Radiation Quantities and Units

Question 1

Radiation Quantities and Units

Answer 1

Exposure (X)
Kerma
Absorbed Dose (D)
Equivalent Dose (EqD)
Effective Dose (EfD)

Question 2

Measurement Units in CT

Answer 2

1. Computed Tomography Dose Index (CTDI)
2. Multiple Scan Average Dose (MSAD)
3. Dose Length Product (DLP)

Question 3

Quantity of XRs or gamma rays required to produce a given amount of ionization (charge) in a unit mass of air

Answer 3

Exposure (X)

Question 4

Exposure (X) is not applicable to photons of energy (1) or specifically, (2)

Answer 4

1. above 3MeV
2. particulate radn

Question 5

Dry, non-humid at a standard temp and pressure

Answer 5

Air

Question 6

Air temp, pressure, and device

Answer 6

750mmHg or 1atm @ sea level, 22deg Celsius, standard or free air ionization chamber

Question 7

Kerma Meaning

Answer 7

Kinetic Energy released in matter

Question 8

Energy absorbed per unit mass from the initial kinetic energy released ub natter if akk electrons liberated by XRs or gamma rays

Answer 8

Kerma

Question 9

Incorporated in modern radiographic and fluoroscopy units

Answer 9

Dose Area Product (DAP)

Question 10

Used to determine the entire amount of energy delivered to the pt by the XR beam

Answer 10

DAP

Question 11

Measure of the amount of radiant energy that has been thrust into a portion of pt’s body surface

Answer 11

DAP

Question 12

DAP Units

Answer 12

mgy-cm^2

Question 13

Amounf of energy per unit mass absorbed by an irradiated object

Answer 13

Absorbed Dose (D)

Question 14

Amounf od ionizing radn a pt receives during a diagnostic procedure

Answer 14

D

Question 15

Total amount of radiant energy transferred by ionizing radn to the body during exposure

Answer 15

Surface Intergral Dose (SID)

Question 16

Surface Intergral Dose (SID) other term

Answer 16

Exposure Area Product

Question 17

Product of the average dose in a tissue or organ in the human body and its associated radn weighting factor chosen for the type and energy of the radn in question

Answer 17

Equivalent Dose (EqD)

Question 18

Used for radn protection purposes when a person receives exposure from various types of ionizing radiation

Answer 18

Equivalent Dose (EqD)

Question 19

Equivalent Dose (EqD)

Equal absorbed doses of diff types of radn produce diff amounts of — in body tissues

Answer 19

biological damage

Question 20

Measure of the overall risk of exposure to humans from ionizing

Answer 20

Effective dose (EfD)

Question 21

Incorporated both the effect o the type of Radiation used and the variability in radiosensitivity of the specific organ of body part irradiated

Answer 21

Effective dose (EfD)

Question 22

1C = — e- charge

Answer 22

6.24x10^(18)

Question 23

Radiation exposure of a population or group from low doses of diff sources of ionizing radiation

Answer 23

Collective Effective Dose (ColEfD)

Question 24

Product of the average EfD for an individual belonging to the exposed population or group and the number of persons exposed

Answer 24

Collective Effective Dose (ColEfD)

Question 25

TEDE vs CEDE

Answer 25

TEDE (Total Effective Dose Equivalent): Sum of effective dose equivalent from external radiation exposures CEDE (Committed Effective Dose Equivalent): Sum of effective dose equivalent from internal radiation exposures

Question 26

Whole-body TEDE limit

Answer 26

Ocupationnally exposed: 0.05sv General public: 0.001sv

Question 27

Who/ What is referred to by: 1. Ocupationnally exposed 2. General public 3. Internal radiation exposures

Answer 27

1. Received by NucMed Techs and IV Technologists/ Radiologists 2. Patient/s 3. Intake of radioactive material

Question 28

Dose in CXR

Answer 28

0.02msv

Question 29

Radiation dose in a single slice over a 10cm length

Answer 29

Computed Tomigraphy Dose Index (CTDI)

Question 30

Measures the radn dose in the primary beam that was delivered to the pt

Answer 30

Computed Tomigraphy Dose Index (CTDI)

Question 31

To measure radiation dose to the pt as measured within primary beam of CT scanner

Answer 31

Computed Tomigraphy Dose Index (CTDI)

Question 32

Average dose a pt receives during an exam, which would include numerous individual scans (or in the case of a helical scanner, a moving scan)

Answer 32

Multiple Scan Average Dose (MSAD)

Question 33

Product of CTDI and slice thickness

Answer 33

Dose Length Product (DLP)

Question 34

Depends only on selected CT parameters and does not reflect pt dose

Answer 34

Dose Length Product (DLP)

Question 35

Rate of decay or disintegration of radioactive material

Answer 35

Radioactivity

Question 36

1 Ci = --- Bq

Answer 36

3.7x10^(10)