imaging Flashcards
what is the imaging test of choice in suspected acute stroke?
non-contrast CT
4 CT signs of stroke
1 - dense middle cerebral artery (MCA)
2 - loss of grey-white differentiation
3 - loss of insular ribbon
4 - effacement of sulci
2-4 are signs of cytoxic edema
how long can a CT still be normal after an acute stroke?
6-24 hours
why is the MCA dense in acute stroke?
clotted blood in the vessel
what is tPA?
tissue plasminogen activator, treatment for acute stroke within 3 hour window, with only precluding factor being hemorrhage on a CT
what can preclude tPA treatment?
hemorrhage on a CT
what is the gold standard for identifying dead brain tissue after a stroke?
- brightness maintained for 10-14 days on diffusion imaging MRI indicates irreversible injury
potential false positives for dead brain tissue
abscess, hemorrhage, MS
common characteristics of epidural hematoma
- 85-95% underlying fracture
- won’t cross bone sutures
- usually at site of impact
- biconvex
- better prognosis than others
management of EDH
- if less than 30cc’s, thinner than 15mm, less than 5mm midline shift, glascow coma scale greater than 8, manageable without operation
- 30cc’s should be evacuated no matter what
- GSC less than 9 with anisocoria (uneven pupils), evacuate ASAP
common characteristics of SDH
- crescentic
- can be coup or countercoup
- midline shift and thickness important
- worse prognosis than EDH
management of SDH
- thickness greater than 10mm or midline shift greater than 5mm should be evacuated
- GCS less than 9, ICP should be monitored
- decrease in GCS by 2 or more, increased ICP, or fixed and dilated or asymmetric pupils are indications for evacuation even if thickness and midline shift criteria are not met
where is the midline shift measured?
- foramen of monro
- (A/2) - B
what is the #1 cause of SAH?
trauma
treatment of SAH?
no specific treatment
