Computed Tomography Exam Prep Material Newest
2025/2026 Complete All Questions And Correct Detailed
Answers (Verified Answers)|Brand New Version!
CT basics - CORRECT ANSWER=• Essentially an x-ray tube that rotates round the pt
• Table moves, feeding pt into the gantry
• Each large is data collected as a series of slices
o Each slice is divided into voxels (volume elements)
Each sweep of the source-detector around the body during CT is called a _____. - CORRECT
ANSWER=translation
Each CT projection records variations in ____. - CORRECT ANSWER=mass density and
effective atomic number
Each CT projection is ____.
1. printed on film
2. stored on the computer
3. displayed on the monitor - CORRECT ANSWER=stored on the computer
The cross-sectional anatomy is translated into ____ during CT reconstruction. - CORRECT
ANSWER=a matrix of values
,The first generation of computed tomography used ______ detector (s). - CORRECT
ANSWER=one
The principal drawback of the first-generation CT scanner was the ____. - CORRECT
ANSWER=long scanning time
What is windowing? - CORRECT ANSWER=A method in which the CT image gray scale can
be manipulated in order to enhance different structures of varying tissues
What are the 2 windowing mechanisms? - CORRECT ANSWER=- Window width
- Window level
What is Window Width (WW)? - CORRECT ANSWER=- The range of the CT numbers in the
image
- Determines the maximum number of shades of gray that can be displayed on the CT monitor
- Effects contrast
What is Window Level (WL)? - CORRECT ANSWER=- The center or midpoint of the range of
CT numbers
- Effects brightness
Wide window widths (400 to 2000 HU) are necessary for ____? - CORRECT
ANSWER=Varying body tissues
Narrow window widths (50 to 350 HU) are necessary for ____? - CORRECT
ANSWER=Different tissues of similar densities
,What are the effects of WW on image contrast? - CORRECT ANSWER=- As the WW
increases, the contrast decreases
- As the WW decreases, the contrast increases
What are the effects of WL on image brightness? - CORRECT ANSWER=- Moving the WL
toward the higher CT numbers results in a darker image
- Moving the WL toward the lower CT numbers results in a brighter image
What is a multi-slice scanner (MSCT)? - CORRECT ANSWER=- CT system equipped with a
multiple-row detector array to simultaneously collect data at different slice locations
- Can scan up to 64 slices
In CT, the attenuated image-forming radiation is detected by what? - CORRECT ANSWER=A
solid state image receptor
What is Helical CT? - CORRECT ANSWER=- Continuous gantry rotation + continuous table
feed
- Scan data traces a helical path or spiral around patient
What is Isotropic Imaging? - CORRECT ANSWER=2D pixel in a CT image represents a 3D
voxel
Name the 3 types of Data acquisition systems? - CORRECT ANSWER=- Conventional
, - Helical single slice (spiral)
- Multi-slice
What is a Linear Attenuation coefficient? - CORRECT ANSWER=Characterizes how easily a
volume of material can be penetrated by the x-rays
What is a bowtie filter? - CORRECT ANSWER=Used to allow a uniform beam to reach
detectors
What occurs with CT filtration? - CORRECT ANSWER=- Removes long wavelength x-rays
which contributes to patient dose
- Shapes the energy distribution across the radiation beam to produce uniform beam hardening
when x-rays pass through the filter and the object causing beam hardening artifacts
What is pitch? What is the formula? - CORRECT ANSWER=Relationship between the patient
couch movement and the x-ray beam collimation and is expressed as a ratio
Pitch = Couch movement each 360 degrees / Slice Thickness
How do different structures appear on CT? - CORRECT ANSWER=- Bone and high density
structures, such as radiopaque contrast media, appear white
- Air and other low density structures appear black
- Fat and organs appear in varying shades of gray
2025/2026 Complete All Questions And Correct Detailed
Answers (Verified Answers)|Brand New Version!
CT basics - CORRECT ANSWER=• Essentially an x-ray tube that rotates round the pt
• Table moves, feeding pt into the gantry
• Each large is data collected as a series of slices
o Each slice is divided into voxels (volume elements)
Each sweep of the source-detector around the body during CT is called a _____. - CORRECT
ANSWER=translation
Each CT projection records variations in ____. - CORRECT ANSWER=mass density and
effective atomic number
Each CT projection is ____.
1. printed on film
2. stored on the computer
3. displayed on the monitor - CORRECT ANSWER=stored on the computer
The cross-sectional anatomy is translated into ____ during CT reconstruction. - CORRECT
ANSWER=a matrix of values
,The first generation of computed tomography used ______ detector (s). - CORRECT
ANSWER=one
The principal drawback of the first-generation CT scanner was the ____. - CORRECT
ANSWER=long scanning time
What is windowing? - CORRECT ANSWER=A method in which the CT image gray scale can
be manipulated in order to enhance different structures of varying tissues
What are the 2 windowing mechanisms? - CORRECT ANSWER=- Window width
- Window level
What is Window Width (WW)? - CORRECT ANSWER=- The range of the CT numbers in the
image
- Determines the maximum number of shades of gray that can be displayed on the CT monitor
- Effects contrast
What is Window Level (WL)? - CORRECT ANSWER=- The center or midpoint of the range of
CT numbers
- Effects brightness
Wide window widths (400 to 2000 HU) are necessary for ____? - CORRECT
ANSWER=Varying body tissues
Narrow window widths (50 to 350 HU) are necessary for ____? - CORRECT
ANSWER=Different tissues of similar densities
,What are the effects of WW on image contrast? - CORRECT ANSWER=- As the WW
increases, the contrast decreases
- As the WW decreases, the contrast increases
What are the effects of WL on image brightness? - CORRECT ANSWER=- Moving the WL
toward the higher CT numbers results in a darker image
- Moving the WL toward the lower CT numbers results in a brighter image
What is a multi-slice scanner (MSCT)? - CORRECT ANSWER=- CT system equipped with a
multiple-row detector array to simultaneously collect data at different slice locations
- Can scan up to 64 slices
In CT, the attenuated image-forming radiation is detected by what? - CORRECT ANSWER=A
solid state image receptor
What is Helical CT? - CORRECT ANSWER=- Continuous gantry rotation + continuous table
feed
- Scan data traces a helical path or spiral around patient
What is Isotropic Imaging? - CORRECT ANSWER=2D pixel in a CT image represents a 3D
voxel
Name the 3 types of Data acquisition systems? - CORRECT ANSWER=- Conventional
, - Helical single slice (spiral)
- Multi-slice
What is a Linear Attenuation coefficient? - CORRECT ANSWER=Characterizes how easily a
volume of material can be penetrated by the x-rays
What is a bowtie filter? - CORRECT ANSWER=Used to allow a uniform beam to reach
detectors
What occurs with CT filtration? - CORRECT ANSWER=- Removes long wavelength x-rays
which contributes to patient dose
- Shapes the energy distribution across the radiation beam to produce uniform beam hardening
when x-rays pass through the filter and the object causing beam hardening artifacts
What is pitch? What is the formula? - CORRECT ANSWER=Relationship between the patient
couch movement and the x-ray beam collimation and is expressed as a ratio
Pitch = Couch movement each 360 degrees / Slice Thickness
How do different structures appear on CT? - CORRECT ANSWER=- Bone and high density
structures, such as radiopaque contrast media, appear white
- Air and other low density structures appear black
- Fat and organs appear in varying shades of gray
