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152 Cards in this Set
- Front
- Back
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Are spinal hemangioblastomas sometimes associated with syrnix
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yes
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Can an endolymphatic sac tumor have a destructive appearance like a glomus jugular
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yea
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Are endolymphatic sac tumors associated with VHL
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yes
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Besides fat and blood what should you suspect if there is bright signal seen on the T1W brain image
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melanoma
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What is a good follow up study if you suspect melonoma
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contrast enhanced CT or MRI
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What is the appearance of metastatic melanoma of the brain on t2 MR
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iso to low intensity
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What are some causes of hemorrhagic brain mets
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breast, lung, renal, thyroid, chorioCA, retinoblastoma, melanoma
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Can angioinvasive infections such as aspergillosis have a hemorrhagic appearance
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yes
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What is the appearance of RCC on MR of the brain
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variable bc it is hemorrhagic but typically bright
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Does the fungal infection zygomcosis cause hemorrhagic infection like aspergillosis
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yes
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What does a mucocele look like
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expansion of a sinus without erosion but with thinning of the walls
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What is the the most common location of a mucocele
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frontal sinus, then ethmoid
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What is the MR signal characteristic of a mucocele
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usually high T1 and T2, but can be low T2 if high protein
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What is a characteristic of a mucocele that is very important to differentiate from a tumor
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Peripheral enhancement is very important in distinguishing from a tumor
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What are 2 potential complications from a mucocele
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Diplopia or proptosis from orbital compression
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What is a complication of a ventricular tumor
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obstructive hydrocephalus
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What is a main cause of transependymal CSF
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obstructive hydrocephalus
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How is an ependymoma able to squeeze through the foramen of magedie or luschia
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It is a soft or “plastic” tumor: squeezes out through 4th ventricle foramina into cisterns
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What percent of ependymoma are infratentorial
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2/3 infratentorial, 4th ventricle
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What percent of ependymomas are supratentorial
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1/3 supratentorial, majority periventricular WM
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Where do supratentorial ependymomas tend to occur
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periventricular WM (intraparenchymal)
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Is calcification of a ependymoma common
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yes, they can calcify (50%)
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Can ependymomas have cyst and hemorrhage
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yes
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What are tumors with CSF dissemination
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Medulloblastoma/PNET
Pineoblastoma Ependymoma Choroid plexus CA |
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Can an ependymoma have a hemorrhage, calcification and cystic change and be intraparenymal when supratentorial
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yes
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What term is used to describe the appearance of the ventricles in agenesis of the corpus callosum
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Steer horn-shaped (and pointed) frontal horns
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What happens to the cingulate gyrus in agenesis of the corpus callosum
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Absent/inverted cingulate gyrus
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What are 6 entities that ACC is associated with
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Assoc w/agyria, pachygyria, Dandy-Walker, heterotopias, septo-optic dysplasia, Chiari
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Can absence of the corpus callosum be associated with lipomas
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yes
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What are the findings of a spinal epidural abscess
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Findings of spondylodiskitis with adjacent enhancing epidural phlegmon +/- peripherally enhancing fluid collection
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Where do epidural abscessi occur more commonly; anterior or posterior
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posterior (80%)
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What are the typical MR signal characteristics of epidural abscesses
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T1WI: iso to hypointense to cord
T2WI: hyperintense |
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Are epidural abscess typically bright on T2 W imaging
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yes (they will enhance on post contrast imaging also
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What are the most common pathogens that cause epidural abscesses
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staph and then TB
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When does a subdural hematoma occur
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subacute timing, anemia
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Snowman
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macroadenoma
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Do macroadenomas enhance
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yes they enhance inhomogeneously
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What are the signal characteristics of a microadenoma
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low on T1 and variable on T2
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When is a microadenoma most easily seen
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post contrast imaging (it willl appear hypointense)
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What are the SS of a microadenoma
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bitemporal hemianopsia
headache other cranial nerve disturbances |
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Do macroadenomas have a propensity for hemorrhage and infarction
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yes
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What is the size of a macroadenoma
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greater than 1 cm if less than 1cm then it is a microadenoma
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What is apoplexy
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Sudden impairment of neurological function, especially that resulting from a cerebral hemorrhage; a strok
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What is the ddx of a suprasellar/sellar mass
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sarcoid
aneurysm, adenoma tertoma, germinoma craniopharyngioma hamartoma meningioma other: mets, EG, TB, dermoid epidermoid |
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How does a craniopharyngioma appear on T1
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T1 signal intensity varies depending on cyst contents, which can appear hyperintense if they contain high protein, blood products, and/or cholesterol (in the classic adamantinomatous type).
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Can craniopharyngiomas appear in the ventricles
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yes, craniopharyngiomas appear as intraventricular, homogeneous, soft-tissue masses without calcification
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What subtype of craniopharyngioma is found in children
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The adamantinous subtype is found in children; > 90% have identifiable calcifications on imaging
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Cyst with calcification of the the walls in the suprasellar region
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craniopharyngioma
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Can a craniopharyioma extend into the sellar turcica
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yes and expand it
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Can a dermoid occur in the region of the supracellar space
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yes
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What artifact may clue you in that a lesion is fatty
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if there is chemical shift.
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What kind of changes are seen in the suprasellar region and at the base of the brain secondary to sarcoid
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enhancing nodular enhancement
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What is the appearance of a tuber cinerum hamartoma
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This is a nonenhancing, small hypothalamic lesion with signal intensity similar to that of the gray matter in the region of the hypothalamus on T1W images
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Can TB cause ring enhancing lesions
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yes
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Can TB also cause intense enhancement of the meninges at the base of the brain when meningitis occurs
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yes
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What are the radiographic characteristis of a choroid glioma
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avid enhancement
hyperdense on CT |
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Where do choroid gliomas most commonly occur
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hypothalamus and anterior 3rd ventricle
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Should choriod glioma be added to the SATCHMO ddx
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yes (put it under C)
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What is an optic nerve glioma
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a type of pilocytic astrocytoma
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What is the MCC of a primary optic nerve glioma
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optic nerve glioma
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What is the mean age of occurence of an optic nerve glioma
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8y
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Do optic nerve gliomas tend to occur in chiilren
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yes
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What syndrome are optic nerve gliomas associated with
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NF1 (often bilateral)
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What are the CT findings of an optic nerve glioma
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enlargement of the optic canal and nerve
fusiform or nodular |
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Do optic nerve gliomas enhance
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they can but it is variable
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Is calcification common with optic nerve gliomas
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yes, calcification is rare
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What are the MR findings in a pt with an optic nerve glioma
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iso T1, iso to high T2, except in NF, often is low in center on T2 w/high signal at periphery, called arachnoidal gliomatosis
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What is a KEY distinguishing feature of an optic nerve glioma
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glioma has epicenter on optic nerve and cannot be distinguished from the nerve
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What part of the history is also important to help with a diagnosis of an optic nerve glioma
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age (mean age is 8y)
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If there are bilateral optic gliomas what should be suspected
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NF 1 (meningiomas also occur with this syndrome)
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Do optic gliomas cause a tram trak appearance of the optic nerves
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no, that is from meningiomas (there will more likely be calcificaiton also)
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What are the findings of an optic nerve meningioma
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Enhancing mass surrounding intraorbital optic nerve w/Ca+
“Tram-tracking”: tumor enhancement or calcification on either side of optic nerve |
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What age do most choriod plexus papillomas occur
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less than 5 y
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What side do choroid plexus papillomas most commonly occur t
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the left side
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50% of choroid plexus papillomas occur in the atrium of the left lat ventricle
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yes
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Why do patients with choroid plexus papillomas get hydrocephalus
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because of overproduction
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What is the CT appearance of a choroid plexus papilloma
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hyperdense, frondlike, 25% have Ca+
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What is the ddx of optic nerve sheath enhancement
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nerve sheath enhancement: sarcoid, mets, lymphoma, pseudotumor (optic glioma will cause enhancement of the entire optic nerve)
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What are the radiographic characteristics of a optic meningioma
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CT: hyperdense
MR: iso T1, variable T2 |
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50% of choroid plexus papillomas occur in the atrium of the left ventricle where do 40% occur
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the 4th ventricle and foramina of luscha
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What is the radiographic appearance of an choriod plexus papilloma
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low T1, mixed T2, heterogeneous from hemorrhage, Ca+, and flow voids
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Does an choroid plexus papilloma enhance avidly
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yes
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What is a concern if there is an ugly choroid plexus papilloma
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a choroid plexus carcinoma
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What is the common presentation of a choriod plexus carcinoma
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Child < 5 y w/enhancing intraventricular mass, ependymal invasion
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What percent of choriod plexus carcinomas will have calcificaiton
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-20-25%
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Do choroid plexus carcinomas sometimes result in CSF seeding
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yes
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Is a choroid plexus carcinoma sometimes difficult to differentiate from a papilloma
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yes
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What is the ddx of an intraventricular mass
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choroid plexus tumor (children)
meningioma mets ependymoma subependymoma astrocytoma central neurocytoma colloid cyst subependymal giant cell astrocytoma |
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Where do subependymal giant cell astrocytomas MC occur
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the foramen of monroe
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Do subependymomas enhance
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no, usually not
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Are subependymomas frequently multiple
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yes
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Do choroid plexus carcinomas avidly enhance
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yes
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What is the best diagnostic clue that a tumor may be a central neurocytoma
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"Bubbly" mass in frontal horn or body of lateral ventricle
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What is the classic appearance of a central neurocytoma
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a bubbly mass attached to the septum pellucidum in the lateral ventricles
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What is the CT appearance of a central neurocytoma
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Usually mixed solid and cystic mass with calcification
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What is the most common complication of a central neurocytoma
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hydrocephalus
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What is the MR appearance of a central neurocytoma
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Heterogeneous, T2 hyperintense, "bubbly" appearance
Moderate to strong heterogeneous enhancement |
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Does a central neurocytoma enhance
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yes, moderate to strong heterogeneous enhancement
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What is the WHO grade of a subependymoma
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grade 1
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Where do most subependymomas arise
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the lateral recess of the 4th ventricle or I, inferior 4th ventricle typical (60%)
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What is the signal characteristic of a subependymoma
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T2/FLAIR hyperintense intraventricular mass
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Why are subependymomas heterogeneous
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Heterogeneity related to cystic changes; blood products or Ca++ may be seen in larger lesions
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Do subependymomas enhance
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Variable enhancement, typically none to mild
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What are the classic findings of herpes encephalitis
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anterior temporal T2 hyperintensity and enhancement
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What type of herpes will cause herpes encephalitis
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type 1
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What are the MR findings of herpes encephalitis
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high T2 in medial temporal lobe(s) and inferior frontal lobe(s), with enlargement, restricted diffusion
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What portions of the brain are typically involved in herpes encephalitis
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Portions of the limbic system (cingulate gyrus and structures in the temporal lobe). temporal lobes, insula, subfrontal area, cingulate gyri
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What is included in the limbic lobe
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with some authors including the paraterminal gyrus, the subcallosal area, the cingulate gyrus, the parahippocampal gyrus, the dentate gyrus, the hippocampus and the subiculum
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What is a hint that a lesion of the temporal lobe is herpes and not a stroke
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Basal ganglia usually spared
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What is the enhancement of herpes encephalitis
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Enhancement variable, may be patchy, gyriform, meningeal
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Can herpes encephalitis have hemorrhage
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yes
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What is heterotopic gray matter
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GM located in wrong place due to arrest of neuronal migration
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What are the signs and symptoms of heterotopic grey matter
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seizures and developmental delay
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What is the density of the HGM on CT
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same as grey matter
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What is the signal of the grey matter on MR
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isointense to GM on all sequences
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Where is the most common location of heterotopic gray matter
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subependymal
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What is it called when there is a band of gray matter because of arrest of migration
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band heterotopia
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When do you classically see hyperintense globi pallidi
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hepatic encephalopathy
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Besides seeing hyperintensi of the globus pallidi in T1 what other condition may cause this
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increased magnanese
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What is a reason a hospitalized patient may have increased magnanese
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TPN
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What is the ddx of hyperintense BG in a T1W sequence
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physiologic Ca+, NF 1 (GP), hepatic encephalopathy, TPN, HIE, CO poisoning (GP), kernicterus (GP), Wilson disease (GP), endocrine (hypothyroid, any parathyroid), Fahr disease
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Are the globi pallidi sometimes hyperintense in a pt with NF
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yes on T1 sequences
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Can CO poisoning cause increase T1 signal of the GP
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yes
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Can wilsons disease and fahrs disease cause increased signal of the BG on T1 sequences
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yes
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What is more lateral the putamen or the globus pallidi
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putamen
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What is the ddx of increased T2 signal within the BG
ton just read through |
Infection: encephalitis (viral MC), Creutzfeldt-Jakob, cryptococcosis, toxoplasmosis
Toxic/metabolic: Leigh, Wilson, MELAS, MERRF, osmotic demyelination syndrome, CO poisoning Ischemia: HIE, lenticulostriate infarct Neoplasm: lymphoma, gliomatosis cerebri, mets, primary NF 1 (myelin vacuolization) ADEM Vasculitis: SLE, HUS, infection (bacterial/TB meningitis) Drug abuse: amphetamines (stroke, vasculitis) Huntington (caudate, putamen) Hallervorden-Spatz |
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What are the infectious causes of increased signal of the BG on T2
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encephalitis (viral MC), Creutzfeldt-Jakob, cryptococcosis,
toxoplasmosis |
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What are the metabolic causes of increased signal of the BG on T2
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Leigh,
Wilson, MELAS, MERRF, osmotic demyelination syndrome, CO poisoning |
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What is a classic finding of creutz feldtz jacobs disease
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increase signal on T2 of the caudate, putamen, medial thalamus, and cortical ribbon
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What is the MC fungal disease of the CNs
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cryptococcus
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What is the hallmark of cryptococcus
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Hallmark is gelatinous pseudocysts in basal ganglia region but can occur other places in the brain
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Where is cryptococcus most commonly found
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Basal ganglia (BG), thalamus, brainstem, cerebellum, dentate nucleus, periventricular white matter (WM)
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What is a common finding of cryptococcus in AIDS patients
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Dilated perivascular spaces in deep gray nuclei of AIDS patient, often no enhancement
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What is the signal intensity of the basal ganglia in leighs disease on T1 and T2
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T1-dark
T2-bright |
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In osmotic demylination sydrome where is the most classic location of increased T2 signal
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Central pons T2 hyperintensity with sparing of periphery
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Where else can osmotic demyleination syndrome occur
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the BG and subcortical gray mattter (you will see areas of increased signal)
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What are the findings of Hallervorden-Spatz Disease (Pantothenate Kinase-associated Neurodegeneration
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bilaterally symmetric hyperintense signal changes in anterior medial globus pallidus with surrounding hypointensity in the globus pallidus on T2-weighted images. These imaging features are fairly diagnostic of HSD and have been termed the “eye-of-the-tiger” sign
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Eye of the tiger
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hallervorden spatz disease
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What is the cause of the abnormal signal in hallervorden spatz disease
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The hyperintensity represents pathologic changes including gliosis, demyelination, neuronal loss, and axonal swelling, and the surrounding hypointensity is due to loss of signal secondary to iron deposition
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What is the ddx of leptomeningeal enhancement
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infection (bacterial, viral, fungal), tumor, sarcoid
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Where is the classic location of enhancement of the TB meningitis
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Classic is TB with basilar meningitis
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What kind of bacterial infection may cause basal cistern leptomeningeal enhancement
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Classic is TB with basilar meningitis
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Do sarcoid and TB leptomeningeal enhancement look similar
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yes, looks like TB get CXR and ACE level
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What type of neoplasms are going to cause leptomeningeal enhancement
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Primary CNS, mets from lung, breast, leukemia, lymphoma
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What is the ddx of pachymeningeal enhancement
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postoperative, ventriculostomy catheters, intracranial hypotension, meningioma, mets (breast, prostate), secondary CNS lymphoma, granulomatous disease
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What are 2 mets that will cause pachymeningeal enhancement
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breast and prostate
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What tends to be more nodular; TB and Sarcoid or Mets
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mets
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If you see diffuse pachymeningeal enhacement thoughout the brain what should you suspect
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intracranial hypotension
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What are the 2 main categories of gyral enhancement
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Vascular: reperfusion of ischemic brain, migraine, PRES, seizures
Inflammatory: meningitis, encephalitis |
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What are the vascular causes of gyral enhancement
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reperfusion of ischemic brain, migraine, PRES, seizures
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What are the inflammatory cause of gyral enhancement
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meningitis, encephalitis
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What is the cause focal cortical and subcortical enhancement
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Hematogenous dissemination of metastatic neoplasms and clot emboli
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