special subjects
Radiographic Contrast Agents
Introduction
Radiographic contrast agents are substances used to distinguish between internal structures in medical imaging, such as various types of x-rays and magnetic resonance imaging (MRI). During Overview of Imaging Tests , contrast agents may be used to distinguish one tissue or structure from its surroundings or to provide greater detail. Contrast agents include Radiopaque contrast agents (sometimes inaccurately called dyes): Substances that can be seen on x-rays Paramagnetic contrast agents: Substances that are used in Magnetic Resonance Imaging (MRI) (MRI) 