Unit 4, 5, 6 Flashcards Preview

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Flashcards in Unit 4, 5, 6 Deck (74):
1

Who is the first founder of the x-rays? And when did he do it?

Wilhelm Conrad Roentgen
November 8, 1895

2

First radiographic patient and of what?

Anna bertha roentgen (wife)
Hand

3

How were x-rays discovered?

Working with the crooks tube

4

Dr Edwin Frost did what?

Credited with making the first diagnostic radiograph

5

Early protection efforts?

Metal helmets
Heavy aprons
Lead screens

6

Henri Bequerel did what?

Discoverer of radioactivity

7

Pierre and Marie Curie did what?

Founded ways to measure the intensity of radiation and finding other elements that emitted radiation

8

Define Intensifying screen

Device that coverts the energy of the x ray beam into visible light

9

Intensifying screens, have four layers. What are they?

Base, reflective, phosphor, protective coating

10

Base layer, location and function? (Intensifying screen)

Farthest from the film
Support the phosphor layer

11

Reflective layer, location and function? (Intensifying screen)

Between phosphor and base
Redirects the light to the film

12

Phosphor Layer, location and function? (intensifying screen)

Below protective layer
Converts the energy of x-ray beam to visible light (Heart of the screen)

13

Protective Coating, location and function? (Intensifying screen)

Closest to the film
Helps eliminate static electricity

14

What is Luminescence

Any material that emits light in response to some outside stimulation

15

2 types of Luminescence?

Florescence = Good
visible light emitted only while the phosphor is stimulated
Phosphorescence = Bad
light emitted after the stimulation has stopped
in a screen is called "screen lag" or "afterglow"

16

Screen speed Defined? (Range)

Screen speeds range from 100 (slow Detail)
to 1200 (very fast, less detail)

17

Factors affecting screen resolution?

Fast screen speed = Low resolution/detail
Large phosphor crystal size = Low resolution
Thick phosphor = Low resolution
High kVp = lower resolution

18

Faster image receptors/screens = ?
Fast screens = ?
Slow image receptors/ screens = ?

Low resolution
decreased detail
high resolution

19

What is image noise?

deterioration of the radiographic image

20

What is quantum mottle?

describes the mottled or noisy appearance or the film due to the number or photons exposing it. (salt/pepper)

21

What is spatial resolution?

ability to produce an accurate and clean image

22

What is resolution?

a measure of the ability of a system to image two separate objects and visually distinguish one from another

23

What is a cassette?

holder that contains the film and intensifying screens

24

How do you care for screens?

Avoid handling
do not dig film out of the cassette
do not leave cassette open

25

Describe screen maintenance.

Cleaned once a month
screen must be completely dry before reloading the cassette

26

Screen- film contact? bad contact?

Checked by wire mesh test
develop film
any areas darkened or blurred = bad contact
should be done annually

27

Only way to render screen useless?

improper handling and maintenance

28

Screen affects on density?

**as screen speed increases density increases
**faster screens produce more light per interaction

29

Screen affects on detail?

increasing screen speed, decreases detail
due to increased quantum mottle at high screen speeds

30

Screen affects on patient dose

as screen speed increases, patient dose decreases
-exposure techniques can be decreased with faster screens

31

What is a latent image?

an image that cannot yet be seen, invisible

32

What is remnant radiation?

x ray that remain after the useful beam exits the patient

33

What is a manifest image?

the observable image formed when the latent image undergoes the proper chemical processing (final image)

34

What are your film parts? (4)

Base
Adhesive layer
Emulsion
Supercoating

35

Film parts, base? What does it do?

Provides the rigid structures onto which the emulsion is placed

36

Film parts, adhesive layer? Where is it?

between film emulsion and base

37

Film parts, emulsion? What is it?

**heart of the x-ray film

38

Film parts, supercoating, What is it?

surrounds the sheet of film and protects it

39

Silver halide crystals do what?

Bound by ionic bonds
fixed in the crystal lattice in ion form

40

Silver halide is what?

active ingredient in emulsion
light sensitive

41

Silver bromide is what?

material that makes up 98% of the sliver halide crystals in a typical emulsion

42

Define sensitivity speck

physical imperfections in the lattice of the emulsion layer that occur during the film manufacturing procces
-at or near the surface

43

Photo interactions with silver halide crystals do what?

forms a latent image (can't see)

44

What is film speed?

degree to which the emulsion is sensitive to x-rays or light
the faster the speed the more sensitive it is

45

What is film contrast?

ability of radiographic film to provide a certain level of image contrast

46

High contrast in film do what?

shows blacks and whites better

47

Low contrast in film do what?

shows shades of gray better

48

What is film latitude?

range of techniques

49

When handling film, what do you do?

don't bend, crease or fold
must have clean hands
avoid lotion and creams

50

What are artifacts?

any irregular density on a radiograph that is not caused by the proper shadowing of an object by the primary beam

51

How do you properly store film?

in a dry cool place (fridge)
heat and humidity can cause increase in fog
and reduce contrast

52

Automatic film processing, what's the purpose?

intensifies latent image and makes it visible (manifest image)

53

What is the sequence of automatic processor?

development
fixing
washing
drying

54

What does the developer do in automatic processing?

converts latent image (invisible) into manifest image (visible)

55

What 3 factors affect development in automatic processing?

developer temperature 95 F
time
concentration

56

What does the fixer do in automatic development?

removes undeveloped sliver halide crystals from the film and fixes (or sets) the film
contributes to archival quality

57

What does the wash do in automatic development?

Removes residual chemicals left in emulsion

58

What does the dryer do in automatic development?

blows warm air over both sides of the film to completely dry the film

59

Processor maintenance, times?

Daily = crack lid open
weekly = cleans crossover and roller assemblies
monthly = completely cleans and chemicals changed

60

Processing affect on density?

increase time/ or temperature = increase density

61

Processing affect on contrast?

increase time/ or temperature = decrease in contrast

62

What is the PSP plate?

Photostimulable phosphor plate

63

PSP plate layers?

Protective layer
phosphor layer
reflective layer
conductive layer
support layer
backing layer

64

PSP plate, protective layer?

protects phosphor layer

65

PSP plate, phosphor layer?

the active layer, trap electrons during exposure

66

PSP plate, reflective layer?

reflects light emitted towards the front (photodetector)

67

PSP plate, conductive layer?

reduces static electricity

68

PSP plate, support layer?

provides the ridged edges

69

PSP plate, backing layer?

soft layer that protects back of cassette

70

What is turbid?

random distribution of phosphor crystals within the active layer

71

What does CCD stand for?

Charge-Coupled Device

72

What does TFT stand for?

Thin-film Transmitter

73

What does PACS stand for?

Picture Archiving & Communications System

74

What does DICOM stand for?

Digital Imaging & Communications in Medicine