Intensifying Screen Flashcards

0
Q

Converts higher energy electromagnetic radiation to a lower energy radiation

A

Intensifying screen

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

A device that converts xrays to visible light

A

Intensifying screen

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

Recommends calcium tungstate

A

Thomas edison

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

Producing radiograph using fluorescent screen - film combination

A

Michael Pupin

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

Introduced the double coated intesifying screen

A

Dr. Max Levy

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

Advocated to decrease the length of exposure

A

Mihran Krikor Kassabian

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

Produced screens from synthetic calcium tungstate

A

Carl V.S. Patterson

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

Protective coating applied over ____ which makes the IS cleanable

A

Phosphor

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

Rare earth phosphors that are more efficient

A

Gadolinium Oxysulfide

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

It is iodine based

A

Dye

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

Advantages of IS

A

Reduces dose required
Short exposure time
Less motion unsharpness

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

Disadvantages of IS

A

Screen unsharpness

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

Sponge will source IS, film and IS

A

Contact belt

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

First base

A

Cardboard

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

Support for all layers of IS

A

Base

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

Base is made up of

A

Polyester

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

Thickness for cassettes

A

250 microns

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

Thickness of screens for automatic film changers.

A

175 u

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

Intercepts light going away from the film and redirects it towards the film

A

Reflective layer

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

Reflective layer is made up of the coating

A

Titanium dioxide

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

Absorbed the light travelling away from the film

A

Absorptive layer

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

Another coating of reflective layer

A

Magnesium oxide

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

Absorptive layer is for

A

mammography

23
Q

Attaches the phosphor layer to the base

A

Substratum

24
Q

Heart of IS

Dispersion of the phosphor crystals within a suitable binder

A

Phosphor layer

25
Q

Emits light / converts xray to light

A

Phosphor layer

26
Q

Phosphor layer is approximately

A

150 u

27
Q

Binder material that is commonly used by the manufacturer is

A

Acetate acrylate

28
Q

Absorbs the light

A

Binder

29
Q

Chatacteristics of binder

A

Flexible
Inert to phosphor crytals
Provides even, known dispersion of the binder
Allows the phosphor layer to be coated

30
Q

It exhibits the property of fluorescence when exposed to xray

A

Phosphor crystals

31
Q

Two kinds of phosphor crystals

A

Calcium tungstate

Rare Earth

32
Q

Ability to emit light in response to some outside stimulation

A

Luminiscence

33
Q

2 types of luminiscence

A

Phosphorescence

Fluorescence

34
Q

Emit lights after stimulation

A

Phosphorescence

35
Q

Emits light only during stimulation

A

Fluorescence

36
Q

Top protective layer of the screen

A

Supercoat

37
Q

Super coat is ____ thick

A

8 u

38
Q

Supercoat is made up of

A

Cellulose acetobiturate

39
Q

Ability of the IS to absorb xray , convert light and allow light to escape from the screen and exposed the film

A

Conversion efficiency

40
Q

Formula of conversion efficiency

A

Efficiency = absorption x convertion x emission

41
Q

Conversion for rare earth

A

1x10 ^ 3 light photons per incident 50 keV Xray photons

42
Q

How efficiently xrays are converted

A

Screen speed

43
Q

The ratio of xray exposure needed to produce the same density

A

Intensification factor

44
Q

The relationship of screen speed and detail is

A

Reciprocal

45
Q

Due to divergent emission of light from the IS

A

Screen unsharpness

46
Q

Result of widening light beam emitted by crystals

A

Crossover effect

47
Q

Not possible to evenly dispersed the phosphor crystals thoughout the binder

A

Structure mottle

48
Q

Caused by low mAs factor (graininess) and high speed IS

A

Quantum mottle

49
Q

Poor film screen contact that causes light emitted by tge IS to diffused before it reaches the film

A

Screen-film contact

50
Q

Types of phosphor

A

Calcium Tungstate

Rare earths

51
Q

Naturally occuring phosphor , produces a continuous spectrum principally tge blue part of spectrum

A

Calcium tungstate

52
Q

Soft , malleable metals that can be made to emit light upon stimulation by xrays

A

Rare earth

53
Q

Lanthanum oxybromide emits

A

Blue

54
Q

Gadolinium oxysulfide emits

A

Green

55
Q

Barium fluorochloride emits

A

Ultraviolet