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9 Cards in this Set
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- Back
- 3rd side (hint)
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What are the 2 classifications of Brain scanning RP?
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Those that cross the blood brain barrier and those that do not
what are the names for these and which type has largely replaced the other? |
newer agents have replaced the older ones which do not cross the bbb, which are called lipophilic and those that do cross are called hydrophilic
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What are the 2 RP used in brain scanning that do not cross the bbb and what is the study for?
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99mTc-DTPA, 99mTcO4
to show integrity of bbb, a positive study willl show increase in activity within the brain area as a result of disease what other important study these 2 RP used for? |
A dynamic cerebral blood flow for assessment of brain death and demonstration of increased or decreased blood flow within the brain
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What is the lipophilic agent that is used for brain imaging?
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99mTc-HMPAO
what is its restriction? |
must be used within 30 min of preparation unless stabilized by methylene blue, which is a stabilizer giving you up to 4 hrs
Have to use fresh tech from a new generator |
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How does HMPAO localize in the brain cells
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passive diffusion into brain cells and then once inside the brain a chemical change takes place preventing washout
how much of it localizes and how is the rest eliminated? |
Only 5%, but 85% remains for 24; 40% is excreted through the urine and 15% via hepatobiliary route
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Indications for brain scan with HMPAO
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diagnose perfusion abnormalities in the brain as in infarction, stroke and tumor
2. localizing epileptic foci through injection during seizure as demonstrated through EEG What type of imaging is used for this? |
SPECT
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Why would you do a brain scan with F-18 (FDG)?
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It is a glucose analog and the brain runs purely on glucose and changes in glucose level indicate increased or decreased function
what are the indicatons? |
study mental illness like schizophrenia, alzheimer's, parkinson's, drug abuse effects, epilepsy and tumor localizaton
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When is a person considered to have epilepsy?
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when they have had 2 or more seizures
_____: The time during a seizure as demonstrated by an EEG. __________: The time between seizures. |
Ictal: The time during a seizure as demonstrated by an EEG.
Inter Ictal: The time between seizures. |
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What is the RP of choice for cisternography and CSF imaging?
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In-111 DTPA, average dose .5 mCi which is administerd intrathecally.
it has a longer half life and is not metabolized by CSF, stable for several days, non-irritating and clears rapidly from the blood |
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How is In-111 localized in a CSF or cistemography scan?
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compartmentalization
Indications? |
Hydrocephalus, dementia, CSF leakage
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