Iohexol

Iohexol is a contrast agent, sold under the trade name Omnipaque. It is available in various concentrations, from 140 to 350 milligrams of iodine per milliliter. Omnipaque 350 is commonly used as a contrast agent during coronary angiography.

The osmolality of iohexol ranges from 322 mOsm/kg—approximately 1.1 times that of blood plasma—to 844 mOsm/kg, almost three times that of blood. Despite this difference, iohexol is still considered a low-osmolality contrast agent; the osmolality of older agents, such as diatrizoate, may be more than twice as high.