30 Questions
What occurs when an additional neutron is forced into a stable nucleus?
A neutron excess
What is the result of forcing an additional proton into a stable nucleus, knocking out a neutron?
A neutron deficit
What is the characteristic of radionuclides produced in a cyclotron?
Short-lived with half-lives ranging from less than a minute to a couple of hours
Why are medical minicyclotrons designed to be located at or near the hospital site?
To produce short-lived radionuclides such as fluorine-18
What is the result of increasing the mass of a nucleus by one, while keeping the atomic number unchanged?
A new element is formed
How many known radionuclides are there?
More than 2700
What is a common characteristic of isotopes of an element?
They have the same atomic number and chemical properties
What is the term for unstable nuclei that decay by emitting radiation?
Radionuclides
What happens when an additional neutron is forced into a stable nucleus?
A neutron excess occurs
What is the primary reason for requiring higher spatial resolution in small animal gamma imaging systems?
To image smaller targeted structures
Which of the following radionuclides is not naturally occurring?
Carbon-14
What is the purpose of producing radionuclides in medical imaging?
To diagnose and visualize internal structures
What is the typical diameter of the holes in a general purpose collimator?
2.5 mm
How many known radionuclides exist?
More than 2700
What is the trade-off for using a high-resolution collimator?
Lower sensitivity and longer imaging times
What is the characteristic of a low-energy collimator?
Thin septa and low sensitivity
What is the primary advantage of using a high-sensitivity collimator?
Faster imaging times
What is the reason for using a non-parallel hole collimator in small animal gamma imaging systems?
To improve the spatial resolution of the system
What are the primary characteristics of a scintillator chosen for gamma ray detection in clinical use?
Inexpensive, with short decay duration, high atomic number, and high density and light output
What is the primary reason why sodium iodide (NaI) scintillators are required to be sealed in airtight containers?
To prevent moisture absorption and fragility
What is the significance of a high atomic number in a scintillator used for gamma ray detection?
It increases the detection efficiency of the scintillator
What is the primary advantage of using a scintillator with a short decay duration in gamma ray detection?
It allows for faster imaging acquisition
What is the purpose of the table listing properties of common scintillators used in conventional gamma cameras?
To compare the properties of different scintillators
What is the primary disadvantage of sodium iodide (NaI) scintillators in gamma ray detection?
Moisture absorption and fragility
What is the primary decay mode of 123I?
Electron capture
What is the main application of 131I in therapy?
Thyroid ablation
What is a characteristic of Xenon-133 (133Xe)?
Somewhat soluble in blood and fat
What is the half-life of 125I?
60 days
What is the method of production of Krypton-81m (81mKr)?
Generator-produced
What is the primary application of Krypton-81m (81mKr)?
Lung ventilation imaging
Learn about isotopes, which are nuclides with the same atomic number and chemical properties, but differ in the number of neutrons, mass number, and physical properties. Examples include Carbon-12, Carbon-14, and Carbon-11.
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