Flashcards in Neuro Deck (19)
What imaging modality should be performed first in the setting of head trauma?
CT w/o contrast (+ normal trauma series)
biconvex or lenticular in shape
overlays fracture site
doesn't cross suture lines
lucid intervals with risk for deterioration and herniation
tearing for bridging veins
cross suture lines
reflects with arachnoid mater at falx but doesn't cross
between arachnoid and pia mater
trauma or rupture of an aneurysm
hyperdense areas on the CT within the sulci and the cisterns
best if detected w/n 12hrs on CT
Feared complication- vasospasm!
tearing of subependymal veins
collection in lateral ventricles
typically results from corpus collosum injury
trauma, hemorrhagic stroke, a ruptured AVM, or a hemorrhagic neoplasm.
The NEXUS Criteria for C-spine imaging
All trauma imaged unless all criteria met:
-No posterior midline c-spine tenderness
-Normal level of alertness
-No focal neurological deficit
-No clinically apparent painful injuries that might distract from pain of a cervical spine injury
Canadian C-Spine Rules for C-spine imaging
Image if high-risk factors:
-Age >65 years
-"Dangerous mechanism"- MVA
-Paresthesias in extremities
Don't image if:
-Simple rear-end MVA
-Sitting position in ED
-Ambulatory at any time
-Delayed onset of neck pain
-Absence of midline cervical tenderness
-Able to actively rotate neck 45° left and right
What is the best modality to look for spinal cord injury or compression?
What is the best modality to look for spinal fractures?
-medial temporal lobe herniates through the tentorial hiatus
-effacement of the suprasellar
-cranial nerve III palsies
Cerebellar tonsillar herniation
-cerebellar tonsils are pushed inferiorly through the foramen magnum
-often seen with posterior fossa masses
Best imaging for Diffuse axonal injury ?
MRI GRE or FLAIR are more sensitive and should follow CT for confirmation.
Rank from most likely to least likely the locations where berry aneurysms are known to occur.
What is the most sensitive examination for detection of acute ischemia?
(CT doesn't show imaging features of infarct until at least 6 hours)
Differential for seizure in immunocompromised patient with history of cerebral aneurysm?
MRI findings which favor toxoplasmosis include:
- Multiple lesions
- Abundant edema
- Target Enhancement
- Deep gray matter (caudate nucleus, basal ganglia) involvement
(Typically due to reactivation of latent disease)
MRI findings suggestive of PCNSL include:
- Solitary lesion
- Subependymal enhancement
- Encasement of the ventricles
- Hypointensity of the core on T2-weighted imaging