CNS

Question 1

prior confirmation steps for brain death

Answer 1

EEG (rept)
bedside tests (doll eyes, pain sensation, resp test)
eval cortical activity/fx (CT scan prior)
nuc med

Question 2

what mimics brain death

Answer 2

intoxication, DRUGS (OD), hypothermia

Question 3

interpretation brain death

Answer 3

flow to carotid arteries is normal in all patients but hot nose is ONLY normal in brain dead patients bc blood go to nose instead of brain

Question 4

tracers

Answer 4

30 mCi of TcO4, TcDTPA (20-30), Ceretec/ECD

Question 5

remember upon injection (methods)

Answer 5

scalp tourniquet, good bolus bc we are looking at flow, rapid dynamic, post flows

Question 6

what collimator do we prefer

Answer 6

LEAP

Question 7

dynamic workflow

Answer 7

same for every tracer and brain death study-FIRST bc followin tracer

computer started b4 inj, prefer LEAP over HiRes bc more sensitive to cts dont care bout details of res, 2 sec/ frame for 90 frames

Question 8

delay workflow

Answer 8

static immediately after dynamic= free tc and TcDTPA bc does not cross BBB
wait 20 min ECD/Ceretec to cross BBB
statics taken for 256 matrix, 500 k, position so cts are not picked up from rest of face (nose and up)

Question 9

what are ECD/Ceretec used for

Answer 9

-cerebral perfusion imaging
-SPECT

Question 10

properties needed to cross BBB

Answer 10

lipophillic, small molecule size, neutral charge, high extraction meaning it deposits in brain on first pass in high quanity, high affinity for brain cells (little to no redistribution)

Question 11

Indications to use ECD/Ceretec

Answer 11

stroke, dementia, epilepsy, trauma, parkinsons, huntingtons, psych disorders, brain death

Question 12

perk of no redistribution

Answer 12

can repeat scan if needed bc will stay in brain cells

Question 13

Ceretec properties

Answer 13

-hexamethylpropylenamine oxime (HMPAO)
-first pass 80%
-peak activity is 1-2 min (how long tracer takes to get in brain/earliest u can image)
-3.5-7% retained in brain bc has to be lipophilic to crss BBB and converted by glutathione to hydrophilic compound so it does not come back out of brain
-unstable in vitro so we like ECD better

Question 14

ECD properties

Answer 14

-Tc99m ethyl cysteinate dimer
-neurolite=brand name
-bicisate= common name
-first pass extraction= >70%
-peak activiy 1-2 min (how long to wait to get good target to bkg ratio)
-6-7% retained in brain
-less uptake in scalp and brain
-stable in vitro so we like better

Question 15

ECD/Ceretec shared properties

Answer 15

flow depends on condition when injected»lights, noise, pain, position
dose=30 mCi
static delay= 30 min ECD and 2 hr Ceretec
(wait longer for ceretec for scalp and facial activity to go away so better target to bkg ratio)

Question 16

ECD/Ceretec

Answer 16

scan
~36 min
-zoom
-circular
-matric =128

Question 17

what changes are abnormal in ecd and ceretec

Answer 17

asymmetry between R and L, excess activity in concentrated area (pain stimulation or seizure, decrease activty in concentrated area (coma= pt not using brain, dementia)

Question 18

ictal focus mean

Answer 18

during a seizure so more upatke happens during this, usually only on one side

Question 19

interictal

Answer 19

in between seizures

Question 20

pre and post ictal

Answer 20

b4 and after seizure respectively

Question 21

post ictal=

Answer 21

decre uptake cuz no firing of signals anymore

Question 22

diamox protocol

Answer 22

=sodium acetazolamide which evalutaes cerebral flow reserve; vasodilator— indicates angioplasty
dose= 1 gram in 50 cc dextrose IV
procedure= infuse over 10 min, wait 10 min to inject if using ECD

Question 23

DaT scan not DiS scan

Answer 23

dose=3-5 mCi I 123 Ioflupane
-looks at dopamine transporters which are receptors for it so if it uptakes it then yay if not then boo
-parkinson vs essential tremors_> confusion between the two

Question 24

indication for cisternogram

Answer 24

hydrocephalus or CSF leak

Question 25

tracer for cisternogram

Answer 25

500 uCi In111DTPA
1 mCi TcDTPA
or
cocktail of both

Question 26

indium dtpa for

Answer 26

slow csf leaks and multiple day studies so hyrdorceph

Question 27

tc DTPA for

Answer 27

csf leaks

Question 28

how to inject for cisternogram

Answer 28

intrathecal
-blind vs fluoro
-sterile
-spinal needle

Question 29

imaging for cisternogrsm

Answer 29

follow flow of CSF, basal cisterns 1 hr, frontal poles ad slyvian fissures at 2-6 hours, cerebral convexities by 12 hours, sinus by 24 hours, shouldn’t enter ventricular system

Question 30

hydrocephalus is when

Answer 30

water on the brain, ventricles are big butterfly, so CSF unable to drain and increases pressure on brain (tumors, congenital malformation, bleeding in the brain)

Question 31

when to image for hydrocephalus

Answer 31

1st day, 24, 48, 72 hours if needed. initial images to include inj site. delays ANT, RLAT, LLAT, Vertex

Question 32

rhinorrhea

Answer 32

csf out the nose

Question 33

ottorhea

Answer 33

csf out the ear

Question 34

spinal leak

Answer 34

from the spine

Question 35

what can cause a csf leak

Answer 35

previous surgery or accident

Question 36

CSF leak tracer infor

Answer 36

1 mCi TcDTPA or InDTPA
HiRes/Medium energy collimator
-image immediately , stop when leak seen or up to 24 hrs
-posterior w obliques

Question 37

CSF leak rhinorrhea and ottorhea

Answer 37

pledges placed by ENT, blood draws and images at 2 and 6 hours, ANT POST RLAT AND LLAT
> 1.5 is abnormal

Question 38

CSF shunt imaging/tracer

Answer 38

1 mCi TcDTPA (sterile)
neuro PA admins
use Co57 markers, dynamics, post flows, pumping to get csf to flow