Transcript Ionizing Radiation Units

S.A.SH.Kowsarian MD.
Imam Khomeini Hospital, Sari
Conventional(cgs): curie(Ci)
37 billion decays/sec
SI: becquerel(Bq)
1 dacay/sec
(rutherford=1000,000 becquerel)
Conventional(cgs): Roentgen(R)
The amount of ionizing radiation that induce 1 ESU
charge in 1 cc of air
1 ESU=1 franklin(Fr)=258 microcoulomb/Kg
SI: coulomb(C)
Conventional(cgs): RAD
Radiation Absorbed Dose
1 RAD = 100 erg/gr
SI: gray(Gy)
1 gray = 1 joule/Kg = 100 RAD
Conventional(cgs): REM
Radiation Equivalent Man
REM=RAD X QUALITY FACTOR (RBE)
SI: sievert(Sv)
1 sievert = 100 REM
RBE (Relative Biological Effectiveness)
Weighting factor
Quality factor
Radiation type
RBE
Electrons, positrons, muons, photons(X-γ)
1
Neutrons < 10 kev
5
Neutrons 10-100 kev
10
Neutrons 100 kev-2 mev
20
Neutrons > 2 mev
5
Alpha ray, fission fragments, heavy nuclei
20
Dental 0.005 mSv
CXR 0.5 mSv
Mammo single shot 2 mSv
Mammo procedure 4-5 mSv
Brain CT 0.8-5 mSv
Chest CT 6-18 mSv
GI series 14 mSv
Average environment yearly 2.4 mSv