Ultraviolet protectants: causative agents for screen and image artifacts in radiography.

Purpose: To determine the specific causative agent(s) and mechanism of formation of opacity artifacts seen on some radiographs acquired at the authors' facility.

Materials And Methods: Various substances likely to come into contact with technologists' hands were tested. Initial test results showed that a hand lotion with sun protection produced artifacts similar to the ones seen clinically and left no visible evidence on the screen after cleaning. Further experimental findings showed that substances without sun protection did not produce the artifacts, while other products with sun protection did produce artifacts. The four most commonly used active ingredients (ultraviolet [UV] filters) in products with sun protection were tested to determine if they produced artifacts. The temporal dependence and penetration depth of the causative agent(s) were determined. A sample of screens commonly used in radiology departments was tested to determine if artifacts were produced.

Results: Each of the UV filters tested caused artifacts when added to a lotion that had no sun protection and did not produce artifacts by itself. The UV filters quickly penetrated the protective layer of the screens and therefore could not be removed with conventional cleaning methods. Artifacts appeared only when using screens with a primary emission in the UV portion of the spectrum.

Conclusion: The UV filters in the products with sun protection absorb the UV light emitted by the screens and cause artifacts. Screens with UV emissions are susceptible to artifacts from the use of UV protectants.