Contrast agents are substances used in medical imaging to enhance the visibility of internal structures in the body. They help improve the clarity of images obtained through techniques like X-rays, CT scans, and MRI. By highlighting specific areas, contrast agents allow healthcare professionals to better diagnose and monitor various conditions. These agents can be administered orally or through injection, depending on the type of imaging required. Common types include iodine-based agents for X-rays and CT scans, and gadolinium-based agents for MRI. While generally safe, some patients may experience allergic reactions or side effects.