A radiopaque contrast agent is a substance used in medical imaging to enhance the visibility of internal structures in the body. When injected or ingested, these agents absorb X-rays more than surrounding tissues, making them appear brighter on imaging scans like X-rays, CT scans, or fluoroscopy. This helps doctors identify abnormalities, such as tumors or blockages. These agents are typically made from iodine or barium, which are effective at blocking X-rays. They are generally safe, but some patients may experience allergic reactions or side effects. Proper use of radiopaque contrast agents is essential for accurate diagnosis and treatment planning.