differentials for neuro

Question 1

Spine tumor intramedullary

Answer 1

astrocytoma: children, cyst/syrinx, solid portion T1 iso, T2 hyper, heterogenous enhance
ependymoma: adult, often hemorrhagic leading to heterogenous MR appearance. T1 iso, T2 hyper, avid homo enhance. NF2 if in kids.

Hemangioblastoma: cyst formation, T1 iso, T2 hyper, marked enhance, numerous flow voids. VHL

Demyelinating: absence of cord expansion.

ganglioglioma/gangliocytoma: Mixed T1, T2 hyper with patchy enhancement. young adults, long segment involvement over 8 vertebral bodies, scoliosis and bony remodeling

paraganglioma salt and pepper appearance in the conus/cauda equina region.

Question 2

Carotid space mass

Answer 2

Paraganglioma: intense enhance, salt+pepper/flow void

1. carotid body: splays ICA and ECA
2. vagal nerve: displaces ICA and ECA anteromedially

Schwannoma (often of vagus): does not enhance as homogenously. displaces ICA and ECA anteromedially

Neurofibroma: cannot distinguish from schwannoma.

Question 3

Periventricular enhancement

Answer 3

Primary CNS lymphoma

Infectious ependymitis

primary glial tumor

MS

Question 4

Gyriform Enhancement

Answer 4

Herpes encephalitis

meningitis

Subacute infarct

PRES

Question 5

Benign parotid neoplasm

Answer 5

Pleomorphic adenoma: like water but enhances. T1 hypointense, T2 hyperintense, enhancing circumscribed mass

Warthin tumor: cystic (T1 dark, T2 brighht) but does not enhance

Question 6

Malignant parotid neoplasm

Answer 6

1. Mucoepidermoid carcinoma (T1 hypo, T2 bright, enhancing, cannot differentiate from pleomorphic adenoma)
2. adenoid cystic carcinoma (enhancing mass with perineural spread)
3. carcinoma ex pleomorphic adenoma (T1 hypo, T2 hypo)
4. squamous cell carcinoma

Question 7

Tumors with a cyst and an enhancing nodule

Answer 7

Juvenile Pilocytic Astrocytoma

Hemangioblastoma

Ganglioglioma

Pleomorphic Xanthoastrocytoma (PXA)

Question 8

High attentuation or increased FLAIR signal in sucharachnoid space

Answer 8

Subarachnoid hemorrhage

meningitis

leptomeningeal carcinomatosis

contrast ( intrathecal )

Question 9

Ring enhancing lesion

Answer 9

MAGIC DR
mets
abscess
glioma
infarct
contusion

demyelinating dz (incomplete ring)
radiation

Question 10

pachymeningeal enhancement

Answer 10

intracranial hypotension
any kind of postop involving tear of dura
meningeal neoplasm
granulomatous dz.

Question 11

Leptomeningeal enhancement

Answer 11

meningitis
leptomeningeal carcinomatosis
viral encephalitis
slow vascular flow (GE FLAIR can suppress this)

Question 12

Tumors with a cyst and an enhancing nodule

Answer 12

Pilocytic astrocytoma
Hemangioblastoma
Pleomorphic Xanthoastrocytoma (PXA)
Ganglioglioma

Question 13

Extramedullary Intradural Lesion

Answer 13

Nerve sheath tumor (schwannoma and neurofibroma): T1 iso T2 hyper with enhancement. Can have bleeding/calc with hypo on T2. Central hypo with peripheral hyper target sign on T2 is suggestive

Meningioma

Dermoid (fat)/Epidermoid cyst

Arachnoiditis.

Question 14

extra axial tumor

Answer 14

meningioma
schwannoma
hemangiopericytoma
neurofibroma
neuroma
Mets

Question 15

Intraventricular mass

Answer 15

Choroid plexus papilloma
Choroid plexus carcinoma
Choroid plexus hemangioma
Choroid plexus xanthogranuloma

Meningioma
Ependymoma
Central neurocytoma
Epidermoid cyst
Dermoid 
Teratoma 
Lipoma

Question 16

Astrocytoma

Answer 16

Grade 1
Pilocytic astrocytoma
Pleomorphic Xanthoastrocytoma
Subependymal giant cell astrocytoma

Grade 2
Diffuse astrocytoma
Brain stem glioma

Grade 3
anaplastic astrocytoma
Gliomatosis cerebri

Grade 4
Glioblastoma
Gliomatosis cerebri

Question 17

Corpus callosal mass lesions

Answer 17

Glioblastoma
Lymphoma

MS
PML
Adrenoleukodystrophy
Marchiafava Bignami disease
PRES

Lipoma
cyst

Susac

Question 18

Embryonal Tumors

Answer 18

Medulloblastoma
Supratentorial PNET
ATRT
DNET

Question 19

Temporal Lobe Lesions

Answer 19

1. ganglioglioma
2. astrocytoma
3. DNET
4. oligodendroglioma
5. PXA
6. DIG

Question 20

Mixed neuronal and glial tumor

Answer 20

1. ganglioglioma
2. DIG
3. oligodendroglioma

Question 21

Calcified CNS

Answer 21

Oligodendroglioma
Ganglioglioma
Astrocytoma
Ependymoma

Meningioma
Craniopharyngioma
Pineal tumor
Ependymoma
Neurocytoma
Choroid plexus papilloma

Question 22

Pineal region germ cell neoplasms

Answer 22

Germinoma
Teratoma
Choriocarcinoma
Yolk sac tumor

Question 23

Pineal region non-germ cell neoplasm

Answer 23

Pinealblastoma
Pineocytoma
Astrocytoma

Question 24

Intrasellar lesions

Answer 24

Congenital lesions  ( Rathke cleft cyst, aplasia/hypoplasia, ectopia)
pituitary adenoma
pituitary apoplexy 
meningioma
aneurysm

granulomatous (LCH, sarcoid)
lymphocitic hypophysitis

Question 25

Suprasellar lesions

Answer 25

Rathke cleft cyst
arachnoid cyst 
craniopharyngioma
meningioma
chiasmatic and hypothalamic astrocytoma
hamartoma of the tuber cinereum
aneurysm

epidermoid, dermoid, teratoma, lipoma

granulomatous (LCH, sarcoid)
germinoma

Question 26

parasellar lesions

Answer 26

meningioma
schwannoma
chondrosarcoma

aneurysm
carotid cavernous fistula
thrombosis of the cavernous sinus

tolosa hunt syndrome

Question 27

Skull base lesions

Answer 27

meningoencephalocele
juvenile angiofibroma
chordoma/chondrosarcoma
fibrous dysplasia