NMTCB BOARD PREP QUESTIONS AND
ANSWERS 100% CORRECT
Nuclides with the same atomic number ( the same number of protons) but a different
number of neutrons are called: - ANSWER-isotopes
Two nuclides with the same atomic mass but different atomic numbers are called: -
ANSWER-isobars
A nuclide that emits particulate or photon energy to achieve a more stable state: -
ANSWER-radionuclide
Another name for a helium ion containing two protons and two neutrons: - ANSWER-
alpha particle
What is a beta particle? - ANSWER-an electron
Why are alpha and beta particles not used for imaging? - ANSWER-They do not
efficiently exit the body, so they can not/ are hard to detect
What ratio of protons and neutrons favors beta decay? - ANSWER-A low proton-to-
neutron ratio, as compared with stable nuclei
What is the relationship between the mean energy and the maximum energy of a beta
spectrum? - ANSWER-The mean energy is about one-third of the max energy
What ratio of protons and neutrons favors positron decay? - ANSWER-A high proton-to-
neutron ratio
What two particles are emitted from the nucleus during beta decay? - ANSWER-A beta
particle and an antineutrino
Two nuclides with the same number of neutrons but different atomic numbers are
called: - ANSWER-Isotones
What particles are released from the nucleus during positron decay? - ANSWER-A
positron and a neutrino
What is the minimum amount of nuclear energy needed required for positron decay? -
ANSWER-1.02 MeV
What is the fate of a positron? - ANSWER-To travel a short distance, combine with an
electron, and be annihilated
,When a positron is annihilated via combination with an electron, the result is the
production of __________. - ANSWER-two nearly opposed 511-keV photons
What ratio of protons and neutrons favors electron capture decay? - ANSWER-A high
proton-to-neutron ratio
What particle is released from the nucleus during electron capture decay? - ANSWER-A
neutrino
What is released from the nucleus during isometric transition? - ANSWER-Gamma rays
Other than wavelength, frequency, and energy intensity, the fundamental difference
between x-rays and gamma rays is _______. - ANSWER-X-rays are produced from
energy released due to changes in the quantum levels/values of orbital electrons of an
atom, while gamma rays are produced from energy shifts within the nucleus
What are the components of a Mo99/Tc99m generator system? - ANSWER-Alumina
(Al203) column loaded with Mo99, an eluting solvent, an evacuated collecting vial, and
shielding
How is a Mo99/Tc99m generator system eluted? - ANSWER-Tc99m is removed by
passing saline through the column
Maximum buildup of Tc99m in a Mo99/Tc99m generator system occurs after ________
hours. - ANSWER-23
What does the term breakthrough mean when applied to a radionuclide generator
system? - ANSWER-A breakthrough occurs when some parent radionuclide elutes off
the column along with a daughter nuclide
What are the major emissions of Tc99m? - ANSWER-140 keV photons
By what method does Tc99m decay? - ANSWER-isomeric transition
When energy from a nuclear transition results in the emission of an orbital electron
rather than a gamma ray, this processes is called: - ANSWER-internal conversion
Internal conversion electrons increase the radiation dose to the patient because
____________. - ANSWER-energy from the electron is absorbed into the patients body
When energy from an orbital transition results in the emission of an orbital electron
rather than an x-ray, the electron is called ___________. - ANSWER-an Auger electron
What dose the term metastable mean? - ANSWER-When an isomeric state is long lived
,After an electron is ejected from an inner shell orbital, what occurs? - ANSWER-Outer
shell electrons release energy by moving to now unoccupied, less energetic inner
orbitals; the energy released by this transition is termed "characteristic of x-ray
radiation"
What are the two methods used to create synthetically radioactive materials? -
ANSWER-Radioactive materials are produced by bombarding a target material with
either ions or with neutrons
What is used to bombard elements with neutrons? - ANSWER-nuclear reactor
What is used to bombard elements with protons? - ANSWER-accelerator (linear or
cyclotron)
What are five cyclotron produced radionuclides? - ANSWER-In-111, I-123, Ga-67, F-18,
and Tl-201
What is a carrier-free radioisotope? - ANSWER-A radioisotope that does not contain
any nonradioactive species
What does the term activity mean? - ANSWER-The rate of disintegration of a
radionuclide
The unit of activity equivalent to 3.7 x 10^10 dps is called __________. - ANSWER-the
curie
What is a becquerel (Bq)? - ANSWER-The derived unit of radioactivity used by modern
metric system, the SI, is called the becquerel. The Bq is equal to one dps or 2.7027 x
10^-11 Ci.
A one-millicurie dose of a radiopharmaceutical is equal to how many becquerels? -
ANSWER-37 million (37 MBq)
What does the term specific activity mean? - ANSWER-The ratio of activity per unit
mass
What are some specific activities? - ANSWER-mCi/mg, mCi/mole, MBq/mg, or
MBq/mole
The time that it takes for a radionuclide to decay to one-half of its original activity is call
its __________ half-life. - ANSWER-physical
What is the relationship between the physical half-life and the decay constant? -
ANSWER-Their product equals 0.693
, The time that is required for a substance in the body to be reduced to half of its
concentration via biological excretion or metabolism is called its ____________ half-life.
- ANSWER-biological
Which type of half-life refers to the overall loss of radioactivity from the body due to
physical and biological decay? - ANSWER-effective half-life
What is the relationship between the effective half-life, biological half-life, and physical
half-life? - ANSWER-1/ physical half-life + 1/biological half-life = 1/effective half-life
A common type of transient equilibrium is a _______ generator. -
ANSWER-Mo99/Tc99m
When a daughter of a radionuclide has a half-life longer than that of the of the parent,
there is __________ equilibrium. - ANSWER-no
When a parent half-life is much longer than that of the daughter, there is ___________
equilibrium. - ANSWER-secular
What are the possible valence states of Tc99m? - ANSWER-eight oxidation states from
-1 to +7
What is the valence state and chemical form of Tc99m eluted from a generator? -
ANSWER-In pertechnetate, Tc is in the +7 oxidation state
Pertechnetate must first be __________ to a valence state of +4 prior to incorporation
into most chelates. - ANSWER-reduced
Reduction of technetium in commercial radiopharmaceutical kits is generally achieved
with ___________. - ANSWER-stannous ion
What is the single radiopharmaceutical in which technetium is not reduced from its +7
oxidation state - ANSWER-sulfur colloid
Where does intravenously administered Tc99m pertechnetate concentrate? - ANSWER-
In the stomach, salivary glands, thyroid, small and large bowel, choroid plexus, lactating
breasts, and kidneys
For lung perfusion scanning with Tc99m MAA, how many particles are typically
administered? - ANSWER-200,000 to 500,000
What is the mode of decay for I-123? - ANSWER-electron capture
What is the mode of decay for I -131? - ANSWER-beta emission
ANSWERS 100% CORRECT
Nuclides with the same atomic number ( the same number of protons) but a different
number of neutrons are called: - ANSWER-isotopes
Two nuclides with the same atomic mass but different atomic numbers are called: -
ANSWER-isobars
A nuclide that emits particulate or photon energy to achieve a more stable state: -
ANSWER-radionuclide
Another name for a helium ion containing two protons and two neutrons: - ANSWER-
alpha particle
What is a beta particle? - ANSWER-an electron
Why are alpha and beta particles not used for imaging? - ANSWER-They do not
efficiently exit the body, so they can not/ are hard to detect
What ratio of protons and neutrons favors beta decay? - ANSWER-A low proton-to-
neutron ratio, as compared with stable nuclei
What is the relationship between the mean energy and the maximum energy of a beta
spectrum? - ANSWER-The mean energy is about one-third of the max energy
What ratio of protons and neutrons favors positron decay? - ANSWER-A high proton-to-
neutron ratio
What two particles are emitted from the nucleus during beta decay? - ANSWER-A beta
particle and an antineutrino
Two nuclides with the same number of neutrons but different atomic numbers are
called: - ANSWER-Isotones
What particles are released from the nucleus during positron decay? - ANSWER-A
positron and a neutrino
What is the minimum amount of nuclear energy needed required for positron decay? -
ANSWER-1.02 MeV
What is the fate of a positron? - ANSWER-To travel a short distance, combine with an
electron, and be annihilated
,When a positron is annihilated via combination with an electron, the result is the
production of __________. - ANSWER-two nearly opposed 511-keV photons
What ratio of protons and neutrons favors electron capture decay? - ANSWER-A high
proton-to-neutron ratio
What particle is released from the nucleus during electron capture decay? - ANSWER-A
neutrino
What is released from the nucleus during isometric transition? - ANSWER-Gamma rays
Other than wavelength, frequency, and energy intensity, the fundamental difference
between x-rays and gamma rays is _______. - ANSWER-X-rays are produced from
energy released due to changes in the quantum levels/values of orbital electrons of an
atom, while gamma rays are produced from energy shifts within the nucleus
What are the components of a Mo99/Tc99m generator system? - ANSWER-Alumina
(Al203) column loaded with Mo99, an eluting solvent, an evacuated collecting vial, and
shielding
How is a Mo99/Tc99m generator system eluted? - ANSWER-Tc99m is removed by
passing saline through the column
Maximum buildup of Tc99m in a Mo99/Tc99m generator system occurs after ________
hours. - ANSWER-23
What does the term breakthrough mean when applied to a radionuclide generator
system? - ANSWER-A breakthrough occurs when some parent radionuclide elutes off
the column along with a daughter nuclide
What are the major emissions of Tc99m? - ANSWER-140 keV photons
By what method does Tc99m decay? - ANSWER-isomeric transition
When energy from a nuclear transition results in the emission of an orbital electron
rather than a gamma ray, this processes is called: - ANSWER-internal conversion
Internal conversion electrons increase the radiation dose to the patient because
____________. - ANSWER-energy from the electron is absorbed into the patients body
When energy from an orbital transition results in the emission of an orbital electron
rather than an x-ray, the electron is called ___________. - ANSWER-an Auger electron
What dose the term metastable mean? - ANSWER-When an isomeric state is long lived
,After an electron is ejected from an inner shell orbital, what occurs? - ANSWER-Outer
shell electrons release energy by moving to now unoccupied, less energetic inner
orbitals; the energy released by this transition is termed "characteristic of x-ray
radiation"
What are the two methods used to create synthetically radioactive materials? -
ANSWER-Radioactive materials are produced by bombarding a target material with
either ions or with neutrons
What is used to bombard elements with neutrons? - ANSWER-nuclear reactor
What is used to bombard elements with protons? - ANSWER-accelerator (linear or
cyclotron)
What are five cyclotron produced radionuclides? - ANSWER-In-111, I-123, Ga-67, F-18,
and Tl-201
What is a carrier-free radioisotope? - ANSWER-A radioisotope that does not contain
any nonradioactive species
What does the term activity mean? - ANSWER-The rate of disintegration of a
radionuclide
The unit of activity equivalent to 3.7 x 10^10 dps is called __________. - ANSWER-the
curie
What is a becquerel (Bq)? - ANSWER-The derived unit of radioactivity used by modern
metric system, the SI, is called the becquerel. The Bq is equal to one dps or 2.7027 x
10^-11 Ci.
A one-millicurie dose of a radiopharmaceutical is equal to how many becquerels? -
ANSWER-37 million (37 MBq)
What does the term specific activity mean? - ANSWER-The ratio of activity per unit
mass
What are some specific activities? - ANSWER-mCi/mg, mCi/mole, MBq/mg, or
MBq/mole
The time that it takes for a radionuclide to decay to one-half of its original activity is call
its __________ half-life. - ANSWER-physical
What is the relationship between the physical half-life and the decay constant? -
ANSWER-Their product equals 0.693
, The time that is required for a substance in the body to be reduced to half of its
concentration via biological excretion or metabolism is called its ____________ half-life.
- ANSWER-biological
Which type of half-life refers to the overall loss of radioactivity from the body due to
physical and biological decay? - ANSWER-effective half-life
What is the relationship between the effective half-life, biological half-life, and physical
half-life? - ANSWER-1/ physical half-life + 1/biological half-life = 1/effective half-life
A common type of transient equilibrium is a _______ generator. -
ANSWER-Mo99/Tc99m
When a daughter of a radionuclide has a half-life longer than that of the of the parent,
there is __________ equilibrium. - ANSWER-no
When a parent half-life is much longer than that of the daughter, there is ___________
equilibrium. - ANSWER-secular
What are the possible valence states of Tc99m? - ANSWER-eight oxidation states from
-1 to +7
What is the valence state and chemical form of Tc99m eluted from a generator? -
ANSWER-In pertechnetate, Tc is in the +7 oxidation state
Pertechnetate must first be __________ to a valence state of +4 prior to incorporation
into most chelates. - ANSWER-reduced
Reduction of technetium in commercial radiopharmaceutical kits is generally achieved
with ___________. - ANSWER-stannous ion
What is the single radiopharmaceutical in which technetium is not reduced from its +7
oxidation state - ANSWER-sulfur colloid
Where does intravenously administered Tc99m pertechnetate concentrate? - ANSWER-
In the stomach, salivary glands, thyroid, small and large bowel, choroid plexus, lactating
breasts, and kidneys
For lung perfusion scanning with Tc99m MAA, how many particles are typically
administered? - ANSWER-200,000 to 500,000
What is the mode of decay for I-123? - ANSWER-electron capture
What is the mode of decay for I -131? - ANSWER-beta emission
