Brainscape's Knowledge GenomeTM

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


See full index

Radiology > Final Exam > Flashcards

Final Exam Flashcards

1
Q

What is crystallography?

A

Based on the diffraction pattern obtained form X-ray scattering off the periodic assembly of molecules or atoms in a crystal, the electron density can be reconstructed

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

Who was the first person to discover X-rays? When?

A

Wilhelm conrad Rontgen in 1895

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

How were X-rays discovered?

A

Roentgen, in 1895, was experimenting with the passage of electrical current through low pressure gas in a glass tube. He found that variable transparency was registered on a photographic plate.

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

What was the first radiograph taken of?

A

Roentgen’s wife’s hand.

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

Who was the first person to discover radioactivity?

A

Antoine henri becquerel

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

In what year did roentgen receive the first nobel prize for physics?

A
  1. For his discovery of X-rays
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two principle components of film?

A

Emulsion - coats both sides of base and consists of photon silver halide grains and suspension vehicle.

Base - a plastic supporting material.

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

There are silver halide crystals in the emulsion of the composition of film. What do they do?

A

Silver halide crystals are chemically altered when struck by an X-ray photon, creating the latent image.

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

What are the two types of X-ray film?

A

Intraoral - direct exposure

Sheet film - intensifiying screens. Planographic, TMJ, cephalometric

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

The dot on the film packet indicates the position of the ___. The dot should be oriented towards the ____ in PAs

A

Bump on the film

Occlusal surface

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

True or false. The dot on the film packet should be oriented TOWARDS the source of the radiation

A

False. The plain side of the film packet should be oriented towards the source of the radiation

Note that the bump, however is raised towards the source of radiation

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

True or false. The bump on the film is raised TOWARDS the source of radiation

A

True

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

What are the five different intraoral film sizes/

A

Size 0 - pedo

Size 1 - adult anterior

Size 2 - adult posterior

Size 3 - long posterior

Size 4 - occlusal

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

The _____ the crystals of silver halide, the faster the film speed.

A

Larger

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

Which film is fastest, C or F?

A

F is fastest. C i slowest.

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

Why is it that film will result in better resolution images than digital?

A

The grain size is smaller than what you can achieve with the smallest pixels digitally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are cassettes?

A

Contain intensifying screens

Require less radiation to expose film

Decreased definition

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

What are 5 things that can contribute to radiographic density?

A 
mA
kVP 
Exposure time
Focal spot to film distance
Subject density
Subject thickness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are grids?

A

Reduces scatter radiation

Can be incorporated in the cassette case or a separate screen placed inside the cassette on the source side of the film

*reduces scatter and fog on a radiograph

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

What are the five steps to processing film in the dark?

A

Developer- converts exposed silver halide crystals to metallic silver grains

Wash - remove developer

Fixer - removes underdeveloped silver halide crystals. Hardens and shrinks emulsifier.

Wash

Drying

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

What are four things to consider regarding darkroom hygiene?

A

Safelight (intraoral film - monochromatic… cassette film - polychromatic)

Light leakage - fogging

Chemical contamination - damage to film

Infection control

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

Which is more light sensitive intraoral film or cassette film?

A

Cassette film

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

For every ____ increase of ____, the rate of the processing reaction doubles

A

10 degree celsius

Temperature

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

Which processing method is cheaper, produces better images, and is less expensive?

A

Manual

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

What are the photographic wastes? (3)

A

Chemicals

Lead

Paper

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

What are three advantages of digital?

A

Lower patient exposure

Faster radiographs (no processing time)

More eco-friendly

Some other advantages include… easy storage of images. Images can easily be sent out. Easy retrieval. Images can be enlarged and vary density. Easy to display radiographs to patients

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

What are 5 disadvantages to digital?

A

Expensive

Damage to sensors

Uncomfortable sensors

Loss of image if not backed up

Not as fine an image if film is ideally processed

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

What are the two types of digital systems?

A

Direct - the sensory directly connects to a computer to provide immediate images

Indirect - reusable phosphor plates is used instead of film. After X-ray exposure a latent image is scanned in a special scanner. The digitized image is stored and read on a computer

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

What is a complementary metal oxide semiconductor (CMOS)? What is its construction?

A

A type of digital sensor.

From outside to inside....
Sealed sensor housing
Shock-protective layer
High sensitivity CSI scinillator 
Fiber optics 
High resolution CMOS sensor 
Electronic portion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is DICOM?

A

This is the standard computer language for the electronic communication of digital images in the medical/dental field

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

True or false… computer monitors can only display the image to a much less degree of accuracy than the sensor can detect

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Without magnification, the human eye can detect ____ line pairs/mm

A

6

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

Define sensor latitude

A

The ability to capture a range of exposures.

The ability to capture subtle differences in tissue density from gingiva to enamel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Define sensor sensitivity

A

The ability to respond to low amounts of radiation

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

Phosphor plate systems allow dose reduction of about ___% compared to F-speed film

A

50

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

F-speed film has an ASA film speed of about ___

A

125

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Describe how a sensor works

A

X-ray photons are converted to visible light as they hit the scintillator. This light is channeled through the fiber optic taper to the CDD

38
Q

What is the function of the scintillator in a sensor?

A

It converted X-ray photons into visible light

39
Q

Describe the cross section of one pixel

A

X ray is converted to light photons through scintillator. Then light photons are converted to electrons as the photons hit the silicon layer. Electrons pass through the embedded circuit. Electrons are then drawn into the well (which is positively charged)

40
Q

Overexposure leads to blooming. What is blooming?

A

More extreme cervical blow out

41
Q

What is high contrast?

A

All the pixels in the same area are averaged to create one pixel with the same grayscale

42
Q

All digital radiography filters are a combination of what four things?

A

Optimizing grayscale

Eliminating noise though smoothing

Sharpening image detail

Extracting features

43
Q

Sensors can sense up to _____ shades of grey. Whereas computer monitors can display ___ shades of grey. Whereas our eyes can detect ___ shades of grey.

A

65,535

256

64

44
Q

What happens when you alter the brightness of an image?

A

The grayscale value of all pixels is increased or decreased equally

45
Q

What happens when you increase the contrast in an image?

A

Shades of gray at opposite ends of the specturm are proportionately reassigned to solid black and pure white. (Fewer greys)

46
Q

What is smoothing?

A

When the average grayscale value of a number of surrounding pixels is assigned to the central pixel

47
Q

What is sharpening?

A

The average grayscale value of surrounding pixels is calculated. If the average is greater than the central pixel value, the center pixel becomes even more light. And vice versa

48
Q

True or false. You should wear gloves during all radiographic procedures, cover all non disposable items, sterilize non disposable items, and disinfect surfaces

A

True. …duh

49
Q

What is the proper infection control technique for handling film

A

With gloves on, open film pack and drop the film into a cup. Then remove gloves and place film in processor

50
Q

Name 7 quality assurance procedures

A 
Replenish X-ray solutions
Check temperatures 
Check quality of films
Log of retakes
Check for darkroom light leakage
Check exposure settings
Calibration of X-ray machine
51
Q

The moving source and receptor generate a zone of sharpness known as the ____. The nearer a structure is to the focal trough the ___ the resulting image

A

Focal trough

Clearer

Structures outside the focal trough are blurred, magnified, reduced in size, or distorted

52
Q

Panoramic images are inherently distorted in both ___ and ___. Distortion is influenced by…

A

Size and shape

Beam angulation, X-ray source to object distance, path of rotational center, position of object within the focal trough.

53
Q

What are ghost images?

A

Objects that are located between X-ray source and center of rotation cast “ghost images”.

Ghost images are typically blurred, magnified, located opposite the anatomical structure on the film and at a higher level due to upward inclination of the X-ray beam

54
Q

Name the three planes that must be aligned when taking a pano.

A

Center mid sagiital plane
(Laser reference)

Frankfort plane - tragic-orbital line parallel to floor

55
Q

How can you tell if the patient was too far forward when taking a pano?

A

Anterior teeth are blurred. You can see a lot of the vertebrae

56
Q

How can you tell if the patient was too far back when taking a pano?

A

White area in the midline of the radiograph (indicates vertebrae). Cannot see vertebrae on the lateral portions of radiograph

57
Q

How can you tell if the patient had their chin tipped down when taking a pano?

A

Smiling appearance

58
Q

How can you tell if the patients chin is too high when taking a pano?

A

Their occlusal plane looks flat or frowny. Hard palate will go over the apical portion of maxillary teeth

59
Q

How can you tell if the patients head was twisted when taking a pano?

A

The rami are asymmetrical.

60
Q

What are other views possible with digital panographic imaging?

A

Extraoral bitewings

TMJ projections

61
Q

True or false… extraoral bitewings have the same diagnostic quality as intraoral bitewings

A

False

62
Q

What is the cephalometric view of the skull?

A

Lateral view of skulll. Typically used by orthodontists

63
Q

True or false… an MRI uses no ionizing radiation

A

True

64
Q

What is the purpose of an MRI?

A

Produces detailed images of organs and structures within the body.

This test shows greater contrast between normal and abnormal tissues. Diagnosis of tumors, tissue damage, and blood flow

65
Q

What is a PET scan?

A

A nuclear medicine imaging technique that produces 3d images of functional PROCESSES in the body

The system detects gamma rays emitted by a tract that is introduced into the body

66
Q

What is the principle of CT?

A

An examination begins with an X-ray beam moving about a fixed axis and the sensor moving on the opposite side of the fulcrum which is located in the area of interest.

67
Q

What is a CT scan?

A

A Ct scan is an imaging procedure that combines the use of Xray with computer technology to produce cross-sectional images in the body.

CT scans produce clear, detailed images of all structures (bone, muscel, fat, organs)

68
Q

If you ___voxel size, you need to increase the amount of radiation to expose all of the voxels

A

Reduce.

So, the larger the voxel size, the less radiation needed

However, smaller voxel size = higher resolution image

69
Q

In order to follow the ALARA principle, you should keep the ___ volume and ___ voxel size possible to get the diagnostic image you need

A

Smallest

Largest

70
Q

Name 7 main reasons for the use of CBCT in modern dental practices

A 
Implant planning 
Endodontic treatment 
Surgery pathology 
Root fractures 
TMJ 
Airway assessment
71
Q

How can you tell if it is cervical blow out or root caries?

A

If it was caries you would most likely see some bone loss

72
Q

What tooth approximates the mental foramen?

A

The second premolar

73
Q

What is internal resorption/

A

Involves resorption of surrounding dentin in pulp chamber or canal. Pulp space enlarges. Tooth may appear pink because of the increased pulp size

74
Q

What is pulpal sclerosis?

A

Diffuse calcification in the pulp

75
Q 
Define each of the following supernumerary teeth... 
mesidens
Parateeth
Distodens
Peridens
A

Mesiodens - occurs between maxillary central incisors

Parateeth - occur in molar area

Distodens - distal to the third molar

Peridens - ectopically erupted supernumerary teeth

76
Q

True or false… supernumaery teeth usually do not erupt and are discovered radiographically

A

True

77
Q

What is transposition?

A

Two teeth that have exchanged position.

78
Q

What is gemination?

A

Twinning

Tooth bud attempts to divide and results in partia or complete division

79
Q

What is concrescence?

A

Root of two or more teeth are united by cementum

80
Q

What is dilaceration?

A

Sharp bend or curve in tooth crown or root

81
Q

What is dens in dente?

A

Infolding of the outer surface into the interior of a tooth

82
Q

What is dens evaginatus?

A

Outfolding of the enamel organ

83
Q

What is enamel hypoplasia?

A

Amelogenesis imperfecta.

84
Q

What is turner’s hypoplasia?

A

Permanent tooth with local hypoplastic defect in crown. Usually due to trauma induced from primary tooth

85
Q

What is a talon cusp?

A

Anomalous hyperplasia of cingulum of maxillary or mandibular incisor

86
Q

What is taurodontism?

A

Longitudinally elongated pulp chambers

87
Q

True or false. A panoramic radiograph gives you a 1 in one million chance of dying due to cancer

A

True

88
Q

True or false. The larger the crystals of silver halide, the faster the film speed.

A

True

89
Q

At 68 degrees F, you should develop for ___ minutes

A

5

90
Q

True or false.. amplification occurs at the scintillation layer

A

True

91
Q

True or false. Interproximal caries makes a triangular shape in the enamel with the broadest base at the tooth surface (cavosurface)

A

True

92
Q

Who own the dental radiographs?

A

The dentist. He is not obligated to give away the originals but he is obligated to make copies if the patient requests it

Radiology (2 decks)

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