1|Page
Computed Tomography Exam Prep Material Newest
2025/ 2026 Complete All Questions And Correct
Detailed Answers (Verified Answers)|Newest Version!!!
how do you reduce beam hardening - Answer-1. Increase
dose
2. Reduce collimation--Reduce slice thickness
3. Increase window width
At what level does the abdominal aortal bifurcate? -
Answer-L4
What is the typical scan delay after injection of contrast
media for studies of the liver? - Answer-30-45 seconds
What window settings provide the best tissue
differentiation within the liver? - Answer-window width=
140, level= 60
What is the window settings that provide the best bone
window for the pelvis? - Answer-window width=2000,
window level=350
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What mAs is typically used in routine CT exams of the
abdomen? - Answer-200-300 mAs
What is the result of the bifurcation of the abdominal
aorta? - Answer-The right and left common iliac arteries
What is the anode target angle? - Answer-12 degrees
At what level do the common carotids bifurcate into the
internal and external carotid arteries? - Answer-C3-C4
The floor of the orbit is formed by the __________ bones.
- Answer-maxillary and zygomatic
The lateral wall of the orbit is formed by the ___________
bones. - Answer-zygomatic and sphenoid
The medial wall of the orbit is formed by the _________
bones. - Answer-ethmoid and lacrimal bones
how do you calculate effective mAs? - Answer-mAs/pitch
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define window level and window width - Answer-LEVEL: a
chosen midpoint in the grayscale
WIDTH: number of grayscale values above and below the
level.
- The width is DIVIDED in HALF and distributed above and
below the level.
- Anything above the window is white
- Anything below the window is black
The wider the window the more grayscale values, the
lower the contrast!
example:
Level 100, Width 300
White = >+250
Black = <-50
Level 100, Width 200
White = >+200
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Black = <0
Level 100, Width 150
White = >+175
Black = <25
factors that affect spatial and contrast resolution - Answer-
Spatial resolution:
1) focal spot
2) detector width (aperture)
3) reconstruction algorithm - bone>soft tissue
4) slice thickness - thinner is better
5) pixel/FOV/matrix
6) pitch - decreased pitch means no gaps
7) nyquist limitations
Contrast resolution: CNR
1) energy of X-rays - kVp - ↑ kVp ↓ contrast
2) number of X-rays - mA - ↑ mA ↓ mottle
3) slice thickness - thicker is better
Computed Tomography Exam Prep Material Newest
2025/ 2026 Complete All Questions And Correct
Detailed Answers (Verified Answers)|Newest Version!!!
how do you reduce beam hardening - Answer-1. Increase
dose
2. Reduce collimation--Reduce slice thickness
3. Increase window width
At what level does the abdominal aortal bifurcate? -
Answer-L4
What is the typical scan delay after injection of contrast
media for studies of the liver? - Answer-30-45 seconds
What window settings provide the best tissue
differentiation within the liver? - Answer-window width=
140, level= 60
What is the window settings that provide the best bone
window for the pelvis? - Answer-window width=2000,
window level=350
,2|Page
What mAs is typically used in routine CT exams of the
abdomen? - Answer-200-300 mAs
What is the result of the bifurcation of the abdominal
aorta? - Answer-The right and left common iliac arteries
What is the anode target angle? - Answer-12 degrees
At what level do the common carotids bifurcate into the
internal and external carotid arteries? - Answer-C3-C4
The floor of the orbit is formed by the __________ bones.
- Answer-maxillary and zygomatic
The lateral wall of the orbit is formed by the ___________
bones. - Answer-zygomatic and sphenoid
The medial wall of the orbit is formed by the _________
bones. - Answer-ethmoid and lacrimal bones
how do you calculate effective mAs? - Answer-mAs/pitch
,3|Page
define window level and window width - Answer-LEVEL: a
chosen midpoint in the grayscale
WIDTH: number of grayscale values above and below the
level.
- The width is DIVIDED in HALF and distributed above and
below the level.
- Anything above the window is white
- Anything below the window is black
The wider the window the more grayscale values, the
lower the contrast!
example:
Level 100, Width 300
White = >+250
Black = <-50
Level 100, Width 200
White = >+200
, 4|Page
Black = <0
Level 100, Width 150
White = >+175
Black = <25
factors that affect spatial and contrast resolution - Answer-
Spatial resolution:
1) focal spot
2) detector width (aperture)
3) reconstruction algorithm - bone>soft tissue
4) slice thickness - thinner is better
5) pixel/FOV/matrix
6) pitch - decreased pitch means no gaps
7) nyquist limitations
Contrast resolution: CNR
1) energy of X-rays - kVp - ↑ kVp ↓ contrast
2) number of X-rays - mA - ↑ mA ↓ mottle
3) slice thickness - thicker is better
