X-ray exposure levels at which solarization occurs were determined for
a new screen-film system and its predecessor, both from the same manu
facturer and both with a speed class of 400. Solarization (contrast re
versal [lead markers imaged as black on a lighter background]) was cle
arly evident with the new system at a cassette exposure level of 132 m
R (3.4 x 10(-5) C/kg). No solarization was exhibited by the old system
even at five times this exposure. In rare cases, solarization can obs
cure bone and soft-tissue detail, thereby degrading the diagnostic acc
uracy of the radiograph.