Chapter 09: Basic Radiation Protection and Radiobiology
Adler: Introduction to Radiologic and Imaging Sciences and Patient Care, 6th Edition
1. The radiation a person receives from the sun (cosmic radiation) is categorized as
a. natural background radiation.
ANS: A
The two basic sources of ionizing radiation exposure are natural (or background) radiation
and human-made (artificial) radiation sources. Background sources occur spontaneously in
nature and can be affected by human activity. These forms include cosmic radiation from the
sun and other planetary bodies and naturally occurring radioactive substances present on
earth (e.g., uranium and radium), which can be inhaled or ingested through food, water, or
air (radon).
REF: p. 104
2. With regard to the ALARA principle, the responsibility of the radiographer is to
b. keep radiation exposures at the lowest levels possible.
ANS: B
The benefit to the patient from performing medical imaging procedures must outweigh the
risk of possible biologic damage. Current studies indicate that an individual’s dose should be
kept as low as reasonably achievable (ALARA).
REF: p. 109
3. The dose equivalent limits for radiation workers are based on the radiation received from
what source(s)?
c. Occupational exposure
ANS: C
Because patients and workers exposed to radiation are at risk for biologic effects, limits
must be set to ensure safe practice for both patients and radiation workers. Dose
measurement for radiation workers is limited exclusively to occupational exposure. The
annual whole-body effective dose limit for the occupational worker is 50 mSv (5 rem).
REF: pp. 108-109
4. A given dose of radiation generally has the greatest potential for damage in tissues that have
c. more rapidly dividing cells.
ANS: C
To study a cell’s response to radiation, a method of classification according to sensitivity
was developed by Bergonie and Tribondeau in 1906. Cells are most sensitive to radiation
during active division, when they are primitive in structure and function. Cells with a high
rate of mitosis are more radiosensitive.
, REF: pp. 110-111
5. Nausea is principally associated with the
a. prodromal period.
ANS: A
Three general stages of response exist for each acute radiation syndrome. The first is the
prodromal stage, commonly referred to as the nausea, vomiting, and diarrhea (NVD) stage.
REF: p. 111
6. The material commonly used for shielding against radiation exposure in protective aprons
and gloves is
a. lead.
ANS: A
Shields are made of lead, which has an atomic number of 82. Lead absorbs x-rays through
the process of photoelectric effect, thereby minimizing patient exposure.
REF: p. 112
7. The photon interaction that results in the highest patient exposure is interactions.
d. photoelectric
ANS: D
Because complete energy absorption takes place in photoelectric interactions, this
constitutes the greatest hazard to patients in diagnostic radiography.
REF: pp. 105-106
8. The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are
1. highly mitotic.
2. undifferentiated.
b. 1 and 2 only.
ANS: B
The law of Bergonie and Tribondeau states that the mitotic activity and specific
characteristics of each cell affected how the cell exhibited radiation damage. Cells are most
sensitive to radiation during active division, when they are primitive in structure and
function (undifferentiated).
REF: pp. 110-111
9. In which of the following x-ray interactions with matter is the energy of the incident photon
completely absorbed?
b. Photoelectric absorption
ANS: B
Adler: Introduction to Radiologic and Imaging Sciences and Patient Care, 6th Edition
1. The radiation a person receives from the sun (cosmic radiation) is categorized as
a. natural background radiation.
ANS: A
The two basic sources of ionizing radiation exposure are natural (or background) radiation
and human-made (artificial) radiation sources. Background sources occur spontaneously in
nature and can be affected by human activity. These forms include cosmic radiation from the
sun and other planetary bodies and naturally occurring radioactive substances present on
earth (e.g., uranium and radium), which can be inhaled or ingested through food, water, or
air (radon).
REF: p. 104
2. With regard to the ALARA principle, the responsibility of the radiographer is to
b. keep radiation exposures at the lowest levels possible.
ANS: B
The benefit to the patient from performing medical imaging procedures must outweigh the
risk of possible biologic damage. Current studies indicate that an individual’s dose should be
kept as low as reasonably achievable (ALARA).
REF: p. 109
3. The dose equivalent limits for radiation workers are based on the radiation received from
what source(s)?
c. Occupational exposure
ANS: C
Because patients and workers exposed to radiation are at risk for biologic effects, limits
must be set to ensure safe practice for both patients and radiation workers. Dose
measurement for radiation workers is limited exclusively to occupational exposure. The
annual whole-body effective dose limit for the occupational worker is 50 mSv (5 rem).
REF: pp. 108-109
4. A given dose of radiation generally has the greatest potential for damage in tissues that have
c. more rapidly dividing cells.
ANS: C
To study a cell’s response to radiation, a method of classification according to sensitivity
was developed by Bergonie and Tribondeau in 1906. Cells are most sensitive to radiation
during active division, when they are primitive in structure and function. Cells with a high
rate of mitosis are more radiosensitive.
, REF: pp. 110-111
5. Nausea is principally associated with the
a. prodromal period.
ANS: A
Three general stages of response exist for each acute radiation syndrome. The first is the
prodromal stage, commonly referred to as the nausea, vomiting, and diarrhea (NVD) stage.
REF: p. 111
6. The material commonly used for shielding against radiation exposure in protective aprons
and gloves is
a. lead.
ANS: A
Shields are made of lead, which has an atomic number of 82. Lead absorbs x-rays through
the process of photoelectric effect, thereby minimizing patient exposure.
REF: p. 112
7. The photon interaction that results in the highest patient exposure is interactions.
d. photoelectric
ANS: D
Because complete energy absorption takes place in photoelectric interactions, this
constitutes the greatest hazard to patients in diagnostic radiography.
REF: pp. 105-106
8. The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are
1. highly mitotic.
2. undifferentiated.
b. 1 and 2 only.
ANS: B
The law of Bergonie and Tribondeau states that the mitotic activity and specific
characteristics of each cell affected how the cell exhibited radiation damage. Cells are most
sensitive to radiation during active division, when they are primitive in structure and
function (undifferentiated).
REF: pp. 110-111
9. In which of the following x-ray interactions with matter is the energy of the incident photon
completely absorbed?
b. Photoelectric absorption
ANS: B
