Radiation Protection Unit IV
questions & answers
What is the best way to measure the quality of an x-ray beam?
a. Spinning top test
b. Half-value layer (HVL)
c. Step wedge
d. Star test pattern - answer b. Half-value layer (HVL)
The lowest intensity of radiation from the patient is scattered:
a. At a 90 degree angle from the patient
b. At a 45 degree angle from the patient
c. Toward the foot of the table
d. Toward the head of the table - answer a. At a 90 degree angle
from the patient
An assumption may be made that the tabletop intensity for every
milliampere of fluoroscopic technique at 80 kVp is:
a. 2 rad/min
b. 12 rad/min
c. 5 rad/min
d. 15 rad/min - answer a. 2 rad/min
What is likely to occur if 25 rad is accidentally delivered to a
recently fertilized ovum?
,a. Skeletal anomalies
b. CNS anomalies
c. Spontaneous abortion
d. Childhood malignancy - answer c. Spontaneous abortion
What is the recommended minimum lead equivalent for
protective gloves worn by the radiographer during a fluoroscopic
procedure?
A. 5.0 mm Pb equivalent
B. 2.5 mm Pb equivalent
C. 0.50 mm Pb equivalent
D. 0.25 mm Pb equivalent - answer D. 0.25 mm Pb equivalent
Some patients, such as infants and children, are unable to
maintain the necessary radiographic position without assistance.
If mechanical restraining devices cannot be used, which of the
following should be requested or permitted to hold this patient?
a. Transporter
b. Patient's father
c. Patient's mother
d. Student radiographer - answer b. Patient's father
The tabletop exposure rate during fluoroscopy shall not exceed
a. 5 mR/min
b. 10 R/min
c. 10 mR/min
,d. 5 R/hr - answer b. 10 R/min
Which of the following will reduce patient dose during
fluoroscopy?
1) Decreasing the source-skin distance (SSD)
2) Using 2.5 mm Al filtration
3) Restricting tabletop intensity to less than 10 R/min - answer 2
and 3
The function of the 5-minutes fluoroscopy timer is to
a. Alert the fluoroscopist that 5 minutes has elapsed
b. Terminate the procedure
c. Alert the technologist to reload the camera
d. Signal completion of the examination - answer a. Alert the
fluoroscopist that 5 minutes has elapsed
The exposure rate from a point source is 200 mR/hr at 100 cm. If
a technologist moves to within 25 cm of the source of radiation,
how many HVLs would be needed to reduce the exposure rate to
100 mR/hr?
a. 0
b. 3
c. 4
d. 5 - answer d. 5
How does filtration affect the primary beam?
, a. It increases the average energy of the primary beam
b. It decreases the average energy of the primary beam
c. It makes the primary beam more penetrating
d. It increases the intensity of the primary beam - answer a. It
increases the average energy of the primary beam
When an image intensifier's magnification mode is used,
1) Output screen gain is increased
2) Resolution increases
3) Patient dose increases - answer 2 and 3
The minimum permissible filtration for general purpose
radiographic or fluoroscopic tubes is:
a. 0.5 mm Al
b. 2.5 mm Al
c. 1.5 mm Al
d. 3.5 mm Al - answer b. 2.5 mm Al
The annual dose-equivalent limit for the lens of the eye for the
general public is ______ rem - answer Answer: 1.5
Which of the following sets of exposure factors would provide the
least patient exposure?
a. 200 mA, 0.4 sec., 70 kVp, 100 speed film, 12:1 grid
b. 400 mA, 0.2 sec., 80 kVp, 200 speed film, 8:1 grid
questions & answers
What is the best way to measure the quality of an x-ray beam?
a. Spinning top test
b. Half-value layer (HVL)
c. Step wedge
d. Star test pattern - answer b. Half-value layer (HVL)
The lowest intensity of radiation from the patient is scattered:
a. At a 90 degree angle from the patient
b. At a 45 degree angle from the patient
c. Toward the foot of the table
d. Toward the head of the table - answer a. At a 90 degree angle
from the patient
An assumption may be made that the tabletop intensity for every
milliampere of fluoroscopic technique at 80 kVp is:
a. 2 rad/min
b. 12 rad/min
c. 5 rad/min
d. 15 rad/min - answer a. 2 rad/min
What is likely to occur if 25 rad is accidentally delivered to a
recently fertilized ovum?
,a. Skeletal anomalies
b. CNS anomalies
c. Spontaneous abortion
d. Childhood malignancy - answer c. Spontaneous abortion
What is the recommended minimum lead equivalent for
protective gloves worn by the radiographer during a fluoroscopic
procedure?
A. 5.0 mm Pb equivalent
B. 2.5 mm Pb equivalent
C. 0.50 mm Pb equivalent
D. 0.25 mm Pb equivalent - answer D. 0.25 mm Pb equivalent
Some patients, such as infants and children, are unable to
maintain the necessary radiographic position without assistance.
If mechanical restraining devices cannot be used, which of the
following should be requested or permitted to hold this patient?
a. Transporter
b. Patient's father
c. Patient's mother
d. Student radiographer - answer b. Patient's father
The tabletop exposure rate during fluoroscopy shall not exceed
a. 5 mR/min
b. 10 R/min
c. 10 mR/min
,d. 5 R/hr - answer b. 10 R/min
Which of the following will reduce patient dose during
fluoroscopy?
1) Decreasing the source-skin distance (SSD)
2) Using 2.5 mm Al filtration
3) Restricting tabletop intensity to less than 10 R/min - answer 2
and 3
The function of the 5-minutes fluoroscopy timer is to
a. Alert the fluoroscopist that 5 minutes has elapsed
b. Terminate the procedure
c. Alert the technologist to reload the camera
d. Signal completion of the examination - answer a. Alert the
fluoroscopist that 5 minutes has elapsed
The exposure rate from a point source is 200 mR/hr at 100 cm. If
a technologist moves to within 25 cm of the source of radiation,
how many HVLs would be needed to reduce the exposure rate to
100 mR/hr?
a. 0
b. 3
c. 4
d. 5 - answer d. 5
How does filtration affect the primary beam?
, a. It increases the average energy of the primary beam
b. It decreases the average energy of the primary beam
c. It makes the primary beam more penetrating
d. It increases the intensity of the primary beam - answer a. It
increases the average energy of the primary beam
When an image intensifier's magnification mode is used,
1) Output screen gain is increased
2) Resolution increases
3) Patient dose increases - answer 2 and 3
The minimum permissible filtration for general purpose
radiographic or fluoroscopic tubes is:
a. 0.5 mm Al
b. 2.5 mm Al
c. 1.5 mm Al
d. 3.5 mm Al - answer b. 2.5 mm Al
The annual dose-equivalent limit for the lens of the eye for the
general public is ______ rem - answer Answer: 1.5
Which of the following sets of exposure factors would provide the
least patient exposure?
a. 200 mA, 0.4 sec., 70 kVp, 100 speed film, 12:1 grid
b. 400 mA, 0.2 sec., 80 kVp, 200 speed film, 8:1 grid
