium-99m sulphur colloid by bone marrow.
MRI- chronci Pagets= fat
> can have sensorineural hearing loss
177
Enlarged inferior tympanic canalliculius
Aberrant ICA
178
Spinal dAVF
High flow, no intervening nidus
Older males
Congestive myelopathy
MRI - long segment of edema (+/– mild cord expansion) + surrounding intradural extramedullary vascular flow voids
CT myelography = serpentine intradural filling defects.
179
Spinal cavernoma
Thoracic cord
Low flow lesion
180
Tolosa Hunt syndrome
Pain + palsies III, IV, V, VI
cavernous sinus thickening and enhancement.
181
Intraventricular meningioma
Older
TRIGONE
homogenously enhance, hypercellular
182
Halloverden Spatz
PANTOTHENATE KINASE DEFICIENCY
Hereditary movement disorder
LOW T1/2 in globus pallidus + central bright area of necrosis
Eye of the tiger
183
Myxopapillary eendymoma
Commonest tumour CE- high T2, peripheral hemosiderrin cap / blooming, canal enlargement
184
Causes of basal ganglia calc
● Idiopathic (most common)
● Infections (toxoplasmosis, cytomegalovirus [CMV])
● Inherited (Cockayne syndrome, MELAS)
● Poisoning (CO, lead)
● Radiation therapy
● Hypo/hyper (hypoparathyroidism, pseudohypoparathyroidism,
hyperparathyroidism, hypoxia at birth)
185
Cortical/ subcortical hamartomas
Broad gyri +/- calc
186
Joubert
Aplastic/ hypoplastic cerebellar vermis
Molar tooth midbrain
Normal posterior fossa
187
Pseduotumour
Enlarged fat, PAINFUL
Lateral rectus often involved
Tendinous insertions involved
188
Lymphocytic hypophysitis
Enlarged pituitary stalk
Assoc: 3rd trimester, PP
189
Chordoma
Sacrum> clivus
Elderly
Amorphous calc + bone destruction
Solid components enhance
Can extend across IV disc space or SIJ
190
Arachnoiditis
Assoc: Spinal surgery, TB
Empty thecal sac, enhances
191
What is the location of glomus jugulare?
Hypotympanum/ jugular bulb/ middle ear
192
Subependymomas
Intraventricular masses
Can calcify
Variable enhancement
No oedema/ mass effect
193
Venous varix
INTRACONAL, linear, changes with movement
194
Orbital lymphangioma/ orbital lymphatic malformation
Kids
Low flow, EXTRACONAL
FLUID FLUID LEVELS
Peripheral enhancement
195
TB Meningitis
Enhancement of basal cisterns + hydrocephalus
196
Creuzfeldt Jacob
CORTICAL GYRIFORM RESTRICTED DIFFUSION
Bilateral FLAIR dorsal medial thalami + pulvinar thalami (posterior thalamus)
197
Tuberous sclerosis
Rash + mental retardation
Subcortical tubers + Subependymal nodules + SEGA
Assoc: AMLS, cardiac rhabdomyoma + LAM
198
Meningioma blood supply
Parafalcine= ECA
Tent= ICA
199
Transverse fracture through petrous bone
Labrintyhe portion CNVII transected
Sensorineural hearing loss
More Vascular Injury (Carotid / Jugular)
200
Astrocytoma feature
T2/ FLAIR mismatch sign
201
DIA/ DIG
Progressive head enlargement
Frontal/ parietal lobe, involves cortex and attaches to leptomeninges
LARGE, spans >1 hemisphere, MUTLICYSTIC
202
Cortically based mass locations
Frontal= Oligo
Temporal= PXA, DNET, Ganglio
203
NPPH
dementia (wacky), gait disturbance (wobbly) and incontinence (wet)
Rounded frontal horns ventricles + transpendymal oedema
Cerebral aqueduct flow void
204
NF1 Neuro findings
Optic nerve gliomas
JPAs
Brainstem gliomas
Irish hamartoms
Bony dysplasia
205
Pilocytic astro > haemangio
Larger
Contains calc
Larger mural nodule
Thick walled
No angiographic blush
206
MS
Optic neuritis: infraorbital segment = most affected
C spine lesions: <2VB, PERIPHERALLY LOCATED
207
Open globe injury signs
Change in contour
Decreased volume
Flat tire sign
Scleral discontinuity
Deep anterior chamber
208
Stroke CBV
Ischaemia, non infarcted:
Decreased CBF, increased MTT, NORMAL/ HIGH CBV - MISMATCH
Infarcted:
Decreased CBF, increased MTT, DECREASED CBV
MISMATCHED
209
Cortical laminar necrosis
Increased T1, serpiginous enhancement
