RTBC Radiation Protection UPDATED
ACTUAL Exam Questions and CORRECT
Answers
The primary purpose of the ALARA principle in diagnostic imaging is to: - CORRECT
ANSWER - Reduce radiation dose to occupational workers
A radiation worker received a radiation dose of 5 milligrays (mGy) while participating in a
fluoroscopy procedure for 10 minutes. What radiation dose would have been received by the
worker if they reduced their time in the radiation field to only 5 minutes? - CORRECT
ANSWER - 2.5 mGy
Which Cardinal rule of radiation protection is mathematically defined by the inverse square law?
- CORRECT ANSWER - Distance
In order to reduce a technologist's occupational dose during a portable radiograph of the chest,
the technologist should: - CORRECT ANSWER - Stand several feet away from the patient
during the exposure
During a surgical procedure using three (3) minutes of fluoroscopy time, a radiographer receives
an effective dose of 1 millisievert (mSv). What effective dose would be experienced by the
radiographer if the fluoroscopy time is doubled? - CORRECT ANSWER - 2 mSv
A radiographer is exposed to a dose rate of 10 mSv/hour while standing 3 feet from the patient
during c-arm procedures. What is the approximate dose rate if the radiographer stands 4 feet
from the patient? - CORRECT ANSWER - 5.6 mSv/hour
A radiologist receives an equivalent dose of 100 μSv while standing 25 cm from a patient during
a fluoroscopy procedure. Estimate the equivalent dose if the radiologist stood at 10 cm from the
patient. - CORRECT ANSWER - 625 μSv
, Which three of the following properties of lead make it a valuable material for radiation
shielding devices? (Select three) - CORRECT ANSWER - - High atomic number
- High mass density
- High attenuation
Which of the following materials requires the smallest half-value layer (HVL) to effectively
attenuation the x-ray beam? - CORRECT ANSWER - Lead
How does radiation dose change if a technologist increases their distance from a radiation source
by a factor of 2? - CORRECT ANSWER - Dose decreases by a factor of 2 squared
A half-value layer (HVL) is the thickness of material required to reduce which of the following
by half? - CORRECT ANSWER - X-ray beam intensity
A shielding device constructed with a thickness equivalent to 1 HVL will reduce the quantity of
radiation to: - CORRECT ANSWER - 50% of the original quantity
A shielding device constructed with a thickness equivalent to 2 HVL will reduce the quantity of
radiation to: - CORRECT ANSWER - 25% of the original quantity
If the half-value layer of shielding material is equal to 2mm, how much radiation will transmit
through 6 mm of this material? - CORRECT ANSWER - 12.5% of the original quantity
What is the most commonly used shielding material in medical imaging? - CORRECT
ANSWER - Lead
What lead thickness equivalence is required for protective lead aprons designated for general
radiography, surgery, and fluoroscopy? - CORRECT ANSWER - 0.50 mm lead (Pb)
ACTUAL Exam Questions and CORRECT
Answers
The primary purpose of the ALARA principle in diagnostic imaging is to: - CORRECT
ANSWER - Reduce radiation dose to occupational workers
A radiation worker received a radiation dose of 5 milligrays (mGy) while participating in a
fluoroscopy procedure for 10 minutes. What radiation dose would have been received by the
worker if they reduced their time in the radiation field to only 5 minutes? - CORRECT
ANSWER - 2.5 mGy
Which Cardinal rule of radiation protection is mathematically defined by the inverse square law?
- CORRECT ANSWER - Distance
In order to reduce a technologist's occupational dose during a portable radiograph of the chest,
the technologist should: - CORRECT ANSWER - Stand several feet away from the patient
during the exposure
During a surgical procedure using three (3) minutes of fluoroscopy time, a radiographer receives
an effective dose of 1 millisievert (mSv). What effective dose would be experienced by the
radiographer if the fluoroscopy time is doubled? - CORRECT ANSWER - 2 mSv
A radiographer is exposed to a dose rate of 10 mSv/hour while standing 3 feet from the patient
during c-arm procedures. What is the approximate dose rate if the radiographer stands 4 feet
from the patient? - CORRECT ANSWER - 5.6 mSv/hour
A radiologist receives an equivalent dose of 100 μSv while standing 25 cm from a patient during
a fluoroscopy procedure. Estimate the equivalent dose if the radiologist stood at 10 cm from the
patient. - CORRECT ANSWER - 625 μSv
, Which three of the following properties of lead make it a valuable material for radiation
shielding devices? (Select three) - CORRECT ANSWER - - High atomic number
- High mass density
- High attenuation
Which of the following materials requires the smallest half-value layer (HVL) to effectively
attenuation the x-ray beam? - CORRECT ANSWER - Lead
How does radiation dose change if a technologist increases their distance from a radiation source
by a factor of 2? - CORRECT ANSWER - Dose decreases by a factor of 2 squared
A half-value layer (HVL) is the thickness of material required to reduce which of the following
by half? - CORRECT ANSWER - X-ray beam intensity
A shielding device constructed with a thickness equivalent to 1 HVL will reduce the quantity of
radiation to: - CORRECT ANSWER - 50% of the original quantity
A shielding device constructed with a thickness equivalent to 2 HVL will reduce the quantity of
radiation to: - CORRECT ANSWER - 25% of the original quantity
If the half-value layer of shielding material is equal to 2mm, how much radiation will transmit
through 6 mm of this material? - CORRECT ANSWER - 12.5% of the original quantity
What is the most commonly used shielding material in medical imaging? - CORRECT
ANSWER - Lead
What lead thickness equivalence is required for protective lead aprons designated for general
radiography, surgery, and fluoroscopy? - CORRECT ANSWER - 0.50 mm lead (Pb)
