Neuro

Front 1

Cyst with mural nodule (with minimal surrouding edema)

Back 1

-pilocytic astrocytoma (grade 1)
-ganglioglioma
-pleomorphic xanthroastrocytoma (grade 1, rare, young, superficial cortical, temporal lobe)

-hemangioblastoma (posterior fossa) - but much more edema

Front 2

Rim enhancement with central necrosis

Back 2

-GBM
-abscess (+diff)
-TB
-demyelinating lesion
-XRT necrosis

Front 3

Fibrillary astrocytoma

Back 3

-low grade vs anaplastic
-better prognosis than GBM
-usually younger age group for low-grade
-eventually degenerate into malignant variant

Grade II (low grade)- usually do not enhance
Grade III (anaplastic) - enhance, but not as avidly as GBM
Grade IV (GBM)

Front 4

Oligodendrogloma

Back 4

-low grade & anaplastic
-younger
-better prognosis than astrocytoma
-frontal lobe common
-cortical involvement common (expands overlying cortex)
-calcium common
-can appear aggressive

Front 5

Common tumors with Ca++

Back 5

-oligodendrogioma
-ependymoma
-craniopharyngioma
-choroid plexus tumor
-meningioma

Front 6

Ependymoma

Back 6

supratentorial - intraparenchymal

infratentorial - intraventricular -tongue of tissue going through 4th vent outflow tract differenatiates from medulloblastoma

Front 7

Meningioma DDx

Back 7

-dural-based mets (prostate, breast, lung, neuroblastoma)

-hemangiopericytoma (vessels in tumor)

-solitary fibrous tumor

-chondrosarcoma (no edema, looks like you can cut it out with scissors)

Front 8

Brain mets

Back 8

-usually multiple, gray-white jxn
-lung, breast, melanoma, GI/GU most common
-intraparenchyma, intraventricular, dural, leptomeningeal, osseous

Front 9

Primary cerebral lymphoma

Back 9

-adults
-multiple enhancing masses in deep gray and whit matter and periventricular
-corpus callosum not an unusual location
-homogeneous low T2 signal and mildly reduced diffusion
-may be centrally necrotic in immune compromised

parenchymal mass in assoc. with a dural component - mets, lymphoma (not GBM)

Front 10

Tumors with low T2 signal

Back 10

Cellular tumors:
-lymphoma
-PNET, medullo, pineoblastoma
-meningioma
-mucinous adeno met

Front 11

Primary neuronal tumor

Back 11

Central neurocytoma
-intraventricular
-attached to septum pellucidum
-enhances
-very vascular

Subependymoma
-attaches to septum
-does NOT enhance

Front 12

Pediatric brain tumors

Back 12

-medulloblastoma (CSF mets)
-JPA
-choroid plexus papilloma
-chraniopharyngioma
-pleomorphic xantroastrocytoma

Front 13

CSF dissemination

Back 13

-PNET
-medulloblastoma
-pineoblastoma
-ependymoma
-choroid plexus CA

Front 14

Diffusion positive mass

Back 14

-epidermoid
-mucinous adeno met
-abscess
-cellular tumors (lymphoma, PNET, meningioma)

Front 15

Tumor mimicking lesions

Back 15

Radiation necrosis
-temporal lobe - hx of nasopharyngioma, chordoma, eyelid squamous cell ca

tumefactive demyelinating lesion

pyogenic abscess

toxoplasmosis encephalitis

Front 16

Solitary fibrous tumor

Back 16

-occurs anywhere in body
-inititially described of primary fibrous tumor of pleura
-very dark T2 of fibrous component
-ddx: -meningioma, hemangiopericytoma

Front 17

Subdural empyema

Back 17

-high mortality
-10% brain abscess, sinus thrombosis
-young kids - meningitis
-adults - paranasal sinuses (like epidural empyema)
-bright DWI!!!
-convexity >50%, parafalcine 20%

DDx:
-subdural effusion - nl DWI, no C+
-chronic SDH - susceptibility on MR
-hygroma - trauma hx

Front 18

Bright subarachnoid signal on FLAIR

Back 18

-tumor
-meningitis
-subarachnoid hemorrhage
-slow flow
-oxygen therapy (diffuse)

Front 19

Leptomeningeal enhancement

Back 19

-follows sulci and cisterns

Ddx:
-meningitis
-leptomeningeal tumor
-sarcoid

Complications:
-infarct
-hydrocephalus
-subdural empyema
-dural sinus thrombosis

CT: insensitive
MR:
-Flair and Gad - SAS abnormality
-DWI - infarct and subdural empyema (complications)

Acute bacterial or fungal:
-C+ over cerebrum
Chronic fungal or TB:
-C+ basilar cisterns

Front 20

Basilar meningeal enhancement

Back 20

DDx:
-TB
-fungal (coccidiomycosis)
-sarcoid

Front 21

Pachymeningeal enhancement

Back 21

-follows the periosteum and dural reflections

Ddx;
-idiopathic hypertrophic cranial pachymeningitis
-intracranial hypotension (SIH)
-dural metastasis
-infection
-sarcoid

Front 22

Ring enhancing lesions

Back 22

-mets - multiple, GW jxn
-pyongenic abscess - light bulb diffusion, thin C+ toward ventricle, daughter lesion, T2 bright center with dark rim
-GBM - solid & necrotic components, hemorrhage, likes CC and deep WM
-hematoma - susceptibility and T1 shortening (subacute)
-radiation necrosis - can mimic tumor recurrence, perfusion may help
-tumefactive demyelination - incomplete ring C+, little mass effect
-Infarct - usually more gyriform C+, except cerebellum and BG
-atypical infection - TB, neurocystercercosis, fungal
-toxo vs lymphoma - know immune status

Front 23

Ventriculitis

Back 23

-usually assoc with meningitis, shunting, or ruptured abscess
-subependymal C+
-high mortality 80%

Front 24

Caseating tuberculoma

Back 24

-rim enhancement

Clues:
-dark T2 signal (not bright as in pyogenic abscess)
-abnormal CXR
-1yr later - calcification after tx

Front 25

Acute disseminated encephalomyelitis (ADEM)

Back 25

-multifocal BG and WM
-post-viral (after infection/vaccination)
-may be tumefactive
-minimal mass effect
-punctate, ring & incomplete C+
-children > adults
-self-limited

Front 26

Neurocystercercosis

Back 26

4 stages
-stage 1- cyst with dot, no edema
-stage 2 - scolex degen, edema, rim C+, T2 hyperintense with dark rim
- stage 3 - cyst wall thickens, dec inflam
stage 4 - lesion calcifies, no edema

Front 27

Invasive aspergillosis

Back 27

neutropenia

enhancement depends on immune status
-immunocompromised - none-little
-immunocompetent - ring C+

Angioinvasion
-hemorrhage (dark T2)

-minimal mass effect

-direct (sinuses) or hematogenous (lungs)

Front 28

HSV encephalitis

Back 28

-most common fatal encephalitis (70%)
-reactiviation of HSV 1 (children & adults)
-medial temporal lobe, cingulate, spare BG
-bilateral, asymmetric
-patchy C+ early and gyriform C+ later
-DWI+

Front 29

Temporal lobe lesions

Back 29

-HSV encephalitis
-MCA infarct (extends into BG)
-low-grade glioma - mass-like Flair hyperintenisty, no C+, no DWI
-gliomatosis

Front 30

Bilateral white matter abnormalities

Back 30

-small vessel ischemic disease
-radiation/chemo
-transependymal CSF
-MS/ADEM

History of HIV:
-HIV -
-PML -
-CMV

Front 31

HIV vs PML

Back 31

HIV
-cognitive decline and dementia
-bilateral, symmetric PVWM hyperintensity & atrophy
-not visible on T1
-no C+

PML
-focal CNS symptoms
-asymmetric, subcortical U fibers
-dark T1 signal
-parieto-occipital, middle cerebellar peduncles

Front 32

Cytomegalovirus

Back 32

-ventriculoencephalitis
-CD 4<50
-chorioretinitis in 25%
-tx ganciclovir
-MRI - thin, pencil lined high T2 ventricles and subependymal C+

Front 33

Basal ganglia lesions

Back 33

Infection:
-toxo (HIV)
-cryptococcus (HIV)
-CJD

Toxic-metabolic:
-extra-pontine myelinolysis (EPM)
-Wilson's
-Leigh's (mitochondrial d/o)

Ischemic:
-lenticulostriate infarct
-hypoxic-ischemic encephalopathy
-internal cerebral vein thrombosis

Neoplasm:
-lymphoma (HIV) or glioma

Front 34

Cryptococcus

Back 34

-5-10% AIDS (most common fungal infxn)
-"gelatinous pseudocysts" - nonenhancing, dilated V-R spaces in BG and thalami
-tx with fluconazole

DDx:
-toxo and lymphoma enhance
-infarct is DWI+

Front 35

Toxo vs lymphoma

Back 35

Toxo:
-multiple BG lesions
-eccentric target sign

Lymphoma:
-subependymal C+
-CC involvement
-dark T2 (hypercellularity)
-SPECT & PET +

Management:
1. Empiric tx: pyrimethamine
2. Radiographic improvement in 7-10 days - toxo
3. No improvement - biopsy

Front 36

Creutzfeldt Jacob Disease (CJD)

Back 36

-Flair hyperintensity caudate & putamen
-Cortical ribboning
-DWI +
-No C+

-prion disease - rapidly progressive dementia

Front 37

Cerebellitis

Back 37

-acute onset cerebellar dysfxn
-resolves spontaneously - months
-infectious or parainfectious
-supportive care

Front 38

Lymphoid conglomerates in neck

Back 38

-lingual tonsils at base of tongue
-palantine tonsils in the lateral wall
-nasopharyngeal tonsil in nasopharynx

Front 39

Posterior neck spaces

Back 39

Perivertebral space (PVS)
-within deep layer of DCF
-around longus colli and longus cappus (prevertebral muscles) anteriorly
-around paraspinous muscles posteriorly
-verterbral bodies, disks
-nerves

Retropharngeal space (RPS)
-between middle and deep layers of DCF
-lateral sleeves called alar fascia
-contains fat and nodes (medial to carotid artery)

Posterior cervical space (PCS)
-fat and nodes between SCM and paraspinous muscles
-CN11 (spinal accessory nerve)

Front 40

Anterior neck spaces

Back 40

Pharynx (pharyngeal mucosal space - PMS)
-lined by middle layer of DCF
-nasopharynx (behind nasal cavity)
-oropharynx (behind oral cavity_
-oral cavity
-hypopharynx (hyoid to esophagus)
-larynx (hyoid to trachea)

Masticator space (MS)
-superficial DCF which surrounds muscles of mastication
-medial and lateral pterygoids (medial)
-masseter (lateral)
-temporalis (superior)
-mandible (bone and teeth)
-CN5 (3 through foramen ovale) innervates muscles of mast

Parotid space (PS)
-also defined by superficial DCF
-salivary gland
-lymph nodes within parotid (mets, lymphoma)
-CN7 runs through parotid

Carotid space (CS)
-lined by superficial, middle, and deep DCF
-carotid artery (and body)
-jugular vein
-CN 9-12

Paraphayrngeal space (PPS)
-superficial, middle, and deep DCF
-triangular area of fat
-direction of displacement of the PPS will localize the mass to its space of origin
-PMS posterolaterally
-MS posteromedially
-CS anterolaterally
-PPS anteromedially

Front 41

Pharyngeal mucosal space mass

Back 41

-nasopharyngeal ca (squamous cell)
-lymphoma

Front 42

Masticator space mass

Back 42

-dental abscess
-rhabdomyosarcoma - child

Front 43

Carotic space mass

Back 43

-nerve sheath tumor (schwannoma, neurofibroma)
-carotid body tumor (splaying of internal and external carotid arteries)

Front 44

Parotid space

Back 44

Pleomorphic adenoma (benign mixed tumor)
-most common benign neoplasm
-well defined, high T2, heterogenous
-can aris from deep lobe of parotid which pushes PPS anteromedially
-can't exclude malignancy (always get FNA)

Front 45

Perivertebral space

Back 45

-discitis-osteomyelitis + prevertebral abscess

Front 46

Retropharygeal space

Back 46

need axial imaging to tell if it's prevertebral or retropharyngeal

-supporative LNs (medial to carotid)

Front 47

Posterior cervical space

Back 47

-cystic hygroma (congenital)
-lymphoma
-squamous cell ca mets in LNs from scalp tumors

Front 48

Multispacial masses

Back 48

Congential
-multilocular lympatic malformation

Aggressive
-parotid carcinoma

Front 49

ICA dissection

Back 49

-Horner's, neck pain, CN12 palsy
-T1 FS - intramural hematoma
-spontaneous - cm above bifruc
-traumatic - distal cervical and skullbase

Dissection when there is irregularity in site that are unusual for athero
-"string sign"
-aneurysmal dilation
-occlusion
-intimal flap

Front 50

Amyloid angiopathy

Back 50

-lobar hemorrhage in elderly - amyloid vs htn
-50% of lobar hemorrhages are amyloid in pts >70
-GRE = mult black dots, microhemorrhages
-spares BG - amyloid

Front 51

Nontraumatic intraparenchymal hemorrhage DDx

Back 51

Underlying lesion
-tumor (solid C+)
-AVM (CTA)
-Cavernoma (look for DVA)
-Aneurysm (CTA)

Amyloid angiopathy (GRE)

Dural venous sinus thrombosis
(subcortical WM)

HTN (BG, pons, cerebellum)

Coagulopathy

Front 52

Multiple calcifications ddx

Back 52

-cavernomas (larger, amorphous)
-neurocystercercosis (punctate)
-prior infection such as toxo

Front 53

Multiple foci of susceptibility ddx

Back 53

-amyloid angiopathy
-HTN
-cavernomas
-shear injury

Front 54

Cavernous malformations (cavernomas)

Back 54

-vascular hamartoma (epithelial-lined sinusoids)
-risk of IPH <1%/year
-75% sporadic
-30% familial - multiple, hispanic (higher risk for hemorrhage)
-angiographically occult
-associated with DVA

MR:
-hemosiderin ring: "black halo"
-"popcorn" T2 hyperintensity
-T1: hyper or hypointense "locules" from repeated hemorrhage
-no C+

CT:
->50% calcify
-DVA
-no mass effect

Front 55

Capillary telangiectasia

Back 55

-brainstem
-radiation
-no T2 signal common
-"brush" C+
-dark GRE
-"don't touch"

Front 56

Arteriovenous Malformation

Back 56

AV shunting and no intervening capillary bed

Congenital
-98% solitary & sporadic
-2% multiple & syndromic (HHT)

Bleeding risk <4%/year

-Spetzler-Martin grading

MR:
-"bag of worms"
-no mass effect
-T2 = gliosis

CT:
-calc 25%
-iso/hyperdense vessels

Front 57

Vascular malformations

Back 57

Shunt
-AVM
-dural AV fistula

No shunt
-cavernous malformation
-developmental venous anomaly (DVA)
-capillary telangiectasia

Front 58

Meningioma embolization

Back 58

-homogenously C+, extra-axial mass
-"mother in law" sign - comes early, stays late
-PVA embolization

DDx:
-met
-hemangiopericytoma
-lymphoma

Front 59

ICA anatomy

Back 59

Lateral view - proximal to distal
-petrous
-cavernous
-supraclinoid

Ophthalmic artery is a proximal branch supraclinoid (helps differentiate between cavernous and supraclinoid portions


AP view of L ICA
-Pcomm is a branch of the supraclinoid ICA and feeds PCA
-supraclinoid comes up to carotid T
-terminal branches are ACA (media) and MCA (lateral)

Front 60

Pcomm aneurysm / SAH

Back 60

3rd nerve palsy:
->50 & involving pupil - pcomm aneurysm until proven otherwise

f/u for complications:
-hydrocephalus
-vasospasm

Front 61

Persistent trigeminal artery

Back 61

-fetal connection: cavernous ICA to basilar artery

DDx fetal PCA comes off supraclinoid ICA, above sella

-risk factor for aneurysm

Front 62

Dural sinus thrombosis

Back 62

Pattern of venous ischemia
-superior sagittal sinus - parasagittal
-transverse - temporal love
-deep - bithalamic

MR: loss of nl flow void
-flair pitfall: acute DST dark
-tof pitfall: T1 shortening

Anatomy:
straight - vein of galen - internal cerebral veins

Venous infarct:
-subcortical white matter
-hemorrhagic
-+/- DWI
-mass-like, mimic neoplasm

Front 63

Moya moya

Back 63

-idiopathic progressive arteriopathy of childhood
-occlusion mainly in anterior circulation
(supraclinoid ICA and prox COW)
-secondary moya moya - sickle cell, NF, radiation, athero
-peds: ischemia
-adults: hemorrhage
Angio
- "puff of smoke" - cloud-like lenticulostriate collaterals

CT/MR:
-BG and leptomeningeal C+ due to slow collateral flow

Front 64

Carotid cavernous fistula

Back 64

-proptosis, bruit, motility d/o

CT/MR:
-dilated superior ophthalmic vein
-proptosis, enlarged EOMs
-retrobulbar fat stranding
-bowed cavernous sinus

Indirect CCF:
-low flow, meningeal branches - dural AVFs, spontaneous, can be observed

Direct CCF:
-high flow, trauma/aneurysm rupture, need immediate tx

Front 65

ECA anatomy

Back 65

Inferior to superior:
-superior thyroid (anterior)
-ascending pharyngeal (deep)
-lingual (anterior)
-facial (anterior)
-occipital (posterior)
-posterior auricular (posterior)

Terminal branches:
-maxillary
-superficial temporal

Front 66

Dense subarachnoid space ddx

Back 66

Blood in SA space (SAH)

Pseudo-SAH (mimickers)
-cellular material - carcinomatosis, infection (TB, pyogenic, fungal), sarcoid
-iodinated contrast - renal failure with meningitis (contrasts leaks into meninges)

Pseudo-pseudo SAH
(look like they have something in SAH, but don't)
(No hydrocephalus)
-CSF hypotension - subdural collections and large dural sinuses
-anoxia - white cerebellum, cannot see basal ganglia

Front 67

Coccidiomycosis meningitis

Back 67

"Valley fever"

airborn fungal infection: lung
acute - flu-like symptoms
chronic: lung abscess
disseminated: bones, brain

-pregnant women and men get chornic or disseminated

-Hispanic or AA have higher likelihood of disseminated form without being immune compromised

"Cellular pseudo-SAH" ddx:
-carcinomatosis
-bacterial, TB, fungus
-sarcoid

Front 68

Idiopathic intracranial hypertension (pseudotumor cerebri)

Back 68

Normal opening pressure = 80-150mmHg

-empty sella
-normal superficial and deep tissues, EXCEPT bilateral absence of mid-transverse sinuses
-flat posterior globes, tortuous and distended optic nerve sheath
-uncommonly slit-like ventricles

-mostly women, 3rd decade
-obese, recent weight gain
-may be medication induced
-papilledema - optic neuropathy
-headaches, transient visual obscurations, diplopia

Front 69

Infarcts in young patients

Back 69

Infarcts <20yrs uncommon
MCA territory most frequent

1. Cardiovascular d/o
-congenital HD, valve ds, LA myxoma
2. Prothormbotic d/o
-sickle-cell, protein c or s,factoe V, polcythemia, leukemia
3.Inherited
-neurocutaneous d/o, CADASIL
-MELAS, homocystinuria
4.Acquired vascular d/o
-dissection, moya-moya
-OCP, "street drugs"

Front 70

Pediatric BG calcifications

Back 70

1.Fahr's syndrome
2. Hypo or hyper-parathyroidism
3. MELAS
4. HIV

Front 71

MELAS

Back 71

Mitochondrial myopathy, encephalopathy, lactic acidosis, & stroke-like episodes

-BG calcification
-acute "stroke-like" coritcal lesions that cross usual vascular territories
-DWI variable
-elevated lactate peak on spectroscopy

-usually 2nd decade
-acute onset headache, hemianopsia
-progressive course, periodic acute exacerbations