What is the most common type of contrast used in CT imaging?

Iodine-based contrast agents are predominantly used in CT imaging due to their high effectiveness in enhancing the visibility of internal structures. These agents have a high atomic number, which contributes to their ability to absorb X-rays, resulting in clear contrast between different types of tissues and blood vessels in the images produced. This makes them particularly useful for visualizing vascular structures, organs, and tumors in detail.

Furthermore, iodine-based contrast agents can be administered intravenously, allowing for effective distribution throughout the circulatory system and highlighting areas of interest during imaging procedures. This versatility in administration and the ability to provide detailed imaging results underscores their common use in CT scans.

In comparison, while barium-based contrast agents are primarily used in gastrointestinal studies, gadolinium-based agents are mainly utilized in magnetic resonance imaging (MRI), and carbon dioxide gas is less frequently used in conventional CT examinations. These alternatives do not match the widespread applicability and effectiveness of iodine-based agents in standard CT imaging practices.