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Operator´s Manual
1000-095-071-EN Rev. 1.1
OMNERA®
2020-09-14
Page 25
Profile of stray radiation for table
The diagram below, Fig. 2-4
Scattered radiation rate expressed in percent of central beam
dose rate, with and without shielding
, shows the dependency of the scattered radiation on
the distance from the central beam, height above the floor and kV potential. The decrease of
the scattered radiation is expressed in percent of the central beam exposure rate (100%).
The diagram also shows the decrease of scattered radiation when using protective clothing,
also this expressed in percent of the central beam dose rate.
Scattered radiation rate expressed in percent of central beam dose rate, with and
, shows that a higher kV increases the scattered radiation slightly. The dia-
gram also shows that the best way to minimize the effect of the scattered radiation is an in-
creased distance to the patient and by using a lead apron.
Central beam exposure parameters used:
KVP: 70, 100, 120 kV
Tube current: 100 mA
Exposure time: 100 ms
Field size: 43x43 cm
Film-Focus distance: 1 m
Patient simulation: 150 mm PMMA
Filter: 0 mm
Central beam dose rate measured on top of PMMA (750 mm from focus).
0
500
1000
1500
2000
0,001
0,010
0,100
1,000
10,000
100,000
Height above floor (mm)
Percent of central beam dose rate (%)
Scattered radiation expressed in percent of central beam dose rate
70KV, 500 mm
100KV, 500mm
120KV, 500mm
70KV, 1000mm
70KV, 1000mm, Lead apron
100KV, 1000mm
100KV, 1000mm, Lead apron
120KV, 1000mm
120KV, 1000mm, Lead apron
central Beam dose rate
Fig. 2-4 Scattered radiation rate expressed in percent of central beam dose rate, with and without
shielding