Why iv contrast not absorb in the body?

IV contrast agents, often containing iodine, are designed to enhance imaging during procedures like CT scans. They are not absorbed by the body because they are large molecules that remain within the vascular system, allowing for clear visualization of blood vessels and organs. Additionally, these agents are typically excreted by the kidneys, minimizing their absorption and potential toxicity. This property ensures that they provide imaging benefits without significantly altering physiological processes.