Radiation Units of Measurement Flashcards
measurement of radiation in air
- exposure
- air KERMA
measurement of radiation in tissue
- absorbed dose
- equivalent dose
- effective dose
exposure
measures the NUMBER of ionizations in air
coulombs/kg
air KERMA
measures the ENERGY of ionizations in air
Gray (1 Joule/kg)
absorbed dose
energy absorbed in matter, per unit mass
Gray (1 Joule/kg)
absorbed dose affected by…
- mA
- kVp
- distance
- density (z-number)
use for absorbed dose
to understand risk of short-term injuries due to radiation
equivalent dose
EqD = D x Wr
Sv
Linear Energy Transfer (LET)
the rate at which radiation energy is deposited in matter. Higher LET radiation causes more biological harm
use for equivalent dose
to compare biological damage from different radiation types
equivalent dose affected by…
- radiation type
- absorbed dose
- mAs
- kVp
- distance
effective dose
EfD = D x Wr x Wt
Sv
use for effective dose
compares the risk of cancer based on different radiation types and different tissue types
effective dose affected by…
- absorbed dose
- radiation type (Wr)
- tissue type (Wt)
- mAs
- kVp
- distance
