The key difference between ionic and nonionic contrast media is that ionic contrast media can dissolve into charged particles when it enters a solution, whereas nonionic contrast media cannot dissolve into charged particles when it enters a solution.
Iodinated contrast media is available in two types as ionic and nonionic contrast media. These are types of intravenous radiocontrast agents that contain iodine as a major component. These agents can enhance the visibility of the vascular structures and organs in living organisms during radiographic processes. Both ionic and nonionic contrast media are useful in radiology because they are relatively harmless agents and are highly soluble as well.
CONTENTS
1. Overview and Key Difference
2. What is Ionic Contrast Media
3. What is Nonionic Contrast Media
4. Ionic vs Nonionic Contrast Media in Tabular Form
5. Summary – Ionic and Nonionic Contrast Media
What is Ionic Contrast Media?
Ionic contrast media are iodinated contrast agents that can dissociate into cations and anions when they enter a solution. In other words, ionic contrast media can dissolve into charged particles when entering a solution. In this type of media, every two cations are associated with three anionic components. Therefore, these agents are commonly known as 3:2 compounds.
Typically, ionic contrast media are high osmolarity contrast agents. Injecting this type of agent can cause a big increase in the number of particles that occurs in the vascular system. The ions that come from dissociation of ionic contrast media have the potential to destroy the electrical charges that are associated with the brain and heart. This disruption condition is named neurotoxicity.
What is Nonionic Contrast Media?
Nonionic contrast media are iodinated contrast agents that do not dissociate into cations and anions when entering a solution. In other words, nonionic contrast media cannot dissolve into charged particles when it enters a solution. This type of media contains one neutral component per every three iodine molecules. Therefore, these are named as 3:1 compounds.
Moreover, most of the nonionic contrast media are low osmolarity contrast media. When a nonionic contrast media is introduced into a vascular system, it can result in the movement of water from body tissues to the vascular system during attempting to equalize the concentrations. This increased fluid volume also can cause dilation of the vascular vessels.
What is the Difference Between Ionic and Nonionic Contrast Media?
Iodinated contrast media is available in two types as ionic and nonionic contrast media. The key difference between ionic and nonionic contrast media is that ionic contrast media can dissolve into charged particles when it is entering a solution, whereas nonionic contrast media cannot dissolve into charged particles when it enters a solution. Moreover, ionic contrast media show high osmolarity media whereas nonionic contrast media show low osmolarity media. In addition, nonionic contrast media is comparatively less toxic than ionic contrast media; therefore, there is a high demand for the nonionic type.
The following table presents the difference between ionic and nonionic contrast media in tabular form for side by side comparison.
Summary – Ionic vs Nonionic Contrast Media
Both ionic and nonionic contrast media are useful in radiology because they are relatively harmless agents that are highly soluble. The key difference between ionic and nonionic contrast media is that ionic contrast media can dissolve into charged particles when entering a solution, whereas nonionic contrast media cannot dissolve into charged particles when entering a solution. Moreover, ionic contrast media are toxic than nonionic contrast media; therefore, there is a high demand for the nonionic type.
Reference:
1. Mohit, Goel. “Contrast Media & Reaction.” SlideShare.
Image Courtesy:
1. “Brain Metastasis From Breast Cancer” By Jmarchn – Own work (CC BY-SA 3.0) via Commons Wikimedia