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14 Cards in this Set
- Front
- Back
- 3rd side (hint)
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What are the 3 methods of producing radiopharmaceticals?
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1. Reactors
2. Accelerators (Cyclotrons) 3. Generators |
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What is the element that is known as "pitchblend" when found in ore that is the heaviest element found naturally that is used in reactors?
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Uranium 238 in natural state, U235 used in reactors
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When U238 is enriched to U235 how is it seperated?
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U238 is combined with Florine to make UF6, then very fast centrifuges separate the 235 from the 238 based upon weight difference
How much energy does one U235 atom release during fission? |
200 MeV, compared to 4 MeV of a carbon atom during combustion
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Neutrons that have a lower energy of about .025 eV are know as what? and why is this important?
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Thermal neutrons, above this energy they have a low probability of interaction with a target nucleus
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What is the device called in a reactor that can be water, heavy water, beryllium, boron or graphite that is used to control fission by absorbing neutrons?
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moderator
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Fission reactions in a reactor produce which isotopes that are used in Nuclear medicine?
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I131, Cs137, Xe133, Mo99
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MICX
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Also in reactors neutron capture takes place to create fission products like Mo99 or Cr51, what is the disadvantage of this method?
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Unlike U fission they are not carrier free and the parent and daughter are the same element making it more difficult to separate. also unlike the other process the specific activity is low
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Cyclotrons produce what isotopes and are they carrier free?
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Yes they are carrier free and are usually proton rich since they are bombarded with neutrons making them positron emitters. Examples include: Ga67, In111, Tl201, F18
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What are the 3 requirements for a target in a nuclear reactor or cyclotron?
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1. able to withstand the heat of reaction.
2. low in contaminants, or contaminants are known 3. desired isotopic abundance is high |
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How is Tc99m made in a generator?
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Mo99 is allowed to decay in an enclosed reactor having an aluminum column. Isotonic saline is used to removed(milked) to remove the resulting Tc99m
What form does it come out in? |
NaTcO4 or Sodium Pertechnetate
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Aluminum ions can contaminate eluate from a Tc99 generator, what is the allowable limits?
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10 micrograms/ml
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Production of Tc99m is an example of what kind of equilibium in a generator?
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Transient equilibrium where the parent half life is only slightly longer than the daughter unlike Secular where the parent is much longer than the daughter
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What is the isotope used for myocardial blood flow studies that has a half life of only 75 seconds?
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Rb82 which is produced in an on-site generator from Sr82
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What eliminates the need of having an on-site cyclotron for PET scanning?
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generator systems that produce positron emitters
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