Week 7- Chapter 15 Flashcards

1
Q

Where is milliamperage adjusted?

A

By the technologist on the console

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2
Q

What does milliamperage control?

A

Resistance in the wire leading to the filament

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2
Q

What happens to electrons when mA is increased?

A

The flow of electrons are increased and the filament heats up which allows more electrons to be boiled off

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3
Q

What impact does an increase in mA have on photon quantity?

A

Increases the quantity (intensity)

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4
Q

What is the proportional relationship between mA and photons?

A

Directly proportional

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5
Q

What controls the intensity of the x-ray beam?

A

The mA station on the console

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6
Q

If mA is doubled how many x-rays will be produced?

A

X-rays will be doubled

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7
Q

How is exposure time measured?

A

In seconds (usually milliseconds)

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8
Q

What is exposure?

A

The amount of time the beam is activated

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9
Q

What is the proportional relationship between exposure and intensity?

A

Directly proportional

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10
Q

What is the proportional relationship between mA and time?

A

They are inversely proportional

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11
Q

If you want to maintain an exposure, how would mA or time be adjusted?

A

Raise mA and lower time OR raise time and lower mA

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12
Q

What is the formula for reciprocity law?

A

mAo x so = mAn x sn

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13
Q

How does the reciprocity law work?

A

The product of mA and time must yield the same mAs to maintain a specific exposure

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14
Q

How is mAs defined?

A

The product of milliamperage and seconds

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15
Q

What is the primary factor of exposure?

A

mAs

16
Q

What does a primary factor mean?

A

Its the preferred way to adjust exposure

17
Q

What is the mAs formula?

A

mA x time = mAs

18
Q

What causes quantum mottle?

A

A lack of exposure

19
Q

What are examples of a lack of exposure?

A

Low mAs, less photon/quanta

20
Q

What is quantum mottle?

A

A grainy appearance, which is a form of noise on an image

21
Q

When does mottle show more?

A

When an image is magnified which is why its important to look at exposure indicator

22
Q

Which systems have noise levels exaggerated in images?

A

Digital systems

23
Q

How do digital systems create exaggerated levels of noise?

A

Amplify signals from pixels

24
Q

How should technologists ensure proper exposure to the IR?

A

Minimize mAs and enter enough kVp to penetrate the part

25
Q

How does mAs affect dose?

A

It directly affects dose

26
Q

How can mAs be realized in imaging?

A

By looking at exposure indicator numbers

27
Q

Is mAs a factor in determining contrast?

A

No because its an electrical factor which can’t be related to recognizability features

28
Q

What does mAs control in an image?

A

Intensity of an exposure, which bears upon brightness and quantum mottle

29
Q

How does motion show in a radiograph?

A

Shows like blur

30
Q

How can motion be reduced in an image?

A

By reducing exposure time

31
Q

What are different types of motion?

A

Movement of hands or peristaltic waves of the esophagus

32
Q

How can motion be reduced in a patient?

A

Communicate with a patient, lower time and increase mA

33
Q

What is milliamperage a unit for measuring?

A

Rate of electrical current flowing during an exposure

34
Q

How does angling the x-ray beam distort the image?

A

Causes elongation

35
Q

What is another way shape distortion can be achieved on an image?

A

By off-centering the beam

36
Q

How does angling the part distort the image?

A

Causes foreshortening