Radiographic density and contrast

Question 1

how do we see each other?

Answer 1

reflected light

Question 2

how do we read?

Answer 2

reflected light

Question 3

how do we interpret radiographs?

Answer 3

transmitted light

Question 4

incident light

Answer 4

total light from source like a view box or illuminator that is partly
Absorbed
Reflected
Transmitted

Question 5

radiographic density

Answer 5

blackness/darkness of an area of film

Question 6

what is the usable range of radiographic density?

Answer 6

0.25-2.5

Question 7

what is the most active component of radiographic film?

Answer 7

AgBr crystals

Question 8

when exposed to xrays or visible light, AgBr is ionized and is converted to

Answer 8

metallic silver

Question 9

the greater the radiation to reach the film, the ______ the amount of metallic silver formation

Answer 9

greater

Question 10

what is the color of metallic silver?

Answer 10

black

Question 11

parts of the film receiving more radiation appear _______

Answer 11

darker

Question 12

what does an unexposed film look like

Answer 12

clear

Question 13

concentration of electrons is _________ related to density

Answer 13

directly

Question 14

radiolucency

Answer 14

an area of a radiograph representing a radiolucent object (dark area)

Question 15

characteristics of radiolucency (6)

Answer 15

1. more x-radiation is transmitted
2. the more trapped electrons, the more and image appears
3. less effective in absorbing
4. dark
5. more x-rays reach receptor
6. more metallic silver

Question 16

radiopacity

Answer 16

area of radiograph representing a radiopaque object (Light area)

Question 17

radiopaque characteristics (6)

Answer 17

1. less transmitted
2. less electrons
3. MORE absorbed
4. lighter
5. less xrays reach receptor
6. less metallic silver

Question 18

radiographic contrast

Answer 18

observed differences in adjoining radiographic densities

Question 19

differentiate structures based on 3 things:

Answer 19

density
thickness
chemical composition

Question 20

density of dentin is similar to the density of what?

Answer 20

cementum

Question 21

if the differences between radiographic densities are GREAT - it is ____ contrast
if the differences are SMALL - it is ______ contrast

Answer 21

HIGH

LOW

Question 22

high contrast characteristics (5)

Answer 22

SHORT scale contrast
LOWER kVp
LESS shades of grey
identifies caries
intraoral kVp: 70

Question 23

low contrast characteristics (5)

Answer 23

LONG scale contrast
HIGHER kVp
MORE shades of grey
identifies less dense objects
extraoral kVp: 90