Contrast material, or contrast dye, is a substance used to make specific organs, blood vessels, or types of tissue (such as tumors) more visible on X-rays. Contrast material may also be used during a CT scan, an ultrasound, or an MRI scan.
            Common contrast material substances include iodine, barium, and gadolinium.
           
         
        
          
            
              Current as of: July 31, 2024