Deck 17: Digital Radiographic Technique

Question 1

Spatial frequency is used to describe the quality of spatial resolution in terms of _____________.

A) pixel size
B) modular transfer function
C) line pairs
D) contrast resolution

Answer 1

line pairs

Question 2

If a digital radiography imaging system has a spatial resolution of 10 lp/mm, what is the pixel size of that system?

A) 0.05 mm
B) 0.5 mm
C) 0.1 mm
D) 0.01 mm

Answer 2

0.05 mm

Question 3

If there were such thing as a perfect imaging system, the MTF would be equal to ________.

A) five
B) one
C) two
D) four

Answer 3

one

Question 4

The two principal characteristics of a medical image are _______________________.

A) spatial resolution and noise
B) spatial resolution and contrast resolution
C) contrast resolution and modular transfer function
D) contrast resolution and dynamic range

Question 5

The portion of useful image-forming x-rays is referred to as the ___________.

A) frequency
B) MTF
C) signal
D) noise

Question 6

As spatial frequency increases, the object size _____ and the spatial resolution _____.

A) increases, increases
B) decreases, decreases
C) decreases, increases
D) increases, decreases

Question 7

In digital imaging, spatial resolution is ultimately limited by ___________________.

A) focal spot size
B) spatial frequency
C) contrast resolution
D) pixel size

Question 8

Screen-film radiography has a dynamic range of __________.

A) 10
B) 100
C) 1000
D) 10,000

Question 9

Image detail is also called _______________________.

A) spatial resolution
B) spatial frequency
C) signal-to-noise ratio
D) dynamic range

Question 10

What is the spatial frequency of a digital system that can resolve 100 µm?

A) 5 lp/mm
B) 10 lp/mm
C) 50 lp/mm
D) 100 lp/mm

Question 11

The number of gray shades that an imaging system can reproduce is called its ________________.

A) spatial frequency
B) contrast
C) spatial resolution
D) dynamic range

Question 12

The human visual system can distinguish ________ shades of gray.

A) 10
B) 30
C) 300
D) 1000

Question 13

The ________________ digital imaging system uses the highest dynamic range.

A) computed tomography
B) mammography
C) magnetic resonance
D) angiography

Question 14

Of all radiographic imaging systems, _____________ has the best contrast resolution.

A) digital radiography
B) mammography
C) magnetic resonance imaging
D) computed tomography

Question 15

The use of two screens in imaging results in a higher _______.

A) spatial frequency
B) pixel size
C) MTF
D) spatial resolution

Question 16

If a digital system has a spatial resolution of 4 lp/mm, it can resolve an object as small as _____ mm.

A) 8
B) 4
C) 0.25
D) 0.125

Question 17

A _______________ test tool is used to acquire data for an MTF curve.

A) bar pattern
B) post-processing
C) signal-to-noise ratio
D) contrast-detail curve

Question 18

Recent studies have shown that denser breast tissue is best imaged with _____________________.

A) xerography
B) computed tomography
C) screen-film mammography
D) digital mammography

Question 19

As mAs is increased the signal-to-noise ratio is ____________.

A) decreased
B) increased
C) not affected
D) doubled

Question 20

The bit capacity of each pixel identifies the ___________ of a digital imaging system.

A) dynamic range
B) gray scale
C) spatial frequency
D) MTF

Question 21

With digital imaging, patient dose can be reduced by using higher ______ techniques.

A) mAs
B) kVp
C) optical density
D) contrast

Question 22

Digital radiography images should be repeated if there is a problem with _________.

A) contrast
B) overexposure
C) brightness
D) None of the above

Question 23

The use of an image receptor with _____ DQE can result in _____ patient doses. I. low, lower
II) high, lower
III) high, higher
IV) low, higher

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

Question 24

DQE is __________________.

A) density quantum effect
B) direct quantum efficiency
C) detective quantum efficiency
D) detective quantum energy

Question 25

If an image receptor has a high probability of interacting with the x-ray beam, then it has a high _______.

A) DQE
B) SNR
C) MTF
D) lp/mm