14. B (RADIATION MEASUREMENTS)

Question 1

T or f

Radiation can be measured in the same manner as other physical concepts, such as time (minutes), distance (miles/kilometers), and weight (pounds or kilograms).

Answer 1

T

Question 2

The International Commission on Radiation Units and Measurement (ICRU) has established special units for the measurement of radiation. Such units are used to define three quantities of radiation:

Answer 2

(1) exposure, (2) dose, (3) dose equivalent.

Question 3

At present, two systems are used to define radiation measurement:

→ the older system, Traditional System or Standard System

→ the newer system which is the _____, SI System or
Système International de’Unités (International System of Units)

Answer 3

metric equivalent

Question 4

records the dose received by person wearing it

Answer 4

DOSIMETER BADGE

Question 5

worn on the surface of the body

Answer 5

DOSIMETER BADGE

Question 6

determining the quantity of radiation exposure or dose, specifically ionizing radiation

Answer 6

DOSIMETRY

Question 7

refers to the measurement of ionization in air produced by x-rays

Answer 7

EXPOSURE

Question 8

measures the intensity of the radiation field as opposed to the amount of radiation absorbed

Answer 8

EXPOSURE

Question 9

The conversion of roentgen and coulombs per kilogram can be expressed as follows:

Answer 9

1 R = 2.58 x 10^-4 C/kg

1 C/kg = 3.88 x 10^3 R

Question 10

Definition

1 R = 87 erg/g

Answer 10

Traditional System: Roentgen (R)

Question 11

Conversion

1 R = 2.58 x 10^-4 C/kg

Answer 11

Traditional System: Roentgen (R)

Question 12

Conversion

1 C/kg = 3880 R

Answer 12

SI System: Coulombs per kg

Question 13

the amount of energy absorbed by a tissue

Answer 13

DOSE

Question 14

measures the total energy absorbed by any type of ionizing radiation per unit of mass of any type of matter

Answer 14

DOSE

Question 15

varies with the type and energy of radiation and type of matter absorbing the energy

Answer 15

DOSE

Question 16

Definition

1 rad = 100 erg/g

Answer 16

Traditional System: Radiation absorbed dose (rad)

Question 17

Conversion

1 rad = 0.01 Gy

Answer 17

Traditional System: Radiation absorbed dose (rad)

Question 18

Definition

1 Gy = 0.01 J/kg

Answer 18

SI System: Gray (Gy)

Question 19

Conversion

1 Gy = 100 rads

Answer 19

SI System: Gray (Gy)

Question 20

The conversions of rad and gray (Gy) can be expressed as follows:

Answer 20

1 rad = 0.01 Gy

1 Gy = 100 rads

Question 21

measurement used to compare the biologic effects of different types of radiation

Answer 21

DOSE EQUIVALENT

Question 22

ex.:
o alpha particles penetrate only a few mm of tissue, loses all
their energy and are totally absorbed; whereas x-rays penetrate much farther, lose some of their energy, and are only partially absorbed

Answer 22

DOSE EQUIVALENT

Question 23

the biological effect of a particular absorbed dose of alpha particles would therefore considered as more severe than similar radiation absorbed dose of-xrays

Answer 23

DOSE EQUIVALENT

Question 24

Definition

1 rem = rads x QF

Answer 24

Traditional System: Roentgen equivalent (in) man (rem)

Question 25

Conversion 1 rem = 0.01 Sv

Answer 25

Traditional System: Roentgen equivalent (in) man (rem)

Question 26

Conversion 1 Sv = 100 rems

Answer 26

Sievert (Sv)

Question 27

Definition 1 Sv = Gy x QF

Answer 27

Sievert (Sv)

Question 28

The conversions of rem and Sievert can be expressed as follows:

Answer 28

1 rem = 0.01 Sv 1 Sv = 100 rems

Question 29

unit of electrical charge; the quantity of electrical charge transferred by 1 ampere in 1 second

Answer 29

Coulombs

Question 30

unit of electrical current strength; current yielded by 1 volt against 1 ohm of resistance

Answer 30

Ampere

Question 31

unit of energy equivalent to 1.0 x 10^-7 joules or to 2.4 x 10^-8 calories

Answer 31

Erg

Question 32

SI unit of energy equivalent to the work done by the force of 1 newton acting over the distance of 1 meter

Answer 32

Joule

Question 33

SI unit of force; the force that, when acting continuously on a mass of 1 kg, will impart to it an acceleration

Answer 33

Newton

Question 34

unit of mass equivalent to 1000 grams or 2.205 pounds

Answer 34

Kilogram

Question 35

in dental radiography, the gray and sievert are equal and the roentgen, rad, and rem are considered approximately equal

Answer 35

MEASUREMENTS USED IN DENTAL RADIOGRAPHY

Question 36

smaller multiples of these radiation units are typically used in dentistry because of the small quantities of radiation use during radiographic procedures

Answer 36

MEASUREMENTS USED IN DENTAL RADIOGRAPHY