Midterm Test Flashcards

1
Q

What is the most effective method to reduce image blur due to pt movement?

A

Good Communication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Which of the following techniques will result in the highest pt dose?

A

Low kvp, high grid ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Which of the following describes grid ratio?

A

The height of the lead strips divided by the distance between them.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Which of the following will increase xray beam attenuation?

A

Increased tissue density & lower kvp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

As mAs decreases, the quantity of radiation reaching the IR?

A

Decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which interaction results in the most pt dose in diagnostic imaging?

A

Photoelectric effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which of the following interactions results in the production of fog?

A

Compton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

For characteristic radiation, an orbital electron must be removed from which shell to produce a useful xray photon?

A

K Shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How much total filtration is required for xray tubes that operate above 70kvp?

A

2.5mm Al

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What mA is necessary to produce 24 mAs if you select 0.06 seconds?

A

400mA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What can the radiographer do to reduce the appearance of noise on a radiographic image

A

Increase mAs & decrease grid ratio

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which of the following materials is commonly used for beam filtration?

A

Aluminum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

1Which of the following interactions between xray phtons & tissue results in the production of secondary xray photon?

A

Compton interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is PBL useful in radiography?

A

To reduce pt dose by limiting the size of the exposure to the size of the receptor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

A tech receives an exposure of40 mR at a distance of 6 feet from the source of exposure. What is the exposure if they were 3 feet from the source of the exposure?

A

160 mR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

To keep pt dose to a minimum, the tech should use?

A

Higher kVp, lower mAs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

An xray beam passes through tissue and loses some of its energy. This is known as?

A

Attenuation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

During a photoelectric interaction, the energy of the photoelectron ejected is = to?

A

Incident photon energy – binding energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If the SID Is doubled, what happens to the intensity of the xray beam?

A

Intensity decreases by a factor of 4.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What happens to the xray emission spectrum when the kvp is increased?

A

The amplitude increases and the spectrum shifts to the right.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which of the following occurs when a projectile electron undergoes a characteristic interaction?

A

An inner shell electron is ionized.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Which interaction, within the diagnostic range, does not involve the removal of an orbital electron?

A

Classical scattering.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Given the following set of exposure factors (40” SID, 200mA, 0.05 seconds, 70kvp, 0.5” OID), which change would result in the greatest increase in magnification?

A

4” OID

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

All of the following are true about Compton scattered photons, except?

A

If the scattered photon strikes the IR, it will provide useful info.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which factor listed results in images with a long scale of contrast?

A

Increased kVp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

If the mAs is too low and the number of photons reaching the IR is too few, the image will display which of the following?

A

More noise

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Which of the following is the term used to describe the blurring around the periphery of the image?

A

Penumbra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The energy of a scattered xray photon is?

A

less than the energy of the primary beam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Which of the following is a measure of beam quality?

A

Half value layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Which of the following describes the production of xrays due to a collision between an incident electron and a k shell electron?

A

Characteristic interaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Which of the following statements is true about xray interactions with matter?

A

Decreasing xray beam quality increases beam attenuation.

32
Q

Which of the following describes automatic variable aperture collimation?

A

PBL

33
Q

The xray beam that leaves the pt in the direction of the IR is often referred to as?

A

Remnant radiation and exit radiation

34
Q

Which of the following affect size distortion?

A

SID & OID

35
Q

Which of the following will result in the biggest increase in distortion on a radiographic image?

A

Increasing CR angle & decreasing SID?

36
Q

Which of the following interactions in the diagnostic range involves the total absorption of the incident photon?

A

Photodisintegration

37
Q

When using a wedge filter:

A

the thickest portion of the filter is placed over the thinnest part of the pt.

38
Q

Which of the following help reduce the amount of scattered radiation reaching the IR?

A

Increased collimation

39
Q

A thicker body part results in which of the following?

A

increased beam attenuation

40
Q

Which of the following occurs if there is not enough tube filtration?

A

An increase in high energy photons & increased pt dose

41
Q

An incident photon can be described as an xray photon that has:

A

not yet hit an object

42
Q

Which of the following statements regarding radiographic grids is true?

A

If the height of the grid strips increases, & the space between them decreases, the grid will be more efficient.

43
Q

A radiograph of an ankle is taken with the CR perpendicular to the IR but the ankle is not parallel to the IR. What type of distortion will be demonstrated on the image?

A

foreshortening

44
Q

The ability to distinguish between adjacent similar tissues best describes?

A

contrast resolution

45
Q

How much radiation can be attenuated by a high quality grid?

A

Up to 97%

46
Q

Which of the following sets of exposure factors would create the highest radiographic beam quality?

A

80kVp, 2.5 mm Al filtration

47
Q

When comparing low kVp techniques to high kVp techniques, which of the following is true?

A

Higher kVp results in fewer photon interactions & increased transmission.

48
Q

What is the purpose of a compensating filter?

A

to replace a radiographic grid

49
Q

Which of the following occurs when collimation is increased?

A

scatter radiation decreases & image contrast increases.

50
Q

The electrostatic attraction between an incident electron & the nucleus of an atom will result in the production of which of the following?

A

Bremsstrahlung xray photon

51
Q

Which of the following affects the amount of scatter radiation interacting with the IR, but does not affect the production of scatter radiation?

A

grid ratio

52
Q

A photon of 10 MeV colliding with a nucleus of an atom will likely result in which of the following interactions?

A

photodisintegration

53
Q

When you increase beam restriction, which of the following occurs?

A

pt dose decreases & image contrast increases

54
Q

A pt has an external fixation device on their lower extremity. This results in a large OID. What can the radiographer do to minimize the resultant distortion on the image?

A

Increase SID

55
Q

Which of the following factors will result in more xray beam transmission?

A

smaller body parts

56
Q

As the exposure field size increases, pt dose ___, due to ___.

A

increases, increased scatter

57
Q

How does filtration affect pt dose?

A

As filtration decreases, pt dose increases.

58
Q

Which of the following circumstances would require the use of a grid?

A

12cm part thickness

59
Q

Which of the following occurs when the volume of tissue irradiates is reduced?

A

decreased amount of scatter production

60
Q

An xray photon looses part of its energy when it interacts with an outer shell electron in a pts tissue. This is known as?

A

attenuation

61
Q

What is the relationship between mAs & pt dose?

A

Directly related

62
Q

The photoelectric effect results in an increased dose to the __, and results in a ___contrast image.

A

pt, high

63
Q

Grids are composed of lead strips & ?

A

aluminum interspace material
plastic fiber interspace material

64
Q

A tech is going to perform a portable abdomen xray on an ICU pt. Which of the following grids would be the most appropriate choice to use?

A

6:1 parallel grid

65
Q

The contrast on an image with a grid divided by the contrast on an image without a grid best describes which of the following?

A

contrast improvement

66
Q

Which of the following will result in the greatest pt radiation dose?

A

Changing from a lower to higher ratio grid

67
Q

Which interaction requires 1.02 MeV of energy?

A

pair production

68
Q

Which of the following exposure factors will result in the greatest exposure to the IR?

A

0.04 secs, 800 mA

69
Q

If collimation is reduced, the image contrast will ___ & the pt dose will____?

A

decrease, increase

70
Q

Which of the following describes how much technique or pt dose increases with the use of a grid?

A

bucky factor

71
Q

The amount of detail present in an image is known as?

A

spatial resolution

72
Q

All of the following help to reduce the production of scatter radiation, EXCEPT?

A

increasing grid ratio

73
Q

As the xray beam interacts with tissue some of the radiation will be absorbed in the tissue & some will be transmitted & strike the IR. This process is referred to as?

A

differential absorption

74
Q

The purpose of filtration is?

A

to remove high energy xray photons

75
Q

Which type of grid must be used at specific distances?

A

focused