Final answer:
The best position to visualize the hepatic flexure on a double-contrast colon series is typically the right lateral decubitus position. This allows the barium to fill the hepatic flexure, providing a clear view for evaluation.
Step-by-step explanation:
The position that best demonstrates the hepatic flexure on a double-contrast colon series is a barium enema examination under fluoroscopy. This imaging study involves filling the colon with a contrast material that contains barium (which helps to visualize the colon on X-rays) and a gas (to expand the colon). The radiologist will take advantage of various patient positions to adequately view and evaluate different segments of the colon. For the hepatic flexure, a right lateral decubitus position (the patient lying on their left side) can help in allowing the barium to fill this area, thereby giving a clear view of the flexure. However, the actual best position may vary based on the patient's anatomy and the specifics of the procedure. It's important for the technologist conducting the exam to work closely with the radiologist to determine the optimal positioning.