What lead thickness is required for the Bucky slot cover of a fluoroscopy system?

• A. 0.75 mm Pb
• B. 0.25 mm Pb
• C. 0.50 mm Pb
• D. 1.0 mm Pb

Answer: (B)

The Bucky slot cover is a secondary barrier designed to protect the operator from leakage and scatter radiation that can emerge through the fluoroscopy bucky slot. The radiation at that slot is relatively low in intensity compared with the primary beam, so only a modest amount of shielding is needed. A lead equivalence of 0.25 mm is the standard thickness used for this purpose, providing enough attenuation to keep exposure within recommended limits while keeping the shield light and practical to handle. Using a thicker shield would add unnecessary weight and cost without a meaningful gain in protection for this location. So, 0.25 mm Pb is the appropriate choice for the bucky slot cover.