Neuro Imaging Flashcards
frontal/coronal viewing how
looking at the patient from the front/back
sagittal viewing how
looking at the patient from a lateral view
axial/transverse/horizontal viewing how
looking at the patient from the top/bottom
CT findings are what
densities
white on CT =
higher density than the brain
hyperdense
bone
black on CT =
lower density than the brain
hypodense
air, CSF
gray’ish on CT =
moderate density
isodense
brain
artifact
either motion or metallic objects
blurring =
motion
unable to follow commands to stay still
streaking =
metallic objects
metal tooth fillings
aneurysm metal coiling/clips
what will u see in a posterior fossa cuts
level of 4th ventricle
tentorial
what will u see in a supratentorial cuts
3rd ventricular level
lateral ventricular level
above the ventricular level
what will you see at the level of the 4th ventricle with a posterior fossa cut
dorsum sellae
basilar artery
temporal lobe
mastoid air cells
4th ventricle
cerebellum
what will you see with a tentorial slice with a posterior fossa cut
frontal sinus
frontal lobe
sylvian fissure
suprasellar cistern
temporal lobe
midbrain
4th ventricle
what will you see at the level of the 3rd ventricular level with a supratentorial cut
frontal sinus
falx cerebri
frontal lobe
3rd ventricle
temporal lobe
quadrigeminal plate cistern
what will you see at the level of the lateral ventricular level with a supratentorial cut
ant horn of lateral ventricle
caudate nucleus
anterior limb of int capsule
globus pallidus and putamen
posterior limb of int cap
choroid plexus
quadrigeminal plate cistern
falx cerebri
ant horn of lateral ventricle
thalamus
post horn of lat vent
what will you see at the level of the about the lateral ventricular level with a supratentorial cut
frontal bone
falx cerebri
parietal bone
subdural/soft tissue window
hypodense water/air is black
isodense brain tissue is gray
hyperdense bone is white
bone window
isodense brain tissue is gray
hyperdense bone is white
non-contrast CT rules out what
hemorrhage - gold standard
what is the sensitivity reports for a non-contrast head CT
poor sensitivty to show early ischemic changes - need >12hr
nearly 100% sensitivity for intracranial hemorrhage (ICH)
when is CT superior to MRI?
evaluating osseous structures - skull fx
MORE concerning if “depressed” skull fx
if ischemic stroke what will it look like on CT
loss of gray-white distinction
loss of sulci - smooshed gyri
hypodensity over time - hours to days
if hemorrhagic stroke what will it look like on CT
hyperdense blood infiltrates brain tissue
non-contrast CT most often used for what
evaluation of neurosurgical emergencies
hemorrhage
herniatic
hydrocephalus
contrast CT
improves sensitivity for detecting neoplasms or infections
what are u looking for with contrast CT
things that alter the permeability of the BBB
intact BBB should not leak contrast into brain tissue
contraindications for head MRIs
pacemakers/simulators
some jt replacements
staples, wires, clips, shrapnel
cochlear implants
IUDs
piercings
some tattoos - esp blue/black ink
T1 MRI
most anatomically relevant images
T1 MRI fluid is -
dark
T1 MRI gray matter is -
darker than white matter
T1 MRI bone is -
bright
T2 MRI
standard addition to T1
T2 MRI fluid is -
bright
WW2 - water is white in T2
T2 MRI gray matter is -
brighter than white matter
T2 MRI bone is -
dark
FLAIR
fluid attenuation inversion recovery
similar to T2 - fluid is dark
when is FLAIR useful
areas of edema/inflammation pathology
