5 Radreview Radiation exposure & monitoring
The operation of personnel radiation monitoring devices can depend on which of the following?
Ionization
Luminescence
Thermoluminescence
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
D 1, 2, and 3
What is the established annual occupational dose-equivalent limit for
the lens of the eye?
A
10 mSv
B
50 mSv
C
150 mSv
D
250 mSv
C 150 mSv
Which of the following is an acceptable approximate entrance skin
exposure (ESE) for a PA chest radiograph?
A
6 mR
B
20 mR
C
38 mR
D
0.6 R
B 20 mR
Medical and dental radiation accounts for what percentage of the
general public's exposure to human-made radiation?
A
10%
B
50%
C
80%
D
95%
C 80%
The operation of personal radiation monitoring can be based on stimulated luminescence. Which of the following personal radiation monitors function(s) in that manner?
OSL dosimeter
TLD
Pocket dosimeter
A
1 only
B
1 and 2 only
C
1 and 3 only
D
1, 2, and 3
B 1 and 2 only
Which of the following is (are) included in whole-body dose equivalents?
Gonads
Lens
Extremities
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
B 1 and 2 only
Which of the following exposures would most likely deliver the
greatest dose to the thyroid?
A
AP skull
B
PA
skull
C
PA esophagus
D
PA chest
A AP skull
The control dosimeter that comes from the monitoring company should
be
A
stored in a radiation-free area
B
kept in a
designated control booth
C
kept in the film-processing area
D
used as an extra badge for new personnel
A stored in a radiation-free area
Which unit of exposure is described as 100 ergs of energy per gram of
irradiated absorber?
A
roentgen
B
rad
C
rem
D
curie
B
rad
The annual dose limit for occupationally exposed individuals is valid
for
A
alpha, beta, and x-radiations.
B
x- and
gamma radiations only.
C
beta, x-, and gamma radiations.
D
all ionizing radiations.
C beta, x-, and gamma radiations.
The tabletop exposure rate during fluoroscopy shall not
exceed
A
5 mR/min
B
10 R/min
C
10 mR/h
D
5 R/h
B 10 R/min
Personal radiation monitor reports must include which of the following information?
Dose equivalents for report period
Dosimeter type
Radiation quality
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
D 1, 2, and 3
According to the NCRP, the pregnant radiographer's gestational
dose-equivalent limit for a 1-month period is
A
1 mSv
B
5 mSv
C
0.1 mSv
D
0.5 mSv
D 0.5 mSv
Which of the following is a measurement of dose to biologic
tissue?
A
Roentgen (C/kg)
B
Rad (Gy)
C
Rem (Sv)
D
RBE
C Rem (Sv)
If the exposure rate to a body standing 5 feet from a radiation
source is 10 mR/min, what will be the dose to that body at a distance
of 8 feet from the source?
A
25.6 mR/min
B
16
mR/min
C
6.25 mR/min
D
3.9 mR/min
D 3.9 mR/min
The annual dose limit for medical imaging personnel includes radiation from
occupational exposure
background radiation
medical x-rays
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
A 1 only
A dose of 25 rad to the fetus during the seventh or eighth week of
pregnancy is likely to cause which of the
following?
A
Spontaneous abortion
B
Skeletal
anomalies
C
Neurologic anomalies
D
Organogenesis
C Neurologic anomalies
All the following statements regarding TLDs are true
except
A
TLDs are reusable
B
a TLD is a personal
radiation monitor
C
TLDs use a lithium fluoride phosphor
D
after x-ray exposure, TLDs emit heat in response to
stimulation by light
D
after x-ray exposure, TLDs emit heat in response to
stimulation by light
A thermoluminescent dosimetry system would use which of the following
crystals?
A
Silver halide
B
Sodium thiosulfate
C
Lithium fluoride
D
Aluminum oxide
C Lithium fluoride
Which of the following is (are) acceptable way(s) to monitor the radiation exposure of those who are occupationally employed?
TLD
OSL dosimeter
Quarterly blood cell count
A
1 only
B
1 and 2 only
C
1 and 3 only
D
1, 2, and 3
B 1 and 2 only
Filters are an important component of film badges. Their function is
to
A
decrease exposure to the user.
B
identify
the quality of radiation exposure.
C
reduce film fog.
D
increase film sensitivity.
B identify the quality of radiation exposure.
It is recommended that a thermoluminescent dosimeter (TLD) or film
badge be worn
A
under the lead apron at waist level
B
outside the lead apron at waist level
C
under
the lead apron at collar level
D
outside the lead apron at
collar level
D outside the lead apron at collar level
An optically stimulated luminescence dosimeter contains which of the
following detectors?
A
Gadolinium
B
Aluminum
oxide
C
Lithium fluoride
D
Photographic film
B Aluminum oxide
Which of the following radiologic examinations would deliver the
greatest ESE?
A
Chest
B
Skull
C
Abdomen
D
Thoracic spine
C Abdomen
Which of the following is recommended for the pregnant
radiographer?
A
Change dosimeters weekly.
B
Wear
a second dosimeter under the lead apron.
C
Wear two
dosimeters and switch their positions appropriately.
D
The
pregnant radiographer must leave radiation areas for duration of the pregnancy.
B Wear a second dosimeter under the lead apron.
The rad may be described as
A
disintegrations per second.
B
ions produced in air.
C
energy deposited in an
absorber.
D
biologic effects.
C energy deposited in an absorber.
Types of secondary radiation barriers include
the control booth
lead aprons
the x-ray tube housing
A
2 only
B
1 and 2 only
C
2 and 3 only
D
1, 2, and 3
D 1, 2, and 3
A dose of 25 rad to the fetus during the fourth or fifth week of
pregnancy is more likely to cause which of the
following:
A
Spontaneous abortion
B
skeletal
anomalies
C
neurologic anomalies
D
organogenesis
B skeletal anomalies
Which of the following statements regarding film badges is (are)
correct?
1. Film badges should be read quarterly.
2. Film
badges must not leave the workplace.
3. Film badges measure
quantity and quality of radiation exposure.
A
1 only
B
1 and 2 only
C
2 and 3 only
D
1, 2,
and 3
C 2 and 3 only
The person responsible for ascertaining that all radiation guidelines
are adhered to and that personnel understand and employ radiation
safety measures is the
A
radiology department manager
B
radiation safety officer
C
chief radiologist
D
chief technologist
B radiation safety officer
What unit of measure is used to express ionizing radiation dose to
biologic material?
A
Roentgen (C/kg)
B
Rad (Gy)
C
Rem (Sv)
D
RBE
C Rem (Sv)
Which of the following personnel monitoring devices used in
diagnostic radiography is considered to be the most sensitive and
accurate?
A
TLD
B
Film badge
C
OSL
dosimeter
D
Pocket dosimeter
C OSL dosimeter
The National Council on Radiation Protection and Measurements (NCRP)
has recommended what total equivalent dose limit to the
embryo/fetus?
A
0.5 mSv
B
5.0 mSv
C
50
mSv
D
500 mSv
B 5.0 mSv
The rad is the unit of
A
radiation dose.
B
exposure.
C
dose equivalent.
D
ionization in air.
A radiation dose.
The National Council on Radiation Protection and Measurements (NCRP)
recommends an annual occupational effective (stochastic) dose
equivalent limit of
A
50 mSv (5 rem).
B
100 mSv
(10 rem).
C
25 mSv (2.5 rem).
D
200 mSv (20 rem).
A 50 mSv (5 rem).
Which of the following refers to a regular program of evaluation that
ensures the proper functioning of x-ray equipment, thereby protecting
both radiation workers and patients?
A
Sensitometry
B
Densitometry
C
Quality assurance
D
Modulation transfer function
C Quality assurance
Radiation output from a diagnostic x-ray tube is measured in which of
the following units of measurement?
A
Rad
B
Rem
C
Roentgen
D
Becqueral
C Roentgen
The purpose of filters in a film badge is
A
to eliminate
harmful rays
B
to measure radiation quality
C
to
prevent exposure by alpha particles
D
as a support for the
film contained within
B to measure radiation quality
Which type of personnel radiation monitor can provide an immediate
reading?
A
Thermoluminescent dosimeter (TLD)
B
Optically stimulated luminescence (OSL)
C
Film
badge
D
Ionization chamber
D Ionization chamber
According to the NCRP, the annual occupational whole-body
dose-equivalent limit is
A
1 mSv
B
50 mSv
C
150 mSv
D
500 mSv
B 50 mSv
What is the annual dose-equivalent limit for the skin and hands of an
occupationally exposed individual?
A
5 rem
B
25
rem
C
50 rem
D
100 rem
C 50 rem
The roentgen is the unit of
A
radiation dose
B
biologic dose
C
dose equivalent
D
ionization in air
D ionization in air
Occupational radiation monitoring is required when it is possible
that the individual might receive more than
A
5 mrem
B
10 mrem
C
one-tenth the annual dose limit
D
one-fourth the annual dose limit
C one-tenth the annual dose limit
Which of the following is considered the unit of exposure in
air?
A
Roentgen (C/kg)
B
Rad (Gy)
C
Rem (Sv)
D
RBE
A Roentgen (C/kg)
How will x-ray photon intensity be affected if the SID is
doubled?
A
Its intensity increases two times.
B
Its intensity increases four times.
C
Its
intensity decreases two times.
D
Its intensity decreases
four times.
D Its intensity decreases four times.
What is the annual TEDE limit for radiation workers?
A
5
mSv
B
500 mSv
C
5,000 mSv
D
50 mSv
D 50 mSv
According to the National Council on Radiation Protection and
Measurements (NCRP), the gestational dose-equivalent limit for
embryo/fetus of a pregnant radiographer is
A
1 mSv
B
0.5 mSv
C
15 mSv
D
50 mSv
B 0.5 mSv
Referring to the nomogram in Figure 3–8, what is the approximate patient ESE from a particular projection made at 105 cm using 125 kVp, 400 mA, 8 ms, and 3.0 mm Al total filtration ?
Reproduced, with permission, from McCullough EC, Cameron JR.
Exposure rates from diagnostic x-ray units. Br J Radiol
1970;43:448–451.
A
23 mR
B
48 mR
C
230 mR
D
480 mR
B 48 mR
The largest dose to the male gonads is most likely to result from
which of the following exposures?
A
Lateral thoracic spine
B
Oblique lumbar spine
C
Cross-table lateral hip
D
AP axial skull
C Cross-table lateral hip
The roentgen, as a unit of measurement,
expresses
A
absorbed dose
B
exposure in air
C
dose equivalent
D
dose to biologic material
B exposure in air
The NCRP recommends an annual effective occupational dose-equivalent
limit of
A
2.5 rem (25 mSv)
B
5 rem (50 mSv)
C
10 rem (100 mSv)
D
20 rem (200 mSv)
B 5 rem (50 mSv)
The unit of absorbed dose is the
A
roentgen (C/kg).
B
rad (Gy).
C
rem (Sv).
D
RBE.
B rad (Gy).
The term effective dose refers to
A
whole-body dose
B
localized organ dose
C
genetic effects
D
somatic and genetic effects
A whole-body dose
The purpose of filters in a film badge is
A
to eliminate
harmful rays.
B
to measure radiation quality.
C
to prevent exposure by alpha particles.
D
as a
support for the film contained within.
B to measure radiation quality.
Which of the following personnel radiation monitors will provide an
immediate reading?
A
TLD
B
Film badge
C
Lithium fluoride chips
D
Pocket dosimeter
D Pocket dosimeter
The unit of measurement used to express occupational exposure is
the
A
roentgen (C/kg)
B
rad (Gy)
C
rem
(Sv)
D
relative biologic effectiveness (RBE)
C rem (Sv)
Any wall that the useful x-ray beam can be directed toward is called
a
A
secondary barrier
B
primary barrier
C
leakage barrier
D
scattered barrier
B primary barrier
The annual dose limit for occupationally exposed individuals is valid
for
A
alpha, beta, and x-radiations
B
x- and
gamma radiations only
C
beta, x-, and gamma radiations
D
all ionizing radiations
C beta, x-, and gamma radiations
What is the established fetal dose-limit guideline for pregnant
radiographers during the entire gestation period?
A
0.1 rem
B
0.5 rem
C
5.0 rem
D
10 rem
B 0.5 rem
According to the NCRP, the annual occupational dose-equivalent limit
(50 rem) to the thyroid, skin, and extremities is
A
50 mSv
B
150 mSv
C
500 mSv
D
1,500 mSv
C 500 mSv