Which grid construction option lists the correct materials?

• A. Lead plates with air gaps
• B. Strips of plastic separated by air gaps
• C. Strips of lead separated by strips of plastic
• D. A single sheet of metal

Answer: (C)

Grids are built from alternating lead strips that absorb scattered photons and radiolucent interspaces that allow the primary beam to pass through. The interspace material is usually plastic (often with aluminum) rather than air, providing stable, uniform spacing and consistent attenuation. That’s why the correct construction is strips of lead separated by strips of plastic: lead does the scattering suppression, while the plastic interspaces keep the grid evenly spaced and radiolucent. The other options either lack the lead components, rely on air gaps in a way that isn’t the standard grid construction, or would block the beam entirely.