Question 1

Data from the computed tomography detectors are first sent to the _________ before going to the computer.

Accepted Answer

A) array processor 
B) host computer 
C) back projector 
D) digitizers 
A) array processor 
B) host computer 
C) back projector 
D) digitizers D

Question 2

Which of the following is not true of a homogeneous beam of radiation?

Accepted Answer

A) all the photons have different energies 
B) all the photons have the same energy 
C) equal thicknesses of the absorber remove equal amounts of radiation 
D) equal thicknesses of the absorber remove different amounts of radiation 
A) all the photons have different energies 
B) all the photons have the same energy 
C) equal thicknesses of the absorber remove equal amounts of radiation 
D) equal thicknesses of the absorber remove different amounts of radiation A

Question 3

Match the following concepts for each group. All answer selections will be used just once.
-All photons have the same energy

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography 
A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography E

Question 4

Match the following concepts for each group. All answer selections will be used just once.
-Range of computed tomography numbers

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography 
A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography

Question 5

Match the following concepts for each group. All answer selections will be used just once.
-Cathode ray tube

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography 
A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography

Question 6

The second step of data acquisition is scanning.

Accepted Answer

A) True 
 B)False

Question 7

Which of the following is used to calculate computed tomography numbers?

Accepted Answer

A) computed tomography number = $\mu$ water + $\mu$ tissue * K 
B) computed tomography number = $\mu$ tissue - $\mu$ water *K/$\mu$ tissue 
C) computed tomography number = $\mu$water - $\mu$ tissue *K/$\mu$water 
D) computed tomography number = $\mu$ tissue - $\mu$ water *K/$\mu$ water 
A) computed tomography number = $\mu$ water + $\mu$ tissue * K 
B) computed tomography number = $\mu$ tissue - $\mu$ water *K/$\mu$ tissue 
C) computed tomography number = $\mu$water - $\mu$ tissue *K/$\mu$water 
D) computed tomography number = $\mu$ tissue - $\mu$ water *K/$\mu$ water

Question 8

The most obvious difference between computed tomography and radiography is that:

Accepted Answer

A) computed tomography shows cross-sectional images or transaxial anatomy 
B) radiography uses sodium iodide detectors 
C) a computer is used to produce the film in radiography 
D) radiography shows cross-sectional images 
A) computed tomography shows cross-sectional images or transaxial anatomy 
B) radiography uses sodium iodide detectors 
C) a computer is used to produce the film in radiography 
D) radiography shows cross-sectional images

Question 9

Data acquisition in computed tomography refers to:

Accepted Answer

A) acquiring the information from the detectors 
B) acquiring the information from the computer 
C) acquiring information from the patient by using special motions of the x-ray tube and detectors 
D) processing the information from the patient 
A) acquiring the information from the detectors 
B) acquiring the information from the computer 
C) acquiring information from the patient by using special motions of the x-ray tube and detectors 
D) processing the information from the patient

Question 10

The limitations of conventional tomography include all of the following except:

Accepted Answer

A) superimposition of structures above and below the focal plane 
B) image blur from movement of the tube and film 
C) contrast degradation from the open beam geometry 
D) the presence of ghost images on the film 
A) superimposition of structures above and below the focal plane 
B) image blur from movement of the tube and film 
C) contrast degradation from the open beam geometry 
D) the presence of ghost images on the film

Question 11

Computed tomography overcomes the limitations of radiography and conventional tomography by: I. reducing the problem of superimposition
II. improving the contrast of the image
III. using quantitative detectors and a computer

Accepted Answer

A) I and II 
B) II and III 
C) I and III 
D) I, II, and III 
A) I and II 
B) II and III 
C) I and III 
D) I, II, and III

Question 12

Which of the following is a limitation of computed tomography compared with conventional radiography?

Accepted Answer

A) decreased spatial resolution 
B) increased contrast resolution 
C) decreased patient dose 
D) decreased visualization of artifacts 
A) decreased spatial resolution 
B) increased contrast resolution 
C) decreased patient dose 
D) decreased visualization of artifacts

Question 13

Match the following concepts for each group. All answer selections will be used just once.
-Collecting data from the patient

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography 
A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography

Question 14

The computed tomography number for water is:

Accepted Answer

A) -1000 
B) -100 
C) 0 
D) 100 
A) -1000 
B) -100 
C) 0 
D) 100

Question 15

Match the following concepts for each group. All answer selections will be used just once.
-All photons do not have the same intensity

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography 
A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography

Question 16

The field of view is:

Accepted Answer

A) the reconstruction circle 
B) the region of interest 
C) a mathematical technique 
D) a digital processing technique 
A) the reconstruction circle 
B) the region of interest 
C) a mathematical technique 
D) a digital processing technique

Question 17

The range of computed tomography numbers in an image is called the:

Accepted Answer

A) window width 
B) window level 
C) region of interest 
D) dynamic range 
A) window width 
B) window level 
C) region of interest 
D) dynamic range

Question 18

A computed tomography image of 12 bits per pixel means :

Accepted Answer

A) each pixel can have a total of 4096 shades of gray 
B) the matrix is 4096* 4096 
C) the pixel size is 12 mm 
D) the voxel size is 12 mm 
A) each pixel can have a total of 4096 shades of gray 
B) the matrix is 4096* 4096 
C) the pixel size is 12 mm 
D) the voxel size is 12 mm

Question 19

The unit of the linear attenuation coefficient ($\mu$) is:

Accepted Answer

A) per centimeter 
B) cm1 
C) 1/cm 
D) per cm-2 
A) per centimeter 
B) cm1 
C) 1/cm 
D) per cm-2

Question 20

Match the following concepts for each group. All answer selections will be used just once.
-Superimposition of structures

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography 
A) Radiography 
B) Heterogeneous beam 
C) Window width 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)Computed tomography

Data from the computed tomography detectors are first sent to the _________ before going to the computer.

Which of the following is not true of a homogeneous beam of radiation?

Match the following concepts for each group. All answer selections will be used just once. -All photons have the same energy

Match the following concepts for each group. All answer selections will be used just once. -Range of computed tomography numbers

Match the following concepts for each group. All answer selections will be used just once. -Cathode ray tube

The second step of data acquisition is scanning.

Which of the following is used to calculate computed tomography numbers?

The most obvious difference between computed tomography and radiography is that:

Data acquisition in computed tomography refers to:

The limitations of conventional tomography include all of the following except:

Computed tomography overcomes the limitations of radiography and conventional tomography by: I. reducing the problem of superimposition II. improving the contrast of the image III. using quantitative detectors and a computer

Which of the following is a limitation of computed tomography compared with conventional radiography?

Match the following concepts for each group. All answer selections will be used just once. -Collecting data from the patient

The computed tomography number for water is:

Match the following concepts for each group. All answer selections will be used just once. -All photons do not have the same intensity

The field of view is:

The range of computed tomography numbers in an image is called the:

A computed tomography image of 12 bits per pixel means :

The unit of the linear attenuation coefficient ( $\mu$ ) is:

Match the following concepts for each group. All answer selections will be used just once. -Superimposition of structures

Computed Tomography: An Overview

Introduction to Computers

Digital Image Processing

Data Acquisition Concepts

Image Reconstruction

Basic Instrumentation

Image Postprocessing and Visualization Tools

Image Quality

Radiation Dose in Computed Tomography

Single-Slice Spiralhelical Computed Tomography: Physical Principles and Instrumentation

Multislice Spiralhelical Computed Tomography: Physical Principles and Instrumentation

Other Technical Applications of Computed Tomography Imaging: Basic Principles

Three-Dimensional Computed Tomography: Basic Concepts

Virtual Reality Imaging

Positron Emission Tomographycomputed Tomography Scanners

Computed Tomography of the Head, Cerebral Vessels, Neck, and Spine

Computed Tomography of the Body

Pediatric Computed Tomography

Quality Control for Computed Tomography Scanners

Filters

Exam 4: Physical Principles of Computed Tomography

Data from the computed tomography detectors are first sent to the _________ before going to the computer.

Which of the following is not true of a homogeneous beam of radiation?

Match the following concepts for each group. All answer selections will be used just once. -All photons have the same energy

Match the following concepts for each group. All answer selections will be used just once. -Range of computed tomography numbers

Match the following concepts for each group. All answer selections will be used just once. -Cathode ray tube

The second step of data acquisition is scanning.

Which of the following is used to calculate computed tomography numbers?

The most obvious difference between computed tomography and radiography is that:

Data acquisition in computed tomography refers to:

The limitations of conventional tomography include all of the following except:

Computed tomography overcomes the limitations of radiography and conventional tomography by: I. reducing the problem of superimposition II. improving the contrast of the image III. using quantitative detectors and a computer

Which of the following is a limitation of computed tomography compared with conventional radiography?

Match the following concepts for each group. All answer selections will be used just once. -Collecting data from the patient

The computed tomography number for water is:

Match the following concepts for each group. All answer selections will be used just once. -All photons do not have the same intensity

The field of view is:

The range of computed tomography numbers in an image is called the:

A computed tomography image of 12 bits per pixel means :

The unit of the linear attenuation coefficient ( μ\muμ ) is:

Match the following concepts for each group. All answer selections will be used just once. -Superimposition of structures

Computed Tomography: An Overview

Introduction to Computers

Digital Image Processing

Data Acquisition Concepts

Image Reconstruction

Basic Instrumentation

Image Postprocessing and Visualization Tools

Image Quality

Radiation Dose in Computed Tomography

Single-Slice Spiralhelical Computed Tomography: Physical Principles and Instrumentation

Multislice Spiralhelical Computed Tomography: Physical Principles and Instrumentation

Other Technical Applications of Computed Tomography Imaging: Basic Principles

Three-Dimensional Computed Tomography: Basic Concepts

Virtual Reality Imaging

Positron Emission Tomographycomputed Tomography Scanners

Computed Tomography of the Head, Cerebral Vessels, Neck, and Spine

Computed Tomography of the Body

Pediatric Computed Tomography

Quality Control for Computed Tomography Scanners

Filters

The unit of the linear attenuation coefficient ( $\mu$ ) is: