Question 1

Which of the following obeys Lambert-Beer's law?

Accepted Answer

A)  A homogeneous beam of radiation 
B)  A heterogeneous beam of radiation 
C)  A polyenergetic beam of radiation 
D)  A polychromatic beam of radiation 
A)  A homogeneous beam of radiation 
B)  A heterogeneous beam of radiation 
C)  A polyenergetic beam of radiation 
D)  A polychromatic beam of radiation

Question 2

The radiation beam used by Hounsfield in his original experiments was:

Accepted Answer

A)  gamma rays. 
B)  X-rays. 
C)  cosmic rays. 
D)  microwaves. 
A)  gamma rays. 
B)  X-rays. 
C)  cosmic rays. 
D)  microwaves.

Question 3

The range of CT numbers in an image is called the:

Accepted Answer

A)  window width (WW). 
B)  window level (WL). 
C)  region of interest (ROI). 
D)  dynamic range. 
A)  window width (WW). 
B)  window level (WL). 
C)  region of interest (ROI). 
D)  dynamic range.

Question 4

Please match the following concepts for each group. All answer selections will be used just once.

-Cross-section or slice of tissue

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL 
A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL

Question 5

Which of the following is a limitation of CT 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 6

Please 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) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL 
A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL

Question 7

Data from the CT 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

Question 8

How many pixels make up a CT image whose matrix size is 512 * 512?

Accepted Answer

A)  100,000 
B)  1024 
C)  262,144 
D)  512 
A)  100,000 
B)  1024 
C)  262,144 
D)  512

Question 9

CT overcomes the limitations of radiography and conventional tomography by achieving all of the following except:

Accepted Answer

A)  reducing the problem of superimposition. 
B)  improving the contrast of the image. 
C)  using quantitative detectors and a computer. 
D)  reducing a patient's radiation dose. 
A)  reducing the problem of superimposition. 
B)  improving the contrast of the image. 
C)  using quantitative detectors and a computer. 
D)  reducing a patient's radiation dose.

Question 10

Please match the following concepts for each group. All answer selections will be used just once.

-Sections of image blur

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL 
A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL

Question 11

The Compton effect occurs largely in soft tissues.

Accepted Answer

A) True 
 B)False

Question 12

A scaling factor of 1000 in the Hounsfield scale (H scale) for K results in a:

Accepted Answer

A)  contrast scale of 0.2% per CT number. 
B)  contrast scale of 0.1 % per CT number. 
C)  contrast scale of 0.5% per CT number. 
D)  contrast scale of 0.8% per CT number. 
A)  contrast scale of 0.2% per CT number. 
B)  contrast scale of 0.1 % per CT number. 
C)  contrast scale of 0.5% per CT number. 
D)  contrast scale of 0.8% per CT number.

Question 13

Please 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) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL 
A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL

Question 14

If the FOV for an examination is 30 cm and the matrix size is 1024 * 1024, what is the approximate pixel size?

Accepted Answer

A)  25 mm 
B)  0.5 mm 
C)  0.3 mm 
D)  0.05 mm 
A)  25 mm 
B)  0.5 mm 
C)  0.3 mm 
D)  0.05 mm

Question 15

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

Accepted Answer

A)  per centimeter. 
B)  cm1. 
C)  1/cm. 
D)  per cmS1U1P1-2S1S1P0 
A)  per centimeter. 
B)  cm1. 
C)  1/cm. 
D)  per cmS1U1P1-2S1S1P0

Question 16

Data acquisition in CT 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 17

Please 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) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL 
A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL

Question 18

Please match the following concepts for each group. All answer selections will be used just once.

-Reduction of the X-ray intensity as the beam passes through the patient

Accepted Answer

A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL 
A) Radiography 
B) Heterogeneous beam 
C) WW 
D) Conventional tomography 
E) Homogeneous beam
F)Display device
G)Attenuation
H)Data acquisition
I)CT
J)WL

Question 19

The most obvious difference between CT and radiography is that:

Accepted Answer

A)  CT 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)  CT 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 20

When a beam of X-rays passes through the patient, the relative transmission or penetration measurement can be calculated by using which of the following?

Accepted Answer

A)  Log of the ratio of intensity of X-rays at the source to the intensity of the detector 
B)  Log of the ratio of the detector intensity to the source intensity 
C)  Ratio of the source intensity to the detector intensity 
D)  Ratio of the detector intensity to the source intensity 
A)  Log of the ratio of intensity of X-rays at the source to the intensity of the detector 
B)  Log of the ratio of the detector intensity to the source intensity 
C)  Ratio of the source intensity to the detector intensity 
D)  Ratio of the detector intensity to the source intensity

Which of the following obeys Lambert-Beer's law?

The radiation beam used by Hounsfield in his original experiments was:

The range of CT numbers in an image is called the:

Please match the following concepts for each group. All answer selections will be used just once. -Cross-section or slice of tissue

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

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

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

How many pixels make up a CT image whose matrix size is 512 * 512?

CT overcomes the limitations of radiography and conventional tomography by achieving all of the following except:

Please match the following concepts for each group. All answer selections will be used just once. -Sections of image blur

The Compton effect occurs largely in soft tissues.

A scaling factor of 1000 in the Hounsfield scale (H scale) for K results in a:

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

If the FOV for an examination is 30 cm and the matrix size is 1024 * 1024, what is the approximate pixel size?

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

Data acquisition in CT refers to:

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

Please match the following concepts for each group. All answer selections will be used just once. -Reduction of the X-ray intensity as the beam passes through the patient

The most obvious difference between CT and radiography is that:

When a beam of X-rays passes through the patient, the relative transmission or penetration measurement can be calculated by using which of the following?

Computed Tomography: an Overview

Digital Image Processing

Data Acquisition Concepts

Image Reconstruction

Iterative Reconstruction Basics

Basic Instrumentation

Image Postprocessing and Visualization Tools

Image Quality

Radiation Dose in Computed Tomography

Multislice Computed Tomography: Physical Principles and Instrumentation

Other Technical Applications of Computed Tomography Imaging: Basic Principles

Three-Dimensional Computed Tomography: Basic Concepts

Positron Emission Tomographyct Petct and Single-Photon Emission Computed Tomographyct Spectct Hybrid 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 3: Physical Principles of Computed Tomography

Which of the following obeys Lambert-Beer's law?

The radiation beam used by Hounsfield in his original experiments was:

The range of CT numbers in an image is called the:

Please match the following concepts for each group. All answer selections will be used just once. -Cross-section or slice of tissue

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

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

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

How many pixels make up a CT image whose matrix size is 512 * 512?

CT overcomes the limitations of radiography and conventional tomography by achieving all of the following except:

Please match the following concepts for each group. All answer selections will be used just once. -Sections of image blur

The Compton effect occurs largely in soft tissues.

A scaling factor of 1000 in the Hounsfield scale (H scale) for K results in a:

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

If the FOV for an examination is 30 cm and the matrix size is 1024 * 1024, what is the approximate pixel size?

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

Data acquisition in CT refers to:

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

Please match the following concepts for each group. All answer selections will be used just once. -Reduction of the X-ray intensity as the beam passes through the patient

The most obvious difference between CT and radiography is that:

When a beam of X-rays passes through the patient, the relative transmission or penetration measurement can be calculated by using which of the following?

Computed Tomography: an Overview

Digital Image Processing

Data Acquisition Concepts

Image Reconstruction

Iterative Reconstruction Basics

Basic Instrumentation

Image Postprocessing and Visualization Tools

Image Quality

Radiation Dose in Computed Tomography

Multislice Computed Tomography: Physical Principles and Instrumentation

Other Technical Applications of Computed Tomography Imaging: Basic Principles

Three-Dimensional Computed Tomography: Basic Concepts

Positron Emission Tomographyct Petct and Single-Photon Emission Computed Tomographyct Spectct Hybrid 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: