BIPS are composed of which materials?

• A. Calcium carbonate beads
• B. Barium impregnated polyethylene spheres
• C. Iodinated oil droplets
• D. Silver-coated pellets

Answer: (B)

The idea being tested is what BIPS are made of. They are tiny radiographic markers designed to be visible on X‑rays, formed by barium that is impregnated into polyethylene spheres. The barium provides the strong radiopacity, so the beads show up clearly on imaging, while the polyethylene shell keeps the particles uniform in size and biologically inert, allowing them to travel through the gastrointestinal tract safely for diagnostic studies. The other materials don’t fit this purpose: calcium carbonate beads don’t offer the same reliable radiopacity; iodinated oil droplets are a liquid contrast rather than solid spheres; and silver-coated pellets aren’t the standard, safe, controlled-type markers used in this context.