MCQ Flashcards
1
Q
Guillan Barre
A
Surface thickening and contrast enhancement of the conus medullaris and nerve roots of the cauda equina.
Anterior nerve roots more commonly involved than posterior.
Contrast important as non-contrast almost normal
2
Q
Lemierre syndrome
A
Thrombophlebitis of jugular veins in setting of oropharyngeal infection, and distant metastatic sepsis
3
Q
Calcific tendinitis longus colli
A
Retropharyngeal fluid without rim enhancement
C1-2 level amorphous calcification
Treat with non steroidals
Enhancement would suggest abscess or tumour
WCC and ESR may be raised
May cause fever
4
Q
Jaw cysts
A
Ameloblastoma - soap-bubble lesion (Septated - most multicystic))
Dentigerous / follicular cyst - surround crown
Radicular cyst / periapical cyst - infection
KCOT - unilocular cyst, may mimic dentigerous cyst
5
Q
DNET
A
T2 bubbly - gelatinous
Wedge shape may mimic infarct. Multinodular. Well circumscribed.
May show minimal enhancement
Minimal mass effect - may scallop inner skull
30% calcify
Associated with cortical dysplasia (up to 80%)
WHO 1
Temporal epilepsy
Cortical or deep grey matter (most commonly temporal)
6
Q
Pilocytic astrocytoma
A
1st 2 decades
Cyst with enhancing nodule
May calcify
Cerebellum and optic pathway
7
Q
Ganglioglioma
A
Cyst with enhancing nodule (solid bit is T2 bright)
May calcify 35%
Temporal lobe epilepsy - most common tumour causing this
WHO 1
(DNETs don’t enhance and calcify a bit less and are T2 bubbly)
8
Q
Pleomorphic xanthoastrocytoma
A
Low grade astrocytoma (2) Rare Cyst with enhancing nodule Temporal lobe epilepsy Calcification rare
9
Q
Minor salivary glands
A
Small unnammed salivary glandular tissue in oral cavity, oropharynx, and mucosa of aerodisgestive tract
10
Q
Adenoic cystic carcinoma
A
55% minor salivary gland
11
Q
Idiopathic intracranial hypertension (pseudotumour cerebri)
A
Partially empty sella
Papilloedema, increased CSF along optic nerves
Enlarged meckels cave
Bilateral venous sinus stenosis (not thrombosis)
Headache, visual problems, tinnitis, photopsia (flashing lights)
Cranial nerve palsies may occur
Diagnose by CSF pressures, and imaging to exclude other causes
Spontaneous resolution may occur
CSF letting may treat, or acetazolamide
Slitlike ventricles (relatively uncommon)
(meningeal enhancement is in HYPOtension)
12
Q
Moyamoya
A
Disease is idiopathic
Otherwise pattern or syndrome
Many causes:
Connective tissue: Marfans, Ehlers Danlos, SLE, antiphospholipid
Phakomas: NF1, TS
Infection: TB, bacterial meningitis
Blood dyscrasia: Sickle cell, PCV, aplastic and fanconi anaemia
Other: Graves, Downs, Aperts, UC, COC, radiation, atherosclerosis
Distal ICAs and COW, unilateral in 18%, vasculo-occlusive disease, with abnormal collaterals -
May haemorrhage from the collaterals - pial and basal ganglia collaterals
Susceptible to aneurysms, especially in posterior circulation
13
Q
Orbital meningioma
A
Majority are extension from intracranial
20% are optic nerve sheath meningioma
Tram track sign on axial, non-enhancing dot on coronal, of enhancing mass surrounding non-enhancing nerve. Cf. glioma where nerve is enlarged
14
Q
Temporal bone fracture
A
Currently otic sparing or otic involving
If otic capsule involved, Facial nerve paralysis, CSF leak, and sensorineural hearing loss all more likely (and epidural and subarachnoid haemorrhage)
Longitudinal (70%) and transverse (30%) old classification.
Longitudinal are associated with incudostapedial dislocation, conductive hearing loss, tympanic membrane rupture, facial paralysis in 25%. CSF ottorhea from tegmen tympnum involvement 15%
Transverse are associated with sensorineural hearing loss, >30% facial nerve palsy (50%), vertigo, otorhoea
Longitudinal - risk of developing cholesteatoma
Longitudinal more common - as above
15
Q
Warthin tumour
A
Cystic 30% - more so than other parotid masses
Multicentric 20% - most common bilateral or multicentric tumour
Otherwise less common than pleomorphic adenoma
Old male predominant
Favour parotid tail (inferior superficial lobe)
Don’t calcify
Moderately enhance on CT
Often hypervascular on USS
Can be treated conservatively
AKA lymphomatous papillary cystadenoma aka adenolymphoma
Lymphoid stroma, double layer or epethilial cells (oncocytic appearance - abdundant mitochondria - granular appearance, polygonal)
Can arise in cervical lymph nodes.
T2 heterogeneous, T1 low/mixed (may haemorrhage), don’t enhance
16
Q
Pleomorphic adenoma
A
Most common salivary gland tumour More common in superficial lobe of parotid Hypoechoic on ultrasound May have through transmission Calcification common Prominent enhancement on CT Small risk of malignant transformation Often recur after surgical excision Mixed histology
High T2, low T1, homogeneously enhance. May have high T1 centrally - mucoid.
Can appear entirely extraparotid if deep lobe, or parotid rest in parapharyngeal space
17
Q
Frontotemporal dementia
A
Pick disease is an example. Outdated name, now called frontotemporal lobar degeneration. Pick disease reserved for if Pick bodies seen on path.
Caudate head volume may be reduced
18
Q
Alzheimers v Lewy body
A
Alzheimers have memory distubrance first
Lewy have frontal disturbance first
Occipital hypoperfusion may aid in diffrentiation Lewy body from Alzheimers.
Occiptial lobes, basal ganglia and thalami, cerebellum, anterior cingulate are spared in Alzheimers.
Normal hippocampi size in Lewy body dementia, cf Alzheimers
19
Q
Enlarged vestibular aqueduct
A
> 1.5mm
One of the most common causes of congenital sensorineural hearing loss
Often present as SNHL after minor trauma
Commonly associated with other abnormalities e.g. Mondini
Bilateral in 50-66%
20
Q
Michel aplasia
A
AKA complete labyrinthine aplasia
Absent inner ear structures.
Cochlear implant contraindicated
21
Q
Mondini malformation
A
AKA type 2 incomplete partition with large vestibular aqueduct
Incomplete apical 1.5 turns but preservation of basal turn
SNHL
22
Q
Incomplete partition type 2
A
Part of spectrum of cochlear abnormalities, depending on timing of insult. Early results in Michel’s / complete labyrinthine aplasia.
Type 2 is 1.5 cochlear turns, with a cystic apex.
Sensorineural hearing loss.
23
Q
Thyroid ultrasound
A
Calcification is the feature most closely associated with malignancy (but can be seen in benign processes)
Microcalc most specific, 95%, and associated with papillary thyroid ca
Intranodular flow usually malignant
Lymph nodes with increased flow suspicious
Coarse calcs may be seen in papillary or medullary, and in benign
Papillary and medullary hypoechoic
Follicular iso
Hyperechoic 5% chance of malignancy
Papillary may be cystic
Taller than wide, and irregular are supicious features
Lymph nodes enlarged suspicious, esp for papillary
Cancers tend to be hypo
A hypoechoic rim is a benign feature - follicular adenoma, but can also be seen in papillary cancer
Large cystic component, comet tail artifact, and hyperechoic are benign features.
Biopsy if <1cm and high suspicion
Or 1-1.5 and micro calc
Or >1.5 and solid or coarse calcs
24
Q
Papillary thyroid
A
Microcalc on ultrasound
Nodal mets at presentation - may cavitate (cystic)
Associated with Cowdens (although Cowden is mosltly associated with follicular), Gardners
(cf follicular which favours haematogenous spread - follicular has Ras oncogene)
Orphan annie nuclear inclusions
Takes up iodine whereas medullary doesn’t.
Most common cancer. Also the most common in thyroglossal duct cysts.
25
Medullary thyroid cancer
MEN2 - so screen for phaes with MIBG or octreotide
VHL
NF1
Calcifies at primary and secondary sites
CEA and calcitonin (parafollicular C cells) (causes hypocalcaemia)
Will uptake MIBG if thyroid blocked by Lugols, 30% (potassium iodide)
Won't concentrate radioactive iodine
PET 75% sensitive for mets
26
Anaplastic thyroid cancer
Typically in the elderly, with poor prognosis
27
Carotid and vertebral dissection
Extracranial more common
ICA more common than VA for both traumatic and spontaneous
Vertebral V2-3 (C6 transverse foramen to dura)
Carotid - 2cm above bulb to skull base. C1-2 level most common. Stroke usually occurs within a week, in at least 75%. Otherwise may have local signs e.g. Horners
Does not extend into petrous. May have seperate petrous.
5-20% of strokes 40-60
Subacute T1 crescent around flow void
Trauma (most common in vertebral, can't find stats for carotid), connective tissue disease, FMD
28
DAI
80% non haemorrhagic
Dorsal brain stem, adjacent to superior cerebellar peduncle, associated with worse prognosis.
Lactate peak associated with worse prognosis.
Can have reversible diffusion restriction
Gray white interface mostly, then corpus callosum - mostly splenium
29
Vasospasm post SAH
40-80% imaging
20-30% clinically
4th to 10th day post bleed
30
Optic pathway glioma
33% occur in patients with NF1
31
Mesial temporal sclerosis
Most common cause of complex partial seizures
Cortical dysplasia is the most common dual pathology
Atrophic body>tail>head>amygdala
PET more sensitive than MRI
32
Germinoma
```
Most common germ cell tumour of pineal
HCG normal
Very responsive to radiotherapy
Positive for placental alkaline phosphatase on immunochemistry
More common in males
```
33
Pineal gland met
Rare
| Lung, breast, GI, kidney
34
Pineocytoma
More common in females
WHO 1
May be cystic, appearing similar to pineal cyst
Slow growing and well circumscribed cf. pineoblastoma
35
Lhermette-Duclos
Rare tumour of cerebellum
AKA dysplastic cerebellar gangliocytoma
Probably a hamartoma, but considered WHO1
Cowden COLD (Cowden Lhermette Duclos) associations
Hypoattenuating, may calcify, doesn't enhance
Striated
36
Herpes encephalitis
Spares basal ganglia
Often bilateral, assymetric
Involves insula, cingulate gyrus (but mostly temporal lobes and inferior frontal)
Mild mass effect
Bimodal, <20 (primary) >50 (reactivation)
95% HSV1
Haemorrhagic necrotising
HSV2 causes more herpetic meningitis, and more in neonates
Alterations in mood, memory, behaviour common
May present subacute with ataxia and seizures
Cowdry intranuclear inclusion bodies (also in CMV, varicella)
Gyriform enhancement
Brainstem more likely to be involved in immunocompromised
37
Cryptococcal infection
In AIDS
Followed dilated VR spaces
Atrophy, hydrocephalus, masses
Cryptococcomas, involve midbrain and basal ganglia
38
Granulomatous meningeal disease
Tends to affect basal pachymeninges - spares convexities
May produce masses with enhancement
Sarcoid, RA, TB, Wegeners, syphilis, fungal
39
Haemangiopericytoma
Rare
| Solitary fibrous tumour of meninges
40
AVM
No mass effect
Contrast CT will detect 90%
Spetzle-Martin grading
Size <3cm 1, 3-6 2, >6 3
Eloquent cortex 1
Deep venous drainage 1
Overall is from 1-5
(Non eloquent is frontal, temporal, and cerebellar hemisphere)
41
Haemangioblastoma
20% produced EPO
Spine: Thoracic (50%), cervical (40%)
Prominent, dilated tortuous vessels on posterior cord surface
75% intramedullary
Almost never calcifies
Paravermian cerebellar - most common primary infratentorial neoplasm in adults
42
Choroid plexus hyperplasia
AKA villous hypertrophy of choroid plexus
Rare
Can result in communicating hydrocephalus
43
Ruptured aneurysm
Urgent treatment to prevent rebleeding permit aggressive vasospasm treatment
IV mannitol for herniation
Calcium antagonists
Clipping and coiling
44
Spinal ependymoma v astrocytoma
Astro in children, epend in adults
Astro expansile, poorly defined, several levels, heterogeneous enhancement
Epend NF2, moor well defined and homogeneous enhancement. Haemorrhage.
Ependymoma of spine don't tend to calcify cf. brain do
Cellular ependymoma most common in thoracic cord
Ependymoma can cause communicating hydrocephalus through neoplastic arachnoiditis and adhesion formation
45
MS
Ovoid lesions, perpendicular to ventricular walls
Loss of hydrophobic myelin so increased T2
80% have spinal involvement. Cervical in 2/3.
12-33% have only spinal
Enhancement lasts 3 months. 90% disappear in 6 months
Parallel to long axis of cord
46
SEGA`
WHO 1
Almost exclusively TS
Marked contrast enhancement
Foramen of Monro typical
>1cm
47
Neurocytoma
Arise from septum pellucidum or ventricular wall
Intratumoral cyst like areas - T2 hetero
Well circumscribed, heavily lobulated
Bubbly
```
20-40
Commonly calcify
Grade 2
Histo similar to oligodendoglioma
Mild to moderate enhancement
```
48
Otitis media
Moraxella, haemophilus, stre pneumoniae
| Moraxella is also 2nd most common COPD exac
49
Tolosa Hunt
Painful opthalmoplegia, cavenous sinus and orbital apex inflammation
Diagnosis of exclusion
Idiopathic
Pseudotumour can cause
50
Parathyroid adenoma
Abnormal parathyroid tissue is T2 very bright and avidly enhancing
Thyroid (33% (superior thyroid common), thyroid-thymus conduit (19%), thymus (15%)
Mot commonly anterosuperior mediastinum or low in neck
51
Cavenous haemangioma
```
Most common orbital lesion
80% intraconal (commonly lateral)
Adult cavernous, paeds capillary (capillary more commonly extraconal)
2/3 in women for adults
Painless proptosis, progressive
```
May have calcified phleboliths
Iso to muscle T1, hyper T2
52
Nasopharyngeal carcinoma
Considered separate to other head and neck SCC
Often centres fossa of Rosenmuller
Perineural spread, nodal involvement
Spread to parapharyngeal space most reliableimaging sign
T stage based on if involves parapharynx (2) bones (3), or intracranium (4)
EBV, diet, genes - increased risk in Chinese and Eskimos
And HPV
Keratinising type, same as other head and neck SCC, smoking and alcohol, ingested nitrosamines (Chinese diet)
Non-keratinising type, EBV, and particularly in asians
53
Retropharyngeal space
Anterior to prevertebral space, posterior to pharyngeal mucosal space
Contains nodes (of Rouviere) and fat
Goes from one carotid space to the other
Visible on CT
54
Spinal cord tracts anatomy
.
55
Capillary telangiectasia
```
Low flow vascular lesion
Most common after DVA on imaging
Asymptomatic
Most in pons, cerebellum, spinal cord
Associated with OWR
Normal brain tissue insterspersed, in contrast to cavernoma
Tend not to bleed
Not seen on DSA, CT
```
56
Pulsatile tinnitus
```
Dehiscent jugular bulb
Persitent stapedial artery - associated with small or absent foramen spinosum, or aberrant ICA
Idiopathic intracranial hypertension
Dural AVF
Glomus tympanicum or jugulare
AVM
Vascular compression of cranial nerve 8
```
57
Tympanic membrane
Pars tensa is most of it, inferiorly
Top part if pars flaccida
Acquired cholesteatoma tends to perforate pars flaccida
58
Intraconal lesions
Glioma, meningioma, haemangioma, pseudotumour, lymphoma (more commonly extra), mets (both), varix
59
Conal lesions
Thyroid eye disease, pseudotumour, rhabdo
60
Extraconal lesions
Pseudotumour (commonly conal, can be anywhere - intraconal fat common, 90% unilateral), cellulitis / abscess, lymphoma (can be intra, or optic nerve sheath complex), mets (both), dermoid / epidermoid, lymphangioma, lacrimal gland tumour (superolateral - lymphoma and salivary gland tumour [adenoid cystic, BMT], also affected by sarcoid and pseudotumour)
61
Corpus callosum dysgenesis
```
Dilated occipital horns
Widely placed ventricles
Heterotopic gray matter association
Associated with non-downs trisomy
Colpocephaly (dilated trigones and occipital horns)
```
62
Spinal meningioma
Most commonly thoracic
Anterior cord surface cervical near foramen magnum next most common
Iso T1 and T2
63
Posterior vertebral body scalloping
Achondroplasia, acromegaly, ependymoma
Bone abnomalities - acromegaly, MPS, achondroplasia, ank spond
Dural ectasia -
Tumour / pressure - ependymoma, hydrocephalus
64
Scoliosis
Convex right in thoracic, left in lumbar, is typical for adult idiopathic
65
Cerebral aneurysm
Anterior COW 90%
Azygos ACA has higher incidence of berry aneurysm (and is associated with lobar holoprosencephaly)
Multiple in 15-20%, more common in females (generally more common in females, but ratio increases further with multiple)
```
5 year aneurysm rupture rate:
<7mm - 0
7-12mm - 2.5%
13-24mm - 15%
>25mm - 40%
Rates slighly higher in posterior circulation
>25mm defines a giant aneurysm
```
66
ICA, CCA angiography
8 at 2, 8-10 at 4
67
De quervains
Low uptake and hyperthyroid (along with amiodarone and exogenous hormone)
Self-limiting subacute granulomatous thyroiditis
F:M 3:1
Associated with URTIS i.e. postviral - mumps, measles, coxsackie
Hypoechoic
68
Giant cell reparative granuloma
Midline mandible lesion
AKA central (anterior to 1st molar) giant cell lesion
2nd, 3rd decade, young women (same as GCTs, which histologically it's the same as, so it's histologically same as Brown tumour also)
Benign cystic lesion
DD Brown tumour, ameloblastoma, ABC
May recur after removal
69
Thyroid eye disease
80% bilateral
Most common cause of proptosis (uni or bi)
Eventually get fatty infiltration
70
Laryngeal cancer
60% glottic, 30% supra, 10% infra
Spreads between cords via anterior commisure
Glottic tumours favour anterior half.
Supraglottic tumours spread to bilateral 2 and 3 level nodes. Needs bilateral treatment.
Subglottic 20% have spread to nodes also.
Glottic rarely metastasises - poor lymphatic drainage.
Level 6 nodes are removed in total laryngectomy as can contain undetected mets
Sub - below vocal fold to inferior edge of cricoid
Survival: Glottic >90%, supra 75%, infra40% (late detection, sparse lymphatics)
Pre-epiglottic fat assessed on sag MR and CT for replacement by cancer cells. (blind clinically but well seen on imaging)
71
Gorlin-Golz
Multiple BCCs, KCOTs,
Other neoplasms: medulloblastoma, meningioma, astrocytoma, craniopharyngioma,
Also have short metacarpals
Other associations.
Sonic hedgehog receptor mutation
AD with incomplete penetrance. Often sporadic
72
Prussak space
Scutum to umbo (central pars tensa, tip of malleus)
| Pars flaccida cholesteatoma typically begins here
73
Tripod fracture
=ZMC fracture
Zygomatic arch
Inferior orbit, anterior and posterior maxillary sinus walls
Lateral orbit
Lateral canthus may be displaced inferiorly
May involve infraorbital nerve, a branch of maxillary nerve
74
Skull base foramina
Ovale - mandibular nerve
| Rotundum - maxillary nerve
75
Parotid gland, ultrasound
More echogenic than submandibular as fatty
| Becomes harder to visualise as older, as fatty replacement
76
Orbital dermoid, epidermoid
Extraconal masses
Most (>80%) upper outer quadrant or lacrimal fossa
Occur near sutures
77
Orbital pseudotumour associations
Wegeners, sarcoid, fibrosing mediastinitis, retroperitoneal fibrosis, thyroiditis, cholangitis, vasculitis, lymphoma
Non-granulomatous inflammatory condition
78
Benign massteric hypertrophy
Unilateral in 50%
| Familial or acquired - malocclusion
79
Calcified globe
Retinoblastoma (most common cause of orbital calc)
Neuroblastoma mets (uncommonly calc, ocular involvement in 20%)
Retinopathy of prematurity (small globe)
80
JNA
Juvenile nasal angiofibroma
Flow voids (punctate and serpentine) - salt and pepper T1
Heterogeneous, intermediate signal
Benign, locally agressive
Male adolescents (almost exclusively)
Widen sphenopalatine foramen (where mass is centred) - bow posterior wall of maxillary sinus
Arise from posterior choanal tissue
Uniform early enhancement (apart form flow voids)
Often recur after surgery. Pre-op embolisation to help with haemostasis
Radiation if incomplete resection
Biopsy contraindicated
DD rhabdomyosarc, nasopharyngeal cancer, teratoma, enthesioneuroblastoma
81
Inverted papilloma
Enhancing mass centred on middle meatus (lateral nasal cavity), extending into maxillary sinus
Cerebriform on T2 and contrast T1
40-60, male prediliction
High association with malignant transformation (to various histologies) so removed
Not related to atopy
82
Follicular thyroid cancer
Ras oncogene
Haematogenous mets, late (favours over nodes)
Can't differentiate adenoma from carcinoma on cyto
Associated with Cowdens
Hurthle cell carcinoma was considered a type of follicular cancer. Hurthle cells also seen in Hashimotos
Takes up radioactive iodine (whereas medullary doesn't)
83
Olfactory neuroblastoma
Peaks in 2nd and 6th decades
| Young adults mostly
84
Nerve sheath tumour
Low attenuation due to fat, myxoid tissue (hypodense to disc)
85
PAN
The most common systemic vasculitis to involve the CNS
86
Hunters angle
Angle of line through metabolites on spectrocopy
| Normal is about 45 degrees (through choline, creatine, NAA)
87
Orbital melanoma
Most common intraocular primary malignancy
Arises from choroid
May cause retinal detachment
Contiguous spread with extraocular spread
High T1, low T2
Don't calcify
88
Sinus anatomy
Haller are infraorbital ethmoids
Onodi - ethmoid superolateral to the sphenoids
Uncinate process forms medial wall of infundibulum
Ostiomeatal unit - common drainage of maxillary, frontal and frontal ethmoids. Infundibulum is drainage of maxillary ostium and anterior ethmoid cells to the hiatus semilunaris
89
Solitary bone cyst
= simple bone cyst
AKA traumatic bone cyst, although only half due to trauma
In the mandible, commonly between canine and third molar or at symphysis (known as solitary in jaw, or traumatic)
Same as UBC elsewhere
90
Cholesterol granuloma
```
Most common cystic lesion of petrous apex
Granulation tissue
High T1 and T2
Faint peripheral enhancement
No DWI
```
91
Otosclerosis
80% fenestral - 85% bilateral - fissula ante fenestrum, anterior to the oval window (Where stapes attaches) - more often conductive loss
20% retrofenestral - more often sensorineural loss
F:M 2:1
Most often conductive loss, but can be any
92
Vestibular schwannoma
Best seen on contrast enhanced T1
95% have hearing loss
Commonest CPA mass
```
Cystic and haemorrhagic areas more common than meningioma (but still haemorrhage uncommon, and only 15% cystic)
T2 hyper (meningioma usually iso)
```
Melanocytic schwannoma is a schwannoma subtype but not commonly vestibular, which can have psammoma bodies - associated with Carney complex (not triad)
93
Petrous apicitis
Gradenigo syndrome - abducens nerve palsy and retro-orbital pain
Meningeal enhancement
Facial pain - trigeminal nerve in Meckels cave
May cause cerebritis, abscess, cavernous sinus thrombosis
94
Paranasal sinus development
Ethmoids, frontals and maxillaries present at birth
| Sphenoids develop later on - pneumatisation starts at around 2
95
Hypoplastic sinuses
Downs
Prader Willi
Otopaltodigital
96
Fungal sinusitis
Non-invasive: allergic, mycetoma
Invasive: acute, chronic, granulomatous
Allergic - young, immunocompetent, associated with asthma, commonly bilateral. Although not invasive, can extend intracranially.
Acute invasive - DM, AIDS, immunocompromised.
Chronic - less immunocompromised
Granulomatous - immunocompetent
(air fluid level may be seen in bacterial sinusitis)
97
Antrochoanal polyp
Arise in maxillary antrum
Widen the ostium, but not the sinus
Prolapse through into nasal cavity, then into nasopharynx
5% of sinonasal polyps
3rd to 5th decades, slighly more common in males
Non-atopic (like other polyps)
98
JNA staging
.
99
Chordoma
```
Clival younger than sacrococcygeal - 20-40 cf 40-60
20-70% calcification on plain film
Bony destruction
Displace basilar artery posteriorly
Physliferous cells
Posteriorly indent pons - thumb sign
```
Mostly low T1, high T2. Haemorrhagic foci as well as calc. Heterogeneous enhancement
100
Paraganglioma
Carotid body tumour splays the external and internal carotids. AKA chemodectoma
Glomus vagale displaces both anteriorly
May have AV shunting
High T2, and salt and pepper, intense enhancement.
4:1 F:M
May have malignant transformation
Tumour excision with pre-operative embolisation
101
Cholesteatoma, complications
Perilymphatic fistula / labyrinthine fistula - communication to middle ear - SNHL, dysequilibrium. Best seen on CT
Other middle ear complications: ossicle destruction, facial nerve palsy, hearing loss, automastoidectomy
And intracranial: Meningitis, sigmoid sinus thrombosis, temporal lobe abscess (if erode through tectum)
Lateral semicircular canal first part of labyrinth involved
102
Cholesteatoma
Extend from pars flaccida into Prussaks space (scutum to umbo), erode scutum
Can extend to mastoid antrum via aditus ad antrum
Associated with reduced mastoid air cell development
T2 high, T1 low, diffusion restrict
Soft tissue attenuation CT
(Cholesterol granulomas are High T1, and don't diffusion restrict)
103
Parapharyngeal space
```
Carotid displaces it anteriorly
Parotid anteromedial
Masticator posteromedial
Pharyngeal mucosal space posterolateral
Retropharyngeal space anterolateral
```
Skull base to hyoid, inverted pyramid
104
Submandibular gland mass
50% malignant.
Only 10% of salivary gland neoplasms
Most masses in parotid and are benign
105
Parotid infantile haemangioma
Most common parotid tumour of childhood
Mostly female, diagnosed at 4 months
Spontaneously resolve, or with medical therapy
Mostly capillary (cavernous is older children, rarely parotid)
T2 hyper, T1 inter, enhances, may have flow voids
106
Parotid MRI
T1 best for extent of mass
107
Benign lymphoepithelial lesions
Mixed solid cystic lesions which enlarge parotid glands (rarely other glands - no lymphoid tissue)
Bilateral in 20%
Usually in HIV patients without AIDS
Usually cervical lymph node enlargement
108
Sjogren
Increased lymphoma risk, aggressive. Biopsy if parotid lesions >2cm or growing
May be unilateral, or bilateral (more often unilateral)
May go on to chronic glandular enlargement with superimposed painless acute swellings
Anti Ro
Anti La
Nodules, abnormal enhancement, cysts, punctate calc.
Change in size, accelerated fat deposition (hyperechoic)
109
Caroticocavernous fistula
Dilated superior opthalmic vein, facial vein, IJV
Direct, young males
Indirect, postmenopausal females
Indirect is branches of carotid circulation, most commonly meningeal
Pulsatile exopthalmos
Feeding vessel aneurysms and retrograde filling of orbital veins are bad prognostic factors
Can treat with embolisation - venous or arterial approach (need both in indirect)
Carotid compression may cause closure of indirect in 30%, 17% direct
Surgery an option
Dural type = indirect, may occur spontaneously
110
Proptosis
```
Thyroid (can involve tendons in 10%)
Infection
Tumour
Vascular malformation
Pseudotumour (90% unilateral - painful acute, responds to steroids)
```
111
Optic canal
Transmits opthalmic artery and optic nerve
112
Orbital lymphangioma
Don't regress whereas 10-15% of head and neck ones do
Progression slows with termination of body growth
Extraconal
113
Carotid sheath
IJV is posterolateral to carotid ICA
114
Thyroglossal duct cysts
More common than branchial cleft - i.e. the most common congenital neck cyst
Not bright on NM
Infrahyoid 65%, hyoid 15%, supra 20%
May be imbedded in infrahyoid (strap) muscles
No enhancement or thin peripheral
Surgically removed
Cancer <1%
Infection 2.5%
115
Branchial cleft
3rd posterior triangle with sinus to pyriform sinus
4th has sinus to pyriform sinus but goes inferiorly, course of recurrent laryngeal nerve, to reach anterior left upper thyroid lobe
116
Fossa of rosenmuller
Commonest site of nasopharyngeal cancer
| Assymetry may be from normal physiological variation in lymphoid tissue
117
Laryngocele
Dilated laryngeal ventricle
Acquired - wind instruments, glass blowing, excessive coughing, or an obstructing mass
Internal if just dilated ventricle
External if herniates through thyrohyoid membrane and external portion dilated
Or mixed
118
Lacrimal gland mass
Inlammatory, neoplastic - lymphoma, salivary
Inflammatory: sarcoid, sjogrens, pseudotumour, infection, rarer infiltrative e.g. amyloid
Neoplastic - pleomoprhic adenoma, adenoid cystic carcinoma (25% of all lacrimal gland tumours, 50% of the malignant ones), other
May have calc in either malignant or benign
119
Sialolithiasis
80-90% Submandibular, rest parotid
| 80-90% SM stones opaque, 60% parotid
120
Multiple sclerosis
T1 blackholes
Perivenular lesions, perpindicular to lateral ventricles, parallel to spinal cord
12-33% spinal only
10% of plaques occur in grey matter
121
MS variants
Balo concentric sclerosis
Marburg variant
Devics - neuromyelitis optica
122
Intracranial epidermoid
```
DWI identifies
Otherwise similar to CSF
"dirty CSF"
90% intradural, 10% extra - skull mostly
40-50% CP angle (3rd most common mass)
Suprasellar cistern, 4th ventricle other common places
```
"white" epidermoid is hyperdense on CT, high T1 due to haemorrhage or high protein - rare
Present with mass effect
123
Colloid cyst
40-50% asymptomatic
90% stable - don't enlarge
2/3 hyperdense - hydration status
2/3 T1 hyperintense - cholesterol status
124
Craniopharyngioma
Adamantinomatous type commonly calcifies (and is mixed solid cystic), papillary type rarely (and more solid)
Often large at presentation
Multilobulated (adamantinomatous) or spherical (papillary), well defined
WHO1
90% enhance
Most common suprasellar mass in children (if question is most common solid mass in this area, pilocytic astroctyoma is answer)
125
Suprasellar arachnoid cyst
Push stalk back
126
Pituitary size
Child 6
Male and post menopausal female 8
Menstrual female 10
Pregnant or lactating 12
127
Cavernoma
Endothelial lined, immature vascular spaces
Haemosiderin rim, popcorn like reticulated T2
Angiographically occult
Associated with DVA
Present 40-60
Fluid levels may be evident
May be multiple if familial
128
Epidural haematoma
Can cross sutures if diastasis
Unilateral in greater than 95%
Venous can occur with dural sinus injury - these are more often seen in children and less often associated with a skull fracture
129
Subdural hygroma
Arachnoid tear
130
CNS lymphoma
Hyperdense CT, low T2, diffusion restrict, enhance (vivid homogeneous). Often periventricular
50% with HIV have multiple lesions. More likely than toxo if multiple. If single lesion then equal likelihood with toxo. Toxo is the most common cerebral mass in AIDS
Can cross corpus callosum
Ring enhancement in AIDS - central necrosis
High grade diffuse large B cell NHL, 350x risk in immunocompromised, EBV associated (low grade lesions are more commonly T cell)
131
Toxoplasmosis v lymphoma
Lymphoma subepenymal spreaf cf toxo scattered through basal ganglia and gray white junction
Toxo ring enhances
Haemorrhage occasionally in toxo, rare in lympho before treatment
Lympho increases choline cf. reduced in toxo
Thalium uptake in lympho, not in toxo
Increased CBV in lympho, decreased in toxo
132
Carotid angiogram
Internal 8 at 2
133
PML v HIV encephalopathy
PML JC virus
PML involves subcortical U fibres and is patchy, multifocal, subcortical and periventricular. Doesn't enhance.
PML 5% of AIDS, low CD4 <100
HIV symmetric atrophy and white matter disease, sparing subcortical U
HIV encephalopathy in 1/3-2/3
134
Radiotherapy, brain
Can increase lactate (as can necrotic tumours in general, and infection)
Normal markers low in radiation, whereas choline increased in tumour recurrence
135
CJD
```
Variant live a few years, younger onset age
Predominantly grey matter disease
Frontal and temporal lobes more common
Mild atrophy
Diffusion restriction
```
Pulvinar sign - bilateral FLAIR hyperintensity in posterior nucleus of thalamus (may involve another nucleus and be a hockey stick)
Hot cross bun sign in pons may be seen in vCJD and multisystems atrophy - cross of T2 hyperintensity in the pons
136
Cerebral aneurysm associations
```
Ehlers Danlos and Marfans
ADPKD - 10%
Bicuspid aortic valve
Coarctation
FMD
NF1
Cerebral AVM
alpha1antitrypsin
Thoracic and abdominal aneurysm
Hereditary haemorrhagic telangiectasia
```
137
Meningioma
10% multiple
Hyperostosis does not indicate infiltration
Intraventricular (5%) have a propensity for trigone - most common trigonal mass
138
Neurosarcoid
Hydrocephalus most common finding
Meninges and cranial nerves more involved than brain
Enhancing nodules
5% of patients with sarcoid - can be first presentation
Hypothalamic / pituitary dyfunction in 5-10%
139
Townes, Waters
Townes AP from 30 degrees cephalid, for skull fractures
| Waters PA with chin up 37 degrees, mostly for facial fractures
140
Central neurocytoma
Young adults, body of lateral ventricle arising from septum pellucidum, or superolateral wall
(meningioma more commonly trigonal and choroid plexus 4th ventricle)
WHO 2
Rarely causes acute ventricular obstruction
Hyperattenuation, punctate calcs, cystic change
Mild to moderate enhancement, T2 high
141
Huntingtons
Caudate nucleus atrophy, lesser extend putamen
Neurodegenerative
AD trinucleotide repeat 4p
142
Floating teeth
Alveolar bone destruction / lamina dura
Periodontal disease, LCH, HPT
Tumours (benign and malignant) and infection
Dahnert also says Pagets
143
Teeth cyst terminology
Radicular cyst = apical cyst
Dentigerous cyst = folliculuar cyst
Fissural cyst - midline mandicle or maxilla, displace roots of teeth
Eruption cyst / eruption haematoma, soft tissue analogue of dentigerous cyst (<10 years, related to crown)
Fissural cyst - historic term for non-odontogenic cyst
Most common is nasopalatine cyst, midline maxilla
Displace teeth roots
144
Atlanto-axial subluxation
Congenital, arthritides, acquired
```
C:
OI
Downs (20%)
NF1
Marfans
Morquious
Sponyloepiphsyeal dysplasia
```
```
A:
RA
Psoriatic
Reiters
Ank spond
SLE
```
Ac:
Trauma
Retropharyngeal abscess / Grisel (inflammmatory ligamentous laxity following retropharyngeal abscess, causing torticollis)
145
Susac
.
146
Transverse myelitis
.
147
Basal ganglia calcification
.
148
Thyroid cancer, age
Papillary and medullary, 20-40
Follicular, 40-60
Anaplastic, 50-70
149
Adenoid cystic carcinoma
.
150
Mucoepidermoid carcinoma
.
151
Mucocele
Most common in frontal and ethmoidal (75%), then maxillary (20%), then sphenoid
152
Normal pressure hydrocephalus
CSF flow rate >24.5mL/min 95% specific
| Narrow callosal angle (50-80 cf. normal of 100-120)
153
Dural enhancement
Infection (TB, fungal, syphilis - granulomatous)
Mets (breast, lung, prostate, melanoma, lymphoma. Neuroblastoma and leukaemia in children)
Sarcoid
LCH
Intracranial hypotension
Extramedullary haematopoiesis
RA
154
Cystic hygroma / lymphangioma
Generally don't extend into sublingual space - otherwise can mimic ranula
Often trans-spatial
Uni or multiloculated
Imperceptible wall
Can be suprahyoid (esp submandibular, masticator), or infrahyoid (esp posterior triangle)
20% axillary, 3-10% mediastinum
Present at birth in 50-65%, evident by 2 years in 80-90%
50-80% associated with aneuploidy. Turners > Downs
Non aneuploidic associations e.g. coarctation
Development of non-immune hydrops = poor prognosis
Treated by surgical excision or sclerosing injection
155
150,151, 146-148,99 (all minus 1) 55, 99
.
156
McDonald criteria
.
157
Chasing the dragon
```
Toxic leukoencephalopathy (various other drugs can cause this e.g. cyclosporin, metronidazole, methotrexate. It is white matter change, particularly splenium of corpus callosum)
Inhaled heroin fumes
```
Posterior limb of internal capsule
Butterfly wing involvement of cerebellar hemispheres
158
Leptomeningeal mets
Lung, breast
Melanoma
Lymphoma
Leukaemia
159
Dural mets
Breast, prostate, lung
Head and neck
Haematological
Neuroblastoma
160
DAI
Grade 1 is subcortical
Grade 2 is corpus callosum also - typically body and splenium, advances anteriorly in more severe injury.
Grade 3 brainstem. Apparently often corticospinal tract often, which runs anteriorly, and medial lemniscus (touch vibration proprioception), which run dorsally in the spinal cord at least
