Deck 27: Contrast

Question 1

The recorded detail of a radiographic image is visible because of

A)sufficient contrast.
B)sufficient density.
C)window level.
D)both a and b

Answer 1

both a and b

Question 2

Contrast decreases with

A)excessive density.
B)inadequate density.
C)a wider range of densities.
D)all of the above

Answer 2

all of the above

Question 3

The concept of contrast as it is displayed on a soft-copy monitor for digital images is described as

A)window width.
B)dynamic range.
C)contrast width.
D)window range.

Answer 3

dynamic range.

Question 4

Which type of radiograph provides the most information?

A)an image with quantum mottle
B)high contrast images
C)low density images
D)low contrast images

Question 5

The principal controlling factor of contrast is

A)kVp.
B)mAs.
C)focal spot size.
D)anode angle.

Question 6

A radiograph that demonstrates considerable differences between densities is called

A)long scale.
B)low contrast.
C)high contrast.
D)all of the above

Question 7

As kVp increases, the percentage of Compton interactions _______ and contrast_______.

A)decreases; decreases
B)decreases; increases
C)increases; decreases
D)increases; increases

Question 8

As kVp ____, a ____ range of photon energies is produced.

A)increases; wider
B)increases; narrower
C)decreases; wider
D)decreases; longer

Question 9

Which generator type results in the greatest decrease in contrast?

A)single-phase, 2-pulse
B)three-phase, 6-pulse
C)three-phase, 12-pulse
D)high frequency

Question 10

The difference between two adjacent densities is

A)recorded detail.
B)quantum mottle.
C)radiographic contrast.
D)distortion.

Question 11

A radiograph that demonstrates considerable differences between densities is called

A)short scale.
B)high contrast.
C)increased contrast.
D)all of the above

Question 12

As the slope of the D log E curve ____, contrast ____.

A)increases; decreases
B)decreases; increases
C)increases; increases
D)moves closer to vertical; decreases

Question 13

Contrast increases with all of the following EXCEPT

A)decreased kVp.
B)decreased field size.
C)decreased part thickness.
D)increased scatter.

Question 14

A radiograph that demonstrates minimal differences between densities is called

A)long scale.
B)low contrast.
C)decreased contrast.
D)all of the above

Question 15

A radiograph that demonstrates minimal differences between density shades is called

A)short scale.
B)low contrast.
C)high contrast.
D)all of the above

Question 16

Image receptor contrast is expressed as the ____ of the D log E curve.

A)slope
B)toe
C)shoulder
D)straight line

Question 17

Which of the choices below does not increase contrast?

A)increasing grid ratio
B)increasing the amount of irradiated tissue
C)decreasing filtration
D)decreasing kVp

Question 18

A radiograph with few shades of gray exhibits

A)low contrast.
B)high contrast.
C)medium contrast.
D)long scale contrast.

Question 19

When the tissue structure of the ankle joint is considered, the dramatic tissue differences between the muscles and bones of the ankle produce

A)high subject contrast.
B)low subject contrast.
C)high radiographic density.
D)low radiographic density.

Question 20

High contrast is directly related to

A)the number of photoelectric interactions.
B)high kVp.
C)the amount of Compton scatter.
D)mAs.

Question 21

Match the following terms with the correct statement below.
high contrast

A)average gradient
B)long scale contrast
C)Compton interactions
D)low contrast
E)short scale contrast
F)high contrast
G)photoelectric interactions
H)subject contrast

Question 22

When choosing between two radiographic grids, the k factor is different.Choosing a grid with the higher K factor will produce an image with

A)longer scale contrast.
B)high contrast.
C)improved recorded detail.
D)a lower S#.

Question 23

After completing a radiograph using 27 mAs at 90 kVp, the image demonstrates adequate overall density but an area that is underpenetrated.In order to produce an optimum image in terms of contrast and penetration, the repeat image should be taken at

A)27 mAs and 100 kVp.
B)54 mAs and 77 kVp.
C)13 mAs and 94 kVp.
D)27 mAs and 94 kVp.

Question 24

Match the following terms with the correct statement below.
fewer shades of gray across the final image

A)average gradient
B)long scale contrast
C)Compton interactions
D)low contrast
E)short scale contrast
F)high contrast
G)photoelectric interactions
H)subject contrast

Question 25

What should you expect to occur with a decrease in kVp?

A)longer scale contrast
B)more Compton interactions
C)lower contrast
D)more photoelectric interactions

Question 26

The total amount of irradiated material is a function of

A)tissue thickness and body position.
B)body part thickness and area of exposure.
C)field size and anode angle.
D)body position and focal spot size.

Question 27

Depending upon the kVp range, a visible change in contrast will not be seen unless kVp is minimally changed

A)2-3%.
B)4-12%.
C)25%.
D)50%.

Question 28

A increase in x-ray beam filtration

A)increases the number of Compton interactions.
B)reduces contrast.
C)increases the average photon energy.
D)all of the above

Question 29

Match the following terms with the correct statement below.
used to calculate slope of the H and D curve

A)average gradient
B)long scale contrast
C)Compton interactions
D)low contrast
E)short scale contrast
F)high contrast
G)photoelectric interactions
H)subject contrast

Question 30

In order to reduce patient entrance skin exposure (ESE), higher kVp exposures are a consideration.It is important to remember that

A)kVp values that are too high reduce density and recorded detail.
B)kVp values that are too high produce more scatter and reduce contrast.
C)a significant loss of image contrast is not a reason to avoid higher kVp values in order to reduce ESE.
D)the digital processing software will correct for any kVp value regardless of how high it is in value.

Question 31

Match the following terms with the correct statement below.
the same as low contrast

A)average gradient
B)long scale contrast
C)Compton interactions
D)low contrast
E)short scale contrast
F)high contrast
G)photoelectric interactions
H)subject contrast

Question 32

All of the following factors would affect radiographic contrast EXCEPT

A)field size.
B)SID and OID.
C)receptor characteristics.
D)focal spot selection.

Question 33

When digital imaging receptors are used,

A)kVp is not a consideration.
B)radiographic grids are not necessary.
C)an exposure at 90 kVp would require a grid.
D)Compton scatter is not a factor.

Question 34

kVp controls the proportional relationship

A)mAs and kVp.
B)Compton and photoelectric interactions.
C)photoelectric and characteristic interactions.
D)SID and patient thickness.

Question 35

With digital imaging systems, the primary factors affecting final image contrast are the

A)window level and brightness.
B)histogram and look-up-table (LUT).
C)EI numbers and grid ratio.
D)kVp and mAs.

Question 36

Match the following terms with the correct statement below.
contributing factor to total image contrast

A)average gradient
B)long scale contrast
C)Compton interactions
D)low contrast
E)short scale contrast
F)high contrast
G)photoelectric interactions
H)subject contrast

Question 37

Match the following terms with the correct statement below.
responsible for high contrast densities on images

A)average gradient
B)long scale contrast
C)Compton interactions
D)low contrast
E)short scale contrast
F)high contrast
G)photoelectric interactions
H)subject contrast

Question 38

A fluoroscopic examination that uses barium as a contrast material would typically produce images with

A)long scale contrast.
B)short scale contrast.
C)low contrast.
D)both a and c