Question

1. what is the radiopaque contrast medium used in radiographic studies of the gastrointestinal tract?

radionuclide
gamma rays
barium sulfate
uptake

Explanation:

Radiopaque contrast media block X-rays, making structures visible. Barium sulfate is insoluble, safe for GI tract imaging, and commonly used. Radionuclides are for nuclear medicine, gamma rays are radiation (not a medium), and uptake refers to absorption (not a contrast medium).

Answer:

Barium sulfate