ARRT SAFETY REVISION EXAMS ANSWERS AND
QUESTIONS SET A+
✔✔What is excitation? - ✔✔Raising an electron to a higher energy level without
removing it from the atom
✔✔What is the primary beam? - ✔✔X ray beam traveling from the tube toward the
patient
✔✔What is remnant radiation? - ✔✔Radiation that exits the patient and reaches the
image receptor
✔✔What is scatter radiation? - ✔✔Radiation that changes direction after interacting with
matter
✔✔What is attenuation? - ✔✔Reduction in x ray beam intensity as the beam passes
through matter
✔✔What two processes primarily contribute to attenuation? - ✔✔Absorption and scatter
✔✔What happens to attenuation as tissue thickness increases? - ✔✔Attenuation
increases
✔✔What happens to attenuation as tissue atomic number increases? - ✔✔Attenuation
increases
✔✔Which tissue attenuates more bone or soft tissue? - ✔✔Bone
✔✔Why does bone attenuate more x rays than soft tissue? - ✔✔Bone has greater
density and effective atomic number
✔✔Which interaction is responsible for most occupational radiation exposure in
diagnostic radiography? - ✔✔Compton interaction
,✔✔Which interaction is the primary source of scatter radiation in diagnostic imaging? -
✔✔Compton interaction
✔✔What happens during a Compton interaction? - ✔✔An incident photon ejects an
outer shell electron and the photon changes direction with reduced energy
✔✔Is the scattered photon completely absorbed during a Compton interaction? - ✔✔No
✔✔What type of electron is ejected during a Compton interaction? - ✔✔Outer shell
electron
✔✔What happens during a photoelectric interaction? - ✔✔The incident photon is
completely absorbed and an inner shell electron is ejected
✔✔What happens to the incident photon during the photoelectric effect? - ✔✔It is
completely absorbed
✔✔What type of electron is ejected during the photoelectric effect? - ✔✔Inner shell
electron
✔✔Which interaction contributes significantly to radiographic subject contrast? -
✔✔Photoelectric effect
✔✔Which interaction increases patient absorbed dose because the photon is
completely absorbed? - ✔✔Photoelectric effect
✔✔Which interaction is more likely in tissues with higher atomic number? -
✔✔Photoelectric effect
✔✔How does increasing atomic number affect the probability of the photoelectric
effect? - ✔✔It increases the probability
✔✔How does increasing photon energy affect the probability of the photoelectric effect
in the diagnostic range? - ✔✔It generally decreases the probability
✔✔Which interaction is mainly dependent on electron density rather than atomic
number? - ✔✔Compton interaction
✔✔What interaction produces scatter that can reach the radiographer? - ✔✔Compton
interaction
,✔✔What is coherent scattering? - ✔✔Low energy interaction in which the photon
changes direction without ionization
✔✔Does coherent scattering cause ionization? - ✔✔No
✔✔Does coherent scattering contribute significantly to patient dose or image formation?
- ✔✔No
✔✔Which diagnostic interaction causes no ionization? - ✔✔Coherent scattering
✔✔What is the inverse square law? - ✔✔Radiation intensity is inversely proportional to
the square of the distance from the source
✔✔If distance from a radiation source doubles what happens to intensity? - ✔✔Intensity
becomes one fourth
✔✔If distance triples what happens to intensity? - ✔✔Intensity becomes one ninth
✔✔If distance is cut in half what happens to intensity? - ✔✔Intensity becomes four
times greater
✔✔What is the most effective way for personnel to rapidly reduce radiation exposure
during an exposure? - ✔✔Increase distance from the source
✔✔Why does increasing distance reduce radiation exposure? - ✔✔Radiation intensity
decreases according to the inverse square law
✔✔What does ALARA stand for? - ✔✔As low as reasonably achievable
✔✔What is the purpose of ALARA? - ✔✔Minimize occupational radiation exposure
while performing necessary procedures
✔✔What are the three basic methods of personnel radiation protection? - ✔✔Time
distance and shielding
✔✔How does reducing time near a radiation source affect dose? - ✔✔Decreases dose
✔✔How does increasing distance from a radiation source affect dose? - ✔✔Decreases
dose
✔✔How does shielding affect radiation exposure? - ✔✔Attenuates radiation before it
reaches the individual
, ✔✔What should a radiographer do whenever possible during an exposure? - ✔✔Leave
the room or stand behind a protective barrier
✔✔Should a radiographer ever stand in the primary beam? - ✔✔No
✔✔What is the greatest source of radiation exposure to personnel during routine
fluoroscopy? - ✔✔Scatter radiation from the patient
✔✔What is the main source of scatter during fluoroscopy? - ✔✔Patient
✔✔Where is scatter generally greatest during fluoroscopy? - ✔✔Near the patient
✔✔Which side of the patient generally produces more scatter during fluoroscopy the x
ray tube side or image receptor side? - ✔✔X ray tube side
✔✔Where should personnel stand during fluoroscopy when possible? - ✔✔On the
image receptor side and as far from the patient as practical
✔✔What is the SI unit of absorbed dose? - ✔✔Gray
✔✔What is the abbreviation for gray? - ✔✔Gy
✔✔What does absorbed dose describe? - ✔✔Energy deposited by ionizing radiation
per unit mass of tissue
✔✔What is one gray equal to? - ✔✔One joule per kilogram
✔✔What traditional unit corresponds to absorbed dose? - ✔✔Rad
✔✔How many rad equal 1 Gy? - ✔✔100 rad
✔✔How many Gy equal 1 rad? - ✔✔0.01 Gy
✔✔What is the SI unit of equivalent dose? - ✔✔Sievert
✔✔What is the abbreviation for sievert? - ✔✔Sv
✔✔What is the traditional unit of equivalent dose? - ✔✔Rem
✔✔How many rem equal 1 Sv? - ✔✔100 rem
✔✔How many Sv equal 1 rem? - ✔✔0.01 Sv
QUESTIONS SET A+
✔✔What is excitation? - ✔✔Raising an electron to a higher energy level without
removing it from the atom
✔✔What is the primary beam? - ✔✔X ray beam traveling from the tube toward the
patient
✔✔What is remnant radiation? - ✔✔Radiation that exits the patient and reaches the
image receptor
✔✔What is scatter radiation? - ✔✔Radiation that changes direction after interacting with
matter
✔✔What is attenuation? - ✔✔Reduction in x ray beam intensity as the beam passes
through matter
✔✔What two processes primarily contribute to attenuation? - ✔✔Absorption and scatter
✔✔What happens to attenuation as tissue thickness increases? - ✔✔Attenuation
increases
✔✔What happens to attenuation as tissue atomic number increases? - ✔✔Attenuation
increases
✔✔Which tissue attenuates more bone or soft tissue? - ✔✔Bone
✔✔Why does bone attenuate more x rays than soft tissue? - ✔✔Bone has greater
density and effective atomic number
✔✔Which interaction is responsible for most occupational radiation exposure in
diagnostic radiography? - ✔✔Compton interaction
,✔✔Which interaction is the primary source of scatter radiation in diagnostic imaging? -
✔✔Compton interaction
✔✔What happens during a Compton interaction? - ✔✔An incident photon ejects an
outer shell electron and the photon changes direction with reduced energy
✔✔Is the scattered photon completely absorbed during a Compton interaction? - ✔✔No
✔✔What type of electron is ejected during a Compton interaction? - ✔✔Outer shell
electron
✔✔What happens during a photoelectric interaction? - ✔✔The incident photon is
completely absorbed and an inner shell electron is ejected
✔✔What happens to the incident photon during the photoelectric effect? - ✔✔It is
completely absorbed
✔✔What type of electron is ejected during the photoelectric effect? - ✔✔Inner shell
electron
✔✔Which interaction contributes significantly to radiographic subject contrast? -
✔✔Photoelectric effect
✔✔Which interaction increases patient absorbed dose because the photon is
completely absorbed? - ✔✔Photoelectric effect
✔✔Which interaction is more likely in tissues with higher atomic number? -
✔✔Photoelectric effect
✔✔How does increasing atomic number affect the probability of the photoelectric
effect? - ✔✔It increases the probability
✔✔How does increasing photon energy affect the probability of the photoelectric effect
in the diagnostic range? - ✔✔It generally decreases the probability
✔✔Which interaction is mainly dependent on electron density rather than atomic
number? - ✔✔Compton interaction
✔✔What interaction produces scatter that can reach the radiographer? - ✔✔Compton
interaction
,✔✔What is coherent scattering? - ✔✔Low energy interaction in which the photon
changes direction without ionization
✔✔Does coherent scattering cause ionization? - ✔✔No
✔✔Does coherent scattering contribute significantly to patient dose or image formation?
- ✔✔No
✔✔Which diagnostic interaction causes no ionization? - ✔✔Coherent scattering
✔✔What is the inverse square law? - ✔✔Radiation intensity is inversely proportional to
the square of the distance from the source
✔✔If distance from a radiation source doubles what happens to intensity? - ✔✔Intensity
becomes one fourth
✔✔If distance triples what happens to intensity? - ✔✔Intensity becomes one ninth
✔✔If distance is cut in half what happens to intensity? - ✔✔Intensity becomes four
times greater
✔✔What is the most effective way for personnel to rapidly reduce radiation exposure
during an exposure? - ✔✔Increase distance from the source
✔✔Why does increasing distance reduce radiation exposure? - ✔✔Radiation intensity
decreases according to the inverse square law
✔✔What does ALARA stand for? - ✔✔As low as reasonably achievable
✔✔What is the purpose of ALARA? - ✔✔Minimize occupational radiation exposure
while performing necessary procedures
✔✔What are the three basic methods of personnel radiation protection? - ✔✔Time
distance and shielding
✔✔How does reducing time near a radiation source affect dose? - ✔✔Decreases dose
✔✔How does increasing distance from a radiation source affect dose? - ✔✔Decreases
dose
✔✔How does shielding affect radiation exposure? - ✔✔Attenuates radiation before it
reaches the individual
, ✔✔What should a radiographer do whenever possible during an exposure? - ✔✔Leave
the room or stand behind a protective barrier
✔✔Should a radiographer ever stand in the primary beam? - ✔✔No
✔✔What is the greatest source of radiation exposure to personnel during routine
fluoroscopy? - ✔✔Scatter radiation from the patient
✔✔What is the main source of scatter during fluoroscopy? - ✔✔Patient
✔✔Where is scatter generally greatest during fluoroscopy? - ✔✔Near the patient
✔✔Which side of the patient generally produces more scatter during fluoroscopy the x
ray tube side or image receptor side? - ✔✔X ray tube side
✔✔Where should personnel stand during fluoroscopy when possible? - ✔✔On the
image receptor side and as far from the patient as practical
✔✔What is the SI unit of absorbed dose? - ✔✔Gray
✔✔What is the abbreviation for gray? - ✔✔Gy
✔✔What does absorbed dose describe? - ✔✔Energy deposited by ionizing radiation
per unit mass of tissue
✔✔What is one gray equal to? - ✔✔One joule per kilogram
✔✔What traditional unit corresponds to absorbed dose? - ✔✔Rad
✔✔How many rad equal 1 Gy? - ✔✔100 rad
✔✔How many Gy equal 1 rad? - ✔✔0.01 Gy
✔✔What is the SI unit of equivalent dose? - ✔✔Sievert
✔✔What is the abbreviation for sievert? - ✔✔Sv
✔✔What is the traditional unit of equivalent dose? - ✔✔Rem
✔✔How many rem equal 1 Sv? - ✔✔100 rem
✔✔How many Sv equal 1 rem? - ✔✔0.01 Sv
