Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

SU14 - Radiology Exam 2 > su14_-_radiology_exam_2_20141210195322 > Flashcards

su14_-_radiology_exam_2_20141210195322 Flashcards

1
Q

What type of light is used to see each other and read?

A

reflected light

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

What type of light is used to interpret radiographs (film and digital)?

A

transmitted light

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

Incident light (total light from source such as view box or illuminator) is partly: ____, ____ and ____.

A

transmitted, absorbed, and reflected

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

When viewing a radiograph, do you want a white or a black background and surroundings?

A

black

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

What is the most active component of radiographic film?

A

AgBr

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

When exposed to x-rays (or visible light), ____ is ____ which, after processing, is converted to ____.

A
  • AgBr- ionized- metallic silver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The greater the amount of radiation that reaches the film, the ____ the amount of metallic silver (Ag) forms.

A

greater

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

What is the color of metallic silver (Ag) on a radiograph?

A

black

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

Parts of the film receiving more radiation appear ____ (darker/lighter) while those receiving less radiation appear ____ (darker/lighter).

A
  • darker- lighter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

If we processed an unexposed film, how would it appear?

A

clear because no AgBr was ionized

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

If we processed a film exposed to substantial amount of x-radiation, how would it appear?

A

black

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

Digital receptors have ____ electrons.

A

trapped

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

In digital receptors, the higher the concentration of trapped electrons, the ____ (higher/lower) the density.

A

higher

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

Is radiolucent a darker or lighter section on a radiograph?

A

darker

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

To make a radiolucent part of a radiograph, ____ (more/less) x-rays will reach the image receptor, ____ (more/less) metallic Ag will form or ____ (more/less) trapped electrons, and a ____ (darker/lighter) image will appear.

A
  • more- more- more- darker
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

To make a radioopaque part of a radiograph, ____ (more/less) x-rays will reach the image receptor, ____ (more/less) metallic Ag will form or ____ (more/less) trapped electrons, and a ____ (darker/lighter) image will appear.

A
  • less- less- less- lighter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Radiolucency and -opacity always refer to nature and characteristic of a ____.

A

object (not to be confused with radiographic density which refers to the blackness or darkness of an area of a film)

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

What is the definition of radiographic density (D)?

A

the blackness or darkness of an area of film; deals with the whole radiograph; may have values 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, etc.

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

What is the usable range of radiograph density?

A

0.25-2.5

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

What is the definition of radiographic contrast?

A

refers to the observed differences in adjoining radiographic densities OR difference in densities between light and dark regions on a radiograph

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

What does good radiographic contrast enable us to do?

A

enables us to differentiate one structure from another, if they differ in density, thickness, and/or chemical composition; helps differentiate between normal and carious enamel, normal and abnormal bone, etc.

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

What is the difference between high and low contrast?

A
  • high contrast: differences between adjoining radiographic densities are greater- low contrast: differences are smaller
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

High contrast is synonymous with a ____ (short/long) scale contrast or in other words, ____ (more/less) shades of gray.

A
  • short scale contrast- less shades of gray
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Low contrast is synonymous with a ____ (short/long) scale contrast or in other words, ____ (more/less) shades of gray.

A
  • long scale contrast- more shades of gray
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

If you are trying to look at an image with a lot of different densities, you want a ____ (higher/lower) contrast because you want ____ (more/less) shades of gray.

A
  • lower- more
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

True or false: Extraoral radiographic examinations constitutes majority of dental imaging.

A

FALSE. INTRAORAL radiographic examinations constitutes the majority of dental imaging.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the 3 categories of intraoral radiographs?

A
  • periapical (PA)- bitewing (BW)- occlusal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What does a full-mouth series consist of?

A

14-17 periapical images4 bitewings

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

What are the criteria (4) for quality images?

A
  • adequate diagnostic quality- completely covers the area of interest- least amount of magnification and distortion- optimal density and contrast
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

True or false: You retake a radiograph only if required information is not of diagnostic quality.

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What are the 2 projection techniques that may be used for periapical radiography?

A
  • paralleling- bisecting angle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What projection technique is most commonly used when taking periapical radiographs?

A

paralleling technique because there is less image distortion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

In a paralleling technique of taking a periapical radiograph, where is the image receptor and where is the central ray directed?

A
  • image receptor is parallel to the long axis of the teeth- central ray directed at right angle to image receptor and teeth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

In paralleling technique of taking a periapical radiograph, should there be a long or short source-to-object distance? Why?

A

long (reduces magnification)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What color positioning instrument and what size film are used for posterior periapical radiographs?

A
  • gold/yellow positioning instrument- size 2 film
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What color positioning instrument and what size film are used for anterior periapical radiographs?

A
  • blue positioning instrument- size 1 film
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How is the tube head angulated for a periapical radiograph?

A
  • adjust the x-ray tube head making sure the central ray is at right angle to the image receptor- make the tube head flush with the positioning instrument (if using positioning instrument with no external ring, keep the end of the cone within 2 cm of patient’s skin)- position the tube head downward for maxillary PAs (positive vertical angulation) or upward for mandibular PAs (negative vertical angulation)- be careful of incorrect horizontal angulation of beam (overlapping of interproximal surfaces of crowns)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is the difference between positive and negative vertical angulation?

A
  • positive vertical angulation: used for maxillary PAs; positioning the tube head downward- negative vertical angulation: used for mandibular PAs; positioning the tube head upward
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What rule is the bisecting angle technique of taking periapical radiographs based on?

A

Cieszynski’s rule of isometry (2 triangles are equal if they share one complete side and have 2 equal angles)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

In the bisecting angle technique of taking periapical radiographs, where is the image receptor placed? Where is the central ray directed?

A
  • image receptor placed as close as possible to lingual surfaces of teeth and palate or lingual surface of mandible; the receptor and teeth meet at an angle- an imaginary bisector line bisects the angle between the image receptor and teeth; central ray of x-ray beam is directed at a right angle to the imaginary bisector
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

For a bisecting angle technique of taking a periapical radiograph, if all four conditions are met, the image is theoretically ____.

A

of the same size as the object (no distortion)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Performing a radiographic exam involves:- ____ procedure- no ____ contact normally- ____ protocol is observed- ____ protocol if needed

A
  • non-invasive procedure- no blood contact normally- barrier protocol is observed- disinfection protocol if needed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

For barrier protocol, plastic bags are used for covering what 3 things?

A
  • chair headrest- x-ray tube head- exposure switch
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

For barrier protocol, what needs to be worn by the operator?

A
  • gloves- face mask- green colored coat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

For barrier protocol, what needs to be worn by the patient?

A
  • protective apron- thyroid shield
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What should be wiped with a caviwipe in a radiographic exam room?

A

all surfaces not protected with a barrier that came in contact with gloved hands or any other contaminants such as saliva

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What are the steps (8) of starting a radiographic exam?

A
  • have the radiographic procedure approved by the supervising faculty member on the clinic floor- make patient sit upright comfortably and explain the procedure- drape patient with protective apron and thyroid shield- wash your hands, wear gloves and face mask- examine the oral cavity- place the film in the positioning instrument and place in the oral cavity- position the PID and go behind the barrier- press the exposure button
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

For periapical radiographs of maxillary anterior teeth, what color positioning instrument is used? What size film? What position should the film be in (vertical/horizontal) and where should it be placed?

A
  • blue-colored positioning instrument- size 1 film- vertical film position- place films as far back (toward throat) as possible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

For periapical radiographs of maxillary posterior teeth, what color positioning instrument is used? What size film? What position should the film be in (vertical/horizontal) and where should it be placed?

A
  • yellow-colored positioning instrument- size 2 film- horizontal position- place film in the midline (away from teeth being imaged)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

For periapical radiographs of mandibular anterior teeth, what color positioning instrument is used? What size film? What position should the film be in (vertical/horizontal) and where should it be placed?

A
  • blue-colored positioning instrument- size 1 film- vertical position- place the film on the floor of the mouth (not on the tongue!) and push the tongue back as far as possible
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

For periapical radiographs of mandibular posterior teeth, what color positioning instrument is used? What size film? What position should the film be in (vertical/horizontal) and where should it be placed?

A
  • yellow-colored positioning instrument- size 2 film- horizontal position- place film on floor of mouth (not on tongue!) between the tongue and alveolar ridge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What is bitewing radiography also called? What is imaged in a bitewing radiograph?

A
  • interproximal radiography- crowns and alveolar crests of maxillary and mandibular teeth (all on same radiograph)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is bitewing radiography used to detect?

A
  • interproximal caries- marginal periodontal bone loss- interproximal calculus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

For posterior molar bitewing, where is the line on the positioning instrument placed?

A

between the 1st and 2nd molars

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What are the 7 special circumstances that make taking a bitewing radiograph difficult?

A
  • gag reflex- infection- trauma- mentally-disabled patient- physically-disabled patient- pregnancy- edentulous patient
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What are the 3 parts of the Buccal Object Rule?

A
  1. image of the area of interest is acquired in a standard way2. a second image is acquired with a changed horizontal angulation of the PID3. object towards the buccal seems to move in the opposite direction of the PID
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

What are some other names for the Buccal Object Rule?

A

image shift principle or SLOB rule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

For the Buccal Object Rule, the object that “moves” in the same direction is ____ (buccal/lingual); the object that “moves” in the opposite direction is ____ (buccal/lingual).

A
  • lingual- buccalHint: remember “Same Lingual Opposite Buccal” (SLOB)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

What is the definition of image sharpness?

A

how well-defined is a boundary between two areas of differing radiodensities (ex. how well you can discern between dentin and enamel)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

What is the definition of image resolution?

A

how well an image is able to reveal very small objects that are very close together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

What are the desired characteristics of image formation?

A
  • minimum magnification- minimum distortion- minimum superimposition- maximum detail
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

True or false: Magnification is present even if film and object are parallel.

A

true

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

Magnification depends on what 3 factors?

A
  • object-film distance (OFD)- source-object distance (SOD)- source-film distance (SFD)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

What are 4 synonyms for “source of radiation”?

A
  • source- target- focal spot- anode
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

If there is a constant source-object distance, increased object-film distance (film moves away from the object), then magnification ____ (increases/decreases).

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

If there is a constant source-film distance, increased object-film distance (object moves towards the source), then magnification ____ (increases/decreases)

A

increases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

Object-film distance should be as ____ (small/large) as possible (affects image sharpness).

A

small

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

More magnification = ____ (more/less) sharp

A

less

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

If there is constant object-film distance, decreased source-film distance, then magnification ____ (increases/decreases).

A

INCREASES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

If there is constant object-film distance, increased source-film distance, then magnification ____ (increases/decreases).

A

decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

True or false: Source-film distance should be short rather than long.

A

FALSE. SFD should be long rather than short (also affects sharpness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

What is the length of a typical short cone and a typical long cone?

A
  • typical short cone: 8” or less- typical long cone: 12” or 16”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

What length of cone is most common? What is recommended?

A
  • most common is 8”- recommended is longer than 8”
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

What is the definition of distortion?

A

variation seen in image from the true shape or proportions of the object (unequal magnification in an image)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

What are the 2 types of distortion?

A
  • distortion of size- distortion of shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
76
Q

Distortion seen in an image is due to ____.

A

disproportionate (non-uniform) magnification; some parts of the image are more magnified than the others

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
77
Q

Minimum distortion occurs when the object and sensor are ____ and the central ray is ____ to both the object and the film.

A
  • parallel- perpendicular
78
Q

If the relationship between the object and film is ____, more acute distortion occurs.

A

angular (not parallel)

79
Q

Using the bisecting angle technique, if the central ray is directed at a right angle to the object, ____ results. If the central ray is directed at a right angle to the sensor, ____ results.

A
  • elongation- foreshortening
80
Q

For proper application of the bisecting angle principle, the length of the image and object ____ (are/are not) equal and distortion ____ (is/is not) present.

81
Q

In improper application of the bisecting angle principle, ____ is too great and there is image ____ and image shift ____.

A
  • vertical angulation- foreshortening- shift occlusally or incisally
82
Q

In improper application of the bisecting angle principle, ____ is too small and there is image ____ and image shift ____.

A
  • vertical angle- elongation- apically (opposite to source of radiation)
83
Q

In proper application of the parallel principle, there is ____ and minimal ____.

A
  • magnification- distortion
84
Q

In improper application of the parallel principle in which the vertical angle is too great, there is no ____ and image shift ____.

A
  • foreshortening- occlusally; may project off of the receptor
85
Q

In improper application of the parallel principle in which the vertical angle is too small, there is no additional ____ and image shift ____.

A
  • elongation- apically (toward root apices); may project off of the receptor
86
Q

The bisecting angle technique is performed by first visualizing the bisector of the angle. Then, you direct the invisible ____ of the x-ray beam at a ____ degree angle to the imaginary bisector. If a mistake is made, it will result in ____ or ____.

A
  • central ray- 90- foreshortening- elongation
87
Q

The paralleling technique is performed by placing the sensor ____ (parallel/perpendicular) to teeth. The central ray is directed at a ____ degree angle to the sensor. If a mistake is made, there is no ____ or ____, but there is ____.

A
  • parallel- 90- foreshortening- elongation- magnification
88
Q

What type of cone is mandatory for the paralleling technique? Why?

A

long cone because you need an increased source-film distance (SFD)

89
Q

True or false: A long cone is necessary for the bisecting angle technique.

A

FALSE. A long cone is not necessary for bisecting angle technique, but there is no disadvantage when a long cone is used.

90
Q

Radiographic detail involves what 3 factors?

A
  • radiographic contrast- resolution- radiographic definition
91
Q

What is the definition of radiographic definition? What is the term “definition” equal to?

A
  • refers to the recorded sharpness of boundaries of structures- definition and sharpness are synonymous; lack of definition and unsharpness are synonymous
92
Q

What are the variables involved in radiographic definition?

A
  • size of the source (focal spot)- OFD, SFD, SOD- movement (of patient or sensor)- nature of the image receptor
93
Q

When determining radiographic definition, a source can either be a ____ source or a ____ source. It can give yield an image due to ____ (actual image) or ____ (periphery of image).

A
  • point source- area source- umbra- penumbra
94
Q

The size of the source and the definition are ____ (directly/inversely) related.

95
Q

The size of the source and the unsharpness are ____ (directly/inversely) related.

96
Q

All factors that ____ (increase/decrease) magnification will ____ (increase/decrease) definition.

A
  • increase- decrease
97
Q

True or false: It is very significant if the source of radiation moves while taking a radiograph.

A

FALSE. Movement of the source of radiation is not very significant.

98
Q

True or false: It is very significant if the patient and/or image receptor moves while taking a radiograph.

99
Q

What is movement of the source of radiation also called? Movement of the patient and/or image receptor?

A
  • geometric unsharpness- motion unsharpness
100
Q

For vertical angulation of maxillary teeth, 0 degrees VA is when the central ray is ____. Positive VA is when the source of radiation is ____.

A
  • parallel to occlusal plane- superior to the point of entry of central ray (PID is pointing downward)
101
Q

When there is an increased or positive vertical angulation of a maxillary PID, what may result in terms of the image?

A

image shifts down (incisal/occlusal edges may be projected off the receptor)

102
Q

If there is a decreased or negative vertical angulation of the PID when taking a maxillary radiograph, what may happen to the image?

A

image shifts up (apices may project off the receptor)

103
Q

For what type of radiograph (maxillary/mandibular) do you want a positive angulation? Negative angulation?

A
  • maxillary teeth- mandibular teeth
104
Q

Negative vertical angulation occurs when the source of radiation is ____.

A

inferior to the point of entry of the central ray; the PID is pointing upward

105
Q

When taking a mandibular radiograph, increasing the vertical angulation causes what change in the image?

A

causes the image to shift up (incisal/occlusal edges may be projected off of the receptor)

106
Q

When taking a mandibular radiograph, decreasing the vertical angulation causes what change in the image?

A

causes the image to shift down (apices may be projected off of the receptor)

107
Q

True or false: The vertical angulation for all maxillary periapicals, bitewings and occlusal radiographs is always positive; there is never an exception.

108
Q

True or false: The vertical angulation for maxillary periapicals is lesser than for bitewings.

A

FALSE. The vertical angulation for maxillary periapicals is GREATER than for bitewings.

109
Q

Which vertical angulation is greater: maxillary anterior periapicals or posterior periapicals?

A

maxillary anterior periapicals

110
Q

What is a 0 degree horizontal angulation? 90 degree? 180 degree?

A
  • 0 degree: central ray is parallel to sagittal plane and directed anteroposteriorly- 90 degree: central ray is perpendicular to the sagittal plane- 180 degree: central ray is parallel to the sagittal plane and directed posteroanteriorly
111
Q

Improper horizontal angulation causes ____.

A

interproximal overlapping

112
Q

Increasing horizontal angulation causes images to shift ____ and results in ____.

A
  • anteriorly- overlapping
113
Q

Decreasing horizontal angulation causes images to shift ____ and results in ____.

A
  • posteriorly- overlapping
114
Q

As we successively expose incisor, canine, premolar, and molar periapicals, in general, horizontal angulation ____.

A

increases (source of radiation moves posteriorly)

115
Q

In periapical radiography, horizontal angulation varies from ____ degrees (incisor periapical) to approximately ____ degrees (molar periapical).

A

0 degrees90 degrees

116
Q

What is the definition of digitization?

A

to represent a particular object (radiograph, photo, diagram, etc.) in form of numerical digits (ex. combination of zeros and ones)

117
Q

What are the 8 types of digital images used in dentistry?

A
  • intraoral- panoramic- cephalometric- skull and sinus- tomography- CT/CBCT, MRI, PET, nucelar medicine- intraoral photography/videography- microscopy (surgical and histological)
118
Q

What is the definition of a digital image?

A

a radiographic image represented in a digital format (combination of zeros and ones)

119
Q

What are the 2 types of digital imaging?

A
  • direct digital imaging- indirect digital imaging
120
Q

What is the difference between direct and indirect digital imaging?

A
  • direct: radiographic images obtained by x-ray exposure of solid-state image detectors- indirect: radiographic images obtained by exposing a digital image detector and scanning or digital photo capture of film radiographs
121
Q

True or false: There is not an intermediate step of “reading” or “scanning” in direct digital imaging.

122
Q

What are the 2 types of direct digital imaging?

A
  • charge-coupled device (CCD)- complementary metal oxide semiconductor (CMOS)
123
Q

What are the 3 types of indirect digital imaging?

A
  • photostimulable storage phosphor plate (PSP)- scanning a film- taking a digital photo of a film
124
Q

What is a charge-coupled device (CCD)? How does it acquire an image?

A
  • image detector that is made of high-grade pure silicone that contains an array of pixels (picture elements) that are coupled to each other- image acquisition is a process of transferring accumulated light or x-ray photons from one electronic well to another on a read-out device; then that analog image is transferred to the Intermediate Electronics Unit which makes it a digital image
125
Q

What is the difference between a processed and unprocessed digital image?

A

an unprocessed image has each pixel assigned a different value of zeros and ones so the image looks very pixelated (boxy)

126
Q

What are the advantages (4) of charge-coupled devices (CCDs)?

A
  • instant availability of images- better image quality compared to PSP- durable- consistent image quality (because they are enclosed in a hard plastic case)
127
Q

What are the disadvantages (4) of charge-coupled devices (CCDs)?

A
  • expensive- bulky- wire attachment- smaller active area compared to an equivalent size film (because there is a lot more hardware taking up space in the digital receptor)
128
Q

What is a complementary metal oxide semiconductor (CMOS)? How does it compare to a CCD?

A
  • silicone-based semiconductor that is widely used in video camera detectors and central processing chips of computers- principle similar to CCD, but simpler circuit design; the photon/electron conversion takes place right at the pixel (unlike CCD)
129
Q

What are the advantages (5) of a complementary metal oxide semiconductor (CMOS)?

A
  • instant availability of image- durable- consistent image quality- less expensive than CCD- slightly more rugged than CCD
130
Q

What are the disadvantages (4) of a complementary metal oxide semiconductor (CMOS)?

A
  • expensive compared to PSP- bulky; wireless is even bulkier- wire attachment- smaller active area compared to an equivalent sized film
131
Q

What type of clinic is the best place to use a Photostimulable Storage Phosphorplate (PSP)?

A

pediatric clinic

132
Q

What are the 2 components of a photostimulable storage phosphorplate (PSP)?

A
  • supporting base- outer coating of radiosensitive phosphor material
133
Q

In photostimulable storage phosphorplates (PSPs), the phosphor is “____-doped” ____ which is similar to ____ phosphors, but the difference is that PSP ____.

A
  • europium-doped- barium fluorohalide (BrFBr:Eu)- intensifying screen- PSP traps a significant number of electrons in its phosphor which is later read by a laser beam
134
Q

In PSPs, the phosphor layer absorbs ____ which moves ____ to ____.

A
  • x-ray photons (energy)- valence electron- conduction band
135
Q

In PSPs, the number of electrons stored is proportional to ____ to produce a ____.

A
  • x-ray photons- latent image
136
Q

PSPs are scanned by a laser beam of ____ nm (____ spectrum).

A
  • 633 nm- red
137
Q

Describe how a photostimulable storage phosphorplates (PSP) takes an image.

A
  • phosphor layer absorbs x-ray photons (energy)- energy moves valence electron to the conduction band (the number of electrons stored is proportional to x-ray photons)- scanned by a laser beam of 633 nm (red spectrum)- trapped electrons return to valence band and emit 300-500 nm light (green spectrum)- transported to photomultiplier tube- light energy is converted to electrical energy (ADC) which is stored and displayed as a digital image
138
Q

What are the advantages (4) of PSPs?

A
  • wider latitude (forgiving in choice of kVp and mAs)- available in all standard sizes- well tolerated by patients- economically priced
139
Q

What are the disadvantages (5) of PSPs?

A
  • prone to scratches (short lifespan)- read-out should be done ASAP (no more than 6-8 hours)- require processing- a semi-dark room is required- require exposure to bright light for erasing previous image before reuse
140
Q

What are the 4 detector characteristics of digital detectors?

A
  • contrast resolution- spatial resolution- detector latitude- detector sensitivity
141
Q

What is the definition of contrast resolution? What bit depth do current digital detectors capture?

A
  • ability to distinguish different densities in radiographic image- capture data at 8-, 10-, 12, or 16-bit depth
142
Q

How many densities/gray levels are there in current digital detectors? In conventional computer monitors? Human visual system? Dental operatory?

A
  • digital detectors: 256-65536 gray levels- computer monitors: 8 bits; 242 gray levels- human visual system: 60 gray levels- dental operatory: less than 30 gray levels
143
Q

What is the definition of spatial resolution?

A

ability to identify two objects placed very close to each other

144
Q

What is the spatial resolution of D-speed films? Of digital images? Of normal (untrained) eyes?

A
  • D-speed film: >20 line pair/mm- digital images: >7-24 line pair/mm- normal eye: 4-6 line pair/mm
145
Q

What is the definition of detector latitude?

A

the ability of an image detector to capture a range of x-ray exposures of tissue densities ranging from (ex.) gingiva to enamel; at the same times, subtle differences in density should be visually apparent

146
Q

What is the useful range of detector latitude?

147
Q

What is the definition of detector sensitivity?

A

ability of detector to respond to a smaller amount of radiation; in intraoral films, known as “speed” (D-, E-, or F-speed); there are no such standards for dental digital detectors

148
Q

For PSP systems, approximately the same dose is required as a ____ film (thus, they have the same detector sensitivity).

149
Q

In hi-resolution CCD and CMOS systems, approximately how much of a dose is required for optimal exposure of an F-speed film?

A

half of a dose

150
Q

A monitor consists of what 3 components?

A
  • display device (cathode ray tube (CRT), thin film transistor (TFT), organic light emitting diode (OLED))- circuitry- enclosure
151
Q

What are the 3 types of display devices?

A
  • cathode ray tube (CRT): 256 gray values- thin film transistor (TFT): ultra hi-resolution- organic light emitting diode (OLED): higher contrast and better viewing angle than LCD
152
Q

A hard copy of a radiograph can be on what two mediums?

A

paper or film

153
Q

What is the definition of image processing? What characteristics of the image does it affect?

A
  • an operation that acts to improve, restore, analyze, or change a digital image- brightness, contrast, gamma value, sharpening and smoothing filters, color, and digital subtraction
154
Q

Why is image processing beneficial? How can it be detrimental?

A
  • improves diagnostic accuracy if used judiciously- may improve the diagnosis of one disease while obscuring another; fraud
155
Q

When looking at caries in a radiographic image, do you want high or low contrast? When looking at bone?

A
  • caries: high contrast- bone: low contrast
156
Q

What was image analysis designed to do? What two things does it do?

A
  • designed to extract diagnostically important information from an image- measurement and diagnosis
157
Q

In image analysis, what are the tools (3) used for measurement?

A
  • digital rulers- densitometers- trabecular bone pattern (osteopenia and osteoporosis)
158
Q

What are the advantages (6) of digital imaging?

A
  • instant images- lower radiation dose- consistent quality- high signal/noise ratio (SNR)- image manipulation- digital subtraction radiography
159
Q

What are the disadvantages (5) of digital imaging?

A
  • relatively lower resolution than film- quality depends on monitor and printer- print quality is often not optimal- higher initial cost- unwanted manipulation of images
160
Q

For CCD, CMOS, PSP, and film, rank the spatial resolution.

A

film > CCD = CMOS > PSP

161
Q

For CCD, CMOS, PSP, and film, rank the exposure latitude.

A

PSP&raquo_space; CCD = CMOS > film

162
Q

For CCD, CMOS, PSP, and film, rank the receptor dimensions.

A

film = PSP < CCD = CMOS

163
Q

For CCD, CMOS, PSP, and film, rank the time required for image acquisition.

A

CCD = CMOS «< PSP = film

164
Q

For CCD, CMOS, PSP, and film, rank the image quality.

A

subjective; film is considered to be a gold standard

165
Q

For CCD, CMOS, and PSP, rank the image adjustment and processing.

A

CCD = CMOS = PSP

166
Q

For digital and film radiography, rank the cost.

A

there is a high initial cost of digital systems

167
Q

For digital and film radiography, rank the reliability.

A

digital systems are more susceptible to problems

168
Q

For CCD, CMOS, PSP, and film, rank the image storage and retrieval.

A

back-up is critical for digital systems

169
Q

For CCD, CMOS, PSP, and film, rank the transmission of images.

A

CCD = CMOS = PSP&raquo_space;> film

170
Q

What is DICOM?

A

“digital imaging and communication in medicine”; recognized standard for communication of images and related information

171
Q

True or false: Use of DICOM is voluntary, but international.

172
Q

True or false: DICOM is only used for radiographs and cannot be used for photography.

A

FALSE. DICOM is applicable to all imaging including radiographs and photographs

173
Q

What are the 3 reasons for the use of DICOM? Describe each.

A
  • efficiency: integration of different modalities in one dental office- portability: simplify exchange of images between dental and medical offices when patients move or require specialist care- integrity: attributes uniquely identify the patient, procedure, procedure date, and protect image integrity
174
Q

Radiographic examination shall only be prescribed on the basis of what 3 selection criteria?

A
  • history- clinical examination- laboratory findings (in some cases)
175
Q

True or false: There is a routine time-based formula for obtaining radiographs.

A

FALSE. There is no routine time-based formula for obtaining radiographs because there are individual circumstances for each patient. Judgements for the care of a specific patient, including radiographic examination, can only be made by using training and expertise.

176
Q

In what year was the selection criteria for radiographic examinations developed? When was it most recently updated?

A
  • 1987- updated in 2004 and then again in 2012
177
Q

In deciding the selection criteria for a radiographic examination, in what 2 groups are patients placed?

A

symptomatic and asymptomatic

178
Q

What radiological exams are recommended for a symptomatic patient?

A
  • use of individual periapical radiographs to examine a specific site or tooth because of specific signs or symptoms or historical findings- use of other radiographic techniques (panoramic, occlusal, head films, CBCT, etc.) should be considered where appropriate (ex. jaw pathosis, trauma, TMJ disorders, implants, paranasal sinuses, etc.)
179
Q

True or false: There are separate guidelines for radiographic exams for symptomatic child, adolescent, and adult.

A

FALSE. There are separate guidelines for radiographic exams for an ASYMPTOMATIC child, adolescent, and adult.

180
Q

For an asymptomatic child who is a new patient, what is the guidelines for radiographic exam of primary dentition? For transitional dentition?

A
  • bitewings if clinical examination is not possible or clinical signs of disease- individual periapicals and/or occlusals and bitewings OR panoramic and bitewings
181
Q

For an asymptomatic child who is a recall patient, what is the guidelines for a radiographic exam if they have clinical caries or are at high caries risk? If they have no clinical caries or are not at high caries risk?

A
  • bitewings every 6 months until no evidence of caries- bitewings every 12-24 month intervals
182
Q

For an asymptomatic child who is a recall patient, what is the guidelines for a radiographic exam if they have periodontal disease or a history of periodontal disease? If they are undergoing a growth and development assessment?

A
  • selected periapicals and/or bitewings of clinically positive sites- selected periapicals, panoramic, and occlusal (as indicated)
183
Q

For an asymptomatic adolescent who is a new patient, what are the guidelines for a radiographic exam?

A
  • posterior bitewings and selected periapicals- full-mouth series when patient presents with clinical evidence of generalized diseaseAND/OR- full-mouth series when patient presents with history of extensive dental treatment
184
Q

For an asymptomatic adolescent who is a recall patient, what is the guidelines for a radiographic exam if they have clinical caries or are at high caries risk? If they have no clinical caries or are not at high caries risk?

A
  • bitewings every 6-12 months until no evidence of caries- posterior bitewings at 18-36 month intervals
185
Q

For an asymptomatic adolescent who is a recall patient, what is the guidelines for a radiographic exam if they have periodontal disease or a history of periodontal disease? If they are undergoing a growth and development assessment?

A
  • selected periapicals and/or bitewings (vertical preferred) of clinically positive sites- perapicals or panoramic to assess developing 3rd molars
186
Q

For an asymptomatic adult who is a new patient, what are the guidelines for a radiographic exam?

A
  • posterior bitweings and selected periapicals- full-mouth series when patient presents with clinical evidence of generalized disease- full-mouth series when patient presents with history of extensive dental treatment
187
Q

For an asymptomatic adult who is a recall patient, what are the guidelines for a radiographic exam if they have clinical caries or are at high caries risk? If they have no clinical caries or are not at high caries

A
  • bitewings every 12-18 months or until no carious lesions are evident- posterior bitewings every 24-36 months
188
Q

For an asymptomatic adult who is a recall patient, what are the guidelines for a radiographic exam if they have periodontal disease or a history of periodontal disease? If they are undergoing a growth and development assessment?

A
  • selected periapicals and/or bitewings (vertical preferred) of clinically positive sites- usually not indicated
189
Q

For an edentulous adult who is a new patient, what are the guidelines for a radiographic exam?

A
  • panoramic radiograph- full-mouth series (usually not required)
190
Q

For an edentulous adult who is a recall patient, what are the guidelines for a radiographic exam?

A
  • no recall radiographic examinations required- selected periapicals or panoramics when disease is suspected
191
Q

What are the special considerations for radiographic exams for patients who are pregnant?

A
  • an appropriate radiographic examination for symptomatic patients- use radiation protection apron (thyroid and body)- if patient is asymptomatic, postpone if possible- fetal exposure is only 1 mGy for a full-mouth series
192
Q

What are the special considerations for radiographic exams for patients undergoing radiation therapy?

A
  • dental exposure is insignificant compared to therapeutic doses (up to 50 Gy)- an appropriate radiographic examination is recommended- average skin dose from dental radiography is 3 mGy- patients at a high risk for “radiation caries,” radiation exam is usually beneficial

SU14 - Radiology Exam 2 (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions