Ch 4 Radiation quantities And Units

Question 1

From ____________ the unit for measuring radiation exposure was for the skin erythema dose

Answer 1

1900-1930

Question 2

Defined as the received quantity of radiation that causes diffuse redness over an area of skin after irradiation?

Answer 2

Skin erythema dose

Question 3

Why was skin erythema dose an often crude inaccurate way to quantify radiation exposure?

Answer 3

Because the amount of radiation required to produce an erythema reaction varies from one person to another.

Question 4

The first international congress of radiology was held where and what year?

Answer 4

London, England in 1925

Question 5

International commission of radiation units and measurements (ICRU) was formed in

Answer 5

1925

Question 6

Is a dose to which occupationally exposed persons could be subjected without any apparent harmful acute effects, such as erythema of the skin?

Answer 6

Tolerance dose

Question 7

Dose of radiation lower than which an individual has a negligible chance of sustaining specific biologic damage?

Answer 7

Threshold dose

Question 8

Maximum permissible dose (MPD), was initially expressed in_______ and has since been replaced by the unit______

Answer 8

Rem
SI, sievert

Question 9

Irradiation of _________ was found to be much more significant to the whole body health of an individual than irradiation of the _______.

Answer 9

Bone marrow
Skin

Question 10

At ICRP adopted the term________, based on the energy deposited in biologic tissue by ionizing radiation and takes in account both of the following: ______________ and __________\

Answer 10

Effective dose (EfD)
The type of radiation
The variable sensitivity of the tissue exposed to the radiation

Question 11

EfD is expressed in_____ and is the best measure of the overall risk arising from the simultaneous irradiation of various biologic tissue and organs within an individual.

Answer 11

SI unit, Sievert

Question 12

____ is the the traditional unit for the radiation quantity equivalent dose (EqD)

Answer 12

Rem

Question 13

Relates to the ionization produced in a small cavity within an irradiated medium or object to the energy absorbed in that medium as a result of its radiation exposure.

Answer 13

The Bragg-Gray theory

Question 14

As the intensity of X-ray exposure of the air volume _________, the number of electron ion pairs produced________

Answer 14

Increases
Increases

Question 15

Radiation ionization in air is termed?

Answer 15

Exposure

Question 16

Amount of radiation responsible for the ionization of a well defined volume of air may be determined by measuring the number of electron-ion pairs or charged particles of either sign in that volume of air, this is termed found known as?

Answer 16

Exposure

Question 17

Is defined as the total electrical charge of one sign, either plus or all minus, per unit mass that X-ray and gamma ray photons with energies up to 3 million electron volts generate in dry air at standard temperature and pressure

Answer 17

Exposure

Question 18

Basic unit of electrical charge?

Answer 18

Coulomb (C)

Question 19

Is another SI quantity that is used to express how energy is transferred from a beam of radiation to air

Answer 19

Air kerma

Question 20

Is the total kinetic energy released in a unit mass of air and is expressed in metric units of joules per kilogram.

Answer 20

Air kerma

Question 21

The sum total of air kerma over the exposed area of the patients surface or in other words a measure of the amount of radiant energy that has been thrust into a portion of the patients body surface

Answer 21

Dose area product

Question 22

Amount of energy per unit mass absorbed by an irradiated object

Answer 22

Absorbed dose

Question 23

Is the amount of energy transferred on average by incident radiation to an object per unit length of track, or passage, through the object and is expressed in units of kilo electron volts per micrometer.

Answer 23

Linear energy transfer (LET)

Question 24

Radiation with ______ LET transfers a large amount of energy into a small area and can therefore potentially do much more biologic damage than radiation with a ____ LET.

Answer 24

High
Low

Question 25

Adjustment multiplier that is employed in the calculation of dose equivalence to detail the specific ability of a dose of any kind of ionizing radiation to cause biological damage.

Answer 25

Quality factor

Question 26

Is the product of the average D in a tissue or organ in the human body and is associated with radiation weighting factor

Answer 26

Equivalent dose (EqD)

Question 27

EqD is obtained by multiplying the _____ by the _____

Answer 27

D (absorbed dose)
Wr (radiation weighing factor)

Question 28

Is the best overall risk of exposure to humans from ionizing radiation?

Answer 28

Effective dose

Question 29

Incorporates both the effects and type of radiation used and the variability in radio sensitivity of the specific organ or body part irradiated through the use of appropriate weighting factors

Answer 29

EfD

Question 30

To determine EfD, D is multiplied by a Wr to obtain______, and that product is multiplied by a tissue weighing factor to give____

Answer 30

EqD
EfD

Question 31

An attempt to describe the radiation exposure of a population or group from low doses of different sources of ionizing radiation

Answer 31

Collective effective dose

Question 32

Is a radiation dosimetry quantity that was defined by the NRC to monitor and control human exposure to ionizing radiation.

Answer 32

Total effective dose equivalent (TEDE)

Question 33

Discover of X-rays and by who?

Answer 33

November 8th 1895 by Wilhelmina Roentgen

Question 34

Roentgen passed electricity through a partially evacuated pear shaped glass tube known as

Answer 34

Crookes tube

Question 35

First death due to radiation?

Answer 35

Clarence Dally in October 1904