CH19 Radiographici FIlm

Question 1

Basic radiographic film components:

Answer 1

Base and Emulsion Gelatin

Question 2

Base

Answer 2

made of a blue tint dye and polyester. Coated with emulsion gelatin

Question 3

Base requirements:

Answer 3

1) Good film contact 2) Flexible 3) Stable 4) Rigid 5) Uniform Lucent

Question 4

Emulsion Coating contains:

Answer 4

Photosensitive silver halide crystals Bromides/Iodide/Chlorine

Question 5

Uniform Lucent

Answer 5

Permits light to pass through with the use of light box.

Question 6

Purpose of blue dye tint?

Answer 6

reduces eye strain and enhances contrast

Question 7

Duplitized

Answer 7

Double coating of emulsion on each side

Question 8

Duplicating film

Answer 8

copy of film, single emulsion

Question 9

Supercoat

Answer 9

surrounds emulsion, layer of hard protective gelatin.

Question 10

Supercoat prevents:

Answer 10

soft emulsions from from being physically or chemically abused. Damage can only occur through use of staples, paper clips, or guide shoes.

Question 11

Panchromatic

Answer 11

Sensitive to all wavelengths.

Question 12

Orthochromatic

Answer 12

Not sensitive to red.

Question 13

Cube lattice:

Answer 13

Form in which silver halide crystals exist.

Question 14

Sensitivity Peak

Answer 14

made of gold or silver, acts as an electrode to attract free silver ions (CUBE LATTICE/Crystals)

Question 15

Direct of non-screen exposure

Answer 15

Enclosed in cardboard, w/o screens, use when need detail.

Question 16

Single emulsion

Answer 16

Extremely fine grains, greater silver content, thicker emulsion layer, loaded face up.

Question 17

Emulsion side appears:

Answer 17

Dull

Question 18

Non emulsion side apears:

Answer 18

shiny

Question 19

Film is sensitive to:

Answer 19

Age, heat, humidity, light, radiation, handling

Question 20

Film should be stored at:

Answer 20

20 deg C (68F), 60-70F

Question 21

Film constantly absorbes:

Answer 21

Photons of both heat and light

Question 22

When storing film:

Answer 22

it should be on end (upright) in a cool dry place.

Question 23

Intensifying Screens:

Answer 23

Used to amplify the incoming xray beam

Question 24

Benefits of an intensifying screen:

Answer 24

Reducing radiation dose to the patients, produced large quantities of light photons.

Question 25

Contruction of intensifying screen:

Answer 25

Base, Reflective layer, Phosphor layer, Protective coat, mounted in pairs.

Question 26

Base made of:

Answer 26

Polyester

Question 27

Reflective layer

Answer 27

base material not transparent, creates latent image, reflects towards film

Question 28

Phosphor layer

Answer 28

Active layer of screen, absorbes light.

Question 29

Protective coat

Answer 29

protects phosphor layer from abrasions and stains

Question 30

Phosphor requirements

Answer 30

High atomic number, conversion efficiency, sepctral emission/spectral matching, Luminescence, phosphorenscence.

Question 31

High phosphor atomic number allows

Answer 31

increased probability of an incident photon interaction

Question 32

Conversion efficiency means

Answer 32

the ability of the phosphors to emit as much light as possible

Question 33

Spectral emission

Answer 33

precise wavelength emitted

Question 34

Luminescence

Answer 34

ability of material to emit light in response to excitation

Question 35

Phosphorenscence

Answer 35

Continued emission of light by a phosphor after the exposure has ended.

Question 36

Screen should be replaced how often?

Answer 36

Every 5-7 years

Question 37

Types of phosphors

Answer 37

Zinc sulfide, Barium lead sulfate, *Calcium Tungstate (CaWO4)

Question 38

Hybrid rare earth screens provide

Answer 38

greater absorbtion, atomic number 51-71, known as rare earth because of it's difficulty to isolate

Question 39

Hybrid rare earth screens can be made of either:

Answer 39

Gadolinium, Lanthanum, Yttrium

Question 40

Quantum Mottle

Answer 40

Uneven density, insuffiecient amount of x-rays. More common in high speed film and digital.

Question 41

Screen characteristics

Answer 41

Same as film 1)Resolution 2)Speed 3)Contrast 4)Lattitude(not error latitude)

Question 42

Screen resolution is

Answer 42

the ability to produce an accurate image.

Question 43

Screen resolution is controlled by

Answer 43

1)size of crystals 2)thickness of the layer 3)Concentration of crystals

Question 44

Smaller Crystal results in

Answer 44

Thinner layer, many more crystals, slower speed, more exposure, and more detail.

Question 45

Larger Crystals results in:

Answer 45

Thickness layer is larger, less crystals, faster speeds, less exposure, less detail.

Question 46

Speed

Answer 46

is determined by the same factors that effect resolution.

Question 47

Higher kVp does what to speed?

Answer 47

Increases speed.

Question 48

Temperature increase will have what effect on speed?

Answer 48

The speed will slow down.

Question 49

Screen speed characteristics

Answer 49

1)Intensification factors 2)Descriptive factors 3)Relative (Speed # ex. RS100 RS200)

Question 50

Spectral matching

Answer 50

Film and screens respond to certain wavelengths, that must match spectrally.

Question 51

Rare earth color is

Answer 51

green

Question 52

Calcium Tungstate color is

Answer 52

purple

Question 53

Cassettes purpose is

Answer 53

to create a portable, light proof case for the film.

Question 54

Cassette requirements are:

Answer 54

1) Rigid 2) Radiolucent 3)Lead->to absorb backscatter