Neuroradiology Flashcards
1
Q
DDx cystic sellar lesions
A
- Rathke cleft cyst
- Arachnoid cyst
- Craniopharyngioma
- Epidermoid cyst
- Dermoid cyst
2
Q
DDx pineal gland tumors
A
- Pineal cyst
- Germ cell tumors (germinoma, non-germinoma: choriocarcinoma, embryonal cell carcinoma, teratoma); engulfs calcium
- Pineoblastoma (exploded calcium)
- Pineocytoma
- Metastases
3
Q
What is Tolosa-Hunt Syndrome?
A
Tolosa-Hunt Syndrome is an idiopathic granulomatous inflammation of the cavernous sinus hat typically presents with painful ophthalmoplegia with involvement of one or multiple cranial nerves located in the cavernous sinus and superior orbital fissure.
4
Q
DDx for a unilateral cavernous sinus mass
A
- Schwannoma
- Meningioma
- Lymphoma
- SCC via perineural spread
- Sarcoidosis
- Tolosa-Hunt Syndrome
- Thrombophlebitis
- Fungal infections
- Aneurysm
5
Q
What disease is associated with a cotton wool appearance of the skull?
A
Paget’s disease
6
Q
DDx for jugular foramen tumors
A
- Glomus jugulare (salt and pepper; erosive bone changes)
- Schwannoma (can be cystic; bone remodeling without destruction)
- Meningioma
- Rare (chondrosarcoma, hemangiopericytoma, plasmacytoma)
7
Q
DDx calcified brain metastases
A
- Breast cancer
- GI mucinous adenocarcinoma
- Papillary thyroid
- Osteosarcoma
- Ovarian
8
Q
What are typical findings of intracranial hypotension?
A
Classic triad: (rarely see all signs)
- Diffuse dural thickening/enhancement
- Downward displacement of brain through incisura (“slumping” midbrain)
- Subdural hygromas/hematomas
(4. distended dural sinuses)
9
Q
What are findings of normal pressure hydrocephalus?
A
- Lateral ventricles enlarge +/- aqueductal flow void
- Transependymal flow
- Enlarged basal cisterns, sylvian fissures; normal sulci
- CC bowed upward or CC thinning
- crowding of the gyri at the vertex
10
Q
What are typical findings of increased intracranial pressure?
A
- Partial empty sella
- Dilation/tortuosity of optic nerve sheath
- Flattening of posterior sclera
- increased fluid around optic nerves
- MRV to exclude dural sinus thrombosis/stenosis
11
Q
What features make up the Mondini malformation of the cochlea?
A
Triad of:
1) 1.5 turns of the cochlea
2) enlarged vestibule with normal SC canals
3) enlarged vestibular aqueduct
12
Q
What is Pendred syndrome?
A
Bilateral SN hearing loss and goitre
Most common cause of syndromic hearing loss
13
Q
What is Michel aplasia?
A
aka complete labyrinthine aplasia, is a congenital abnormality of the inner ear and is characterized by bilateral absence of differentiated inner ear structures with resultant anacusis
14
Q
Absence of the semi-circular ducts is frequently associated with what congenital syndrome?
A
CHARGE syndrome (coloboma, heart defects, atresia [choanal], retardation, genital hypoplasia, ear abnormalities/deafness)
15
Q
What is the normal size of the vestibular aqueduct?
A
Should not exceed 1.5 mm or the width of the posterior semicircular canal
16
Q
What is the classic triad of Gradenigo syndrome?
A
1) petrous apicitis
2) CN 6 palsy
3) Trigeminal neuralgia or retro-oribtal pain
17
Q
What are the 3 most common expansile masses at the petrous apex?
A
- Cholesterol granuloma
- Cholesteatoma
- Mucocele
18
Q
What is a cholesterol granuloma?
A
Foreign body giant cell reaction to cholesterol deposits occurring in obstructed fluid-filled air cells developing a recurrent cycle of hemorrhage and granulation.
19
Q
What is a cholesteatoma?
A
Cholesteatoma is histologically equivalent to an epidermoid cyst and is composed of desquamated keratinizing stratified squamous epithelium forming a mass. Usually present with conductive hearing loss.
20
Q
What are the most common tumors at the CP angle (4)?
A
“AMEN”
- Acoustic schwannoma (~80%)
- Meningioma (~10%)
- Ependymoma (~5%)
- Neuroepithelial cyst (epidermoid/arachnoid) (~5%)
21
Q
What are typical MR findings of metachromatic leukodystrophy?
A
- symmetric confluent T2 hyperintensity periventricular and deep WM
- Tigroid pattern: sparing of perivenular WM
- Early: spares subcortical U-fibers
- Later: involves U-fibers and atrophy may be present
22
Q
What are imaging features of Chiari I malformation?
A
- Peg-like cerebellar tonsils > 5 mm below foramen magnum
- may see assoc syringohydromyelia
- may see elongation of the fourth ventricle
23
Q
What is Stenson’s duct?
A
Parotid gland duct
24
Q
What is Wharton’s duct?
A
Submandibular gland duct
25
What is the major duct of the sublingual gland called?
Bartholin duct
26
What is Plummer disease?
toxic adenoma within multi nodular goiter or just toxic MNG
27
Which brain metastases have increased T1 signal before contrast administration?
-melanoma, kidney, lung, choriocarcinoma and bowel (due to mucin)
28
What brain tumors may be low on T2-WI?
- CNS lymphoma
- PNET
- mucinous-adeno metastases (GI, lung, breast, GU)
- melanoma met
- germinoma
- GBM can be
- Calcificied masses (e.g. meningioma)
- Blood (old hemorrhage in tumor or vascular malformation)
29
What are possible causes of PRES?
Many aetiologies with HTN
- Acute/subacute systemic HTN
- Pre-eclampsia, eclampsia
- Drug toxicity (e.g. cisplatin, cyclosporine)
- Uremic encephalopathies
- Thrombotic microangiopathies (DIC, TTP)
30
What is the pattern of inheritance for NF 2? Which chromosome?
- AD
| - Chromosome 22
31
What does MISME in NF 2 stand for?
Multiple inherited schwannomas, meningiomas, and ependymomas
32
What is the pattern of inheritance for NF 1? Which chromosome?
- AD; but 50% new mutations
| - chromosome 17q11.2
33
```
Which one of the following is MOST likely to cause a jugular foramen mass?
A. Paraganglioma
B. Astrocytoma
C. Schwannoma
D. Meningioma
```
A. Paraganglioma is the most common tumor of the jugular foramen.
34
What structures are located within the cavernous sinus?
- cavernous ICA
- CN 3, 4, V1, V2 (laterally)
- CN 6 (medially)
- venous plexus
35
Perineural spread of neoplasm involves which cranial nerves most commonly?
CN V and VII
36
DDx for ring-enhancing cerebral lesions
"MAGIC DR"
- metastases
- abscess
- GBM
- infarct (subacute phase)
- contusion
- demyelinating disease
- radiation necrosis or resolving hematoma
37
What is the Chamberlain line? What is its significance?
The Chamberlain line extends from the posterior margin of the hard palate to the opisthion (posterior margin of the foramen magnum). It is abnormal if the tip of the odontoid projects >5 mm above this line.
38
What syndromes may involve the craniovertebral junction and cause atlantoaxial instability?
- Klippel-Feil syndrome
- Down syndrome
- Connective tissue disorders, such as Ehlers-Danlos
- Inflammatory conditions such as RA
- Achondroplasia
- Mucopolysaccharidoses
- Osteogenesis imperfecta
39
What are the common locations for cysticercosis?
1) Hematogenous spread produces lesions at the GW junction
2) intraventricular lesions
3) subarachnoid space lesions (racemose type) are the third most common site
40
When does acute disseminated encephalomyelitis (ADEM) occur?
1 to 3 weeks after nonspecific viral illness (may be subclinical) or vaccination
41
What are typical clinical findings of CJD?
Rapid progression of dementia, myoclonus, and mutism
42
What are the MR findings of CJD?
-symmetric high signal in the basal ganglia (better seen on DWI), no enhancement, bilateral symmetrical involvement of the thalamic pulvinars is typical, and the occipital cortex may also be involved. CT usually only shows atrophy.
43
What is Rasmussen encephalitis?
It is a chronic focal encephalitis that is progressive and unilateral. Etiology is uncertain, but likely viral then autoimmune.
Late disease shows unilateral cortical atrophy with ex-vacuo ventricular dilatation. T2 hyperintense in the affected hemisphere. May have restriction. No significant post-contrast enhancement.
44
What is the most common leukodystrophy?
Metachromatic leukodystrophy (1:100,000 newborns)
45
DDx for dural ectasia
- NF 1
- Ankylosing spondylitis
- Marfan syndrome
- Ehler Danlos syndrome
- Osteogenesis imperfecta
- Post traumatic
46
DDx solitary parotid gland mass
- Pleomorphic adenoma (benign mixed tumor; most common; 10-25% risk of malignant transformation)
- Warthin tumor (second MC; cigarette smoking; may have cysts)
- Lymphoma
- Mets
- Mucoepidermoid/ACC
- Acinic cell carcinoma
- First branchial cleft cyst
- Oncocytoma
- Neurogenic tumor
- Lymphangioma
47
DDx nasal cavity mass
- Nasal polyp
- Juvenile angiofibroma (very vascular)
- Inverting papilloma (cerebriform pattern; 5-15% risk of degen into SCC)
- SCC (usually make smokers)
- Olfactory neuroblastoma (esthesioneuroblastoma)
- Encephelocele (rarely)
48
DDx bilateral parotid gland lesions
- benign lymphoepithelial cysts (HIV)
- Sjogren syndrome
- Warthin tumor
- lymphoma
- metastatic lymphadenopathy
- sarcoidosis
- Oncocytoma
49
DDx suprasellar mass in adults
"SATCH MOE"
- Suprasellar adenoma
- Aneurysm
- Teratoma
- Craniopharyngioma (arise from Rathe's cleft; age 40s, typically calcified and cystic)
- Histiocytosis; Hypothalamic glioma
- Meningioma; Metastases
- Optic nerve glioma
- Eosinophilic granuloma; Epidermoid cyst
50
How can you differentiate between pineal germinoma and pineoblastoma?
- Germinoma tends to have "central engulfed calcium".
- Pineoblastoma tends to "blast" the calcium outwards.
- Germinomas show higher ADC values than pineal cell tumors.
51
What disease is associated with salt and pepper skull?
Hyperparathyroidism
52
DDx posterior fossa tumors in children
"BEAM"
- Brainstem glioma (tectal, pontine, diffuse intrinsic pontine glioma); causes mass effect on floor of the 4th ventricle
- Ependymoma
- Astrocytoma (pilocytic)
- Medulloblastoma
53
What structures go through Foramen Ovale?
"OVALE"
- Otic ganglion (situated directly under the foramen)
- V3 cranial nerve (mandibular nerve)
- Accessory meningeal artery
- Lesser petrosal nerve (of CN IX)
- Emissary veins (from the cavernous sinus to the pterygoid plexus)
54
What runs through Foramen Spinosum?
- Middle meningeal artery
| - Posterior trunk of the middle meningeal vein
55
What runs through Foramen Rotundum?
Rotunda connect the middle cranial fossa and the pterygopalatine fossa.
-CN V2 (maxillary nerve) passes through and exits the skull
56
What are the branches of the external carotid artery?
"Some Anatomists Like Freaking Out Poor Medical Students"
```
From inferior to superior:
-Superior thyroid a (arises from anterior aspect)
-Ascending pharyngeal a (medial deep aspect)
-Lingual a (ant. aspect)
-Facial a (ant. aspect)
-Occipital a (post. aspect)
-Posterior auricular a (post. aspect)
Terminal branches:
-Maxillary a
-Superficial temporal a
```
57
Where is Meckel's cave? What is located there?
- Situated posterolateral to the cavernous sinus on either side of the sphenoid bone
- Trigeminal ganglion (aka Gasserian or semilunar ganglion) lies within Meckel's cave
58
DDx of intradural, intramedullary lesions of the spine
- Ependymoma
- Astrocytoma
- Hemangioblastoma
- Lipoma/Epidermoid
- Syringohydromyelia
- Intramedullary AVM
- Rare site: metastasis, abscess
59
DDx of intradural, extramedullary lesions of the spine
- Meningioma
- Schwannoma/neurinoma
- Neurofibroma
- Hemangiopericytoma
- Lipoma/Epidermoid
- Arachnoid cyst, adhesion
- Drop or leptomeningeal metastasis
- Veins (extramedullary AVM)
60
DDx of extradural lesions of the spine
```
Degenerative:
-Herniated disc, diskal cyst
-Synovial cyst
-Osteophyte
-Rheumatoid pannus
Non-degenerative:
-Metastasis
-Epidural Abscess
-Epidural hematoma
-Primary tumor expansion or invasion
-Epidural lipomatosis
```
61
What is the most common tumor involving the filum terminale?
Myxopapillary ependymoma (>90% of tumors in this region)
62
DDx for neoplasms of the caudal equina
- Myxopapillary ependymoma
- Schwannoma
- Paraganglioma
- Intradural metastases
- Hemangioblastoma
- Meningioma
- Astrocytoma
- Spinal PNET
- Ganglioglioma
- Lipoma of the filum terminale
- Dermoid/Epidermoid
63
Medulloblastomas are associated with which syndromes?
- Gorlin syndrome
- Turcot syndrome
- Li-Fraumeni
- Cowden
- Gardner
64
What are the entrances/exits of the pterygopalatine fossa?
Posteriorly:
-Foramen rotundum: middle cranial fossa
-Vidian canal: middle cranial fossa, foramen lacerum
-palatovaginal canal (pharyngeal): nasal cavity/nasopharynx
Anteriorly: inferior orbital fissure: orbit
Medially: sphenopalatine foramen: nasal cavity
Laterally: pterygomaxillary fissure: infratemporal fossa
Inferiorly:
-Greater palatine foramen
-Lesser palatine foramen
65
Which is the most common odontoid fracture?
Type II
66
Which odontoid fractures are stable or unstable?
Type 1: fracture of the upper part of the odontoid peg; usually considered stable
Type 2: fracture at the base of the odontoid; risk of non-union; unstable
Type 3: through the odontoid and into the lateral masses of C2; relatively stable if not excessively displaced
67
What is Powers ratio?
Powers ratio defines a normal relationship between the base of the skull and the atlas. Length of a line drawn from the basin to the spinolaminar line of C1 divided by the length of a line drawn from the opisthion to the posterior margin of the anterior arch of C1. If the ratio is
68
What does MELAS stand for?
Myopathy
Encephalopathy
Lactic Acidosis
Strokes
69
What are MRI findings of MELAS?
Large cerebral infarctions involving both white (parieto-occipital) and gray (deep nuclei) matter.
70
What are MRI findings in Wilson Disease?
MRI shows high T2 and FLAIR signal in the basal ganglia (particularly lateral putamina) and claustra; high signal intensity in the midbrain with preservation of low T2 signal in red nuclei and substantial nigra is typical ("Panda face" sign). DWI may show some restriction of diffusion in these areas.
71
What are MRI findings in Wernicke Encephalopathy?
MRI shows high T2 and FLAIR SI in medial thalamic and periaqueductal gray matter, and contrast enhancement of mammillary bodies. MRS shows low metabolites, but high lactate is occasionally present.
72
What is Marchiafava-Bignami syndrome?
Marchiafava-Bignami disease (MBD) is a rare CNS disorder usually seen in the context of alcoholism and malnutrition. The condition classically involves the corpus callosum with necrosis and demyelination. Typically begins in the CC body and later involves the genu and then splenium.
73
What are MRI findings in chronic liver disease?
Chronic liver dz is characterized by high T1 signal in the basal ganglia, dorsal brainstem and adenohypophysis resulting from manganese deposition.
74
DDx for symmetrical basal ganglia calcifications
- Idioatphic/senescent
- Hypo- or hyperparathyroidism
- Fahr's disease (familial idiopathic cerebral ferrocalcinosis)
- Postinflammatory conditions
- Post anoxia
- AIDS in children
- Cockayne's disease
75
What are the MRI findings of Huntington Disease?
- MRI shows atrophy of caudate nuclei (particularly their heads) and putamina; diffuse atrophy is also present. Occasionally these areas show high T2 and FLAIR and signal.
- Increased iron deposition in basal ganglia is seen as low signal on T2/FLAIR
76
What is the most common cause of medically intractable complex partial seizures?
Hippocampal sclerosis
77
What is the most common finding of hippocampal sclerosis?
- Loss of volume (>80%)
- high SI on T2WI/FLAIR is seen in 10% to 70%
- Bilateral in 10-15%
78
What are MRI findings of Alzheimer Disease?
MRI shows diffuse atrophy, marked atrophy of the hippocampi, areas of increased T2 and FLAIR SI in the WM (more than expected for age), increased T2 and FLAIR SI in the cortex of the temporal lobes, and icnreased deposition of iron in parietal regions and BG.
79
What are MRI findings of multisystem atrophy?
- Severe atrophy of the brainstem and cerebellum
- High T2 and FLAIR signal in the pons (base may have a "hot cross bun" appearance)
- Increased iron deposition in BG (dark T2)
- Generalized brain atrophy
80
What disease is associated with the "hummingbird" sign?
Progressive supra nuclear palsy (PSP)
81
What are MRI findings of carbon monoxide intoxication?
Necrosis of the globus pallidi (also hippocampi and cortex) and diffuse brain swelling. Acutely these regions may show restricted diffusion.
82
What are MRI findings in Methanol intoxication?
- Bilateral hemorrhagic (bright T1) putaminal necrosis is characteristic
- Hemorrhagic subcortical necrosis
- White matter hypointense lesions (confluent hemispheric ± optic nerves)
- Lesions usually restrict and may also enhance
83
What MRI findings are seen in liver failure and total parenteral nutrition?
- May cause increased SI in the BG on T1WI while they appear normal on T2WI and have no corresponding abnormalities on CT. (related to deposition of paramagnetic cations, particularly manganese; no correlation with hepatic encephalopathy)
- BG may become normal about 3 months after liver txx or discontinuation of TPN
84
What are the most common sites of involvement in pontine and extrapontine osmotic myelinolysis?
- Pons is the most common site (75% with central pontine)
- Followed by midbrain, thalami, BG, and WM (10% with extrapontine myelinolysis)
- Affected areas show high T2, FLAIR, DWI
85
What are imaging findings of Hyperglycemia?
- CT shows increased density in striatum (caudate nucleus head and putamen); and no contrast enh
- MRI shows increased T1 SI in striatum, generally with no corresponding T2 abn or only mild increased SI; DWI may show restriction
86
What are imaging findings of Hypoglycemia?
- Parietal/temporal/occipital lobes, basal ganglia, ± hippocampi
- Hyperintensity in parietooccipital cortex and basal ganglia
- Thalami, subcortical/deep white matter and cerebellum generally spared
- Restricted diffusion, ↓ ADC (may be transient)
- ↓ NAA, ↑ lactate
87
What is Ramsay-Hunt syndrome?
Ramsay Hunt syndrome (RMS), also known as herpes zoster oticus, is essentially shingles of the facial nerve. Latent infection is present in the geniculate ganglion with painful vesicles showing in the external acoustic meatus, tympanic membrane and pinna associated with facial palsy.
88
What condition is associated with Notch 3 gene mutation?
CADASIL results from a mutation on chromosome 19q12 involving the Notch 3 gene.
-Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is an autosomal dominant microvasculopathy, characterised by recurrent lacunar and subcortical white matter ischaemic strokes and vascular dementia in young and middle age patients without known vascular risk factors.
89
What is the classic triad of tuberous sclerosis?
Facial angiofibromas, seizures (80-100% of pts), and mental retardation
"zits, fits, and nitwits"
90
What chromosomes are involved in tuberous sclerosis?
Chromosomes 9q34.3 (hamartin) and 16q13.3 (tuberin); autosomal dominant
91
Von-Hippel-Lindau disease is linked to a defect in which chromosome?
What is its pattern of inheritance?
- chromosome 3 (defective tumor suppressor gene)
| - autosomal dominant
92
DDx dural-based mass
- Meningioma
- Hemangiopericytoma (flow voids)
- Lymphoma (iso- to hypo- T2)
- dural based metastasis (e.g. breast, lung, prostate)
- solitary fibrous tumor
- melanocytic lesions
- Rosai-Dorfman disease (rare, benign histiocytosis a/w painless cervical adenopathy)
- Erdheim-Chester disease (rare non Langerhans cell histiocytosis)
- TB
- Neurosarcoidosis
- EBV associated smooth muscle tumors (leiomyoma and leiomyosarcoma) in AIDS patients
93
DDx hyperintense T1 basal ganglia
- methaemoglobin in intracranial hemorrhage
- calcium (idiopathic calcification, calcium and phosphate abnormalities)
- hepatic failure/encephalopathy
- hamartoma in NF type 1
- hyperalimentation or long term parenteral nutrition (manganese)
- carbon monoxide
- Wilson's disease (copper)
- acquired non-Wilson's hepatocerebral degeneration
- haemorrhagic infarct
- Japanese encephalitis
- global hypoxia
- hyperglycemia associated chorea-ballism: non-ketotic hyperglycaemic hemichorea (NHH)
94
DDx cyst plus nodule appearance brain lesion
-pilocytic astrocytoma (peds usually)
-hemangioblastoma
-pleomorphic xanthroastrocytoma (PXA)
-ganglioglioma
-cystic metastases
-possibly GBM
-Infections (neurocysticercosis and too)
(Radprimer)
95
What is are typical imaging features of vertebral hemangioma on CT and MRI?
- CT: thickened trabeculae ("corduroy pattern" on sag reformation and "salt and pepper" pattern in axial images)
- MRI: high SI on T1; may be slightly high SI on T2WI and show contrast enhancement
- Occasionally, aggressive hemangiomas show lower SI on both T1 (less fat) and T2, and are indistinguishable from metastases.
96
Where are chordomas most commonly found?
Chordomas arise from notochord remnants at the sacrum (50%) (most common primary sacral tumor), clivus (35%), and cervical and thoracic regions (15%).
They are locally aggressive and mets are seen in 10% to 40% of patients.
97
What are modic changes of the spine and their signal characteristics (types 1, 2 and 3)?
Modic type endplate changes represent a classification for vertebral body end-plate MRI signal. It is widely recognised by radiologists and clinicians and is a useful shorthand for reporting MRIs of the spine.
Modic type I (represents bone marrow oedema and inflammation)
T1: low signal
T2: high signal
Modic type II (represents normal red haemopoietic bone marrow conversion into yellow fatty marrow as a result of marrow ischaemia)
T1: high signal
T2: iso to high signal
Modic type III (represents subchondral bony sclerosis)
T1: low signal
T2: low signal
98
In vertebral compression fracture, what MRI features suggest a benign etiology?
- lack of accompanying soft tissue mass
- preservation of posterior cortical margin and wedge shape
- preservation of normal bone marrow signal intensity
- bone fragment in canal
- gas or fluid in vertebral body
- dark T2 line of compacted bone at fracture site
- little to no contrast enhancement
99
In vertebral compression fracture, what MRI features suggest a malignant/pathological etiology?
- Soft tissue mass especially in ventral epidural space
- absent well-defined bone margins
- enhancing soft tissues
- lesions in other vertebrae
- restricted diffusion
100
DDx nasopharyngeal space mass
-SCC (>80%)
-adenocarcinoma
-minor salivary gland tumors
-lymphoma
(Tumors begin in the fossa of Rosenmuller and hav elocal extension with initial metastases to the lateral retropharyngeal nodes of Rouviere, spinal accessory [level 5] nodes, and lastly to the IJV nodes [levels 2, 3, 4])
101
DDx paraphyarngeal space mass
- Prestyloid compartment (80% of massess occur here and ar mostly pleomorphic adenomas), and poststyloid compartment (20% of masses arise here and are mostly neurogenic tumors and paragangliomas).
- In children, consider second brnchail cleft cysts, abscesses, and pleomorphic adenomas.
102
DDx parotid space mass
-For a child: hemangioma, lymphangioma, first branchial cleft cyst, and pleomorphic adenoma
-For pts with AIDS: consider benign lymphoepithelial cysts, infection, and lymphoma
-In adults:
--benign mixed tumor (pleomorphic adenoma) (>80%)
--Warthin tumor (esp. in older men with bilateral parotid masses)
--mucoepidermoid carcinoma
--adenoid cystic carcinoma
--mets
--lymphoma
[MRI reveals that benign tumors are hyperintense on T2WI, while malignant tumors are hypointense on T2WI
103
DDx retropharyngeal space mass
- Most commonly inflammatory/infectious process (e.g. reactive adenopathy or abscesses)
- In adults, LN's here are suspicious for mets until proven otherwise
- Other ddx: hemangioma, lipoma, lymphoma an ddirect invasion by carcinoma
104
DDx oral cavity and oropharyngeal space masses
- Only 7% of masses in the oral cavity and oropharyngeal space are malignant, but more than 90% of malignancies are SCC, followed by lymphoma, adenoid cystic carcinoma, mucoepidermoid carcinoma, and adenocarcinoma.
- In children, the most common lesions at this location are hemangioma, lymphngioma or cystic hygroma, and tonsillar abscesses
105
DDx masticator space masses
- odontogenic infections (may track superiorly under the temporalis muscle)
- primary or secondary bone tumors
- neurogenic tumors
- lymphoma
- invasion from SCC originating in the retromolar triangle
106
DDx sublingual space mass
- SCC
- tumors of the sublingual gland
- cellulitis or abscess
- calculi
- ranulas
- lymphangioma
- epidermoid or dermoid
- ectopic thryoid
- hemangioma (in kids)
107
DDx submandibular space mass
- metastases
- invasion of SCC from the mouth
- submandibular gladn tumors
- lipoma
- epidermoid or dermoid
- ranulas
- infections
- second brnchial cleft cyst
- lymphangioma
108
DDx calcified lymph nodes in the neck
- TB
- treated lymphoma
- mets from neuroblastoma and papillary thryoid carcinoma
109
DDx of hemorrhagic LN's in the neck
-mets from RCC, thyroid and breast carcinomas
110
DDx cystic lymph nodes in the neck
- papillary thryoid mets
- SCC mets
- tuberculous lymphadenitis
- treated lymphoma
- others...
111
DDx carotid space mass
- carotid body tumor (paraganglioma arising at the CCA bifurcation, 10% are multiple, 10% are malignant, and they occur in the fifth decade of life)
- schwannoma (usually from the Vagus nerve)
- nodal metastases (from airway SCC or lymphoma)
- pseudoaneurysm
- extracranial meningiomas
112
What are the types of thyroid carcinomas?
- Papillary (>50%, has the best prognosis)
- follicular (20%)
- medullary (10%)
- anaplastic (>5%, worst prognosis)
- Hurthle cell (>2%)
113
Which thyroid malignancies tend to invade the trachea?
- Anaplastic carcinoma
| - Lymphoma
114
DDx paranasal sinus malignancy
- Squamous CC (80%)
- undifferentiated carcinoma
- lymphoma
- adenoid cystic carcinoma (10%)
- primary sarcomas (e.g. osteosarcoma and chondrosarcoma) are rare and destructive tumors that contain calcifications on CT
- Other processes such as mucormycosis or Wegener's granulomatosis could simulate a malignant appearance
115
What is the most common lesion of the petrous apex?
cholesterol granuloma- results from obstruction (due to Eustachian tube dysfunction) of aerated petrous bone apex with accumulation of secretions and repeated hemorrhage
[Not to be confused with congenital cholesteatoma (epidermoid) of he petrous apex, which is usually of CSF-like signal intensity on MRI]
116
What are the MRI characteristics of cholesterol granuloma?
Cholesterol granuloma is characteristically expansile and bright on both T1 and T2WI (due to presence of cholesterol crystals), and may show peripheral contrast enhancement.
117
What is the most common tumor of the middle ear in adults?
glomus tympanicum- generally occurs in women older than 30 years of age
-located at the cochlear promontory
118
What are the two types of otospongiosis (otosclerosis)?
Both types are characterized by development of fibrous and vascularized changes in bone that later on may result in new bone formation.
1) Fenestral (more common): affects the margins of the oval window and stapes footplate and produces conductive hearing loss; tx is stapedectomy
2) Retrofenestral (cochlear) type: the process affects the otic capsule (especially around the cochlea) and produces sensorineural deafness; tx is vitamin D, fluoride, or cochlear implant
119
What are the two most common causes of leukocoria?
1) retinoblastoma
2) persistent hyperplastic primary vitreous
Others: retinopathy of prematurity, congenital cataract, toxocariasis, Coats' disease
120
DDx intra-orbital mass
- cavernous hemangioma (most common intraconal tumor in adults)
- meningioma
- schwannoma
- lymphangioma
121
DDx enlargement of the lacrimal gland
- most often related to viral infections
- Sjogren's syndrome (lymphocytic infiltration of lacrimal glands with decrease lacrimation; a/w rheumatoid arthritis, SLE, or scleroderma)
- Mikulicz syndrome (nonspecific enlargement of salivary and lacrimal glands)
- sarcoid
- lymphoma/leukemia
122
What are the most common lacrimal gland tumors?
-benign mixed tumors or pleomorphic tumors (25%)
-adenoid cystic carcinoma (25%)
-lymphoma
-mets are rare
-Dermoids are the most common congenital lesion
(Neuroradiology Companion)
123
What disease entities are associated with inflammatory pseudotumor of the orbit?
- Wegener's granulomatosis
- fibrosing mediastinhtis
- autoimmune thyroiditis
- sclerosing cholangitis
124
In Graves' ophthalmopathy, what is the order of muscle involvement?
```
"IM SLOw"
-inferior rectus
-medial rectus
-superior rectus
-lateral rectus
-obliques
The tendon is typically spared (although it can be involved in acute cases) with the swelling largely confined to the muscle belly. This appearance if often referred to as 'coke bottle' in nature (coca-cola bottle sign).
```
125
What are possible complications of post-septal orbital cellulitis?
- ophthalmic vein and cavernous sinus septic thrombosis
- epidural and subdural empyemas
- cerebritis
- meningitis
126
DDx for "bubbly-appearing" intraventricular mass
- choroid plexus cysts
- xanthogranuloma
- Neurocysticercosis
- central neurocytoma
- ependymoma
- subependymoma
- epidermoid cyst
- cavernous malformation
- choroid plexus papilloma/carcinoma
127
At carotid Doppler ultrasound, what peak systolic velocities are associated with significant ICA stenosis?
- PSV of > 230 cm/sec corresponds to > 70% stenosis
- PSV of 125-230 cm/sec corresponds to 50-70% stenosis
- PSV of
128
When does radionecrosis typically occur?
3 to 12 months following radiotherapy?
129
What are MR characteristics of radionecrosis?
Rim of enhancement is usually fluffy and not nodular.
| Usually have low rCBV
130
DDx cyst with enhancing nodule in the posterior fossa
- Hemangioblastoma (more adults)
| - Pilocytic astrocytoma (more paediatric)
131
DDx cyst with enhancing nodule (supratentorial location)
1. Metastasis
2. Pleomorphic xanthoastrocytoma
3. Pilocytic astrocytoma
4. Ganglioglioma
5. DNET
132
DDx dural enhancing mass
- Meningioma
- Hemangiopericytoma
- Dural metastasis
- Lymphoma
- TB with dural involvement
- Sarcoidosis, histiocytosis
133
DDx cystic lesion in the sublingual space
- Ranula or diving ranula if extends posteriorly into the submandibular space
- epidermoid cyst
- cystic hygroma
134
What opening pressure is associated with intracranial hypertension?
Greater than 25 cm H2O
135
What is Parinaud syndrome?
- paralysis of upgrade gaze
- lid retraction
- abnormal pupillary reactions
136
At what time after an acute SAH is symptomatic vasospasm most likely to occur?
between the fifth and twelfth days
137
What structure separates the internal auditory canal into superior and inferior portions?
crista falciformis
138
What are two common vascular causes of acute bilateral thalamic lesions?
- Infarction of the artery of Percheron.
| - Deep venous thrombosis (internal cerebral veins).
139
What are the 3 most common locations of hypertensive bleeds?
1) basal ganglia
2) thalami
3) pons
(in order of decreasing frequency)
140
What syndrome/disease is associated with Lhermitte Duclos?
Cowden disease
141
What is moyamoya disease?
Moyamoya disease is an idiopathic, non inflammatory, non atherosclerotic progressive vasculo-occlusive disease involving the circle of Willis, typically the supraclinoid internal carotid arteries.
142
What is moyamoya syndrome?
Moyamoya syndrome, also termed the moyamoya pattern or phenomenon, is due to numerous conditions that can cause arterial occlusion of the circle of Willis, with resultant collaterals, and appearances reminiscent of moyamoya disease.
143
What are possible causes of moyamoya syndrome?
"RAINS" = radiation, atherosclerosis, idiopathic, NF1, sickle cell
- atherosclerosis
- cranial radiotherapy
- neurofibromatosis type 1(NF1)
- tuberous sclerosis (TS)
- connective tissue disorders
- --systemic lupus erythematosus (SLE)
- --antiphospholipid syndrome
- collagen vascular
- --Marfan syndrome
- --Ehlers-Danlos syndrome
- haemoglobinopathies
- --sickle cell disease
- infection
- --tuberculous meningitis
- --bacterial meningitis
- --post-varicella vasculitis
144
How can you differentiate recurrent brain tumor from radiation necrosis?
Radiation necrosis will show very low relative cerebral blood volume (rCBV), as well as very low choline levels at MR spectroscopy.
145
DDx for bilateral middle cerebral peduncle involvement
- MS
- Lymphoma
- Neurodegenerative: fragile-X associated tremor/ataxia syndrome (FXTAS)
- Encephalitis
- Metabolic: Wilson's, Adrenoleukodystrophy
- HIV encephalopathy
146
DDx for bilateral symmetric extensive white matter involvement
- drug toxicity/abuse
- end stage MS
- Metachromatic leukodystrophy (adult onset leukodystrophy)
- Encaphalitides
- Metabolic: Wilson's or Adrenoleukodystrophy
- HIV encephalopathy
147
DDx for anterior temporal lobe WM change
- CADASIL
- Extensive microvascular disease
- MS
- Vasculitis
- Radiation
148
What is the triad of lesions seen in septa-optic dysplasia (deMorsier's syndrome)?
1) Complete or partial absence of the septum pellucid
2) Optic nerve hypoplasia
3) Hypothalamic-pituitary dysfunction, which typically manifests as growth retardation and short stature. There may be an ectopic posterior pituitary gland.
149
DDx benign-appearing expansile petrous apex mass
- cholesterol granuloma
- epidermoid cyst
- mucocele
- meningocele
- occasionally aneurysm of the ICA
150
What is the characteristic MRI appearance of metachromatic leukodystrophy?
Confluent, symmetric WM abnormality that begins in the frontal lobes and progresses posteriorly. There is usually relative sparing the subcortical U-fibers and the WM within the basal ganglia.
151
DDx for intraventricular neoplasms
"MENCHS"
- Meningioma
- Ependymoma/Subependymoma
- Neurocytoma (attached to septum pellucidum)
- Choroid plexus papilloma
- Hematologic metastases
- Subependymal giant cell astrocytoma
152
DDx cyst with enhancing nodule
Pilocytic astrocytoma
Gangliogliomas
Hemangioblastomas
Pleomorphic xanthoastrocytoma (PXA)
153
DDx peripheral cortical tumors
"CHANGE OX"
- Cortical mets
- Hemangioblastoma
- Astrocytoma
- (D)NET
- Ganglioglioma
- Ependymoma
- Oligodendroglioma
- (pleomorphic) xanthoastrocytoma (PXA)
154
DDx for diffuse hyperintensity in the CSF on FLAIR
- SAH
- meningitis
- meningeal carcinomatosis
- superior sagittal sinus thrombosis
- status epilepticus
- renal failure
- hyperoxygenation
- leptomeningeal melanosis
- retained gadolinium
155
What are the 5 stages of neurocysticercosis?
- noncystic
- vesicular
- colloidal vesicular
- granular nodular
- calcified nodular
156
Which cranial nerves pass through the jugular foramen?
- pars nervosa?
- pars vascularis?
Anteromedial pars nervosa = CN 9 (glossopharyngeal)
| Posterolateral pars vascularis = CN 10 & 11 (vagus and spinal accessory nerves)
157
What is the most common malignant tumor of the parotid gland?
What is the most common mass in the parotid gland?
- 1st: mucoepidermoid carcinoma
- 2nd: adenoid cystic carcinoma
- Most common mass is a benign mixed tumor or pleomorphic adenoma
158
Most common malignant lacrimal gland tumor?
adenoid cystic carcinoma
159
Symptoms of Susac syndrome?
- sensorineural hearing loss
- acute or subacute encephalopathy which could manifest in a broad spectrum of symptoms, such as: memory impairment, confusion, behavioral disturbances, ataxia, dysarthria, paranoid psychosis, and headaches
- retinal arterial occlusions leading to scotomata and vision distortion
160
Causes of PRES?
- Severe HTN: post partum, eclampsia/pre-eclampsia, acute glomerulonephritis
- hemolytic uremic syndrome
- TTP
- SLE
- Drug toxicity (cisplatin, interferon, EPO, tacrolimus, cyclosporin, azathioprine)
- Bone marrow or stem cell transplantation
- sepsis
- hyperammonemia
161
List the 4 types of possible persistent carotid basilar artery anastomoses
1) persistent trigeminal artery
2) otic artery: courses via IAC
3) hypoglossal artery: courses via hypoglossal canal
4) proatlantal intersegmental: cervical ICA to V3 segment of vertebral artery
162
What is the most frequent neurological manifestation of human immunodeficiency virus (HIV) infection?
a) PML
b) HIV encephalitis
c) toxoplasmosis
d) CMV infection
b) HIV encephalitis
163
How do you distinguish between PML and HIV encephalitis?
HIV encephalitis typically presents on imaging with atrophy and bilateral T2 and FLAIR hyperintensity in the periventricular white matter and centrum semiovale with no enhancement. There is sparing of the subcortical U-fibers, which helps distinguish HIV encephalitis from progressive multifocal leukoencephalopathy.
164
What percentage of tumors of the parotid gland are benign? Submandibular gland? Sublingual gland?
- parotid 80%; submandibular 50%; sublingual 20%
- An easy way to remember the incidence of benign mixed tumor is that the percentage is large in the largest gland (80% in parotid), smaller in the mid-sized gland (50% in submandibular gland) and small in the smallest gland (20% in sublingual gland). The other 50% of tumors of the submandibular gland are malignant carcinomas (mostly adenoid cystic and mucoepidermoid carcinomas).
165
What are the signal characteristics of hemorrhage? (hyperacute, acute, early subacute, late subacute, chronic)
IB, ID, BD, BB, DD
"It Be, ID [itty], BD [bitty], BaBy, Doo-Doo"
Hyperacute (hours) (IB- iso/bright)
- intracellular oxyhaemoglobin
- isointense T1
- isointense to hyperintense on T2
Acute (1 to 2 days) (ID- iso/dark)
- intracellular deoxyhaemoglobin
- T1 remains intermediate-to-long
- T2 signal intensity drops (T2 shortening)
Early subacute (2 to 7 days) (BD)
- intracellular methaemoglobin
- T1 signal gradually increases (T1 shortening) to become hyperintense
- T2 dark
```
Late subacute (7 to 14-28 days) (BB)
-extracellular methaemoglobin: over the next few weeks, -as cells break down, extracellular methaemoglobin leads -to an increase in T2 signal
```
Chronic (>14-28 days) (DD)
-low T1 and low T2
166
Imaging features of Chiari II malformation?
-Antenatal US: lemon sign, banana sign
MRI:
- small posterior fossa with a low attachment of the tentorium and low torcula
- cervicomedullary "kink" (70%)
- brainstem appears 'pulled' down with an elongated and low lying fourth ventricle
- tectal beaking
- towering cerebellum compresses midbrain
- cerebellum "wraps" around the medulla
- cerebellar tonsils and vermis are displaced inferiorly through foramen magnum which appears crowded
- elongation of the 4th ventricle
- hydrosyringomyelia (20-90%)
167
What portions of CN 7 enhance normally?
Typically enhancement is seen:
- anterior genu (geniculate ganglion)
- posterior genu (between tympanic and mastoid segments)
- some enhancement can also be seen in the labyrinthine, tympanic and mastoid segments.
- proximal greater superfical petrosal nerve
No enhancement should be seen in:
- cisternal segment (that in the cerebellopontine angle)
- meatal segment (that in the internal acoustic meatus)
- extracranial segment (beyond the stylomastoid foramen)
168
DDx facial nerve enhancement (outside normally enhancing segments)
Inflammatory: Bell's palsy, Ramsay Hunt syndrome, sarcoid, Lyme disease
Neoplastic: lymphoma, perineurial mets, schwannoma, hemangioma
169
DDx pulsatile mass in the middle ear
- glomus tumor
- aberrant ICA
- high-riding jugular build
- persistent stapedial artery
170
DDx intrazonal intra-orbital lesions
"Mel Met Rita Mending Hems On Poor Charlie's Grave"
- Melanoma
- Metastasis
- Retinoblastoma
- Meningioma
- Hemangioma
- Optic glioma
- Pseudotumor
- Cellulitis
- Grave disease
171
DDx nasopharynx mass
"NASAL PIPE"
- Nasopharyngeal carcinoma
- Angiofibroma (juvenile)
- Spine/skull fracture
- Adenoids
- Lymphoma
- Polyp
- Infection
- Plasmacytoma
- Extension of neoplasm (sphenoid/ethmoid sinus ca)
172
Regions for ASPECTS
- caudate
- putamen
- internal capsule
- insular cortex
- M1: "anterior MCA cortex," corresponding to frontal operculum
- M2: "MCA cortex lateral to insular ribbon" corresponding to anterior temporal lobe
- M3: "posterior MCA cortex" corresponding to posterior temporal lobe
- M4: "anterior MCA territory immediately superior to M1"
- M5: "lateral MCA territory immediately superior to M2"
- M6: "posterior MCA territory immediately superior to M3"
