Deck 6: Image Reconstruction

Question 1

The Fourier reconstruction is used in both computed tomography and magnetic resonance imaging.

Answer 1

False

Question 2

Which of the following reconstruction algorithms was used by Hounsfield in his original experiments?

A)back projection
B)algebraic reconstruction technique
C)Fourier transform
D)filtered back projection

Answer 2

algebraic reconstruction technique

Question 3

Which of the following refers to a function that relates to the amplitude and phases of a sine wave and corresponds to a specific frequency?

A)Fourier transform
B)algorithm
C)convolution
D)interpolation

Answer 3

Fourier transform

Question 4

An algorithm is a set of rules for solving a problem.

Question 5

A set of ray sums is referred to as a:

A)ray sum
B)projection
C)total ray projection
D)view

Question 6

The result of the preprocessing of the signals from the computed tomography detectors is called:

A)convolved data
B)raw data
C)image data
D)back-projected data

Question 7

The signals that leave the computed tomography detectors are subject to preprocessing.

Question 8

A large cone beam will result in cone-beam artifacts.

Question 9

The basic problem with the back-projection algorithm is: I. the image is blurred and not useful
II) it compares assumptions with measured values
III) the image suffers from the star pattern artifact

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

Question 10

Which of the following is a digital image processing technique used to modify images through a filter function?

A)convolution
B)interpolation
C)back projection
D)projection filter

Question 11

Which is a mathematical technique used to estimate the value of a function from known values on either side of the function?

A)convolution
B)interpolation
C)back projection
D)projection ratio

Question 12

Hounsfield's first scanner used _________________ beam projections acquired through a 180-degree rotation.

A)perpendicular
B)parallel
C)long
D)short

Question 13

The algorithms for three-dimensional imaging are based on those used in computer graphics and visual perception science.

Question 14

The results of preprocessing are referred to as image data.

Question 15

Which of the following algorithms is most commonly used in state-of-the-art computed tomography scanners?

A)iterative algorithms
B)back projection
C)filtered back projection
D)Fourier reconstruction

Question 16

The algorithms for the single-slice and multislice computed tomography scanners with four detector rows are referred to as spiral/helical fan-beam approximation algorithms.

Question 17

The new generation of multislice computed tomography scanners requires modified image reconstruction algorithms.

Question 18

The Fourier transform is a technique for estimating a function from known values on both sides of it.

Question 19

Which of the following belongs to the class of analytical algorithms for computed tomography? I. back projection
II) filtered back projection
III) Fourier reconstruction

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

Question 20

Convolution kernels can be applied to any type of data.

Question 21

Please match the image reconstruction concepts. All answer selections will be used just once.

Interpolation

A)Set of rules for solving a problem
B)Mathematical technique of value estimation
C)Converts signals in the spatial domain to the frequency domain
D)Digital image processing
E)Linear superposition method

Question 22

The first operation to which raw data is subjected is referred to as:

A)convolution
B)back projection
C)three-dimensional surface shading
D)interpolation

Question 23

Which of the following will allow the user to interactively visualize, manipulate, and measure large three-dimensional objects on general-purpose workstations?

A)three-dimensional algorithms
B)interpolation algorithms
C)Fourier transform
D)three-dimensional convolution

Question 24

Image data are obtained:

A)after convolution
B)after preprocessing
C)after back projection
D)before back projection

Question 25

Which of the following cone beam algorithms are available for use with the new generation of multislice computed tomography scanners? I. exact cone-beam algorithms
II) filtered cone-beam algorithms
III) approximate cone-beam algorithms

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

Question 26

Which of the following refers to a defined set of instructions for solving a problem?

A)algorithm
B)Fourier transform
C)interpolation
D)convolution

Question 27

The use of __________ coefficients makes it possible to reconstruct an image in computed tomography.

A)Hounsfield
B)convolution
C)Fourier
D)Ambrose

Question 28

Please match the image reconstruction concepts. All answer selections will be used just once.

Convolution

A)Set of rules for solving a problem
B)Mathematical technique of value estimation
C)Converts signals in the spatial domain to the frequency domain
D)Digital image processing
E)Linear superposition method

Question 29

Please match the image reconstruction concepts. All answer selections will be used just once.

Fourier transform

A)Set of rules for solving a problem
B)Mathematical technique of value estimation
C)Converts signals in the spatial domain to the frequency domain
D)Digital image processing
E)Linear superposition method

Question 30

Please match the image reconstruction concepts. All answer selections will be used just once.

Algorithm

A)Set of rules for solving a problem
B)Mathematical technique of value estimation
C)Converts signals in the spatial domain to the frequency domain
D)Digital image processing
E)Linear superposition method

Question 31

Which of the following describes the beam that diverges from the x-ray tube to the outer edges of the detectors?

A)cone beam
B)aperture beam
C)straight beam
D)fan beam

Question 32

Filtered back projection is also referred to as the ______________ _______________.

A)convolution method
B)interpolation method
C)algorithm method
D)iterative method

Question 33

Please match the image reconstruction concepts. All answer selections will be used just once.

Algorithm

A)Set of rules for solving a problem
B)Mathematical technique of value estimation
C)Converts signals in the spatial domain to the frequency domain
D)Digital image processing
E)Linear superposition method

Question 34

Which of the following removes the classical star pattern (blur) of the back-projection algorithm? I. filtered back projection
II) interpolation
III) convolution

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

Question 35

Which of the following algorithms compares an assumption with the measured values, makes corrections, and then repeats the process?

A)analytical reconstruction algorithms
B)back projection
C)iterative reconstruction algorithms
D)Fourier reconstruction algorithms