Neuroradiology Review Flashcards
Dense MCA sign
early ischemia
Insular ribbon sign
early ischemia, insula hypodense
Loss of sulcal effacement
early ischemia
obscuration of lentiform nucleus/blurred BG
early ischemia
Best MRI sequence for blood?
Gradient
Can unilarteral PICA infarcts cross midline?
No, because vermian branches do not cross midline
Medial lenticulostriate
Supplied by M1
Lateral lenticulostriate
Supplied by A1
M2 and M3
M2 supplies area of sylvian fissure, M3 supplies cortical patietal region
Cortical border zone infarcts
Watershed, between ACA and MCA, or between MCA and PCA
Internal border zone infarcts
At the border between the lenticulostriate (A1/M1 tributaries) and the Deep penetrating MCA.
What to look at with Internal border zone infarcts?
Carotids
What to look for in border zone infarcts in general?
Carotids - makes sence, because this causes hypoperfusion.
“Lacunar”?
Lake like, in areas of BG, thalamus, white matter
Virchow-Robin Spaces (VRS)
Area where arteries enter brain parenchyma, can look like hypodense lacunes. Will be CSF intense on T2, black on flair.
PRES
Posterior Reversible Encephalopathy Syndrome
Is PRES vasgenic or cytotoxic
vasogenic
What does PRES look like on MRI
Should be PCA but can happen anywhere, hyperintense on FLAIR.
PRES associated with?
Hypertension, eclampsia, cyclosporine. Hypoperfusion –> vasogenic edema
Risk factors for venous thrombosis
Dehydration, pregnancy, hypercoaguability, mastoiditis
Presentation of venous stroke
Often presents as hemmoragic stroke in atypical location
How to find a venous stroke?
MRV
Glial
Astrocytoma, oligodendroglioma
Non-Glial
Meningioma, Schwannoma, Pituitary, Pineal, Lymphoma
Mets
Lung, Breast, Melanoma, Renal, Colon
What percentage of each?
1/3. 1/3. 1/3
Age under 2
Choroid plexus papilloma, Anaplastic astrocytoma, teratomas
Age under 10
Medulloblastoma, astrocytomas, ependymomas, craniopharyngiomas, gliomas.
Age adult
GBM, astrocytomas, meningiomas, oligodendrgliomas, pituitary, schwannomas
Common intra-axial supratentorial tumors in kids
astrocytoma, pleomorphic xanthoastrocytoma, PNET, DNET
Common intra-axial infratumors in kids
Juvenile pilocytic astrocytoma, PNET, ependymomas
Common intra-axial supratentorial tumors in adults
Gliomas, mets
Common intra-axial infratumors in adults
Mets, hemangioblastomas (METS ARE TOP 3 IN DIFFERENTIAL!)
Most adult intraaxial
MET
Most adult extraaxial
Meningioma, Schwannoma
Signs of extraaxial masses
CSF cleft, gray matter between the mass and white matter, brioad dural based, subarachnoid vessels displaced circumfrentially, Bony reaction.
Dural Tail
Meningioma, can see with schwannoma, but RARE
Enhancement of Intra/Extra axial
Extra axial should enhance, because NO BBB
Primitive neuroectodermal tumours (PNET)
Rare, from undifferentiated nerve cells (medullablastoma, pineal tumors)
What tumors cross midline?
GBM, meningioma, lymphoma, epidermoid cyst
How does GBM cross midline
IT infiltrates the corpus
How does Meningioma cross midline
Can spread long the meninges
How does Lymphoma cross midline
It is usually near the midline
How does epidermoid cyst cross midline
Via the subarachnoid space
Tumors seen in NFI
Optic glioma, astrocytoma
Tumors seen in NFII
Meningiomas, ependymomas
Tumors seen in Tuberous Sclerosis
Subependymal giant cell astrocytoma, ependymomas
Tumors seen in Von-Hippel Lindau
Hemangiomas
Tumors that are cotically based
Most tumors are white matter based. So cortical ones can be: oligodendroglioma, ganglioglioma, Dysembryoplastic neuroepithelial tumor (DNET)
Fat on CT HU?
It is -100
Fat on MRI?
Should have signal on both T1 and T2, however check fat sat and out of phase!
Fat satted tumors?
Lipoma, Dermoid Cysts, teratomas
What shows up high intensity on T1 that is not fat?
Melanin, Slow flow (IE hemangioma), blood (IE hematoma)
Calcified intraaxial tumors
Oligodendrogliomas almost always have calcification. However since astrocytomas are vastly more common, most calcified masses are astrocytomas (even though a small fraction have calcifications)
Calcifieed extraacxial tumors
Craniopharyngioma - Slow growing. Suprasellar, cystic squamous sell, in kids, rathke’s pouch
Cystic CNS lesions
Epidermoid, dermoid, arachnoid, neuroenteric. All are cystic. VRS can mimic
Appearance of cystic lesions on MRI
Intense on T2, isointense to CSF on most sequences because fluid.
High intensity on T1
Methhemoglobin, high protein, fat, cholesterol, melanin, slow flow.
What tumors show low intensity on T2
Dense tumors with high NC ratio: LYMPHOMA
Why does a lymphoma show up low intensity on T2
Becauese it has a high NC ratio
Melanoma metastesis
High T1, Low T2
When is restricted diffusion seen?
Abcesses, acute infarct, epidermoid cyst
What do tumors looks like on DWI
Most tumors do not cause restricted diffusion even in necrotic components. So most of the time the tumor will look hypointense.
Which type of tumors enhance?
Extra axial, because contrast does not have to cross the BBB.
What are some exaples of typical enhancing tumors
Meningioma, Schwannoma, Pituitary, Pineal
Does the pituitary have a BBB?
NO
Does the Ppineal gland have a BBB?
NO (Pineocytoma enhances!)
When will an intraaxial tumor enhance?
When the BBB is destroyed
What is an example of a tumor that breaks BBB?
GBM high grade, if it breaks BBB then it can enhance
What are some non-tumoral enhancing lesions
MS, infarctions
What lesions are expected to NOT enhance
Dermoid, Epidermoid, arachnoid cysts, low grade astrocytoma
What lesion has limited mass effect even when large, patchy enhancement, edema.
GBM - large infiltrative growth beyond MRI finidings
Ring enhancement
Mets, GBM, abcess (MAGIC DR)
Tumor arising from the Clivus
Chordoma
Tumors arising from the skull base
Chordoma, chondrosarcoma, fibrous dysplasia
Chordoma vs Chondrosarcoma
Chordoma midline, chondrsarcoma off-midline
Sellar and suprasellar lesions
Pituitary, cranio, meingio, chiasmatic glioma, any cyst, schwannoma, met
Name: Supracellar cystern, calcifications on CT, cystic component that shows no enhacement
craniopharyngioma
Common tumors in CP angle
Schwannoma, meningioma, cysts, mets
Intraventricular Tumors
Ependymoma, subependymoma, choroid plexis papilloma, central neurocytoma, colloid cyst, meningioma, giant cell astrocytoma
4th ventricular tumors in kids
Astrocytoma (pilocytic?), medulloblastoma, ependymoma
What do the saggital sinuses drain into?
Straight sinus
What does the vein of Galen Drain?
Drains deep central veins: thalamostriate, internal cerebral into straight sinus
What does the vein of Labbe drain?
temporal lobe into transverse sinus
What does the vein of Trolard drain?
Drains cortical to superior saggital sinus
Cause of venous thrombosis in neonate?
Shock, dehydration
Cause of venous thrombosis in children?
Sinusitis, mastitis
Cause of venous thrombosis in adults?
Coagulopathy, in women its OCP/pregnancy as highest risk factors
What is the dense clot sign?
Sometimes the clot shows up hyper dense on CT. Can see in straight, transverse, sigmoid, etc
What is the cord sign, and the dense vessel sign?
Same as dense clot sign
What is the empty delta sign?
Contrast CT scan shows a contrast void in the superior sagital sinus on axial. Looks like a delta with hypersense contrast around the central clot
First sign of venous thrombosis?
Edema, then possibly hemorrhagic conversion
What type of edema will VT cause?
Vasogenic
What is the distribution
Bilateral often
What does vasogenic edema look like
Finger-like
What if you see some vasogenic edema in temporal
Vein of Labbe
What if you see intensity on flair in thalamus and basal ganglia bilaterally? What does it mean?
BL means venous possibly, intensity is edema, location is Galen, or one of the other deep veins that Galen drains.
MR venograph types
Time of flight, phase contrast, contrast enhanced
Time of Flight venography
Uses the phenomenon of flow void, to create a signal intensity
Phase contrast venography
Development of phase shift due to flow, created an angio…
Contrast enhanced MRV
Uses T1 shortening of gado
What can mimic a venous clot?
Aracnoid granulation
Does MRV have pitfalls?
Lots. CTV is more reliable. Contrast MRV is better than the phase contrast or TOF MRV.
What does the quadragemial Cistern look like
Smiley face
What does the suprasellar cistern look like
Star of david
What are the three parts of the extradural ICA?
Cervical, petrous, cavernous
What is the Torcula?
Confluence of the sinuses
What structure pass through the optic canal
CNII, opthalmic artery, and vein
What structures pass through SOF
CNIII, IV, V1
What structures pass through IOF
V2
What are the three compartments of Orbit
Intraconal space, conal space (muscles), extraconal space
What is the blood supply to the globe
central retinal artery
What is more lateral, ICA vs IJV?
IJV
What are the divisions of the neck?
Supra, and infra hyoid neck
What are the four muscles of mastication
Medial/lateral pterygoid, masseter, temporalis
What term is used for cystic cavitation of an old infarct?
encephalomalacia
What looks like beads on string on CTA?
FMD
Five common causes of intraparenchymal hemmorage?
Amyloid, tumor, coagulopathy, venous infarct, AVM.
Where does spontaneous hemmorage occur
External capsule and basal ganglia and pons and cerebellum
Acute blood on CT? HU?
forty five
MAGICAL DRS
Mets, Abcess, Glioblastoma, Infarct, Contusion, AIDS, Lymphoma, Demylination, Resolving hematoma, Septic embolus
What are the two most common causes of SAH?
Trauma, Ruptured Berry aneurysm
What does an AVM look like on angiogram?
One large vessel feeding a tangle of abnormal vessels.
Two most common brain mets
lung and breast
What is the mnmonic for mets causing intracranial hemorrhage?
MRI CT
MRICT
Melanoma, RCC, insulinoma, choriocarcinoma, thyroid carcinoma
What is the treatment for a solitary met
surgical removal
What is the characteristic bony change for meningioma?
hyperostosis
What does meningioma look like on CT?
isodense, with homogenous enhacement and possible calcs, with hyperostosis
What does meningioma look like on MRI?
Isointense with bright enhancement
What is DISH
diffuse idiopathic skeletal hyperostosis. Anterior fusion flowing dyndesmophytes
Pineal region differential
Germ cell tumor, pinealocytoma, pinealblastoa, tecta glioma, meningioma, metastesis, aneurysm of the vein of galen.
What is an empty sella? How?
Defect in the diaphram sella that allows CSF pulsations to flatten the pituitary.
Cerebellar tumors?
Mets, hemangioma, astrocytoma, medulloblastoma, lymphoma, abcess
What is the mnmonic for VHL
HIPPEL RR
HIPPEL RR
Hemangioblastoma, islet cell tumors, pheo, pacreatic cystadenoma, epididymal cysts, liver cysts, retinal angioma, RCC (and cysts)
What does a hemangioblastoma look like on CT?
Cystic mass with enhancing mural nodule
Posterior fossa masses in child? Mnmonic
GAME
GAME
Glioma, Astrocytoma, medulloblastoma, ependymoma
What does a juvenile pilocytic astrocytoma look like on MRI
Cystic t2 bright lesion with mural enhancing nodule usually located in the cerebellum.
Where are ependymomas usually located?
Floor of the fourth ventricle
What is the appearance of ependymoma on MRI?
Tooth paste squeezing from the fourth ventricle and out the foramen of magendie and luschka
Two common congenital abnormalities of CNS
Arnold-chiari and Dandy-Walker
What is arnold-Chiari 1
Downward displacement of cerebellar tonsils through foramen magnum, small fourth ventricle, syringomyelia, fusion of c1 with cranium. Treatment can be removal of posterior part of c1 and cranium to allow for space.
What is arnold-chiari 2
inferiorly placed tentoria, small posterior fossa, large foramen magnum, meningomylocele, agenesis of corpus callosum, stenogyria, inferiorly displaced brainstem, elongated medulla, vermian peg
Dandy-walker
enlarged fourth ventricle, agenesis of vermis, varying degrees of hypoplasia of cerebellar hemispheres, high confluence of sinuses
What tumor is associated with TS
Supepedymal Giant cell astrocytoma
What are four characteristics of TS
Adenoma sebaceum, multiple subependymal hamartomas, renal angiomyolipomas, tubers (high t2 intensity)
What is encephalofacial angiomatosis called?
Sturge Webber
What are five features of sturge webber
Vascular facial nevi, vascular malfomations involving meninges, calcs along gyri, cerebral atrophy, glaucoma.
Described aging blood - Acute, sub, chron?
Dense, Iso, hypo
What does subfalcine herniation look like?
Midline shift and distortion of the horns of the lateral ventricles
What does transtentorial herniation look like?
Obliteration of the quadrageminal plate cisterns with hydrocephalus via compression of the cerebral aqueduct
What will you see with meningitis?
Leptomeningeal enhancement
How would you differentiate an abcess from another ring enhancing lesion on MRI?
DWI
What does it look like on that image sequence?
Bright on DWI because of restriction.
What does bilateral asymmetric white matter lesions in an immunocompromised person represent?
Possible multifocal leukencephalopathy
Best imaging sequence for MS?
Flair
Where are the lesions in MS characteristically located and what are they called?
Dawson’s fingers are located periventricularly
Patients with metabolic derangement and white matter lesions in the brainstem suggest what pathology?
CPML
What is the most common cause of cerebellar atrophy
Alcoholism affects the anterior and superior vermis
When people have complex seizure disorders you expect to see what radiologic finding?
Mesial temporal sclerosis, you will see gliosis of the hippocampus and parahippocampal regions.
What does MTS look like on MRI
abnormal T2 intensity on this area
What are the two types of hydrocephalus
COmmunicating and non-communicating
What are four causes of CHC?
Infection, post SAH, DVT, NPH
What are three causes of NCHC?
Aqueductal stenosis, mass, congenital
What tumor causes hydrcephalus by over production
Choroid plexus papilloma
Hydrocephalus can be mimicked in appearance by general brain atrophy, called?
HYdrocephalus ex vacuo
Age changes in vertebral discs is called? What does it look like?
Disc dessication, Looks like decreased T2 signal.
What are the two parts of the IV disc?
Nucleus pulposus, nucleus fibrosis
What is it called when a disc herniated into an adjacent body?
Schmorl’s Node
What is a disc bulg?
Greater than 180 degrees
What is a disc protrusion?
less than 180 degrees
What is a disc extrusion?
Focal protrusion with extruded part wider than the base. Pedunculated almost.
How do you localize a disc herniation?
Central, paramedian, foraminal, extraforaminal
What are some things you expect to see with DJD of the spine?
Disc space narrowing, osteophyte formation, sclerosis, vacuum disc phenomenon
List the three places a spinal tumor can be located
Extradural, intradural extramedullary, intramedullary. Try to describe how these look.
If you have enlargement of the spinal cord what type of lesion do you suspect?
Intramedullary
What changes on MRI will a patient s/p radiation have on MRI on T1?
Increased signal because of fatty replacement
Mnemonic for vertebral column tumors?
COAG
What does this stand for?
Chordoma, osteoblastoma, aneurysmal bone cyst, giant cell tumor
Pterion
Suture
What is transependymal flow?
edema associated with hydrocephalus
What is a persistent metopic suture?
Can be see as a sagital suture line that extends through the frontal bone
What does the vidian canal go to?
vidian canal is aka pterygoid canal, it connects the middle cranial fossa to the pterygopalantine fossa
What does Uncal herniation look like and what is the management?
effacement of the quadrageminal cistern. Surgical management
What is a Duret hemmorhage?
Linear density of the region of the pons indicating a bleed. Duret hemmorhages can expand
what happens in an orbital blowout fracture?
direct blow to the eye: fracture of the floor of the orbit, can pooch into the maxillary sinus
What components are involved in a zygomaticomaxillary complex fracture (ZMC).
Sometimes called the tripod fracture because it has at least three fractures involved. It can involve the lateral or medial walls of the orbit, (can also involve the orbital floor like a blowout fracture), as well as the zygomatic arch.
What are lefort fractures?
Fractures that are either vertical or horizontal involving the maxilla.
Old Elephants Age Gracefully
For calcified masses: Oligo, Epend, Astro, Glioblastoma
What shows up as FLAIR intensity that looks like an infiltrative process of the white matter with thickening of the corpus callosum and possible extension into the cortical white matter.
Gliomatosis cerebri
This shows up as a T2 bright lesion that has a complete rim. A GRE (gradient) will show marked susceptibility
Cavernous malformation
When will a stroke show up on CT scan (number of hours?)
longer than 4 hours. Use DWI
What is the appearance of AVM on a contrast study
Early opacification of the veins on an angiogram
What genetic condition presents with subcortical infarcts and leukencephalopathy?
CADASIL (cerebral AD subcortical infarcts and leukencephalopathy)
When does this usually present?
30-50
What is the difference between Moyamoya disease and regular moyamoya?
The disease is idiopathic whereas Moyamoya can be secondary to primary diseased like NF1 and Sickle cell.
The presence of what factor is highly specific for an abcess on MRI?
restricted diffusion
What would MR spectroscopy tell you if there was a lactate/lipid peak?
Likely abcess
In an immunocompromised individual with scattered white mattered lesions on MRI what would your diagnosis be?
PML
What would you see cortical ribboning and thalamic restricted diffusion in? Along with progressive dementia?
CJD
What does imbrication mean?
Normal overlap of the apophyseal joints
What is the Harris ring?
The normal lateral appearance of C2
What does a burst fracture look like?
Lateral radiograph: bowing of posterior vertebral line, and disruption of the spinolaminar line.
What should you not see with a burst?
dislocation of the facet joints
What does a dislocation look like?
Facet joint locking, listhesis.
What are good studies for herniated nucleus pulposis?
MRI, myelogram
What are the seven projections that attach to the vertebral arch?
one spinous, two transverse, four articular.
Spinous points down where?
Cervical
Spinous points up where?
Thoracic and lumbar
What is another name for the articular joints?
Joints of luschka
What is a common finding in older people in the joints of luschka
Uncovertebral hypertrophy
What is spondylolyses?
Shearing off of the pars interarticularis, common, and looks like a collar on the scotty dog
Which lubar transverse processes are usually longest?
L3
What are some components of spondolytic change?
Facet hypertrophy, ligamentum flavum hypertrophy, disc bulge
Osteophyte vs syndesmophyte
Osteophyte is horizontal spikes that accentuate the endplates. Syndesmophytes are arching connections between two endplates of adjacent vertebrae. Ostephytes = calcs of annulus fibrosis. Syndes = calcs of Sharpey fibers at margins of the disc
DISH has which?
Syndesmophytes
What are some high risk factors for spinal injury?
GCS 65, dangerous mechanism, parasthesias, Ank spond or DISH
What are some low-risk factors for spinal injury?
None of the above, simple accidents, ambulatory, absence of midline neck tenderness,no focal findings, no intox, normal GCS
What do anterior disc herniations cause?
Limbus deformities, which appear as anterior opacities, without the jigsaw sign, and with sclerotic margins indicating that it’s not a fracture. The sclerotic margins indicate a schmorls node.
How do you describe listhesis?
You say “Antero/retro of TOP over BOTTOM”
Benign tumors of the spine?
COAG: osteoid osteoma, osteoblastoma, aneurysmal bone cyst, giant cell tumor
Malignant tumors of the spine?
Chordoma, chondrosarc, mets, multiple myeloma, lymphoma,
MRI features of osteomyelitis/discitis?
Loss of disc height, endplate edema, abnormal disc space fluid.
What are the posterior elements
Pedicle, lamina, spinous processes
How many vertebrae in each set?
7, 12, 5, 5
How many cervical nerves?
eight
Where do cervical vs. Lumbar exit?
Lower vs upper
Where is the conus?
T12
What are common features of facial fracture?
Cortical disruption, fragment displacement, asymmetry, opacification or air fluid levels in the sinus, orbital emphysema, STS
What is the best radiographic view for nasal fracture?
water’s view
What is a FIZL fracture the same as?
ZMC, Frontozygomatic suture, infraorbital rim, zygomatic arch , lateral maxillary wall
What structure is always involved in Le Fort fractures?
Pterygoid plate (fractures are floating palate, maxilla, and face.
What is the ADI? normal measurement?
Atlantodental interval - should be less than 3 mm in adults
What is the BDI?
Basion to dens interval should be less than 12mm
What is a hangman’s fracture and what motion is it associated with?
Hyperextension. C2 pars fracture.
What are radiographic features of hangmans?
Pars fracture of C2, POsterior displacement of spinolaminar line, anterior inferior avulsion fracture with anterior longitudinal ligament rupture, prevertebral soft tissue swelling
What is a flexion tear drop injury?
Severe flexion injury. Bad outcome because very unstable
What does a teardrop refer to/look like
The anterior vertebral body fracture resembles a tear drop, there is subluxation of the posterior vertebral body, prevertebral hematomas, cord compression
What is SCIWORA
Spinal cord injury without radiographic abnormality
What test to order if you cannot evaluate traumatic nerve root injury with MRI?
CT myelogram
What is the radiographic appearance of a compression fracture vs a burst fracture?
Compression fracture will look like disc wedging on laterals, burst fracture has comminution and may have retropulsion of fragments into spinal canal
What is a “Chance” injury?
Unstable injury perpendicular to spinal axis which extends through intervertebral disc. These injuries typically happen as “seat” belt injuries” where the point of fixation is at a point anterior to the fracture.
Name: medial lobe temporal atrophy, and parietal atrophy
Alzheimers
Frontal lobe and atrophy of the temporal pole
FTLD
global atrophy, with diffuse white matter lesions, lacunes
vascular dementia
How is medial temporal lobe atrophy scored?
0-4, 4 being the worst, with severe volume loss of the hippicampus
If you saw a MTA (medial temporal lobe atrophy) score of 4 what is usually the diagnosis? then second?
Alzheimers, then vascular
What scale is used to grade white matter disease on FLAIR?
Fazekas: 0 is no, or a single lesion, 3 is large confluent lesions.
What scale is used to grade parietal atrophy?
Koedam: 0 is normal, 3 is extreme widening of the posterior cingulate and parieto-occipital sulci
What will you see with Cerebral amyloid angiopathy?
Multiple peripheral punctate microhemorrhages
What type of dementia will give you the characteristic hummingbird sign?
Progressive supranuclear palsy, the midbrain atrophies and gives this characteristic appearance
What type of dementia will give you the characteristic Hot Cross Bun sign?
Multiple system atrophy, atrophy of the pons shows a big + on axial imaging.
What shows up on FLAIR and DWI or a combination as neo-cortical ribboning?
CJD
What disease would cause atrophy of the head of the caudate and subsequent enlargement of the frontal horns of the lateral ventricles?
HD
What are the two most common causes of epilepsy?
Mesialtemporal sclerosis, and focal cortical displasia
What are some other cause of epilepsy?
Polymicrogyria, SW, TS, cavernous hemangioma, tumors
What are the best sequences to visualize MTS?
Coronal T2 and FLAIR
What if you have hyperintensity on FLAIR and T2 in the mesialtemporal lobe but NO atrophy?!
Could be status epilepticus, or a tumor, or encephalitis
What does SE look like on MRI?
temporal lobe intesity on T2, with possible swelling and DWI restriction because of cytotoxic edema
What would show up as a subtle blurred interface between grey and white matter in a focal area?
Focal cortical dysplasia, a congenital failed migration of neurons that is second most common cause of epilepsy after MTS
What is the transmantle sign?
Seen in FCD where white matter extends from the ventricle all the way to the cortex
Diagnosis? Focally shrunken cortex with atrophy and gliosis in the underlying white matter
Ulegyria: caused by congenital lack of blood supply to an area. Looks like pedunculated gyri on stacks of white matter
What will show up on SWI and T2 with blooming artifact and hyperintense appearance?
Cavernoma (or cavernous angioma)
What characteristically appears as a popcorn ball?
Same as above
What would be the differential for multiple punctate microbleeds?
Cerebral amyloid angiopathy, cavernomas, DAI
What disease is characterized by hamartomarous growth of one side of the brain with bony enlargement of the skull, dysplastic thick cortex only on one side?
Hemimegalencephaly
What disease shows up as hemiatrophy of the brain of unknown origin, with ventriculomegaly and progressive hemiplegia?
Rasmussen’s encephalitis
What is “Fitz, zitz, nitwitz
TS - adenoma sebaceum, epilepsy, MR
What disease is characterized by vascular malformation with leptomeningeal enhancement and capillary venous angiomas in the face. Atrophy of the cortex is mainly in the occipital lobes
Sturge-Weber
What is the pathophysiology behind SW?
Venous occlusion causes ischemia and angiomatosis with atrophy and cortical calcium deposits.
What is a key feature of the calcifications of SW?
Tram-track like calficications because of the calcified venous angiomatosis.
What eye finding do you have to worry about in SW?
choroidal hemangioma, which shows up as intensity on FLAIR
What is a cleft from ventricular space to the subarachnoid space that is lined by polymicrogyric gray matter?
Schizencephaly
What is the typical distribution of MS White matter lesions?
Corpus, periventricular, spinal, U-fibers, enhancement, dawsons
What is the typical distribution of vascular white matter lesions?
cortical infarctions and BG nuclei lesions
What is the distribution of brainstem lesions in MS vs Vascular?
MS peripheral, Vascular
What are juxtacortical lesions?
Could be classified as “periventricular” but these are not abutting the ventricles but close to the cortex.
What should be characteristic about the axis of the priventricular lesions?
perpendicular to ventricles
What do MS spinal lesions look like?
Should be small and peripheral not extending past 2 vertebral lengths
What is a good sequence for looking at spinal chord lesions in MS?
Proton density, because it has good contrast for the structures
Do dawson’s fingers enhance?
Yes, for about a month after they appear
Would enhancing periventrucular lesions mixed with non-enhancing lesions help you make a MS diagnosis? why?
Lesions in space and time; lesions for MS will only enhance for about a month
What is the “incomplete ring” a sign of?
Tumefactive MS, most ring enhancing lesions are circumfrential.
What other disease would you think about with bilateral optic neuritis?
Neuromyelitis optica (devic’s disease)
How would you tell this apart from MS?
NMO should have more extensive spinal cord lesions that are longer that in MS (think more than a few segments)
What Ab titer will be high in NMP?
AQP4-AB
How would you differentiate MS from ADEM?
Acute disseminated encephalomyelitis is similar to ms. The patient could also be younger s/p vaccination or illness
What criteria is used for MS grading?
McDonald Criteria
What are the criteria?
Dissemination in space (greater than one lesion in two out of four areas: periventricular, juxtacortical, infratentorial, spinal), Dissemination in time (Either a new enhancing lesion on follow up, or a multiple lesions where at least one isnt enhancing at one time)
Tumors from the gland
Adenoma, rathkes cleft cyst, craniopharyngioma
Tumors from the stalk
Rathke’s cleft cyst, craniopharyngioma, herminoma, eosinophilic granuloma, mets
Tumors from the optic chiasm
Gliomas
Tumors from the hypothalamus
Gliomas, hamartomas, germinomas, eosinophilic granulomas
Tumors/lesions from the Carotids
Aneurysm, ectasia, anomalies
Tumors/lesions from the cavernous sinus
Schwannoma, inflammation, car-cav fistula. Watch for thombosis, and CN VI impingement.
Tumors/lesions from cavernous meninges
Meningioma, inflammation
Tumors/lesions from the sphenoid/skull base
SCC, chordoma, sarcoma, mets, inflammation
What pathology can cause chemosis, headache, cn IV problems?
Cavernous sinus thombosis
What signs would be helpful in the diagnosis?
opthalmic vein engorgement, swi?
Definition of Microadenoma
Less than 10mm
Definition of macroadenoma
greater than 10mm, classic snowman look
What does a Rathke’s cleft cyst look like?
T2 bright, should be able to see a normal pituitary in the sella on UNENHANCED scan, if the cyst isnt too large
Pars interarticularis defect
could be congenital. Associated with anterolisthesis of L4 on L5
Cerebral palsy, features on MRI
Ischemic injury early, could see periventrucular leukomalacia, or cortical disease
grading of disc protrusion
can be done on sagittals: mild, mod, severe. Mild: keyhole maintained, moderate, keyhole fat disrupted, severe nerve root impingement
MS considerations
Want to look to see if there are NEW lesions, especially if they are enhancing, this tells the clinicial if the disease is getting worse despite treatment. Look on FLAIRs
What classification system is used for MS?
McDonald: criteria for where 2/4 gets the dx, locations, time/space
What are two types of MS?
Relapsing/remitting, progressive
What is optic nerve drusen?
focal punctate calcification usually bilateral in posterior orbit at the junction of the optic nerve and globe
What is a cavum septum pellucidum?
Bifircated septum
Where would you see a DVA?
enhancing in the brain parenchyma
What three tumors will uniformly enhance?
meningioma, nerve sheath tumors, lymphoma
What does posterior longitudinal hypertrophy in the high cervical region look like?
Epidural hematoma. But this finding is very common in patients with RA
What is a haller cell?
seen in 20% of people. Its an infraorbital air cell just of note, usually not associated with pathology.
What are some causes of medullary nephrocalc
PTH, RTA, sickle, gout
What does a left sided IVC empty into?
Usually the coronary sinus
What are the posterior calcifications on a plain film lateral xray of the cspine?
nuchal ligament calcifications
What is a toddler’s fracture?
lucent line from the tibial plateau extending inferiorly
What is the vascular supply to the head of the caudate?
Artery of Hubnert. Which is a branch of the ACA
What two foramen look like the footprint of a high heel?
Ovale and Spinosum
Where does the vidian canal go?
Pteragopalatine fossa?
Where does the urachus go?
Umbilicus to the dome of the bladder
What is the largest pathologic lymph node in the body?
Node of Winslow at 2.5 cm
What is the smallest pathologic lymph node in the body?
Retrocrural lymph node? at 7mm
What does subfalcine herniation look like?
midline shift
What does uncal herniation look like?
effacement of the suprasellar cystern
What is the mnemonic for trigeminal nerve holes?
SRO: standing room only, S/V1: SOF, R/V2: rotundum, O/V3: ovale
Why does the posterior pituitary light up on t1 imaging?
ADH is bright (maybe its the protein?) normal.
