IMAGING & other DM lectures Flashcards
4 Types of Structural imaging
CT, CTA, MRI, MRA
4 Types of functional imaging
EEG, MEG, fMRI, PET
EEG & what it is used for
cheap way to measure brain waves/ electrical activity
used for seizure d/o, sleep d/o, changes in electrical activity
not detailed but could be ok for surgery
MEG & pros/cons
measures magnetic field from neuronal electrical activity but electrodes don’t touch patient
pros- exact location of seizure, preoperative planning & epilepsy surgery, alzheimers, psych d/o, head injury
CONS- more costly then EEG, fMRI
fMRI
measures metabolic fx, changes in o2 from brain activity
PROS- no radiation, good for pre-surgical brain maps
CONS- more expensive than EEG
PET
radioactive tracer goes into vein then watch to see where its used in brain
good for evaluation of cancer and seizures that dont respond to meds, and memory d/o
CT & Uses
cross-sectional xray images with radiation
uses- head trauma, hydrocephalus/ventricles, intracranial lesions, hemorrhage
Why use CT
theres no magnets so its safe for ppl w/ metal
faster than an MRI
Interpreting CTS
used for BBB
Blood & bone are white, brain is grey
CTA
used for blood vessels and tissues
caution with renal fx bc it uses contrast
MRI
uses magnets, radiowaves to make images; no radiation
avoid w/ ppl w/ metal
Myelography
uses contrast dye & X-ray to look at spinal canal; can be paired w/ CT
pros- disk herniations, r/o nerve compression; good for ppl who cant get MRI
cons– invasive, radiation
Ultrasound
uses- carotid artery patency, new born screening
pros- risk free, no radiation, portable
cons- operator-dependent, can’t use for brain after fontanelles have closed
what is Bacterial meningitis? what is the classic triad sx?
infection of CNS membrane
triad–fever, neck stiffness, headache
also vomiting, seizures, photophobia
what are signs of bacterial meningitis?
fever
bulging fontanelle
focal neurologic findings
papilledema
rash
what are indications for lumbar puncture?
subarachnoid hemorrhage
CNS infection like meningitis
NS d/o like Guillain-barre, MS, etc
some cancers
Psuedotumor cerebri from excess CSF in brain
infectious indications in children
fever of unknown origin
fever in child < 3 months
kid 3mon-3yo w/ fever, irritability, vomiting
Kernig’s sign vs Brudzinski’s Sign
kernig’s sign: lay down flex hip & leg then straighten leg; pain & spasms= + for meningitis
brudzinski’s sign: flexion of neck causes legs to draw up
BOTH: test for meningitis, can be used in over 3 year old
Contraindications for LP
infection in tissues near puncture site
increased ICP (papilledema–can do after imaging)
coagulopathy or less platelet count
lateralizing signs or signs of uncal herniation (spinal deformity)
what are the two positions for lumbar puncture
lateral recumbent position
sitting position– increased risk of post-LP HA
what is tuffier’s line?
the superior iliac crest intersection @ L4
at what spinal level is needle inserted with lumbar puncture?
L3/4 in most adults
L5/5 or L5/S1 in kids
