title: Sessile polyps: analysis of radiographic projections with the aid of a double-contrast phantom.
mesh_terms: D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D003287:Contrast Media; D006801:Humans; D007417:Intestinal Polyps / Q000000981:diagnostic imaging*; D008961:Models, Structural; D011859:Radiography
chemical_list: D003287:Contrast Media