What sign is required to be posted in imaging rooms according to the NRC?

In nuclear medicine imaging rooms, it is critical to ensure that proper signage is displayed as a safety measure for both patients and staff. The Nuclear Regulatory Commission (NRC) requires specific warnings to be posted in areas where radioactive materials are used.

The correct sign, "Caution: Radioactive materials," is essential because it informs individuals entering the area that they may be in proximity to materials that emit radiation. This helps to prevent unnecessary exposure and ensures that everyone is aware of the potential hazards associated with radioactive substances. These signs serve as a protective measure, emphasizing the importance of following safety protocols in imaging rooms where radioactive materials are present during diagnostic or therapeutic procedures.

Other options like "Caution: Radiation area" or "Caution: High Radiation Area" are similar but pertain to different levels of radiation exposure potential. "Caution: Radiation area" is used for areas where an individual could receive a dose greater than a certain threshold in an hour, while "Caution: High Radiation Area" indicates zones where the radiation doses are significantly higher. However, in the context of imaging rooms specifically dealing with radioactive materials, the indication of "Caution: Radioactive materials" is the most relevant and legally mandated sign that must be present.