RADIATION PROTECTION - RADREVIEW | FROM
QUESTION TO PERFECTION| STUDY WITH CONFIDENCE!
Which of the following would be most likely to cause the greatest skin dose (ESE)?
A. Short SID
B. High kilovoltage
C. Increased filtration
D. Decreased milliamperage Answer:short SID
Types of secondary radiation barriers include
1. the control booth
2. lead aprons
3. the x-ray tube housing Answer:1, 2, and 3
Which of the following is most likely to require the lowest patient exposure?
A. Decreasing kilovoltage by 15% and doubling the milliampere-seconds value
B. Increasing kilovoltage by 15% and cutting the milliampere-seconds value in half
C. Changing collimation from 10 × 12 to 14 × 17
D. Changing from an 8:1 grid technique to nongrid Answer:Changing from an 8:1 grid technique
to nongrid
-Converting from an 8:1 grid to nongrid requires about a fourfold decrease in milliampere-
seconds. Increasing the kilovoltage by 15% and cutting the milliampere-seconds in half would
reduce patient dose by half. Doubling the mAs would double patient dose. Therefore, the
largest decrease will occur with removal of a grid.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,With milliamperes (mA) increased to maintain fluoroscopic output intensity, how is the ESE
affected as the source-to-skin distance (SSD) is increased? Answer:The ESE decreases
-Because of the divergent quality of the x-ray beam, as source-to-skin distance (SSD) increases,
entrance skin exposure (ESE) decreases for the necessary exit dose. SSD must be at least 30 cm
on mobile fluoroscopic equipment, and at least 38 cm on fixed fluoroscopic equipment.
The operation of personnel radiation monitoring devices can depend on which of the
following?
1. Ionization
2. Luminescence
3. Thermoluminescence Answer:1, 2, and 3
The largest dose to the male gonads is most likely to result from which of the following
exposures? Answer:Cross-table hip
All of the following statements regarding dual x-ray absorptiometry are true, except
1. radiation dose is considerable.
2. two x-ray photon energies are used.
3. photon attenuation by bone is calculated. Answer:1 only
-Dual x-ray absorptiometry (DXA) imaging is used to evaluate bone mineral density (BMD). It is
the most widely used method of bone densitometry—it is low dose, precise, and
uncomplicated to use/perform. DXA uses two photon energies—one for soft tissue and one for
bone. Since bone is more dense and attenuates x-ray photons more readily, their attenuation is
calculated to represent the degree of bone density. Bone densitometry, DXA, can be used to
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
, evaluate bone mineral content of the body, or part of it, to diagnose osteoporosis or to
evaluate the effectiveness of treatments for osteoporosis.
The minimum requirement for lead-equivalent content in protective aprons is? Answer:0.25
mm Pb.
-NCRP recommends .50 mm Pb
Which of the following will increase patient dose during fluoroscopy?
1. Decreasing the SSD
2. Using 2.5 mm Al filtration
3. Restricting tabletop intensity to less than 100 mGya/min Answer:1 only
-Patient dose during fluoroscopy can be considerable because the x-ray tube is in close
proximity to the patient. Therefore, we can decrease patient dose by increasing the SSD as
much as possible. The law states that the SSD must be at least 38 cm with fixed fluoroscopic
equipment and at least 30 cm with mobile fluoroscopic equipment. The use of 2.5-mm-Al-
equivalent filtration in equipment operated above 70 kVp is also required by law to reduce
patient skin dose. Another requirement of fluoroscopic equipment is that the tabletop intensity
not exceed 100 mGya/min.
The most efficient type of male gonadal shielding for use during fluoroscopy is? Answer:shaped
contact (contour)
Which of the following groups of exposure factors will deliver the least patient dose?
A. 300 mA, 250 ms, 70 kVp
B. 300 mA, 125 ms, 80 kVp
C. 400 mA, 90 ms, 80 kVp
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
QUESTION TO PERFECTION| STUDY WITH CONFIDENCE!
Which of the following would be most likely to cause the greatest skin dose (ESE)?
A. Short SID
B. High kilovoltage
C. Increased filtration
D. Decreased milliamperage Answer:short SID
Types of secondary radiation barriers include
1. the control booth
2. lead aprons
3. the x-ray tube housing Answer:1, 2, and 3
Which of the following is most likely to require the lowest patient exposure?
A. Decreasing kilovoltage by 15% and doubling the milliampere-seconds value
B. Increasing kilovoltage by 15% and cutting the milliampere-seconds value in half
C. Changing collimation from 10 × 12 to 14 × 17
D. Changing from an 8:1 grid technique to nongrid Answer:Changing from an 8:1 grid technique
to nongrid
-Converting from an 8:1 grid to nongrid requires about a fourfold decrease in milliampere-
seconds. Increasing the kilovoltage by 15% and cutting the milliampere-seconds in half would
reduce patient dose by half. Doubling the mAs would double patient dose. Therefore, the
largest decrease will occur with removal of a grid.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,With milliamperes (mA) increased to maintain fluoroscopic output intensity, how is the ESE
affected as the source-to-skin distance (SSD) is increased? Answer:The ESE decreases
-Because of the divergent quality of the x-ray beam, as source-to-skin distance (SSD) increases,
entrance skin exposure (ESE) decreases for the necessary exit dose. SSD must be at least 30 cm
on mobile fluoroscopic equipment, and at least 38 cm on fixed fluoroscopic equipment.
The operation of personnel radiation monitoring devices can depend on which of the
following?
1. Ionization
2. Luminescence
3. Thermoluminescence Answer:1, 2, and 3
The largest dose to the male gonads is most likely to result from which of the following
exposures? Answer:Cross-table hip
All of the following statements regarding dual x-ray absorptiometry are true, except
1. radiation dose is considerable.
2. two x-ray photon energies are used.
3. photon attenuation by bone is calculated. Answer:1 only
-Dual x-ray absorptiometry (DXA) imaging is used to evaluate bone mineral density (BMD). It is
the most widely used method of bone densitometry—it is low dose, precise, and
uncomplicated to use/perform. DXA uses two photon energies—one for soft tissue and one for
bone. Since bone is more dense and attenuates x-ray photons more readily, their attenuation is
calculated to represent the degree of bone density. Bone densitometry, DXA, can be used to
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
, evaluate bone mineral content of the body, or part of it, to diagnose osteoporosis or to
evaluate the effectiveness of treatments for osteoporosis.
The minimum requirement for lead-equivalent content in protective aprons is? Answer:0.25
mm Pb.
-NCRP recommends .50 mm Pb
Which of the following will increase patient dose during fluoroscopy?
1. Decreasing the SSD
2. Using 2.5 mm Al filtration
3. Restricting tabletop intensity to less than 100 mGya/min Answer:1 only
-Patient dose during fluoroscopy can be considerable because the x-ray tube is in close
proximity to the patient. Therefore, we can decrease patient dose by increasing the SSD as
much as possible. The law states that the SSD must be at least 38 cm with fixed fluoroscopic
equipment and at least 30 cm with mobile fluoroscopic equipment. The use of 2.5-mm-Al-
equivalent filtration in equipment operated above 70 kVp is also required by law to reduce
patient skin dose. Another requirement of fluoroscopic equipment is that the tabletop intensity
not exceed 100 mGya/min.
The most efficient type of male gonadal shielding for use during fluoroscopy is? Answer:shaped
contact (contour)
Which of the following groups of exposure factors will deliver the least patient dose?
A. 300 mA, 250 ms, 70 kVp
B. 300 mA, 125 ms, 80 kVp
C. 400 mA, 90 ms, 80 kVp
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
