Rad Bio: Chapter 35,36,37 and 39 evolve questions
if the HVL in a radiology department is 0.25 mm Pb, then how
thick should a shield be to reduce the technologists' exposure to
one fourth the incident scatter? - answer 0.5 mm Pb or 2 HVL's
the exposure rate from a point source is 1 mGya/hr (100mR/hr) at
120 cm. if a radiologic technologist moves to within 30 cm of the
source of radiation, bow many HVL's would be needed to reduce
the exposure rate to 1 mGya/hr ( 100mR/hr)? - answer 4
the HVL for 70 kVp is greater: - answer with high filtration than
with low filtration
what effect would halving the exposure time during an x-ray
image have on a patient's radiation exposure dose? - answer half
T or F: if a radiologic technologist's doubles their distance from
the patient during a fluoroscopic exam, their exposure dose is
reduced by 75% - answer False
when calculating one's estimated radiation exposure in terms of
distance changes, what site must be determined? - answer point
source
What material does most diagnostic radiology shielding consist of
to reduce radiation exposure to the best ability while remaining
functional? - answer lead
,Because the whole body is not typically exposed during a
radiologic exam, what is used to determine the whole-body dose
equivalent? - answer effective dose
what term is used to describe the relative radiosensitivity of each
tissue and organ of the human body? - answer tissue weighting
factor
A KUB (supine abdomen) radiograph results in an average tissue
dose of 0.1 mGy (100 uGy) to the stomach, colon, bladder, and
gonads. What is the patients cumulative effective dose for this
radiograph? - answer 49 uGy
a radiologic technologist's occupational radiation exposure dose is
measured by a radiation monitor. This device must be worn where
to give an accurate reading? - answer collar outside of shielding
who does not qualify as an emergency responder?
a. police
b. patient
c. fire fighter
d. radiologic technologist - answer patient
T or F: an outer boundary is established when radiologic terrorism
radiation exposures exceed the inner boundary and additional
distance is necessary for safety - answer True
,What equipment should be available to emergency responders
during a radiologic terrorism event?
a. radiation detection équipement
b. personal protective coveralls
c. protective respiratory devices
d. 1,2,3 - answer D; 1,2,3
what type of radiologic terrorism device is sealed source of
radiosensitive material that can directly expose people? - answer
Radiation exposure device ( RED)
Half-Value Layer (HVL) is related to which of the following
principles of radiation protection? - answer Shielding
If all other factors remain constant, radiation dose is related to x-
ray beam on time: - answer Directly
If all other factors remain constant, radiation dose is related to
source-to-object distance (SOD): - answer by the inverse square
law
if all other factors remain constant, radiation dose is related to
shielding: - answer Exponentially
one tenth-value layer (TVL) is defined as: - answer the shielding
necessary to reduce the exposure to 1/10
, one TVL is equal to approximately how many HVL's? - answer 3.3
during radiography, the best position for the radiologic
technologist is? - answer behind the operating console
the exposure rate from a point source is 1 mGya/hr (100mR/hr) at
120 cm. if a radiologic technologist moves to within 30 cm of the
source of radiation, how many HVL's would be needed to reduce
the exposure rate to 1 mGya/hr (100mR/hr)? - answer 4
if a survey meter reads 0.25 mGya/hr(25 mR/hr), how long can a
person stay at that location before receiving an exposure of 1
mGya (100 mR)? - answer 4 hours
if the exposure rate 1m from a source is 90 mGya/hr (9000
mR/hr). what is the exposure rate at 3m from the source? -
answer 10 mGya/hr (1000 mR/hr)
the exposure rate alongside a fluoroscopic table ( distance=60cm
from the source) is 4mGya/hr (400 mR/hr). Therefore, if the
radiologic technologist: - answer completed a 3-minute barium
enema, the exposure would be 0.2 mGya (20 mR)
the DL for a radiologic technologist is: - answer 50 mSv (5000
rem) per year
if the HVL in a radiology department is 0.25 mm Pb, then how
thick should a shield be to reduce the technologists' exposure to
one fourth the incident scatter? - answer 0.5 mm Pb or 2 HVL's
the exposure rate from a point source is 1 mGya/hr (100mR/hr) at
120 cm. if a radiologic technologist moves to within 30 cm of the
source of radiation, bow many HVL's would be needed to reduce
the exposure rate to 1 mGya/hr ( 100mR/hr)? - answer 4
the HVL for 70 kVp is greater: - answer with high filtration than
with low filtration
what effect would halving the exposure time during an x-ray
image have on a patient's radiation exposure dose? - answer half
T or F: if a radiologic technologist's doubles their distance from
the patient during a fluoroscopic exam, their exposure dose is
reduced by 75% - answer False
when calculating one's estimated radiation exposure in terms of
distance changes, what site must be determined? - answer point
source
What material does most diagnostic radiology shielding consist of
to reduce radiation exposure to the best ability while remaining
functional? - answer lead
,Because the whole body is not typically exposed during a
radiologic exam, what is used to determine the whole-body dose
equivalent? - answer effective dose
what term is used to describe the relative radiosensitivity of each
tissue and organ of the human body? - answer tissue weighting
factor
A KUB (supine abdomen) radiograph results in an average tissue
dose of 0.1 mGy (100 uGy) to the stomach, colon, bladder, and
gonads. What is the patients cumulative effective dose for this
radiograph? - answer 49 uGy
a radiologic technologist's occupational radiation exposure dose is
measured by a radiation monitor. This device must be worn where
to give an accurate reading? - answer collar outside of shielding
who does not qualify as an emergency responder?
a. police
b. patient
c. fire fighter
d. radiologic technologist - answer patient
T or F: an outer boundary is established when radiologic terrorism
radiation exposures exceed the inner boundary and additional
distance is necessary for safety - answer True
,What equipment should be available to emergency responders
during a radiologic terrorism event?
a. radiation detection équipement
b. personal protective coveralls
c. protective respiratory devices
d. 1,2,3 - answer D; 1,2,3
what type of radiologic terrorism device is sealed source of
radiosensitive material that can directly expose people? - answer
Radiation exposure device ( RED)
Half-Value Layer (HVL) is related to which of the following
principles of radiation protection? - answer Shielding
If all other factors remain constant, radiation dose is related to x-
ray beam on time: - answer Directly
If all other factors remain constant, radiation dose is related to
source-to-object distance (SOD): - answer by the inverse square
law
if all other factors remain constant, radiation dose is related to
shielding: - answer Exponentially
one tenth-value layer (TVL) is defined as: - answer the shielding
necessary to reduce the exposure to 1/10
, one TVL is equal to approximately how many HVL's? - answer 3.3
during radiography, the best position for the radiologic
technologist is? - answer behind the operating console
the exposure rate from a point source is 1 mGya/hr (100mR/hr) at
120 cm. if a radiologic technologist moves to within 30 cm of the
source of radiation, how many HVL's would be needed to reduce
the exposure rate to 1 mGya/hr (100mR/hr)? - answer 4
if a survey meter reads 0.25 mGya/hr(25 mR/hr), how long can a
person stay at that location before receiving an exposure of 1
mGya (100 mR)? - answer 4 hours
if the exposure rate 1m from a source is 90 mGya/hr (9000
mR/hr). what is the exposure rate at 3m from the source? -
answer 10 mGya/hr (1000 mR/hr)
the exposure rate alongside a fluoroscopic table ( distance=60cm
from the source) is 4mGya/hr (400 mR/hr). Therefore, if the
radiologic technologist: - answer completed a 3-minute barium
enema, the exposure would be 0.2 mGya (20 mR)
the DL for a radiologic technologist is: - answer 50 mSv (5000
rem) per year
