Filtratrion Flashcards

1
Q

What is the function of FILTRATION?

A

Eliminates undesirable low energy X-ray photons by absorbing materials into the primary beam

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2
Q

What is the Half Value Layer? (HVL)

A

Amount of filtration needed to reduce the beam to half of its original intensity

Below 51 = 0..5 Al/Eq
51-70 = 1.5 Al/Eq
Above 70 = 2.5 Al/Eq

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3
Q

What is the standard filtering material?

A

Aluminum (Al/Eq)
(Al/Eq = Aluminum Equivalency)

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4
Q

In x-ray machines that operate between 51-70 kvp, the minimum amount of required filtration is?

A

1.5 Al/Eq

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5
Q

In x-ray machines that operate below 51 kvp, the minimum amount of required filtration is?

A

0.5 Al/Eq

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6
Q

A filter made of one or more material is called?

A

Compound Filter

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7
Q

In x-ray machines that operate above 70 kvp the minimum amount of required filtration is?

A

2.5 Al/Eq

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8
Q

Increasing the thickness of a filter will _____ patient dose

(Increase, decrease, not affect)

A

Decrease

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9
Q

Any material designed to selectively absorb photons from the X-ray beam is called a ?

A

Filter

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10
Q

Thoraeus filter combines these 3 materials
(List all 3)

A
  1. Tin
  2. Copper
  3. Aluminum
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11
Q

Filtration that is a result of the composition of the tube and housing is called ?

A

Inherent Filtration

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12
Q

Which material can be used as a compensating filter material? (List all 3)

A
  1. Clear Pb or plastics
  2. Saline
  3. Aluminum
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13
Q

Problems of uneven image receptor exposure due to heel effect is solved by a ___ ?

A

Compensating Filter

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14
Q

How do you find the average energy?

A

Add up all of the photons and divide by the # of photons

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15
Q

Does peak energy ever change?

A

No

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16
Q

Should the average energy be higher or lower than the original intensity after filtering?

A

Higher

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17
Q

True or False
The thickest portion of the wedge filter is placed over the less dense part of the patient

A

True

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18
Q

Does filtering soften or harden?

A

Harden

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19
Q

What is total filtration?

A

The sum of inherent and added filtration

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20
Q

When more than one filtering material is used, as in a compound filter, how are the materials arranged in relationship to the X-ray source?

A

Compound filters place the HIGHEST atomic number material closest to the tube and the LOWEST atomic number material closest to the patient

The final layer is aluminum

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21
Q

What is the final layer?

A

Aluminum

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22
Q

What is aluminum’s atomic number?

A

13

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23
Q

Filtration hardens or softens the X-ray beam?

A

Hardens

24
Q

What is the purpose of filtration?

A

To protect the patient

25
Q

Filtration ____ the average energy of the X-ray beam

(Increases, decreases, doesn’t affect)

A

Increases

26
Q

Filtration _____ the peak energy of the X-ray beam

(Increases, decreases, doesn’t affect)

A

Doesn’t affect

27
Q

Filtration _____ the intensity of the X-ray beam

(Decreases, increases, doesn’t affect)

A

Decreases

28
Q

Filter that reduces intensity of x-ray beam to half its initial amount is called ?

A

Half value layer (HVL)

29
Q

The sum of inherent and added filtration is called?

A

Total Filtration

30
Q

List 5 types of filtration

A
  1. Inherent
  2. Added
  3. Total
  4. Compound
  5. Compensating
31
Q

Any filtration that occurs on the outside of the tube and housing and before the image receptor is called ?

A

Added filtration

32
Q

What kind of compensating filter can be used when radiographing the lungs and mediastinum?

A

Trough

33
Q

Which curve on the chart is considered filtration?

A

The smaller one

34
Q

The atomic number 13 is ____?

A

Aluminum

35
Q

In mammography tubes, the glass window or the tube is replaced with ____ to reduce patient skin exposure.

A

Beryllium

36
Q

What is added filtration?

A

Any filtration that occurs outside of the tube and housing

37
Q

What is the collimators average Al/Eq for added filtration?

A

1mm

38
Q

Where does most of the filtration come from in added filtration?

A

The silver of the mirror

39
Q

What is inherent filtration?

A

The result of the composition of the tube and housing

40
Q

What does inherent filtration consist of? (What parts are considered filtering)

A
  1. Thickness of glass envelope (most comes from here)
  2. Dielectric oil
  3. Glass window
41
Q

Where does most filtration come from with inherent filtration?

A

Window of the glass envelope

42
Q

Total inherent filtration = ____ Al/Eq

A

0.5 - 1mm Al/Eq

43
Q

Tube aging _____ inherent filtration

(Decreases, increases, doesn’t affect)

A

Increases

44
Q

What is compensating filtration?

A

Designed to solve a problem involving unequal subject DENSITIES

45
Q

Is compensating filtration a radiation protection device?

A

NO

46
Q

List 2 of the most popular compensating filters

A
  1. Wedge filter
  2. Trough filter
47
Q

How does filtration affect patient dose and beam intensity?

A
  1. Filtration reduces patient exposure dose by eliminating low energy X-ray photons from the primary beam
  2. To compensate for loss of exposure; when filtration is increased, technical factors must be increased to maintain the same image receptor exposure
48
Q

To compensate for loss of exposure, when filtration is _____, technical factors must be _____ to maintain the same image receptor exposure

(Decrease, increase)

A

Increase, increase

49
Q

The layer farthest from the patient and closest to the source is made up of _____ ?

A

Copper

50
Q

The highest atomic number material is closest to the ____?

A

Tube (far from patient)

51
Q

The lowest atomic number material is closest to the ____?

A

Patient

52
Q

What is compound filtration?

A

When 2 or more materials in 1 filter that compliment one another in their absorbing abilities

53
Q

What does each layer absorb in compound filtration?

A

Each layer absorbs characteristic photons created by the previous layer

54
Q

What is compound filtration also referred to as?

A

K-edge

55
Q

Give me 2 different definitions of filtration

A
  1. Process of eliminating undesirable low X-ray photons by absorbing materials into primary beam
                                  OR
  2. Process of increasing the average energy of the X-ray beam by taking out low energy X-rays
    (Also known as hardening)
56
Q

Not only does filtration reduce patient exposure dose by eliminating low-energy photons from the primary x-ray beam, it also removes a portion of the useful beam. To compensate for the loss of film density when filtration is increased, technical factors must be
(decreased/increased/not changed)
_____________________________________________
to maintain the same radiographic density.

A

Increased

57
Q

In order to produce a uniform density radiograph of anatomy that has different thicknesses and/or different subject densities a (n) ________________filter should be used.

A

Compensating