Page | 1
NMTCB PET Questions and Answers (Expert
Solutions)
Q: The exposure rate of an activity of 1 millicurie (mCi) measured at 1 centimeter (cm) is
called
ANS 🗹🗹: - The exposure rate constant (ERC)
For positron emitters, the exposure rate constant (ERC) is about 6 R/h per milli-
curie at 1 cm. The exposure rate of a 10 mCi dose of F-18 is approximately six times
greater than that of a 10 mCi dose of Tc-99 m at a distance of approxi- mately 8
inches.
Q: Quantitative bias that refers to the underestimation of counts density which differs
from what they should be is called:
ANS 🗹🗹: Partial-volume effect
PVE is caused by the finite spatial resolution of the imaging system which reveals
how far the signal "spills out" around its actual location. The signal spreading
falsely increases the object size and volume. Image sampling, where voxels in ROI
include the signal from underlying tissues, also contributes to the phenomenon
known as partial-volume effect.
Q: Truncation artifacts in PET/CT imaging are produced by
ANS 🗹🗹: Difference in size of FOV between PET and the CT
Discrepancy between fields of view (FOVs) in a PET/CT scanner—70 cm causes a
truncation artifact when imaging extends beyond the CT FOV-50 cm; as a result no
attenuation correction values for the truncated anatomy are being applied.
Q: Dental fillings, hip prosthetics, or chemotherapy port are examples of PET/CT
imaging artifacts described as:
ANS 🗹🗹: Metallic implants artifacts
Metallic implants create streaking artifacts on CT images because of their high
photon absorption. Higher Hounsfield numbers consequently produce high PET
attenuation coefficients and an overestimation of PET findings.
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Q: The Property of PET detectors that allows them faster timing signals for coincidence
detection and to work at high count rates is called:
ANS 🗹🗹: The decay constant
The decay constant decides how long the scintillation flashes in the crystal; a short
decay time reduces detector dead time and as a result higher annihilation rates can
be accepted.
Q: The picturing, description, and measurement of biological processes at the particle
and cellular level is known as
ANS 🗹🗹: Molecular imaging
Radionuclide originated molecular imaging techniques such as positron emission
tomography
(PET) and single-photon emission computed tomography (SPECT) capture
functional or phenotypic changes associated with pathology and unfold the
molecular abnormalities responsible to form basis of many diseases.
Q: A PET system capacity to distinguish between two points after image reconstruction
is called:
ANS 🗹🗹:
Q: Allergic reaction that begins within seconds/minutes of contrast media admin-
istration and rapidly progresses to cause airway constriction, skin and intestinal irritation,
and altered heart rhythms is called:
ANS 🗹🗹: Anaphylaxis
Q: The first PET radiopharmaceutical to receive the U.S. Food and Drug Administration
approval in 1989 was:
ANS 🗹🗹: Rb-82
Q: The dose calibrator quality control procedure performed to assess the device's ability
to measure accurately a range of a low to high activities is called:
ANS 🗹🗹: Linearity
Q: The following positron-emitting radionuclides are isotopes of natural elements
present in most biochemical processes EXCEPT:
, Page | 3
(A) O-15
(B) F-18
(C) C-11
(D) N-13
ANS 🗹🗹: F-18
Q: Two photons arising from the same annihilation event and detected by two detectors
within the coincidence time-window are:
ANS 🗹🗹: True coincidences
Q: Serves as the building blocks for proteins synthesis
ANS 🗹🗹: Amino acids
Q: Positronium (Ps) is an arrangement of:
ANS 🗹🗹: An electron and a positron
Q: The most common site of brown fat localization
ANS 🗹🗹: Neck
Q: Scintillator commonly used in PET imaging that has the highest stopping power
ANS 🗹🗹: BGO (bismuth germinate)
Q: A malignant neoplasm of the skin linked with approximately 75% of skin cancer-
related mortality is called:
ANS 🗹🗹: Melanoma
Q: PET tracers have demonstrated significant potential utility and application in the
following clinical areas EXCEPT:
(A) Oncology
(B) Cardiology
(C) Pulmonology
(D) Neurology
ANS 🗹🗹: C - Pulmonology
, Page | 4
Q: The sum of the weighted equivalent doses in all the tissues and organs of the body is
called:
ANS 🗹🗹: Effective dose
Q: The combined whole-body effective dose for a clinically diagnostic PET/CT is
typically in the range:
ANS 🗹🗹: 20-30 mSv
Q: The positron has the same mass as an electron and an electric charge of:
ANS 🗹🗹: + 1
Q: The initial diagnosis of melanoma is established by:
ANS 🗹🗹: Histologic evaluation
Q: In PET scanning process raw data acquired and identified as coincidence events along
their LOR are stored in the raw data format called:
ANS 🗹🗹: Sinograms
Q: Cyclotron produced positron-emitting radionuclide
ANS 🗹🗹: Nitrogen-13
Q: A piece of equipment that sorts out photons of different radionuclides with different
photon energies and to separate scattered photons from the useful ones is called:
ANS 🗹🗹: Pulse height analyzer
Q: DNA synthesis is a measure of cellular:
ANS 🗹🗹: Proliferation
Q: The F-18 fluoride bone uptake mechanism is similar to that of:
ANS 🗹🗹: Tc-99 m methylenediphosphonate (MDP)
Q: The process by which new blood vessels are formed is called:
NMTCB PET Questions and Answers (Expert
Solutions)
Q: The exposure rate of an activity of 1 millicurie (mCi) measured at 1 centimeter (cm) is
called
ANS 🗹🗹: - The exposure rate constant (ERC)
For positron emitters, the exposure rate constant (ERC) is about 6 R/h per milli-
curie at 1 cm. The exposure rate of a 10 mCi dose of F-18 is approximately six times
greater than that of a 10 mCi dose of Tc-99 m at a distance of approxi- mately 8
inches.
Q: Quantitative bias that refers to the underestimation of counts density which differs
from what they should be is called:
ANS 🗹🗹: Partial-volume effect
PVE is caused by the finite spatial resolution of the imaging system which reveals
how far the signal "spills out" around its actual location. The signal spreading
falsely increases the object size and volume. Image sampling, where voxels in ROI
include the signal from underlying tissues, also contributes to the phenomenon
known as partial-volume effect.
Q: Truncation artifacts in PET/CT imaging are produced by
ANS 🗹🗹: Difference in size of FOV between PET and the CT
Discrepancy between fields of view (FOVs) in a PET/CT scanner—70 cm causes a
truncation artifact when imaging extends beyond the CT FOV-50 cm; as a result no
attenuation correction values for the truncated anatomy are being applied.
Q: Dental fillings, hip prosthetics, or chemotherapy port are examples of PET/CT
imaging artifacts described as:
ANS 🗹🗹: Metallic implants artifacts
Metallic implants create streaking artifacts on CT images because of their high
photon absorption. Higher Hounsfield numbers consequently produce high PET
attenuation coefficients and an overestimation of PET findings.
, Page | 2
Q: The Property of PET detectors that allows them faster timing signals for coincidence
detection and to work at high count rates is called:
ANS 🗹🗹: The decay constant
The decay constant decides how long the scintillation flashes in the crystal; a short
decay time reduces detector dead time and as a result higher annihilation rates can
be accepted.
Q: The picturing, description, and measurement of biological processes at the particle
and cellular level is known as
ANS 🗹🗹: Molecular imaging
Radionuclide originated molecular imaging techniques such as positron emission
tomography
(PET) and single-photon emission computed tomography (SPECT) capture
functional or phenotypic changes associated with pathology and unfold the
molecular abnormalities responsible to form basis of many diseases.
Q: A PET system capacity to distinguish between two points after image reconstruction
is called:
ANS 🗹🗹:
Q: Allergic reaction that begins within seconds/minutes of contrast media admin-
istration and rapidly progresses to cause airway constriction, skin and intestinal irritation,
and altered heart rhythms is called:
ANS 🗹🗹: Anaphylaxis
Q: The first PET radiopharmaceutical to receive the U.S. Food and Drug Administration
approval in 1989 was:
ANS 🗹🗹: Rb-82
Q: The dose calibrator quality control procedure performed to assess the device's ability
to measure accurately a range of a low to high activities is called:
ANS 🗹🗹: Linearity
Q: The following positron-emitting radionuclides are isotopes of natural elements
present in most biochemical processes EXCEPT:
, Page | 3
(A) O-15
(B) F-18
(C) C-11
(D) N-13
ANS 🗹🗹: F-18
Q: Two photons arising from the same annihilation event and detected by two detectors
within the coincidence time-window are:
ANS 🗹🗹: True coincidences
Q: Serves as the building blocks for proteins synthesis
ANS 🗹🗹: Amino acids
Q: Positronium (Ps) is an arrangement of:
ANS 🗹🗹: An electron and a positron
Q: The most common site of brown fat localization
ANS 🗹🗹: Neck
Q: Scintillator commonly used in PET imaging that has the highest stopping power
ANS 🗹🗹: BGO (bismuth germinate)
Q: A malignant neoplasm of the skin linked with approximately 75% of skin cancer-
related mortality is called:
ANS 🗹🗹: Melanoma
Q: PET tracers have demonstrated significant potential utility and application in the
following clinical areas EXCEPT:
(A) Oncology
(B) Cardiology
(C) Pulmonology
(D) Neurology
ANS 🗹🗹: C - Pulmonology
, Page | 4
Q: The sum of the weighted equivalent doses in all the tissues and organs of the body is
called:
ANS 🗹🗹: Effective dose
Q: The combined whole-body effective dose for a clinically diagnostic PET/CT is
typically in the range:
ANS 🗹🗹: 20-30 mSv
Q: The positron has the same mass as an electron and an electric charge of:
ANS 🗹🗹: + 1
Q: The initial diagnosis of melanoma is established by:
ANS 🗹🗹: Histologic evaluation
Q: In PET scanning process raw data acquired and identified as coincidence events along
their LOR are stored in the raw data format called:
ANS 🗹🗹: Sinograms
Q: Cyclotron produced positron-emitting radionuclide
ANS 🗹🗹: Nitrogen-13
Q: A piece of equipment that sorts out photons of different radionuclides with different
photon energies and to separate scattered photons from the useful ones is called:
ANS 🗹🗹: Pulse height analyzer
Q: DNA synthesis is a measure of cellular:
ANS 🗹🗹: Proliferation
Q: The F-18 fluoride bone uptake mechanism is similar to that of:
ANS 🗹🗹: Tc-99 m methylenediphosphonate (MDP)
Q: The process by which new blood vessels are formed is called:
