Fluoroscopy Exam California UPDATED
ACTUAL QUESTIONS AND CORRECT
ANSWERS
Linear, non threshold - CORRECT ANSWER Most cancers
Linear, threshold - CORRECT ANSWER Deterministic effects, cataracts and skin
Nonlinear, non threshold - CORRECT ANSWER Small radiation to see large damage
Nonlinear, threshold - CORRECT ANSWER High dose response, cataracts
Short term effects - CORRECT ANSWER Acute injury, 25 rads or less, minutes days
weeks
Long term effects - CORRECT ANSWER Years after exposure, long latent period.
Acute high dose or chronic low dose over years.
Deterministic effects - CORRECT ANSWER Radiation response increases in severity
with increasing radiation dose. Occurs within days after radiation exposure. Cataracts, skin
damage, threshold dose
Stochastic effects - CORRECT ANSWER Cancer. Incidence of radiation response
increases with increasing radiation dose. Is not observed for months or years. Non-threshold,
randomly occurring.
Radiation induced congenital abnormalities - CORRECT ANSWER Occurs within 10
days to 12 weeks after conception. Skeletal abnormalities 3 to 20 weeks
Spontaneous abortion - CORRECT ANSWER Absorbed dose of 50 rads to fetus
Doubling dose for humans - CORRECT ANSWER 1.56 SV
Compton effect - CORRECT ANSWER scatter of x-ray photons from the atoms of the
body, incoming x-ray photon knocks outer shell electron out of shell
Photoelectric absorption - CORRECT ANSWER X-ray photon interacts with inner
shell electrons. Occurs in Adams with higher atomic number and higher tissue density. 97 to
, 99 percent of incident x-rays are absorbed by the patient. Only half of remnant beam interacts
with IR. Photo electron is absorbed within 1 to 2 mm of soft tissue
Coherent ( classical ) scatter - CORRECT ANSWER Interaction which occurs between
low energy x-ray photons and matter. Below 10 KEV
Thomson - CORRECT ANSWER Type of scatter. Single outershell electrons of an
atom is involved in the interaction.
Rayleigh scattering - CORRECT ANSWER All electrons of atom are involved in
interaction
Tungsten filament - CORRECT ANSWER 2 mm diameter, one or 2 cm long. Addition
of 1 to 2 percent thorium to tungsten filament Enhances the efficiency of thermionic emission
and prolongs tube life
Space charge effect - CORRECT ANSWER Cloud of electrons that make it difficult
for subsequent electrons to be emitted by the filament because of electrostatic repulsion
Saturation current - CORRECT ANSWER Further increase in KVP does not result in
higher ma because all of the available electrons have been used
Line focus principle - CORRECT ANSWER The size of the effective focal spot
influences image sharpness. Effective focal spot size is much less than actual focal spot size
Bremsstrahlung radiation - CORRECT ANSWER Most photons are produced by these
target interactions. Occur only when the incident electron interacts with the force field of the
nucleus. Incident electron must have enough energy to pass through the orbital shells and
approach the nucleus.
Characteristic radiation - CORRECT ANSWER Formed within the target atoms as a
result of interactions with the K-shell electrons. Characteristic cascade is created when higher
energy outer adjoining shell electron drops into the hole and then the next and the next
Frequency - CORRECT ANSWER the number of complete wavelengths that pass a
point in a given time, measured in Hz or cycle per second
Amount of primary beam x-rays absorbed by the patient - CORRECT ANSWER 97-
99%
Speed of light (c) - CORRECT ANSWER 3.00 x 10^8 m/s
ACTUAL QUESTIONS AND CORRECT
ANSWERS
Linear, non threshold - CORRECT ANSWER Most cancers
Linear, threshold - CORRECT ANSWER Deterministic effects, cataracts and skin
Nonlinear, non threshold - CORRECT ANSWER Small radiation to see large damage
Nonlinear, threshold - CORRECT ANSWER High dose response, cataracts
Short term effects - CORRECT ANSWER Acute injury, 25 rads or less, minutes days
weeks
Long term effects - CORRECT ANSWER Years after exposure, long latent period.
Acute high dose or chronic low dose over years.
Deterministic effects - CORRECT ANSWER Radiation response increases in severity
with increasing radiation dose. Occurs within days after radiation exposure. Cataracts, skin
damage, threshold dose
Stochastic effects - CORRECT ANSWER Cancer. Incidence of radiation response
increases with increasing radiation dose. Is not observed for months or years. Non-threshold,
randomly occurring.
Radiation induced congenital abnormalities - CORRECT ANSWER Occurs within 10
days to 12 weeks after conception. Skeletal abnormalities 3 to 20 weeks
Spontaneous abortion - CORRECT ANSWER Absorbed dose of 50 rads to fetus
Doubling dose for humans - CORRECT ANSWER 1.56 SV
Compton effect - CORRECT ANSWER scatter of x-ray photons from the atoms of the
body, incoming x-ray photon knocks outer shell electron out of shell
Photoelectric absorption - CORRECT ANSWER X-ray photon interacts with inner
shell electrons. Occurs in Adams with higher atomic number and higher tissue density. 97 to
, 99 percent of incident x-rays are absorbed by the patient. Only half of remnant beam interacts
with IR. Photo electron is absorbed within 1 to 2 mm of soft tissue
Coherent ( classical ) scatter - CORRECT ANSWER Interaction which occurs between
low energy x-ray photons and matter. Below 10 KEV
Thomson - CORRECT ANSWER Type of scatter. Single outershell electrons of an
atom is involved in the interaction.
Rayleigh scattering - CORRECT ANSWER All electrons of atom are involved in
interaction
Tungsten filament - CORRECT ANSWER 2 mm diameter, one or 2 cm long. Addition
of 1 to 2 percent thorium to tungsten filament Enhances the efficiency of thermionic emission
and prolongs tube life
Space charge effect - CORRECT ANSWER Cloud of electrons that make it difficult
for subsequent electrons to be emitted by the filament because of electrostatic repulsion
Saturation current - CORRECT ANSWER Further increase in KVP does not result in
higher ma because all of the available electrons have been used
Line focus principle - CORRECT ANSWER The size of the effective focal spot
influences image sharpness. Effective focal spot size is much less than actual focal spot size
Bremsstrahlung radiation - CORRECT ANSWER Most photons are produced by these
target interactions. Occur only when the incident electron interacts with the force field of the
nucleus. Incident electron must have enough energy to pass through the orbital shells and
approach the nucleus.
Characteristic radiation - CORRECT ANSWER Formed within the target atoms as a
result of interactions with the K-shell electrons. Characteristic cascade is created when higher
energy outer adjoining shell electron drops into the hole and then the next and the next
Frequency - CORRECT ANSWER the number of complete wavelengths that pass a
point in a given time, measured in Hz or cycle per second
Amount of primary beam x-rays absorbed by the patient - CORRECT ANSWER 97-
99%
Speed of light (c) - CORRECT ANSWER 3.00 x 10^8 m/s
