Radiation Characteristics

Question 1

x-ray beam quality

Answer 1

refers to the mean energy or penetrating ability of the x-ray beam and is controlled by the kilovoltage

Question 2

voltage

Answer 2

a measurement of force that refers to the potential difference between two electrical charges

Question 3

kilovoltage

Answer 3

regulates speed and energy of electrons
increasing kilovoltage results in a higher energy x-ray beam with increased penetrating ability

Question 4

density

Answer 4

overall degree of blackness on a radiograph
important in diagnosis of disease

Question 5

increased kVp =

Answer 5

increased overall darkness or density of image

Question 6

decreased kV =

Answer 6

overal decreased density (lighter)

Question 7

contrast

Answer 7

how sharply dark and light areas are separated on an image

Question 8

contrast and kVp

Answer 8

low kVp = high contrast (detection of caries)
high kVp = low contrast (detection of periodontal disease)

Question 9

exposure time

Answer 9

measured in impulses

Question 10

exposure time and kilovoltage

Answer 10

inversely related
longer exposure time = darker image
shorter exposure time = lighter image

Question 11

subject thickness

Answer 11

inverse relationship between thickness and density
thicker object = less dense or lighter image

Question 12

quantity of x-ray beam

Answer 12

the number of x-rays produced in the dental x-ray unit

Question 13

amperage

Answer 13

number of electrons passing through cathode filament
increase number of electrons = increase number of x-rays

Question 14

ampere

Answer 14

describe number of electrons flowing through cathode filament

Question 15

milliamperage mA

Answer 15

controls quantity
regulates temperature of cathode filament

Question 16

density and milliamperage

Answer 16

increase in milliamperage = darker image and vice versa

Question 17

exposure time and milliamperage

Answer 17

inversely related (same as kV)

Question 18

intensity

Answer 18

the product of the quantity and quality per unit of area per unit of time of exposure

Question 19

x-ray beam intensity: kilovoltage

Answer 19

controls speed of electrons traveling between cathode and anode
higher kilovoltage = increase intensity

Question 20

x-ray beam intensity: milliamperage

Answer 20

controls number of electrons produced in x-ray tube and number of x-rays produced
higher milliampere = increased intensity

Question 21

x-ray beam intensity: exposure time

Answer 21

increase in exposure time = more intense x-ray beam

Question 22

target-surface distance

Answer 22

tungsten target to patient’s skin

Question 23

target-object distance

Answer 23

tungsten target to tooth

Question 24

target-receptor distance

Answer 24

tungsten target to receptor

Question 25

inverse square law

Answer 25

doubling the distance from the source to the receptor will result in a beam that is 1/4 as intense

Question 26

half-value layer

Answer 26

reduce the intensity of the x-ray beam
aluminum filter
too low filtration = unnecessary radiation to patient
too high filtration = increase kVp and mAs = shortening tube life