Ch. 3 TEST MATERIAL Flashcards

1
Q

The atomic number of iodine is:

A

53

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2
Q

The atomic number of barium is:

A

56

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3
Q

Place the following tissue densities in order of easiest to hardest to penetrate by x-ray:

Lung
Muscle
Fat
Bone

A

Lung
Fat
Muscle
Bone

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4
Q

The total reduction in the number of x rays remaining in an x ray beam after penetration through a given thickness of tissue is called:

A

attenuation

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5
Q

Place the following tissue densities in order of hardest to easiest to penetrate by X-ray:

Lung
Muscle
Fat
Bone

A

Bone
Muscle
Fat
Lung

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6
Q

Coherent scattering is an interaction between low energy x rays and _____

A

Whole atoms

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7
Q

An x ray image results from the difference between those x rays absorbed photoelectrically in the patient and those transmitted to the image receptor.
This difference in x ray interaction is called ____

A

Differential absorption

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8
Q

air is considered a negative contrast agent
True or False

A

True because it appears dark on an image due to low-density

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9
Q

X rays throughout the diagnostic range can undergo an interaction with outer-shell electrons that not only scatters the x ray but reduces its energy and ionizes the atoms as well.
This interaction is called:

A

Compton Scatter

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10
Q

What type of x-ray interaction with matter is the source of most of the occupational radiation exposure that radiographers receive?

A

Compton Scattering

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11
Q

How could you decrease quantum noise in a digital image?
(fill in the bank on the test)

A

Increase mAs

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12
Q

The principal source of radiographic fog is _______.

A

scatter

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13
Q

How can a technologist compensate for the involuntary motion of the patient?

A

Short exposure time

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14
Q

Which factor has the greatest effect on size distortion?

A

OID

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15
Q

Which factor would cause an increase in spatial resolution?

A

long SID

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16
Q

The two types of shape distortion are:

A

Elongation and Foreshortening

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17
Q

High contrast; short scale or long scale?

A

Short scale ( few shades of gray)
long low lots of gray

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18
Q

What is considered to be the most detrimental to spatial resolution and the number one cause of repeat X-rays?

A

Motion blur

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19
Q

Fat tissue absorbs less radiation than muscle because fat tissue has a lower:

A

density

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20
Q

As compared to the patient with a 24 cm thick abdomen, imaging a patient with a 30 cm thick abdomen will result in ___________ scatter being produced and ________ image contrast

A

more, lower

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21
Q

Due to the anode heel effect, radiation intensity can vary by as much as:
(fill in the blank on the test)

A

45 Percent

22
Q

What is defined as the range of exposure intensity that an IR can accurately detect?

A

Dynamic Range

23
Q

An increase in kVp will have what effect on digital imaging?
- More Scatter?
- Higher Exposure Rate?
- Lower Contrast?

A

ALL THREE
- More Scatter
- More Exposure
- Less Contrast

24
Q

What controls contrast on an image?
(fill in the blank on the test)

A

kVp

25
Q

What controls the density or brightness on an image?
(fill in the blank on the test)

A

mAs

26
Q

What would be an example of a low-contrast image?
(fill in the blank on the test)

A

Abdomen

27
Q

What interaction is only dependent on the energy of the photon?

A

Compton

28
Q

Unwanted exposure to the IR due to scatter radiation is called:

A

Fog

29
Q

What is another name for the invisible image on the image receptor before processing?

A

Latent Image

30
Q

What is another name for the invisible image after processing?

A

Manifest image or visible image

31
Q

What kind of radiation has passed through the patient and on the way to the IR?

A

Remnant Radiation

32
Q

Digital radiography has better or worse contrast when compared to conventional?

A

Better

33
Q

What kind of radiography has the highest spatial resolution?
(fill in the blank on test)

A

Film or Digitial Mammo

34
Q

Digital radiography has a shorter or wider dynamic range when compared to conventional radiography

A

Wider

35
Q

When the x-ray photon travels completely through the patient or through the part without an interaction is it called:

A

Transmission

36
Q

The photoelectric effect involves the removal (ejection) of an electron. This process of removing an electron from an atom is known as:

A

Ionization

37
Q

Visibility of the image is dependent on what two factors?

A

Contrast and Spatial Resolution

38
Q

As tissue thickness increases, what happens to scatter attenuation?

A

scatter attenuation also increases

39
Q

What reduces image contrast?

A

Compton Scattering

40
Q

What interaction with matter acts independently of the atomic number of tissue?

A

Compton

41
Q

the photoelectric absorption of x-rays produces the ____ areas in a radiograph.

A

White

42
Q

Compton scatter X-rays can be deflected in any direction, including 180 degrees from the incident x-ray?
true or false

A

True

43
Q

A photoelectric interaction can not occur unless the incident x-ray has equal to or greater energy than the electron binding energy?

True or False

A

True

44
Q

The result of coherent scatter is the change in the direction of the x-ray without a change in its energy.

True or False

A

True

45
Q

X-rays scattered back in the direction of the incident X-ray beam is called ________.

A

Backscatter radiation

46
Q

X rays in the diagnostic range undergo ionizing interactions with inner shell electrons. The x-ray is not scattered but is totally absorbed. This process is called:

A

Photoelectric Effect

47
Q

The x ray image is a product of absorption and transmission. True or False

A

True

48
Q

High-contrast images display…

A

fewer shades of gray but greater difference among them

49
Q

Low-contrast images display….

A

a greater number of gray shades but smaller differences among them

50
Q

____ is the loss of some energy from the x ray beam as it passes through the imaged tissue.

A

attenuation