Chapter 12

Question 1

What are the three principal factors that affect x-ray emissions that are under direct control of the radiographer?

Answer 1

The prime factors; mAs, kVp, and distance

Question 2

What are two terms that can describe the x-ray beam?

Answer 2

quantity and quality

Question 3

What is x-ray quantity?

Answer 3

a measure of the number of x-ray photons in the useful beam.

Question 4

What is another name for x-ray quantity?

Answer 4

x-ray output, intensity, or exposure

Question 5

What is the measurement of x-ray quantity?

Answer 5

roentgen (R)

Question 6

What are the factors that directly affect x-ray quantity?

Answer 6

mAs, kVp, and filtration

Question 7

What is x-ray quality?

Answer 7

a measurement of the penetrating ability of the x-ray beam

Question 8

What does penetrability describe?

Answer 8

the distance an x-ray beam travels in matter

Question 9

Which travels farther high energy photons or low energy photons?

Answer 9

high energy photons; therefore they penetrate more

Question 10

What is another name for highly penetrating x-rays?

Answer 10

hard x-rays

Question 11

What is another name for low-penetrating x-rays?

Answer 11

soft x-rays

Question 12

How is x-ray quality numerically represented?

Answer 12

the half-value layer

Question 13

What is the half-value layer of an x-ray beam?

Answer 13

that thickness if absorbing material needed to reduce the x-ray intensity(quantity) to half its original value

Question 14

What are the factors that directly affect x-ray quality?

Answer 14

kilovoltage and filtration

Question 15

What are the factors that control quantity and/or quality of x-ray emission?

Answer 15

the prime factors and filtration

Question 16

Can radiographers control filtration from exposure to exposure?

Answer 16

no

Question 17

What is milliampeage (mA)?

Answer 17

a measurement of x-ray tube current- the number of electrons crossing the tube from cathode to anode per second

Question 18

Milliamperage is directly or inversely proportional to tube current?

Answer 18

directly

Question 19

When mA doubles, what else doubles?

Answer 19

the number of electrons able to cross the tube

Question 20

What is the number of electrons reaching the target controlled by?

Answer 20

the length of time the tube is energized

Question 21

How is the x-ray exposure time measured?

Answer 21

seconds

Question 22

X-ray quantity is directly or inversely proportional to mAs?

Answer 22

directly

Question 23

What else doubles when the mAs doubles?

Answer 23

x-ray exposures

Question 24

What records the image that is then displayed on the monitor for viewing?

Answer 24

the image receptor

Question 25

What is radiographic density?

Answer 25

the degree of blackening of an x-ray film

Question 26

How is radiographic density created?

Answer 26

by deposits of black metallic silver within the emulsion fo an x-ray film that has been exposed to light or x-ray and then processed.

Question 27

What happens to the image if the EI and IR exposure numbers are outside of the acceptable range?

Answer 27

the image has then been underexposed or overexposed and must be repeated

Question 28

Insufficient amount of mAs will result in?

Answer 28

an underexposed image

Question 29

Excessive amount of mAs will result in?

Answer 29

an overexposed image

Question 30

What does kVp control?

Answer 30

both the quantity and quality of the x-ray beam

Question 31

What will happen if you increase the kVp on the x-ray control panel?

Answer 31

it will cause and increase in the speed and energy of the electrons applied across the x-ray tube

Question 32

What does the 15 percent rule state?

Answer 32

an increase in kVp by 15 percent will cause a doubling in IR exposure, the same effect as doubling the mA or doubling exposure time

Question 33

The intensity of x-rays varies greatly with changes in ____.

Answer 33

distance

Question 34

The x-ray intensity will ____ as the distance is increased.

Answer 34

decrease

Question 35

What is x-ray intensity(exposure) measured in?

Answer 35

roentgens (R)

Question 36

What does the inverse square law state?

Answer 36

that the intensity of radiation at a given distance from the point source is inversely proportional to the square of the distance