Physics Ch 8 Flashcards

1
Q

Roentgens (or grays) are the measurement for x-ray ____.

A
  • quantity
  • exposure
  • intensity
  • all of the above (correct answer, your response)
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2
Q

The number of x-rays in the useful beam defines x-ray _____.

A

quantity

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3
Q

Standard x-ray machines produce about ______ mR/mAs at 70 kVp measured at 100 cm SID.

A

5

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4
Q

X-ray quantity increases in direct proportion to increases in ______.

A

mAs

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5
Q

If the distance from the source to the image (SID) is reduced by half, how is the x-ray intensity at the image affected?

A

It is increased 4 times

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6
Q

If filter thickness is ____, then x-ray intensity is ______.

A
  • reduced, reduced
  • increased, reduced
  • reduced, increased
  • both b and c (correct answer)
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7
Q

A 10% increase in kVp has ____ effect on x-ray intensity than/as a 10% increase in mAs.

A

much greater

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8
Q

If x-ray quantity is doubled, the optical density on the finished radiograph will be ______.

A

increased by a factor of two

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9
Q

If a technologist changes the technique from 70 kVp @ 200 mAs to 70 kVp @ 400 mAs, the x-ray intensity will _____ and optical density will _____.

A

double, double

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10
Q

The inverse square law has the same effect on optical density and x-ray ______.

A

intensity
• expousure
• quantity
• all the above (correct answer

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11
Q

An increase of 15% in kVp is equivalent to increasing mAs _____.

A

100%

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12
Q

If the intensity of a 70 kVp exposure at 2 mAs is 100 mR, what would be 25 mR at 5 mAs?

A

25mR

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13
Q

If an exposure is 50 mR at an SID of 40 inches, what would the exposure be at an SID of 60 inches?

A

22.2 mR

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14
Q

X-ray intensity is proportional to ______

A

kVp^2

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15
Q

The penetrability of an x-ray beam is called x-ray ________.

A

quality

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16
Q

An x-ray that could pass through thick tissue would have high ____.

A
  • penetrability
  • quality
  • quantity
  • both A and B (correct answer)
17
Q

A low quality beam would also have low _______

A

penetrability

18
Q

Beam quality is affected by ____.

A

kVp and filtration

19
Q

The half value layer (HVL) of an x-ray beam is a measurement of beam ______.

A

quality

20
Q

Image contrast is affected by _______.

A
  • beam quality
  • kVp
  • mAs
  • both A and B (correct answer)
21
Q

The HVL is lowered by a decrease in ______.

A

kVp

22
Q

X-ray beam quality is improved by ______.

A

increasing filtration

23
Q

The main purpose of added filtration is to reduce _____.

A

beam penetrability

24
Q

Added filtration will ____ beam quality and _______ beam quantity.

A

increase, decrease

25
Q

A compensation filter is used to create _____ optical density with a body part of ______ thickness.

A

uniform, non-uniform