Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DH 120 - Radiography > LO 2 > Flashcards

LO 2 Flashcards

1
Q

_______ of the wave determines penetrating power of the beam

A

Wavelength - shorter wavelengths= more penetrating power

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

Quality is used to describe ______

A

Mean energy or penetrating power of the x-ray beam

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

Quality of the x-ray beam is controlled by ______

A

The kilovoltage

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

Voltage is the measure of electrical _______

A

Force

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

Describe kilovoltage peak

A
  1. Maximum peak voltage of an alternating current (Ac)
  2. Regulates the speed and energy of the electrons and determines penetrating ability
  3. Increasing results in a higher energy beam (shorter wavelengths)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When kVp is increase, what happens to x-ray quality, density, and contrast?

A

Quality ⬆️
Density ⬆️
Contrast ⬇️

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

Describe density

A

The overall darkness of a film - kVp increases, film will appear darker

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

Describe contrast

A

How sharply dark and light areas are differentiated on film

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

Low kilovoltage settings (65-70kvp) creates _______ contrast film

A

High

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

Low contrast images created by higher kVp setting are good for detecting ______

A

Periodontal periapical disease

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

Exposure time is measured in ______

A

Impulses

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

When kVp increases, exposure time should _______

A

Decrease

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

Quantity refers to _______

A

The number of x-rays produced in the x-ray unit (controlled by mA - 7-15)

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

When mA is increased, exposure time is to be decreased to maintain constant ______

A

Density

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

A higher miliamperage setting _______ the temperature of the cathode filiment

A

Increases - results in more electrons boiling off

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

All dental x-ray machines have these three exposure factor settings

A
  1. kV
  2. mA
  3. Time
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

When miliamperage is increased, describe quantity, density, and exposure time

A

Quantity ⬆️
Density ⬆️
Exposure time ⬇️

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

How can kilovoltage and miliamperage increase intensity of the beam?

A
  1. Kilovoltage - can increase speed of electrons travelling between anode and cathode, resulting in a beam with more energy
  2. Miliamperage - can increase the number of electrons produced, resulting in more x-rays being produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does exposure time affect the intensity of the beam?

A

Longer exposures allow for the creation of more x-rays, resulting in a more intense beam

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

How is x-ray intensity measured/calculated?

A

Intensity = 1/d^2

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

What are the 5 factors that affect intensity of the x-ray beam?

A
  1. kVp
  2. mA
  3. Exposure time
  4. Distance
  5. Filters
22
Q

What are the 3 distances to consider when taking an x-ray?

A
  1. Target-surface (source to patient’s skin)
  2. Target-object (source to tooth)
  3. Target-film (source to film)
23
Q

When x-rays travel from their point of origin, they diverge and spread over a larger area. What happens to the intensity of the beam?

A

Decreases

24
Q

What is the inverse square law?

A

The intensity of radiation is inversely proportional to the square of the distance from the source of radiation

25
Q

When the distance of the beam is doubled, the beam is ______

A

1/4 as intense

26
Q

When the distance is halved, the beam is _______

A

4 time more intense

27
Q

Describe the half-value layer

A

The thickness of a specified material that reduces the intensity by half (aluminum discs)

28
Q

What is the benefit of filtering long, low-energy x-rays from the beam?

A

Increases mean penetrating power while reducing intensity

29
Q

What are the two types of x-ray machines?

A

Intraoral and extraoral

30
Q

______ is a device used to hold and align intraoral dental x-ray receptors in the mouth

A

Receptor holder

31
Q

___________ is an instrument used to help position the PID relative to the tooth and receptor

A

Beam alignment device (XCP or BAI)

32
Q

What do collimating devices do?

A

Can be retrofitted onto a PID to restrict the size of the beam

33
Q

What part of a radiograph is most radiolucent?

A

Black areas - show mostly air around the tooth

34
Q

What part of a radiograph is most radiopaque?

A

White areas - resists passage of x-ray beam

35
Q

What are the visual charactersistocs of a radiograph

A

Density and contrast

36
Q

What are the geometric characteristics of a radiograph?

A

Sharpness, magnification, distortion

37
Q

What are the 4 influencing factors of density (or the overall darkness) of a radiograph?

A
  1. mA
  2. kVp
  3. Exposure time
  4. Subject thickness
38
Q

The difference in degrees of blackness between adjacent areas of a radiograph is ________

A

Contrast

39
Q

What is the only influencing factor of contrast?

A

kVp

40
Q

Short scale contrast is ______

A

High contrast

41
Q

Long scale contrast is

A

Low contrast

42
Q

Short scale contrast occurs at ______ kVp

A

Low

43
Q

Long scale contrast occurs at _____ kVp

A

High

44
Q

Sharpness, also known as resolution or definition, is the capability of the x-ray film to ______

A

Reproduce distinct outlines of an object

45
Q

The lack of image sharpness present in every radiograph is known as _______

A

Penumbra

46
Q

What are the influencing factors of sharpness?

A
  1. Focal spot size - smaller focal spot = sharper image
  2. Film composition - smaller crystals = greater sharpness
  3. Movement - film or patient could move causing loss of sharpness
47
Q

_______ results from the divergent paths of the x-ray beam as they radiate from the focal spot

A

Magnification

48
Q

What are the influencing factors of magnification?

A
  1. Target-film distance - longer means less magnification
  2. Object-film distance - decrease means less magnification

Tooth and x-ray film should always be placed as close together as possible

49
Q

________ is a variation in the true size and shape of an object being radiographed and results from unequal magnification of different parts of the same object

A

Distortion

50
Q

What are the influencing factors of distortion?

A
  1. Object-film alignment - must be parallel
  2. x-ray beam angulation - beam must be perpendicular to tooth and film

DH 120 - Radiography (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions