CT Procedures Unit 1 Questions with
Accurate Answers
Define computed tomography and the individual whom was awarded the Nobel
Prize for the invention correct answer Imaging modality that can produce a cross
sectional tomographic plane of any part of the body- Cormick and Hounsfield
Define Hounsfield Scale also identify the number used to identify the following
elements: Water Bone & Air correct answer Measure of beam attenuation
capability of a specific structure.
Water: 0
Bone: 1000
Air: -1000
Define the following computer tomography terminology: Pixel, Voxel, Matrix
correct answer Pixel: Picture element- 2D square element
Voxel: 3D picture element
Matrix: Rows and columns of pixels
Define the purpose of the following detector efficiencies: Capture, absorption and
conversion efficiency correct answer Capture efficiency: How well the detectors
receive photons from the patient. Depends on detector size and distance
between detectors
, Absorption efficiency: How well the detectors convert incoming x-ray photons.
Depends on tube material used and thickness of detectors
Conversion efficiency: How well the detector converts the absorbed photon info
to a digital signal for the computer.
Define the term extravasation. correct answer Leakage of a vessel into a tissue
Define the term osmolality. correct answer # of particles in solution, per unit
liquid compared to that of blood
Describe the importance slip ring technology had on helical or spiral imaging
correct answer Provides continuous scanning power to the x-ray system
Describe the medications used to reduce or eliminate allergic effects. correct
answer Epinephrine, Benadryl, Allegra, Diphenhydramine, Lidocaine
Describe the purpose of the "bow tie" filter used in computed tomography
correct answer Provides a more uniform beam intensity
Explain detector dose efficiency and the three factors in which it is composed.
correct answer How efficient the detector is at capturing an x-ray and is
controlled by capture efficiency, absorption efficiency, and conversion efficiency
Explain the difference between reconstructing and reformatting an image in
computed tomography. correct answer Reconstruction- Images that are digitized
using an algorithm in which the image was already received by computer , uses
raw data (puts filter on the image-lung window)
Accurate Answers
Define computed tomography and the individual whom was awarded the Nobel
Prize for the invention correct answer Imaging modality that can produce a cross
sectional tomographic plane of any part of the body- Cormick and Hounsfield
Define Hounsfield Scale also identify the number used to identify the following
elements: Water Bone & Air correct answer Measure of beam attenuation
capability of a specific structure.
Water: 0
Bone: 1000
Air: -1000
Define the following computer tomography terminology: Pixel, Voxel, Matrix
correct answer Pixel: Picture element- 2D square element
Voxel: 3D picture element
Matrix: Rows and columns of pixels
Define the purpose of the following detector efficiencies: Capture, absorption and
conversion efficiency correct answer Capture efficiency: How well the detectors
receive photons from the patient. Depends on detector size and distance
between detectors
, Absorption efficiency: How well the detectors convert incoming x-ray photons.
Depends on tube material used and thickness of detectors
Conversion efficiency: How well the detector converts the absorbed photon info
to a digital signal for the computer.
Define the term extravasation. correct answer Leakage of a vessel into a tissue
Define the term osmolality. correct answer # of particles in solution, per unit
liquid compared to that of blood
Describe the importance slip ring technology had on helical or spiral imaging
correct answer Provides continuous scanning power to the x-ray system
Describe the medications used to reduce or eliminate allergic effects. correct
answer Epinephrine, Benadryl, Allegra, Diphenhydramine, Lidocaine
Describe the purpose of the "bow tie" filter used in computed tomography
correct answer Provides a more uniform beam intensity
Explain detector dose efficiency and the three factors in which it is composed.
correct answer How efficient the detector is at capturing an x-ray and is
controlled by capture efficiency, absorption efficiency, and conversion efficiency
Explain the difference between reconstructing and reformatting an image in
computed tomography. correct answer Reconstruction- Images that are digitized
using an algorithm in which the image was already received by computer , uses
raw data (puts filter on the image-lung window)
