chapter 4 EXAM 2

Question 1

somatic damage

Answer 1

biologic damage to the body of the exposed individual

Question 2

who was the first recognized american xray fatality

Answer 2

clarence daily

died oct. 1904

Question 3

occupational exposure

Answer 3

radiation exposure received by radiation workers in the course of exercising their professional responsibilities

Question 4

what diseases are more common among radiologist than non radiologists

Answer 4

aplastic anemia and leukemia

Question 5

british xray and radium protection committee

Answer 5

formed in 1921 to investigate methods for reducing radiation exposure
unfortunately they could not agree on things and did not fulfill their responsibility

Question 6

skin erythema dose

Answer 6

the first unit for measuring radiation exposure (1900-1930)

Question 7

skin erythema dose definition

Answer 7

received quantity of radiation that causes diffused redness over an area of skin after irradiation

Question 8

first international congress of radiology

Answer 8

in london england in 1925
allowed collaboration of rads from around the world
no decisions for measuring ionizing radiation

Question 9

the international commission on radiation units and measurements ICRU

Answer 9

formed in 1925
finished the job from the second international congress of radiology
roentgen became the internationally accepted unit of measurement for x radiation and gamma radiation

Question 10

second international congress of radiology

Answer 10

stockholm sweeden 1928

made the roentgen accepted as a unit of exposure but could not define it so the ICRU did in 1937

Question 11

short term somatic effects (early or acute effects)

definition

Answer 11

somatic effects that appear within minutes hours days or weeks of the time of radiation exposure

Question 12

list of short term somatic effects (early or acute effects)

Answer 12

nausea 
fatigue
redness of skin
loss of hair
fever
blood disorders
shedding of skin

Question 13

tolerance dose

Answer 13

a radiation dose to which occupationally exposed persons could be continuously subjected without any apparent harmful acute effects
believed nothing would happen as long as it was kept below dose

Question 14

in 1934 internation xray and radium protection committee recommended a tolerance dose of

Answer 14

0.2 roentgen a day

was reduced to 0.1 roentgen a day in 1936

Question 15

threshold dose

Answer 15

a dose of radiation below which an individual has a negligible chance of sustaining specific biologic damage

Question 16

long term or late somatic effects definition

Answer 16

effects of ionizing radiation that appeared months or years following exposure to ionizing radiation

Question 17

long term or late somatic effects list

Answer 17

cancer
embryonic effects (birth defects)
formation of cataracts

Question 18

the general conference of weights and measurements created

Answer 18

the international system of units to be able to interchange units throughout the world

Question 19

when was tolerance dose replaced and what was it replaced by

Answer 19

early 1950s and it was replaced by the maximum permissible dose MPD

Question 20

maximum permissible dose MPD

Answer 20

a term used in the past to indicate the maximum dose equivalent of ionizing radiation that an occupationally exposed person could absorb in a specified time without sustaining bodily injury

Question 21

MPD meant that

Answer 21

no amount of radiation was considered completely safe

Question 22

1 sievert is equal to how many rem

Answer 22

100 rem

Question 23

what are the 5 radiation quantities

Answer 23

1. exposure
2. air kerma
3. absorbed dose
4. equivalent dose
5. effective dose

Question 24

exposure is measured in

Answer 24

reontgen (traditional)

columb per kilogram (SI)

Question 25

air kerma is measured in

Answer 25

gray with subscripts "a" or "t"

Question 26

absorbed dose is measured in

Answer 26

Rad (traditional) | gray (SI)

Question 27

equivalent does is measured in

Answer 27

Rem (traditional) | sievert (SI)

Question 28

effective dose is measured in

Answer 28

Rem (traditional) | sievert (SI)

Question 29

exposure (x)

Answer 29

the total electrical charge of one sign, either all pluses or minuses, per unit mass basically measures the amount of ion pairs in the air.

Question 30

exposure is measured by an

Answer 30

ionization chamber

Question 31

coulomb (C)

Answer 31

a basic unit of electrical charge

Question 32

how do you convert from roentgens to coulombs per kilogram

Answer 32

multiply the number of roentgens by 2.58 x 10^-4

Question 33

how do you convert coulombs per kilogram to roentgens

Answer 33

divide the coulombs per kilogram by 2.58x10^-4

Question 34

air kerma

Answer 34

SI quantity that can be used to express radiation concentration transferred to a point kinetic energy released in a unit mass of air basically indicates a calculation of radiation intensity in air

Question 35

air kerma is replacing what

Answer 35

the traditional quantity, exposure

Question 36

Kerma is an acronym for

Answer 36

kinetic energy released in matter | kinetic energy released per unit mass

Question 37

air kerma is expressed in metric units of

Answer 37

joule per kilogram

Question 38

joule is the metric unit of

Answer 38

energy

Question 39

tissue kerma

Answer 39

energy released in a unit mass of tissue

Question 40

tissue kerma is measured in

Answer 40

Gray

Question 41

air kerma is expressed as

Answer 41

Gya

Question 42

tissue kerma is expressed as

Answer 42

Gyt

Question 43

if the air kerma is measured at a point where soft tissue is located,

Answer 43

the absorbed dose in the tissue will be about the equal to the air kerma

Question 44

dose area product

Answer 44

the sum total or air kerma over the exposed area of the patients surface

Question 45

DAP is expressed in units of

Answer 45

mGy/cm^2

Question 46

DAP is the most practical quantity for

Answer 46

monitoring the radiation delivered to patients

Question 47

absorbed dose (D)

Answer 47

the amount of energy per unit mass absorbed by the irradiated object

Question 48

absorbed dose is used to indicate

Answer 48

the amount of ionizing radiation a patient receives during a procedure

Question 49

amount of energy absorbed by a patient depends on

Answer 49

atomic number (Z) mass density energy of incoming photon

Question 50

absorption increases as

Answer 50

atomic number and mass density increases and photon energy decreases

Question 51

effective atomic number (Zeff)

Answer 51

weighted average of atomic numbers

Question 52

T or F | bone has a higher effective atomic number than soft tissue

Answer 52

true

Question 53

Zeff of bone =

Answer 53

13.8

Question 54

Zeff of soft tissue =

Answer 54

7.4

Question 55

what is the only measure of ionization in air and not other tissues

Answer 55

exposure

Question 56

1 gray = how many joules/kilogram

Answer 56

1 joule/kilogram

Question 57

what is the traditional unit for joule

Answer 57

erg

Question 58

1 gray = how many rads

Answer 58

100 rad

Question 59

how do you convert rad to gray

Answer 59

divide the rad by 100 to get gray

Question 60

how to convert gray to rad

Answer 60

multiply the gray by 100

Question 61

how to convert from gray to milligray

Answer 61

multiply by 1000

Question 62

how to convert from milligray to gray

Answer 62

divide by 1000

Question 63

in therapeutic radiology what is replacing the rad for recording absorbed dose

Answer 63

the centigray

Question 64

to convert gray to centigray

Answer 64

multiply by 100

Question 65

surface integral dose SID

Answer 65

the total amount of radiant energy transferred by ionizing radiation to the body during an exposure

Question 66

quality factor AKA radiation weighting factor

Answer 66

an adjustment multiplier used in the calculation of dose equivalent

Question 67

linear energy transfer LET

Answer 67

the amount of energy deposited on average by ionizing radiation in an object per unit length of track as it passes through the object

Question 68

Linear energy transfer is measured in

Answer 68

KeV/micrometer

Question 69

high LET

Answer 69

departs energy quickly and causes more biologic damage | alpha particles have a high LET

Question 70

low LET

Answer 70

more sparsely ionizing. | less chance of producing biologic damage because it disperses its energy

Question 71

LET helps explain

Answer 71

the quality factor or modifying factors for different types of ionizing radiation

Question 72

equivalent dose enables the calculation of

Answer 72

effective dose

Question 73

stochastic effects

Answer 73

non threshold, randomly occurring biologic effects of ionizing radiation

Question 74

the probability of stochastic effects depends on

Answer 74

radiation dose and type of energy of the ionizing radiation

Question 75

the higher the radiation weighting factor of a type of ionizing radiation, the more

Answer 75

effective it is at producing biologic damage

Question 76

equivalent dose is obtained by multiplying

Answer 76

the absorbed dose (D) by the radiation weighting factor (Wr) | or Sv = Gy x Wr

Question 77

how to convert the sievert to the microsievert

Answer 77

multiply the sievert by 1,000,000

Question 78

effective dose

Answer 78

the sum of the weighted equivalent doses for all irradiated tissues and organs

Question 79

effective dose includes

Answer 79

the type of radiation and the radiosensitivity of the specific organ or body part

Question 80

tissue weighting factor

Answer 80

a value that denotes the percentage of the stochastic risk stemming from the irradiation of tissue

Question 81

how to determine effective dose

Answer 81

an absorbed dose (D) is multiplied by a radiation weighting factor to obtain the equivalent dose. then the equivalent dose is multiplied by a tissue weighting factor to obtain the effective dose.

Question 82

collective effective dose ColEfD

Answer 82

the product of the average effective dose for an individual belonging to the exposed population or group and the number of persons exposed

Question 83

what is the unit for ColEfD

Answer 83

person-sievert

Question 84

what does the total effective dose equivalent do TEDE

Answer 84

to monitor and control human exposure to ionizing radiation

Question 85

what is the TEDE

Answer 85

the sum of effective dose equivalent from external radiation sources and a quantity called committed effective dose equivalent (CEDE) from internal exposures

Question 86

TEDE is a useful dose monitor for

Answer 86

occupationally exposed personnel

Question 87

for occupationally exposed personnel, the whole body TEDE regulatory limit is

Answer 87

0.05 sieverts or 50 milisieverts