What type of contrast media is generally iodine-based?

Iodine-based contrast media are classified as positive contrast agents. This classification is due to their ability to enhance the visibility of structures in imaging studies by increasing the attenuation of X-rays. The high atomic number of iodine allows it to absorb X-rays more effectively than surrounding tissues, resulting in a clearer contrast between the area of interest and adjacent tissues on the imaging study.

Positive contrast media, such as iodine-based solutions, are primarily used in various imaging techniques like computed tomography (CT) and certain types of fluoroscopy to visualize blood vessels, tumors, and other anatomical structures. These agents are particularly beneficial in outlining vascular anatomy and highlighting pathological changes within the body.

In contrast, negative contrast media typically includes substances like air or carbon dioxide, which create a dark image on X-rays due to their low density. Neutral contrast media usually have a neutral pH and are sometimes used in specific situations, but they do not significantly alter the contrast on imaging as iodine-based agents do. Aqueous contrast media refers more to the state of the contrast rather than its properties as positive or negative. Thus, iodine-based agents distinctly fall into the category of positive contrast media.