Film

Question 1

Film Construction includes:

Answer 1

1-Base
2-Emulsion
3-Adhesive layer
4-Suppercoat

Question 2

Base is made of:

Answer 2

Polyester

Question 3

Base Characteristics:

Answer 3

1-transparent
2-rigid but flexible
3-untearable
4-uniform thickness and color
5-impermeable in water and processing solution
6-non inflammable
7-chemically inactive
8-dimensionally stability

Question 4

Base function:

Answer 4

1-support for emulsion layer

2-transmit light to new image

Question 5

Emulsion (or double emulsion) made of:

Answer 5

1-Gelatin

2-Silver halide crystal

Question 6

Emulsion functions:

Answer 6

1-Heart of the x-ray film

2-stores latent image

Question 7

Gelatin material:

Answer 7

1- 3 to 5 µm

2-provide mechanical support [for silver halide crystal]

Question 8

Silver Halide Crystals functions:

Answer 8

1-interaction of x-rays
2-differences in speed, contrast and resolution results from the manufacturing process and mixture of these crystals within the gelatin

Question 9

Formation [how to make] of the Latent image

Answer 9

1-the image is on the film prior to processing, however, cannot be seen
2-photoelectric effect/Gurney-Mott Theory
3-with proper chemical processing, the latent image becomes a manifested image.

Question 10

what is Gurney-Mott therory [process]?

Answer 10

1-incident photon (ligh/x-ray) interact with silver halide
2-ejected electron (e-) is freed and attracted/trapped by sensitivity speck
3-speck (-) charge attracts free silver ion
4-Silver ions; migrate to (-) sensitivity speck
5-and 6- development process: converts silver ions to metallic silver grain

Question 11

list 4 Film factors:

Answer 11

1-Resolution
2-speed
3-contrast
4-latitude

Question 12

Relationshipe of film crystals to film factors:

Crystal Size = Small

Answer 12

Results:

1-Resolution is high [better image]
2-Speed is slow
3-Contrast is high
4-Latitude is narrow

Question 13

Crystal size = large

Answer 13

Results:
1-Resolution is low [blur image]
2-Speed is fast
3-Contrast is low
4-Latitude is wide

Question 14

Relationship of emulsion layer to film factors:

Emulsion layer = thin

Answer 14

Results:
1-Resolution is high [better image]
2-speed is slow
3-contrast is high
4-latitude is narrow [shor scale, picky to produce image]

Question 15

Emulsion layer = thick

Answer 15

Resutls:
1-Resolution is low
2-Speed is fast
3-Contrast is low
4-latitude is wide [long scale,easy to produce image]

Question 16

What is film speed and what do we need to know about it?

Answer 16

1-film speed refers to how film blackening occurs in an exposure
2-the faster the film, the shorter the exposure can be, and this has an obvious benefits for lower patient exposure
3-faster films produce images that are more grainy (reduce image detail) than slower speed films