Diffuse astrocytic and oligodendrogial tumors Flashcards
1
Q
Diffuse astrocytoma, IDH mutant
A
ATRX, loss T2/FLAIR hyperintense, expansile, involves both cortex and white matter Vasogenic edema is absent Non enhancing ? Majority of diffuse astrocytomas CDKN2A/B retained -> WHO grade 2 or 3 CDKN2A/B homozygotely deleted or necrosis/MVP -> WHO grade 4 FLAIR-mismatch, age <40, size >6cm
2
Q
Oligodendroglioma, IDH mutant and 1p/19q codeleted
A
ATRX retained
T1 hypo
T2/FLAIR hyperintense
expansile, indistinct margins, hetergenenous, involves both cortex and white matter, frontal lobe
Vasogenic edema is absent
SWI - blooming (calcifications)
CE - variable 50% and not prognostic
DWI - normal
Moderatly elevated rCBV
PET - FDG - if as gray matter or MET/FET anaplastic
MRS - moderate Cho, decreased Naa, no lactate (anaplastic have lactate)
3
Q
Pilocytic astrocytoma
A
WHO grade 1
BRAF-fusion - MAPK-pathway - good prognosis
Most common pediatric tumor and most common pediatric cerebellar tumor
NF-1 (PA, optic pathway glioma)
expansive - cerbellum (60%)/cerebral hemispheres
- well circumsribed with solid part (T2/FLAIR hyper, T1 hypo, intense CE) and cystic part (+/-wall enhancement, fluid content (follows CSF)). No edema
infiltrative - elongating and widening of the optic nerve, T2 hyper, moderate CE
MRS - high Cho, latate doublets
DWI - high ADC
PWI - low rCBV, first-pass curve
new - high grade astrocytoma with piloid features (IDH wt, CDKN2A/B, ATRX)
4
Q
Pilomyxoid astrocytoma
A
WHO grade 2 BRAF V600E (substitution) Young children Hypothalamus/optic chiasm (60%) T2 hyper DWI - high ADC SWI - hemorrhage 20% intese heterogenous CE CSF dissimination is common
5
Q
Pleomorphic xhantoastrocytoma
A
WHO grade 2-3 BRAF V600E (substitution) Young adults cortical temporal lobe seizures dural attachement/tail well circumscribed Solid component (iso on CT, T1 and T2, FLAIR hyper) CE homo/heterogeneous marked vasogenic edema 50% cysts associated with cortical dysplasia, ganglioglioma
6
Q
Ganglioglioma
A
WHO grade 1 BRAF V600E (substitution) most common glionerual neoplasm, 1% of intracranial tumors glial component affects the biological behavior temporal, frontal lobe shrply/poorly margins, solid/cystic/ cyst with a nodule CT - low density no edema Ca 35% erosion of inner table of scull T2 hyper T1 variable signal CE - variable
7
Q
Hemangioblastoma
A
flow voids
peritumoral edema
elevated rCBV (8-10)
vHL
8
Q
Ependymoma
A
Anywhere in the CNS, posterior fossa
1-6y (supratentorial 18-24y)
3-5% of intracranial neoplasms
plastic - extends through foramina
Cysts
Calcification
Hemorrhage
DWI - mildly restricted
can seed
RELA - supratentorial, older children, poor prognosis
YAP1 - supratentorial, younger children, good prognosis
Posterior fossa A - young, lateral recess, poor prognosis
Posterior fossa B - older children, midline, good prognosis
9
Q
Medulloblastoma
A
DWI
10
Q
Causes of temporal lobe epilepsy
A
Mesial temporal sclerosis Ganglioglioma -40% DNET -20% Diffuse low grade astrocytoma -20% Other -20% (pilocytic astrocytoma, pleomorphic xantoastrocytoma, oligodendroglioma)
11
Q
Neurofibroma
A
WHO grad 1 NF1 fusiform no cyst/hemorrhage T1 hypo T2 hyper +/- hypo central (target sign) CE - heterogenous mild or no enhancement 3 types: localised intraneural (90%), diffuse cutaneous, plexiform
12
Q
Schwannoma
A
WHO grade 1 Antoni A/B growth pattern Local mass effect/nerve dysfunction CN (not olfactory (filia) or optic), vestibulocochlear is most common Round Cysts/hemorrhage/fatty degeneration Displace nerves NF2/schwannomatosis T1 iso/hypo T2 heterogenous SWI - hemosidering in larger tumors CE - strong Subtraction imaging for assessment of growth
13
Q
Meningioma of pontine angle
A
Dural base Dural tail Isointense with gray matter Perpendicular to nerves courses Homogeneous enhancement
14
Q
Multinodular and vacuolating tumor
A
parietal and temporal seizures juxtacortical cluster of tiny well-defined nodules T2/FLAIR hyper (ddx PVS) no edema no enhancement
15
Q
Dysembryoblastic neuroepitelial tumor
A
Supratentorial WHO grade 1 temporal and frontal seizures associated with cortical dysplasia wedge shape, multycystic "bubbly" T2 hyper FLAIR - bright rim sign enhancement 33% no edema remoddeling of adjecent bone ddx: diffuse astrocytoma, oligodendroglioma, pleomorphic xanthoastrocytoma, ganglioglioma)
16
Q
Gangliocytoma
A
Supratentorial
very rare
exclusive ganglion cells
17
Q
Desmoplastic infantile ganglioglioma
A
Supratentorial Very large tumor in 1st year frontal, parietal both cystic and solid poor prognosis ddx: teratomas, choroid plexus papilloma, AT/RT
18
Q
Papillary glioneural tumor
A
Supratentorial
19
Q
Central neurocytoma
A
Intraventricular (may be extraventricular) WHO grade 2 Young and middle age adults Third and lateral ventricles, attached to the septum pellucidum Ca 50-70% CT - mixed density T1 iso T2 bubbly FLAIR heterogeneous hydrocephalus is common CE - moderate/heterogenenous
20
Q
Rosette-forming glioneural tumor of the 4th ventricle
A
Infratentorial intraventricular
21
Q
Dysplastic gangliocytoma of the cerebellum (Lhermitte-Duclos)
A
Infratentorial parenchymal Cerebellum or vermis WHO grade 1 T2 striate pattern (hyper/iso) Cowdens syndrom (multiple hamartoma syndrome)
22
Q
Cerebellar liponeurocytoma
A
Infratentorial parenchymal
23
Q
Paraganglioma
A
filum terminale
WHO grade 1
very rare
increased vascularity - feeding vessel
24
Q
Myxopapillary ependymoma
A
WHO grade 2 (2021) children and young adults glial cell of filum terminale 83% of primary tumors in that area multiple in 43%
25
Embryonal tumors with multilayered rosettes
```
C19MC 95% - amplification (cluster of fetal neural tubes)
LIN28A - if present poor prognosis
under 2 years
poor outcome
Cerebral hemispheres 76%, cerebellum, brain stem, pre-sacral space, optic nerve
Large
heterogeneous (haemorrhage/Ca/cysts/necrosis)
may be exophytic
No edema
DWI - restricted
CE - mild/no
CT - hyperdense
```
26
Atypical teratoid rhabdoid tumor
WHO grade 4
2% of CNS tumors in children 10% under 1 y, can be congenital
INI1 gene - loss of tumor suppression
BRG1 gene
somatic or germ line mutation (rhabdoid tumor predisposition syndrome, kidney, lugns, skin, liver)
if no mutation (CNS embryonal tumor with rhabdoid features)
posterior fossa 52%, supratentoral 39%, pineal, spinal, multifocal
intra/extra axial
marginal cyst, calcification, haemorrhages
DWI - restricted
PWI - increased
MRS - high Cho, lipid peak, no creatin/Naa
rapid growth
CE - may not enhance
DWI to look for metastasis
27
Medulloblastoma
CT hyperdens
Calcification, haemorrhage, cysts, necrosis
T1
T2
Ce - no/homogeneous/inhomogeneous
DWI - restricted
SHH 25% hemispheric (A), mildine-intraventricular (B), midline-extraventricular/vermis (C)
WHT 11% midline - intraventricular (A), midline-cisternal (B), off-midline-intraforaminal (C), off-midline-intracisterna (D)
Group 3 + 4 65%, midline-intraventricular
MYC - poor prognosis
28
Desmoplastic medulloblastoma
younger than 3y
29
Keratocytic odontogenic
primary odontogenic, most common, uni-or multicystic, PTCH, mandible, tooth displacement and tooth resorption, tendency of recurrence, GorlinGoltz syndrome (multiple), DWI
30
Ameloblastoma
primary odontogenic, second most common, partially solid/multicystic, BRAFV600, unerupted 3rt molar, locally invasive mandible
31
Odontogenic myxoma
primary odontogenic, multilocular, expansile, well defined borders, honeycomb
32
Odontoma
primary odontogenic, malformation (hamartoma) compound (tooth) or complex (doesn’t look like tooth)
33
Osteoma
osteogenic, cortical, fronto-ethmoid, jaws (angle, coronoid process, condyle), Gardners syndrome (multiple)50-60y
34
Osteoblastoma
osteogenic, >2cm, cortical and cancellous, fronto-ethmoid, orbit or jaw, 20y
35
Chondroblastoma
chondrogenic, maxilla, mandible or skull base, lytic with areas of calcification
36
Osteochondroma
pedunculated exophytic bony projection of cortical and cancellous bone, condyle or coronoid process
37
Giant cell tumor
osteolytic +/-matrix calcification, hemorrhage, mandible, maxilla, ethmoid, sphenoid, temporal bone
38
Fibrous dysplasia
Fibro-osseous lesions (+ ossifying fibroma, osseous dysplasia)
expansile proliferation of trabecular bone + fibrous tissue, maxilla, mandible, zygoma, spheno-ethmoid, externa cortical bone protrusions, notion of growth by Gd
39
Ossyfying fibroma
Fibro-osseous lesion (+ fibrous dysplasia osseous dysplasia)
| fibrocellular and mineralized, mandible, maxilla, paranasal sinus. Demarcation and encapsulation
40
Osseous dysplasia
Fibre-Osseous lesions (+ fibrous dysplasia ossifying fibroma)
replacement of bone by fibrous tissue and metaplastic bone, periodontal ligament
41
Chondrosarcoma
chondrogenic, osteolyticm cortical destruction, calc soft tissue, alveolar maxilla, maxillary sinus, spetum zygomatic bone
42
Osteosarcoma
osteogenic, lobulated, lytic,-mixed or sclerotic, alveolar maxilla, body mandible
43
Pleomorphic adenoma
Benign
44
Adenocystic carcinoma
Malignant
45
Mucoepidermoid carcinoma
Malignant
46
Adenocarcinoma
Malignant
47
Dentigerous cyst (follicular cyst)
Pseudotumor, encloses crown of unerupted tooth, attaches to the cement-enamel junction
48
Primoderal cyst
Pseudotumor, replace tooth
49
Residual cyst
Pseudotumor, following tooth extraction
50
Inflammatory cyst (radicular cyst)
Pseudotumor, result of apical periodontitis, maxilla and mandible
51
Naso-palatine cyst
Non-odontogenic (fissural) cyst, developmental, foramen incisivum, sometimes unilateral
52
Naso-alveolar cyst
Non-odontogenic (fissural) cyst, developmental, submucosal anterior to premaxilla, posterior to nasal ala
53
Simple bone cyst
Non-odontogenic pseudocysts, corticallated scalloped unilocular cyst in mandible, no root resorption, nonexpansile
54
Stafne cyst
Non-odontogenic pseudocysts, developmental defect anterior to angle of mandible, part of submandibular gland
55
Perineural spread
most common in cutaneous and mucosal malignances (BCC, SCC), salivary gland malignancies (especially ACC), nasopharyngeal carcinoma, desmoplastic melanoma, lymphoma, leukemia and myeloma
56
Diffuse astrocytoma, IDH wt
```
WHO grade 4
Older,
multifocal
brainstem
No cystic changes
DWI - restricted
CE - variable
PWI - difficult
MRS - 2HG IDH might be lowered
```
57
Diffuse midline glioma
```
H3.1/3, K27M, H3 27 wt
WHO grade 4
5-11y
poor prognosis
midline - thalamus, pons, spinal cord
```
58
Gliomatosis cerebri
Growth pattern,
| 3 lobes
59
T2-FLAIR mismatch
```
Indicative of No CE IDH-m
in astrocytomas (not oligodendrogliomas)
T2 hyperintense
FLAIR hypo with hyperintense rim
ddx bright rim sign in DNET
```
60
MR-IDH status
T2-FLAIR mismatch - IDHm
DWI - restricted - IDHwt
MRS - 2HG - IDHm
61
Glioblastoma
most common malignant brain tumor
Intraaxial, gray+white matter, more frequent supratentorial
CE - solid/necrotic/cystic, non spherical
PWI - rCBV >1.75, increased permeability, high CBF
SWI - intratumor suseptibility (necrosis/hemorrhage + vessels)
DWI - variable, often restricted diffusion
non-enhancing tumor - WM, may involve GM, MRS - Cho peak, APT, DWI and PWI may be abnormal
62
Abscess
DWI - restricted in necrosis
| PWI - DSC no angiogenisis
63
Acute demyelination lesion
```
Low mass effect
incomplete ring
look for other lesions
DWI - varaible
PWI - normal rCBV in enhancing part
```
64
Subacute infarct
high T1 in cortex
gyriform enhancement
PWI - normal rCBV in enhancing part
SWI - low cortical signal
65
PWI - rCBV
High - glioblastoma, high-grade glioma, metastasis, medulloblastoma, capillary telangiectasia
Low - lymphoma, desmoplastic medulloblastomas, pilocytic astrocytoma, vascular, traumatic contusion, inflammation, abscess
66
Lymphoma
Solid enhancement (rarely necrotic/HIV)
DWI - restricted
PWI - rCBV normal or low, high K2
SWI - normal
67
Metastasis
Solid or necrotic, spherical
MRS - lipids
PWI - high rCBV
Edema - centered by the lesion, marked T2/FLAIR, no mass effect, facilitated DWI, low PWI, normal MRS
68
Subependymoma
```
0.5% of intracranial neoplasms
fourth ventricle, lateral ventricle
50-60y
WHO grade 1
well circumscribed, cysts are common, can calcification/haemorrhage
CE - no or minimal
No CSF seeding
```
69
Choroid plexus tumors
```
<5y (2-4% of paediatric brain tumors)
trigone of lateral ventricle
Papilloma - WHO grade 1
Atypical papilloma - WHO grade 2
Carcinoma - WHO grade 3
Cauliflowerlike lobulated mass, can haemorrhage/calcifications/necrosis
Hydrocephalus is common
CSF seeding
CE - present
```
70
Subependymal giant cell tumor
```
Foramen of Monroe, well marginated, lobulated, heterogenenous (calcifications)
15% of patients with TS
WHO grade 1
No CSF seeding
CE - strong
Hydrocephalus
```
71
Intraventricular meningioma
```
Atrium of lateral ventricle
30-60y
Slow growing (large size)
Can cyst/calcification
CT iso/hyper
Local CSF-obstruction
```
72
Central neurocytoma
```
0.5% on intracranial neoplasm
Septum pellucidum or lateral wall of lateral ventricle
Well circumscribed lobulated mass, bubbly, can haemorrhage/calcifications
CT hyper
CE - variable
29y
Hydrocephalus
WHO grade 2
```
Synaptophysin stain
73
Rosette-forming Glioneural tumor
```
Rare
WHO grade 1
31.5y
Hydrocephalus
Fourth ventricle
Fairly well circumscribed, heterogeneous solid and cystic
```
74
CSF drop metastasis
```
Ependymoma
Choroid plexus tumors
Germinoma
Medulloblastoma
Pineoblastoma
Enedymal invasion - GBM
```
75
Craniopharyngeoma
craniopharyngeal duct remnant - floor of third - pituitary
10-14y/40-60y
Cystic/solid with variable signal in cysts, can calcification
T1 hyper
CE - solid nodules
76
Germinoma
```
child/young adults
Pineal and/or hypothalamus
T2 hyper
CE - homogeneous
CT - slight hyper
```
77
Meningioma
15-20% of intracranial tumor in adult
Arachnoid cap cells/meningocytes
50% falx, parasagittal, lateral convexity
40% basal, subfrontal, olfactory groove, sphenoid wing and suprasellar
Dural based, CSF cleft, widening of subarachnoid spaces, intervening vessels, dural tail, hyperostosis (reactive hypervascularity)/erosion of calvarium
CT - hyperdense
T1 iso/hypo
T2 iso/hyper
CE - homogeneous, in bone - intraosseous
Edema 60%
Hemorrhage is rare
WHO grade 1, 2 (atypical, papillary, rhabdoid) and 3 (anaplastic - may infiltrate of brain)
Look for vascular encasement, venous infiltration, hypervascularity
78
Epidermoid
CSF like on CT, T1 and T2
| DWI - restricted
79
Hemangiopericytoma
```
Younger than meningioma
Agressive tumor
CE - vivid
T2 - flow voids
Narrow base of dural attachment
Edema in adjacent brain
```
80
Primary CNS lymphoma
B-cell 90%
45-70y
immunodeficiency
Parenchymal mass close to surface
T2 hypo
DWI - restricted (EBV hyperintense rim)
Solitary or multiple (50%)
CE - homogeneous, ring (HIV, EBV - 90%), perivascular, ascent
Hemorrhage (HIV, EBV - 70%)
steroid treatment - tumor regression, decrease CE and rCBV and increase ADC
Differentiate from GMB: ADC, rCBV and FDG-PET
Cave - post treatment T1 hyper
Treatment - MATRIx - response DWI, PWI and FDG-PET
81
Secondary CNS lymphoma
10-15% of NHL
More frequent in relapsing disease
2/3 leptomeningeal, 1/3 parenchymal
CE - leptomeningeal, dural, subependymal, CN
82
Leukaemia
ALL - children - CNS profylax is standard
AML - adults
Leptomeningeal and CN infiltration
Granulocytic sarcomas (chloromas) - intraparenchymal, CE - strong, DWI - restrict, can be hemorrhagic, dural based, calvarium, orbit, sinuses
Cerebral hemorrhage
Bone marrow infiltration
83
Neurofibromatosis Type 1
1/3000
Cafe-au-lait, neurofibroma/plexiform neurofibroma, axillary/ingunial freckling, optic nerve glioma (PA, 4-5y), Lisch noduli, sphenoid dysplasia, relative with NF1
Gliomas in NF1 - brainstem (diffuse/focal) medullary, pontine, midbrain
UBO - appear at 3-4y and disappears 10-12y - no mass effect or CE, MRS - preserved Cho/Naa ratio
Gliomas - slow progression, might regress
Moyamoya, arteria ectasia and aneurysm
84
Plexiform neurofibromas
WHO grade 1
Tortuous, aggressive, infiltrating the nerves
T1 iso to muscle
T2 hyper, inhomogeneous
CE - inhomogeneous
10% malignant peripheral nerve sheath tumor
85
Spinal neurofibroma
Scoliosis
NF1
Dumbell
86
Neuroblastoma
Peripheral nerves
7-8% of paediatric tumors
<5y
87
Neurofibromatosis Type 2
1/25000
Merling
MISME (multiple inherited schwannomas, meningiomas and ependymomas)
Bilateral schwannomas or relative with NF2
Meningiomangiomatosis - rare hamartomatous lesion
88
Tuberous Sclerosis Complex
1/6000
Hamartin, Tuberin
Cortical tuper (=focal cortical dysplasia), often calcification
WM abnormalities - transmantal sign
Subependymal nodules - lateral wall of lateral ventricle, candle guttering, calcification common, may enhancement
SEGA - foramen of monroe, 2-26%, rapamycin
89
Sturge-Weber
Facial capillary vascular malformation - trigeminal territory
Leptomeningeal angiomatosis - multiple thin vessels in leptomeninges - enhancement of cortical surface - atrophy and calcifications
Angiomatosis of the choroid of ipsilateral eye
Hypertrophy of choroid plexus
No tumor
90
Von Hippel-Lindau
Systemic
| Hemangioblastoma - highly vascularised nodule that abuts the pial surface cystic component (reactive)
91
Hemangioblastoma
```
highly vascularised nodule that abuts the pial surface cystic component (reactive)
Cherry on angiography
T1 hypo
T2 hyper
CE - strong, non enhancing cyst wall
PWI - high rCBV
```
92
Neurocutaneous syndroms
```
NF1 - PA, neurofibroma
NF2 - schwannoma, meningioma, ependymoma
Tuberous sclerosis - subependymal giant cell astrocytoma
Sturge-Webe syndrome - none
Von Hippel Lindau - hemangioblastoma
```
93
Spinal Ependymoma
```
40-50y (NF2 - children)
T2 hyper
T1 hypo
85% central
CE - vivid
Well defined borders, neoplastic cysts (tumoral/non tumoral)
30% cap sign
```
94
Myxopapillary ependymoma
```
Conus and cauda
WHO grade 1
multilobulated, cystic, haemorrhage
CE - always
Scalloping of vertebral bodies
CFS spread
```
95
Spinal Astrocytoma
```
30-40y (most common intramedullary tumor in children, PA)
Fusiform expansion of cord
T1 iso/hypo
T2 hyper
inhomogeneous, illdefined margins
CE - heterogeneous, 60-70%
May have haemorrhage
30% satellits cysts
```
96
Spinal Hemangioblastoma
Benign, rich vascularised (flow void)
2-6% of spinal tumors
If multiple - vHL
small nodule with extensive edema or extensive cyst
97
Intramedullary metastasis
Edema
T1 iso
T2 hyper
CE - nodular
98
Intramedullary epidermoid
"cholesteatoma"
1%
slow growing, lumbosacral, dermal sinus in children
congenital or acquired
99
Melanocytoma
```
Leptomeningeal melanocytes, intradural extramedullary
WHO grade 1
T1 hyper
T2 hypo
CE - uniform
```
100
Spinal Meningioma
Intradural, extramedullary
80% thoracic (posterolateral), 15% cervical (anterior)
50-60y
T2 hyper
T1 iso/hypo
CE - vivid, homogeneous
well circumscribed, delineated from the spinal cord
101
Spinal nerve sheath tumor
60% intradural extramedullary, 25% extradural, 15% both
cervical or lumbar
schwannoma 65%, neurofibroma, ganglioneuroma (rare)
40y
T1 iso
T2 hyper, sometimes target sign
CE - variable
102
Spinal neurofibromas
Neurofibromin
NF1
T2 target sign
CE - central or heterogeneous
103
Spinal schwannomas
```
= neurinoma
Merlin
NF2
hemorrhage, cyst
CE - diffuse
```
104
Paraganglioma
```
Adrenal (pheocromocytoma), carotid body and gloms jugular
Conus, cauda and filum
30-60y
WHO grade 1
SDHD - mutation
T1 iso
T2 hyper
inhomogeneous, haemorrhage, intratumoral and adjacent vessels with flow void and strong enhancement
```
105
Spinal eosinophilic granuloma
0-10y, vertebral body
106
Spinal osteoid osteoma
10-20y, posterior elements
107
Spinal aneurysmatic bone cyst
10-20y, involvement of adjacent levels, posterior elements
108
Spinal giant cell tumor
20-50y, involvement of adjacent levels, vertebral body, posterior elements
109
Plasmacytoma
40-60y, involvement of adjacent levels, vertebral body
| oval with sharp margins in scull base, clivus and petroclival
110
Chordoma
40-60y, involvement of adjacent levels, vertebral body
111
Spinal hemangioma
40-60y, multiple lesions, vertebral body
112
Multiple myeloma
50-70y, multiple lesions, vertebral body
113
Spinal metastasis
50-70y, multiple lesions, vertebral body
114
Spinal lymphoma
Multiple lesions, involvement of adjacent levels, vertebral body
115
Spinal sarcoma
Involvement of adjacent levels, posterior elements
116
Spinal metastasis
Arterial seeding, retrograde venous or direct extension
SPECT - osteoblastic
WB-MRI and/or PET
117
Malignant spinal bone tumors
Lytic without marginal sclerosis
surrounding bone edema
invasion of neighbouring structures
Diagnostic clues: multiplicity, age, imaging characteristics and location
118
Normal red marrow
<6 moths - low/homogeneous, no enhancemnet
6 months - 45y - intermediate/homogeneous, very limited enhancemnet
>45 y - intermediate/heterogeneous, no enhancement (high SI - more fat, low SI - more cells)
119
Bone marrow metastasis
Decreased signal =
120
Spinal hemangioma
```
T1 high to low
T2 high
Fat-sat-fluid-sensitive - high
CE - yes
CT - polka dot
```
121
Benign notochord cell tumor
```
T1 low
T2 high
Fat-sat-fluid-sensitive - intermediate
CE - no
Small, sclerotic, hydrated, non-enhancing
```
122
Focal red marrow hyperplasia
```
T1 low
T2 low
Fat-sat-fluid-sensitive - intermediate
CE - subtle
signal as cellular red marrow
CT - normal/subtle sclerosis
```
123
Ethmoid mucocele
Completely opacified and expanded sinus (cell)
124
Allergic fungal sinusitis
Expanded sinuses with hyper dense stuff
Images /symptoms mismatch
Teenagers
125
Encephalocele
```
Ideopathic intracranial hypertension
Lateral sphenoid (NOT sternbergs canal)
```
126
Persistant craniopharyngeal canal
.
127
Inferior median clival canal
= canalis basilaris medianas, fossa naviculars
128
Ecchordosis physaliphora
Remnant of notochord
T1 hypo
T2 hyper
CE - variable
129
Chordoma
From clivus, osteolytic, hypodense, may be off midline
T2 very high
DWI - very high ADC
CE - variable (minimal)
130
Chondrosarcoma
Petroclival junction (cartilage)
whirls of calcs 50%
CE - stippled
DWI - very high ADC
131
Hemangioma of cavernous sinus
T2 very high
DWI - very high ADC
CE - avidly enhancement
132
Glomus jugulare
Enhancing mass with flow voids
| Infiltrative osteolysis
133
Jugular schwannoma
Smooth bone remodelling
DWI - high ADC
T2 hyper
CE - avid
134
Endolymphatic sac tumor
```
T1 hyper
T2 hyper
Infiltrative, osteolytic
Centered at endolymphatic duct
CE - heterogeneous
```
135
Cholesterol granuloma
Smooth, sharp
Petrous apex expansion
T1 hyper
T2 hyper, hemosiderin rim
136
Arachnoid granulations
Along sinuses
Lobulated bone remodeling
Not always T2 hyper
137
Pituitary adenoma
CE - less and more slow than normal pituitary
| Ddx - meningioma ehnacenes more than pituitary, reduces artery
138
Cavernous angioma
CE - centripetal
139
Rathke cleft cyst
mucoid 25%
| intracystic nodules
140
Head and neck lymphoma
Type 1 - nodal
Type 2 - extranodal (waldeyers ring/outside waldeyers ring)
Type 3 - combined 1+2
Type 4 - multifocal extranodal
nodes 2-10cm
CE - variable (less than reactive)
necrosis
calcifications after treatment
Reactive - multiple, well defined, mild enhancement, ADC >1 (metastasis larger, necrosis, ADC>0.7)
HL - 90% nodal, T2 hyper
NHL - multiple, bilateral solid, CE - moderate (retropharyngeal, occipital, parotid, posterior triangle, submandibular), T2 iso
5% of salivary tumors, parotid 70%
Ocular adnexa >60y most common orbital malignancy
141
Mucocele
thin rim of the bone
| MR signal, CT density variable
142
Inflammatory pseudotumor
rare, benign
| nonspecific imaging - rule out other lesions
143
Dacroadenitis
OID
gland, orbital and palpebral lobes,
almond shape
144
Myositis
OID
unilateral thickening of one or two EOM
superior oblique
surrounding fat, tenons and myotendinous junction
ddx: thyroid (I'm slow), cellulitis (CT), CCF (enlarged vein), metastasis (focal mass), lymphoma (focal mass, ADC)
145
Optic perineuritis
```
OID
optic nerve sheath
pain
CE - enhancement of sheath and adjacent fat
ddx: meningioma, optic neuritis
```
146
Optic meningioma
Tram-track
no pain
CT - calcifications
147
Optic neuritis
```
spare soft tissue
different vision imparement
swollen nerve
T2 hyper
CE - contrast enhancement
```
148
Periscleraitis
sclera, uvea and tenons capsule
| thickening along the outer rim of the eye, periscleral fluid collection
