Isotopes of Elements

What occurs when an additional neutron is forced into a stable nucleus?

A proton excess
An atomic number decrease
A neutron excess (correct)
A neutron deficit

What is the result of forcing an additional proton into a stable nucleus, knocking out a neutron?

A neutron deficit (correct)
A decrease in atomic number
An increase in mass number
A neutron excess

What is the characteristic of radionuclides produced in a cyclotron?

Long-lived with half-lives ranging from years to decades
Short-lived with half-lives ranging from less than a minute to a couple of hours (correct)
Radioactive with varying half-lives
Stable with no half-lives

Why are medical minicyclotrons designed to be located at or near the hospital site?

To produce short-lived radionuclides such as fluorine-18 (C) Signup and view all the answers

What is the result of increasing the mass of a nucleus by one, while keeping the atomic number unchanged?

A new element is formed (A) Signup and view all the answers

How many known radionuclides are there?

More than 2700 (A) Signup and view all the answers

What is a common characteristic of isotopes of an element?

They have the same atomic number and chemical properties (A) Signup and view all the answers

What is the term for unstable nuclei that decay by emitting radiation?

Radionuclides (A) Signup and view all the answers

What happens when an additional neutron is forced into a stable nucleus?

A neutron excess occurs (C) Signup and view all the answers

What is the primary reason for requiring higher spatial resolution in small animal gamma imaging systems?

To image smaller targeted structures (D) Signup and view all the answers

Which of the following radionuclides is not naturally occurring?

Carbon-14 (C) Signup and view all the answers

What is the purpose of producing radionuclides in medical imaging?

To diagnose and visualize internal structures (D) Signup and view all the answers

What is the typical diameter of the holes in a general purpose collimator?

2.5 mm (D) Signup and view all the answers

How many known radionuclides exist?

More than 2700 (C) Signup and view all the answers

What is the trade-off for using a high-resolution collimator?

Lower sensitivity and longer imaging times (A) Signup and view all the answers

What is the characteristic of a low-energy collimator?

Thin septa and low sensitivity (C) Signup and view all the answers

What is the primary advantage of using a high-sensitivity collimator?

Faster imaging times (B) Signup and view all the answers

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 (D) Signup and view all the answers

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 (A) Signup and view all the answers

What is the primary reason why sodium iodide (NaI) scintillators are required to be sealed in airtight containers?

To prevent moisture absorption and fragility (D) Signup and view all the answers

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 (B) Signup and view all the answers

What is the primary advantage of using a scintillator with a short decay duration in gamma ray detection?

It allows for faster imaging acquisition (C) Signup and view all the answers

What is the purpose of the table listing properties of common scintillators used in conventional gamma cameras?

To compare the properties of different scintillators (C) Signup and view all the answers

What is the primary disadvantage of sodium iodide (NaI) scintillators in gamma ray detection?

Moisture absorption and fragility (A) Signup and view all the answers

What is the primary decay mode of 123I?

Electron capture (B) Signup and view all the answers

What is the main application of 131I in therapy?

Thyroid ablation (A) Signup and view all the answers

What is a characteristic of Xenon-133 (133Xe)?

Somewhat soluble in blood and fat (D) Signup and view all the answers

What is the half-life of 125I?

60 days (B) Signup and view all the answers

What is the method of production of Krypton-81m (81mKr)?

Generator-produced (C) Signup and view all the answers

What is the primary application of Krypton-81m (81mKr)?

Lung ventilation imaging (C) Signup and view all the answers