Brainscape's Knowledge GenomeTM

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


See full index

Oral Radiology > Projection Geometry: Intraoral Radiographic Technique- 9/19- DONE over powerpoint but add study guide stuff > Flashcards

Projection Geometry: Intraoral Radiographic Technique- 9/19- DONE over powerpoint but add study guide stuff Flashcards

1
Q

Geometric characteristics include: (3)

A
  1. image sharpness
  2. image magnification
  3. image shape distortion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Fuzzy, unsharp margin of radiographic image:

A

unsharpness

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

Penumbra:

A

unsharp margin of the image

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

umbra:

A

shadow

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

We want to minimize ____ or maximize ____

A

unsharpness; sharpness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the 3 rules to maximize sharpness?

A
  1. Radiation source should be as small as possible
  2. Source- to-object distance should be as long as possible
  3. Object-to-receptor distance should be as short as possible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the benefit of having a smaller focal spot?

A

Fewer x-ray photons that interact with the edge of the object leading to a sharper image

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

The source is the ____, when referring to “source-to-object”

A

focal spot

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

The closer the object is tot he focal spot, the more___ the x-ray photons are that are going to interact with the edge of the tooth

A

divergent

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

The shorter the source-to-object distance, the greater the ___ meaning ____

A

penumbra; the greater the unsharpness of the margin

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

How do we control the course-to-object distance?

A

by the length of the cone

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

We prefer to use a ___ cone than a ___ cone because the x-rays that interact with the object are more parallel which will maximize sharpness.

A

longer cone; shorter cone

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

You want the object or tooth to be as close to the ____ as possible

A

image receptor

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

We have greater ____ with longer object-to-receptor distance

A

Penumbra

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

The equal enlargement of the object:

A

magnification

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

2 rules to minimize magnification include:

A
  1. source-to-object distance should be as long as possible
  2. Object-to-receptor distance should be as short as possible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Enlargement of radiographic image, compared to actual size of the object:

A

magnification

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

With magnification, the image shows the:

A

true shape of the object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

If the distance of the source to the tooth is short, then the x-rays that interact with the tooth will be fairly ____ leading to ____.

A

divergent; greater magnification

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

If the distance of the source to the tooth is longer, then the x-rays in the beam that interact with the tooth will be more ____ leading to less ____.

A

parallel; magnification

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

Unequal enlargement:

A

distortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Variation from tube shape of object:

A

distortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Shape distortion has more to do with ___ than ___.

A

angles; distances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Unequal magnification of parts of an object:

A

distortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Distortion can be caused by:

A

improper alignment of receptor, object, or beam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the rules for minimizing shape distortion? (2)

A
  1. object and receptor should be parallel
  2. beam should be perpendicular to object & receptor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

CR in the diagrams stands for:

A

central ray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

The radiographic image of the object is shorter than the object itself

A

foreshortening

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Tooth is not parallel to the receptor and beam directed perpendicular can lead to what type of shape distortion? (2)

A

foreshortening & elongation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

The radiographic image is longer than the object itself:

A

elongation

31
Q

5 rules for accurate image formation:

A
  1. focal spot as small as possible
  2. source-object distance as long as possible (cone length)
  3. Object-receptor distance as short as possible (Film placement)
  4. object parallel to receptor (image receptor placement)
  5. beam perpindicular to object and receptor
32
Q

Projection techniques for periodical radiography include: (2)

A
  1. paralleling technique: use long cone
  2. bisecting angle technique: use long or short cone
33
Q

What are the two steps for the paralleling technique?

A
  1. receptor parallel to tooth
  2. beam perpendicular to tooth
34
Q

In the paralleling technique when having the receptor parallel to the tooth, we want ____ object-receptor distance, and ___ source-receptor distance

A

increased; increased

35
Q

What balances out the increased object-receptor distance when using the paralleling technique?

A

increased source-to-receptor distance (minimizing unsharpness & magnification)

36
Q

What type of cone is used to increase the source-to-receptor distance using the paralleling technique?

A

Long cone

37
Q

Getting the image receptor parallel to the teeth allows for correct ____ angulation

A

vertical

38
Q

If you are using the XCP correctly and you line up the beam with the cone, the x-ray beam will image:

A

entire area of interest (no cone cuts)

39
Q

Cone cut shows up on the radiograph as:

A

white area

40
Q

Getting a cone cut means you automatically have to retake the image (T/F)

A

False; as long as you obtain the area of interest

41
Q

In a PA radiograph, we want ___ mm of bone around the apices

A

2-3mm (pretty sure)

42
Q

If the contacts are open in the areas of interest this tells us that ____ angulation was correct

A

horizontal

43
Q

The ____ technique is the preferred technique but the ____ technique may be used if the first choice technique does not work.

A

paralleling technique; bisecting angle technique

44
Q

With he bisecting angle technique, you are not trying to get the image receptor parallel to the tooth, you are just trying to get it ___ to the tooth

A

close

45
Q

The bisecting angle technique is based on:

A

The rule of isometry

46
Q

In the bisecting angle technique, if two triangles have two equal angles and a common side, then:

A

the two triangles are equal

47
Q

The bisecting angle technique states that the angle formed by the plane of the tooth and plane of receptor is bisected and the beam is directed ____ to the bisecting line

A

perpendicular

48
Q

The ____ technique has more limitations than the ____ technique

A

bisecting angle technique; paralleling technique

49
Q

Why is the paralleling technique preferred technique over the bisecting angle technique?

A

a little more distortion with the bisecting angle technique

50
Q

The bitewing is used to see:

A

crowns, inter proximal bone levels, alveolar bone support, caries, periodontal condition, calculus, crown margins

51
Q

Bitewings are not used to view:

A

periapical regions of the tooth

52
Q

Bitewing technique: The ___ angle is more of a challenge than the ____ angle.

A

horizontal; vertical

53
Q

In the bitewing technique, you’d like to us a ____ vertical angulation

A

slightly positive (+5 to10 degrees depending on location)

54
Q

If the horizontal angulation is incorrect in the bitewing technique, then the image will display:

A

overlapping contacts

55
Q

____ includes periapical and bitewing radiographs showing all teeth:

A

full mouth series

56
Q

When viewing radiographs, what’s on the providers right is actually the patients:

A

left

57
Q

Radiographic localization includes: (2)

A
  1. right angle method
  2. tube shift method (SLOB)
58
Q

The right angle method states that:

A

if you take radiographs at right angles to each other of the areas of interest you can localize the area in question

59
Q

If you take radiographs at right angles to each other of the areas of interest, you can localize the area in question:

A

right angle methodT

60
Q

Same Lingual Opposite Buccal:

A

SLOB rule

61
Q

Tube shift method may also be called:

A

SLOB rule

62
Q

In the tube shift method, you will take a second radiograph of the same area but alter the ____.

A

horizontal angulation

63
Q

In the tube shift method, if you take the first radiograph straight on, you may take the second radiograph ____ (for example)

A

mesially

64
Q

If the object moves in the same direction as what you moved the tubehead, then the object is ____ to the reference point (SAME)

A

lingual

65
Q

If you take a straight on view of the premolars and you see the lesion apical to the apex, you rotate the tube head mesially, and the the lesion now moved distal to the apex of the tooth. This is the example of:

A

Opposite- buccal

66
Q

The tube shift method technique, you can move the tube ___ or ____ on the second image.

A

mesially or distally (potentially even vertically)

67
Q

First radiograph: supernumerary tooth overlapping the mesial of the root of the second molar

Move tube mesially

Second radiograph: the supernumerary tooth now does not overlap the mesial root of the second molar (shifted slightly mesial),

This means the lesion is:

A

lingual

68
Q

SLOB stands for:

A

same lingual opposite buccal

69
Q

shadow; the image of the object we receive

A

umbra

70
Q

Edge gradient; the unsharp area; area around the margins of the object

A

penumbra

71
Q

What do we try to minimize when taking radiographs?

A

penumbra

72
Q

How do we minimize penumbra?

A

by having an increased source to object ratio

73
Q

3 factors that affect the

A

Oral Radiology (21 decks)

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