LMRT-Radiography Essentials Exam
Questions and Answers
Which of the following changes in (KVP) will result in the greatest reduction of patient dose, when (MAS)
is adjusted to compensate for the change? - Answer-Increase kVp by 30%
Which of the following (IR) system speeds will result in the lowest patient dose? - Answer-Faster speed
IR system
What is the primary purpose of using gonad shields during radiography? - Answer-Reduce the likelihood
of genetic effects
Contact & shadow are two types of gonad shield - Answer-TRUE
When should gonad shields be used? - Answer-When the gonads are within 5cm of the radiation field
The greatest cause of unnecessary radiation to patients that can be controlled by the limited operator
are: - Answer-repeat exposures
The limited operator can reduce repeat exposures by: - Answer-clearly instructing patients
,How does x-ray beam restriction minimize patient exposure - Answer-It limits the radiation field to the
area of interest
What is the device that allows the limited operator to vary the size of the radiation field - Answer-
Collimator
How does filtration reduce patient exposure - Answer-Removes longer wavelength photons
What is the National Council on Radiation Protection and Measurements (NCRP) recommendation for
the amount of total filtration - Answer-2.5mm Al Equivalent
What are the three principal methods used to protect limited operators from unnecessary radiation
exposure? - Answer-1. Time
2. Distance
3. Shielding
Which of the following is NOT a type of personnel radiation shielding? - Answer-a. Apron
b. Glove
c. Thyroid shield
d. Shadow******** CORRECT
Personnel shielding must be worn on the rare occasion during which the limited operator may need to
remain in the radiographic room during an exposure to assist the patient in maintaining the proper
position. What is the source of the greatest radiation hazard under this circumstance? - Answer-
Scattered radiation from the patient
What is the term from radiation that escapes from the x-ray tube housing? - Answer-leakage radiation
, Why are limited operators prohibited from activities that result in direct exposure to the primary x-ray
beam? - Answer-They are considered occupationally exposed individuals
Distance, as a method used to limit operator exposure, means that: - Answer-the operator should
maximize the distance from the source during an exposure.
Shielding worn for personnel protection is designed to attenuate what source of exposure - Answer-
scatter radiation
Which of the following is an acronym for a common type of personnel dosimeter - Answer-TLD
What is the recommended placement for a personnel dosimeter on the body of the limited operator -
Answer-The badge should be worn in the region of the collar on the anterior surface of the body and
outside the lead apron if worn.
What is the NCRP recommended annual effective dose limit for occupational exposure - Answer-5.0
rem (0.05 severt)
What is the NCRP recommended monthly effective (or equivalent) dose limit to the fetus for a prego
worker? - Answer-0.05 rem (0.0005 Sv)
Radiation monitoring of personnel is required when what percentage of the annual occupational
effective dose limit is likely to be received - Answer-10%
What is the conventional (British system) radiation unit to express radiation intensity in air? - Answer-
Roentgen
Questions and Answers
Which of the following changes in (KVP) will result in the greatest reduction of patient dose, when (MAS)
is adjusted to compensate for the change? - Answer-Increase kVp by 30%
Which of the following (IR) system speeds will result in the lowest patient dose? - Answer-Faster speed
IR system
What is the primary purpose of using gonad shields during radiography? - Answer-Reduce the likelihood
of genetic effects
Contact & shadow are two types of gonad shield - Answer-TRUE
When should gonad shields be used? - Answer-When the gonads are within 5cm of the radiation field
The greatest cause of unnecessary radiation to patients that can be controlled by the limited operator
are: - Answer-repeat exposures
The limited operator can reduce repeat exposures by: - Answer-clearly instructing patients
,How does x-ray beam restriction minimize patient exposure - Answer-It limits the radiation field to the
area of interest
What is the device that allows the limited operator to vary the size of the radiation field - Answer-
Collimator
How does filtration reduce patient exposure - Answer-Removes longer wavelength photons
What is the National Council on Radiation Protection and Measurements (NCRP) recommendation for
the amount of total filtration - Answer-2.5mm Al Equivalent
What are the three principal methods used to protect limited operators from unnecessary radiation
exposure? - Answer-1. Time
2. Distance
3. Shielding
Which of the following is NOT a type of personnel radiation shielding? - Answer-a. Apron
b. Glove
c. Thyroid shield
d. Shadow******** CORRECT
Personnel shielding must be worn on the rare occasion during which the limited operator may need to
remain in the radiographic room during an exposure to assist the patient in maintaining the proper
position. What is the source of the greatest radiation hazard under this circumstance? - Answer-
Scattered radiation from the patient
What is the term from radiation that escapes from the x-ray tube housing? - Answer-leakage radiation
, Why are limited operators prohibited from activities that result in direct exposure to the primary x-ray
beam? - Answer-They are considered occupationally exposed individuals
Distance, as a method used to limit operator exposure, means that: - Answer-the operator should
maximize the distance from the source during an exposure.
Shielding worn for personnel protection is designed to attenuate what source of exposure - Answer-
scatter radiation
Which of the following is an acronym for a common type of personnel dosimeter - Answer-TLD
What is the recommended placement for a personnel dosimeter on the body of the limited operator -
Answer-The badge should be worn in the region of the collar on the anterior surface of the body and
outside the lead apron if worn.
What is the NCRP recommended annual effective dose limit for occupational exposure - Answer-5.0
rem (0.05 severt)
What is the NCRP recommended monthly effective (or equivalent) dose limit to the fetus for a prego
worker? - Answer-0.05 rem (0.0005 Sv)
Radiation monitoring of personnel is required when what percentage of the annual occupational
effective dose limit is likely to be received - Answer-10%
What is the conventional (British system) radiation unit to express radiation intensity in air? - Answer-
Roentgen
