Exposure

Question 1

Define contrast

Answer 1

difference in adjacent densities

Question 2

Define quantity

Answer 2

The radiation intensity or the number of x rays in the beam, measured in mR

Question 3

Define the relationship between ma and tube current

Answer 3

Directly proportional

Question 4

Define the relationship between ma and mR

Answer 4

Directly proportional

Question 5

Describe the relationship between exposure time and density

Answer 5

Directly proportional

Question 6

Describe the relationship between time and mR

Answer 6

Directly proportional

Question 7

Describe the relationship between mAs and density

Answer 7

Directly proportional

Question 8

describe the relationship between kVp and mR

Answer 8

Inversely proportional

Question 9

Describe the relationship between SID and mR

Answer 9

inversely proportional

Question 10

Identify 4 imaging characteristics controlled by SID

Answer 10

magnification, distortion, penumbra and density

Question 11

Define the reciprocity law.

Answer 11

Any combination of mA and time can be used to get the same mAs with the same result in density.

Question 12

What is the 15% rule?

Answer 12

If kVp is increased by 15%, mAs will be halved. If kVp is decreased by 15%, mAs will be doubled.

Question 13

ma + s =

Answer 13

mAs

Question 14

What is the density maintenance formula?

Answer 14

new mAs/old mAs = new D^2/old D^2

Question 15

What is meant by low contrast?

Answer 15

lots of gray

Question 16

What is meant by high contrast?

Answer 16

few shades of gray

Question 17

How do you get a higher contrast on a film?

Answer 17

lower the kVp

Question 18

How do you get a lower contrast on a film?

Answer 18

Use a higher kVp

Question 19

What are the prime factors for exposure?

Answer 19

mA, kVp, distance and time

Question 20

What is quality?

Answer 20

the penetrability of the beam

Question 21

What is the controlling factor of contrast?

Answer 21

kVp

Question 22

What is the controlling factor of density?

Answer 22

mAs

Question 23

What is the relationship between kVp and scatter?

Answer 23

Directly proportional

Question 24

What is the function of contrast?

Answer 24

To make details visible

Question 25

What is meant by short scale contrast?

Answer 25

Few shades of gray

Question 26

What is meant by long scale of contrast?

Answer 26

Many shades of gray

Question 27

What is subject contrast?

Answer 27

The range of differences in the intensity of the remnant x ray beam after it has been attenuated by the patient.

Question 28

What is image receptor contrast?

Answer 28

The range of densities the image receptor is capable of recording.

Question 29

Five factors that affect image receptor contrast

Answer 29

H & D curve, image density, processing, digital image receptors, intensifying screens

Question 30

Three factors that affect subject contrast?

Answer 30

kVp, amount of tissue irradiated, type of tissue irradiated.

Question 31

How does mAs affect radiographic contrast

Answer 31

Under or over exposure

Question 32

How does focal spot size affect radiographic contrast

Answer 32

No influence.

Question 33

How does the anode heel effect affect radiographic contrast?

Answer 33

Little effect

Question 34

How does filtration affect contrast?

Answer 34

Inversely related.

Question 35

How does beam restriction (collimation) affect contrast?

Answer 35

Inversely related.

Question 36

How do grids affect contrast?

Answer 36

Directly related.

Question 37

What are two types of motion?

Answer 37

Involuntary and voluntary.

Question 38

Give an example of involuntary motion.

Answer 38

pain, breathing, chills, spasms

Question 39

What is the typical range for O.D?

Answer 39

0.25 to 2.5

Question 40

How does SID affect density?

Answer 40

By a factor of 4 (inversely).

Question 41

What are the seven types of radiologic tissue types.

Answer 41

metal, enamel, bone, muscle, fluids, fat and air/gas

Question 42

Give an example of voluntary motion.

Answer 42

nervousness, discomfort, fear, excitability

Question 43

Define density.

Answer 43

The overall blackness on the image. Also described as the amount of black metallic silver on a film.

Question 44

What is fog?

Answer 44

Unwanted density on the film.

Question 45

The total quantity of x rays produced in an x ray beam is determined by the _____.

Answer 45

mAs

Question 46

The distance between the x ray tube and the film is?

Answer 46

Source to image distance (SID)

Question 47

Low radiographic contrast is called?

Answer 47

long scale contrast

Question 48

Two factors that directly control the amount of x rays emitted by the tube are?

Answer 48

ma and time

Question 49

The shorter the SID, the __________ the intensity of the xray beam?

Answer 49

greater

Question 50

Radiographic density if produced by?

Answer 50

The quantity of x rays reaching the image receptor.

Question 51

Scattered radiation has what effect on radiographic contrast?

Answer 51

It decreases it.

Question 52

Describe the relationship between filtration and density.

Answer 52

Inversely related.

Question 53

descibe the relationship between collimation and density

Answer 53

inversely related

Question 54

Describe the relationship between thickness and density.

Answer 54

Inversely related

Question 55

Describe the relationship between grid ratio and density.

Answer 55

Inversely related.

Question 56

Describe the relationship between thickness and contrast.

Answer 56

Inversely related.

Question 57

Describe the relationship between processing time and contrast

Answer 57

Inversely related.