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Flashcards in ch 12 Deck (64)
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1
Q

The two basic layers of radiographic film are the _____ and the _____.

A

base and emulsion

2
Q

Modern radiographic film base is made of _____.

A

polyester

3
Q

The main purpose of the gelatin emulsion in radiographic film is to _____.

A

hold the silver halide crystals

4
Q

Crystals in film emulsion consist of _____ and _____.

A

silver bromide, silver iodide

5
Q

Latent image formation occurs during film _____.

A

exposure

6
Q

A contaminant in the silver halide crystal creates the _____.

A

sensitivity speck

7
Q

Direct exposure film has a _____ emulsion and _____ silver halide crystals than screen-film

A

thicker, more

8
Q

The latent image can be seen _____.

A

only after development

9
Q

Film is made with double emulsion to enhance film _____.

A

speed

10
Q

Storing film in very low humidity conditions can cause _____.

A

static artifacts

11
Q

Heart of xray film

A

emulsion

12
Q

overcoat protects from

A

scratching, oils from handling, etc

13
Q

Latent Image is

A

unobservable until processed

14
Q

Manifest image is

A

observable image

15
Q

Specks attract____ during image formation

A

free silver ions

16
Q

Photons that interact with film

A

light or xray photons

17
Q

Optimally charged film has ____ silver atoms at each sensitivity speck

A

4-10

18
Q

More silver atoms produce _____ film

A

overexposed

19
Q

Less silver atoms produce ____ film

A

underexposed

20
Q

Elephant example

A
LONG trunk (long scale)
Needs to duck LOW (Low contrast)
Is GRAY
Is LARGE (large grains)
Is HIGH up (High Latitude)
21
Q

Penguin example

A
They are SHORT (Short scale)
Must jump HIGH (High contrast)
Are BLACK AND WHITE
Are SMALL (Small grains)
Are LOW to ground (Low contrast)
22
Q

____ grains are more sensitive than _____ which are faster.

A

Large, Small

23
Q

All films respond to what color light

A

Violet and blue

24
Q

What colors do films respond to if sensitive to it

A

Green, Yellow, And Red

25
Q

Blue sensitive film uses _____ safelight

A

amber or red

26
Q

Green sensitive film uses ____ safelight

A

red

27
Q

Green and amber have similar _____

A

wavelengths

28
Q

Intensity X Time =

A

constant optical density

29
Q

Long or short exposure times will produce ____ speed

A

reduced

30
Q

Direct exposure requires ____ times more radiation

A

10-100

31
Q

Mammography uses ____ emulsion

A

single

32
Q

High heat/humidity causes

A

fog

33
Q

Low humidity/temperature causes

A

static

34
Q

Maximum storage time for film

A

30 days

35
Q

% of xrays that interact with film

A

1%

36
Q

% of xrays that interact with screen

A

30%

37
Q

Intensifying screen decreases ____ and increases ____

A

dose, image blur

38
Q

protective coating is layer

A

closest to film

39
Q

protective coating is ____ to light

A

transparent

40
Q

phosphor is ____ layer of intensifying screen

A

active

41
Q

Phosphor converts ____ to ____

A

xray bream, light

42
Q

What does reflective layer do to light headed away from film

A

intercepts it and redirects it toward film

43
Q

Base is ____ from film

A

furthest

44
Q

Base is _____ support for phosphor layer

A

mechanical

45
Q

Older screens were made of

A

calcium tungstate

46
Q

Newer screens are made from

A

rare earth materials

47
Q

Higher atomic # means higher

A

DQE

48
Q

Conversion efficiency

A

amount of light emitted for each xray absorbed

49
Q

Higher conversion efficiency, the _____ the patient dose

A

lower

50
Q

higher conversion efficiency results in _____ noise

A

increased

51
Q

luminescence

A

emission of visible light

52
Q

2 types of luminescence

A

fluorescence, phosphorescence

53
Q

Fluorescence

A

light emitted when phosphor is stimulated

54
Q

Phosphorescence

A

light emitted during & after stimulation is terminated

55
Q

Phosphorescence is called

A

afterglow

56
Q

Relative # describes how

A

efficiently xrays are converted to light

57
Q

MHLGGLL

ex-chest

A
More quantum
Higher speed
Larger phosphor
Greater thickness
Greater efficiency
Less detail
Less technique
58
Q

LLSLLMM

ex-finger

A
Less quantum
Lower speed
Smaller phosphor
Less thickness
Less efficiency
More detail
More technique
59
Q

Spatial resolution

A

Small objects with high subject contrast

60
Q

When xrays interact w/ intensifying screen light is emitted ____

A

isotropically

61
Q

Isotropic

A

equal intensity in all directions

62
Q

Greater emulsion thickness, ____ spatial resolution

A

decreased

63
Q

Great phosphor size, ____ spatial resolution

A

decreased

64
Q

Direct exposure film is higher detail because of

A

no light spread