Radiological Units, Quantities, And Terminology Flashcards
Exposure
Energy deposited by ionization radiation
Roentgen (R)
The amount of x-ray or gamma radiation less than or equal to 3 MeV, rthat will produce in 2.58x10^-4 charge per kg of air.
Absorbed Dose (D)
The energy imparted by ionizing radiation per unit of mass of irradiated material (Energy = per unit of mass)
Units of absorbed dose
Gray or rad.
Rad
Unit of absorbed dose that is qual to the absorption of 100 ergs per gram
Quality Factor
The factor that is multiplied by the absorbed dose (D) to obtain a quantity which is equal to the dose equivalent (HT)
HT=DQ
Quality factor for photons (gamma rays and x-rays)
1
Quality factor for beta+ and beta-
1
Quality factor for thermal neutrons
2
Quality factor for fast neutrons
10
Quality factor for Protons
10
Quality factor for Alpha particles
20
Dose Equivalent (HT)
HT=DQ
Purpose is to have a single unit of radiation regardless of type to have a single unit to describe it’s effects on humans.
Rem per NAVMED P50-55
Unit of HT which is = to the absorbed dose in rad multiplied by the quality factor
(HT=DQ)
Rem per NNPP
(Know this verbatim)
“The amount of any type of radiation that will cause the biological damage equivalent to 1 rad of gamma radiation”
Sievert
1 Sv = 100 rem
Man-rem
Total amount of radiation dose received by all the individuals in a specific group over a specific time.
Effective Dose Equivalent (HE)
The sum of the weighting factors as applicable to each of the body organs or tissue and the dose equivalent to these body organs and tissues (HE=WT*HT)
Deep Dose equivalent (Hd)
External exposure to the entire body at a tissue depth of 1 cm.
Shallow Dose Equivalent (Hs)
External exposure to the skin at a tissue depth of 0.007 cm
Eye Dose Equivalent
External exposure to the lens of the the eye at a tissue depth of 0.3 cm
Committed Dose Equivalent (HT,50)
Dose equivalent to an organ or tissue that will be received from an intake of radioactive material by an individual over the 50-year period after the intake
Committed Effective Dose Equivalent
The sum of products of the weighting factors applicable to Each of the body tissues or tissues that are irradiated and the committed dose equivalent to these organs or tissues.
More simply put, the Internal dose of radiation.
Total Effective Dose Equivalent (TEDE)
TEDE=DDE+CEDE
The external dose and internal dose put together.
