MODULE 2

Question 1

• 1st reconstruction algorithm
• also called summation method or linear superposition method
• 1st used by Oldendorf 1961 & Kuhl and Edwards 1963

Answer 1

Back-projection Algorithm

Question 2

process: ray sum data acquired from each projection (data sample) is projected back onto a matrix

Answer 2

Back-projection Algorithm

Question 3

problem: low spatial resolution
blurring & produces star pattern artifact

Answer 3

Back projection Algorithm

Question 4

• designed to remove star pattern artifact
• also called as convolution method

Answer 4

Filter Back-projection

Question 5

process of applying filter to an attenuation profile is called

Answer 5

conduction/ kernel

Question 6

filter function can only be applied to:

Answer 6

raw data

Question 7

p < 1

Answer 7

oversampling

Question 8

p > 1

Answer 8

undersampling

Question 9

p = 0

Answer 9

xray beams are contiguous for adjacent rotations

Question 10

2 types of data:

Answer 10

Raw data
Image data

Question 11

• no assigned value yet

Answer 11

Raw data

Question 12

automatically produced during scanning

Answer 12

Prospective Reconstruction

Question 13

process of generating new image after scanning

Answer 13

Retrospective Reconstruction

Question 14

reduction of the intensity of a beam of radiation as it passes through an object—some photons are absorbed, but others are scattered.

Answer 14

Attenuation

Question 15

what was utilized to tackle the prominent undesirable apperance in the 1st reconstruction algorithm?

Answer 15

Filtered back projection

Question 16

what mathematical method will you use if you have missing data?

Answer 16

Interpolation

Question 17

other term for back projection?

Answer 17

linear superposition method

Question 18

downsides of back projection?

Answer 18

blurring
low spatial resolution
star pattern artifact