The non-ionic isotonic contrast agents. Perspectives and controversies.

The non-ionic isotonic contrast agents represent a new class of intravascular iodinated x-ray contrast agents. They are highly hydrophilic, resulting in low chemotoxicity, are non-ionic, thereby eliminating Coulomb interactions, and are formulated in solutions iso-osmolar with the respective body fluids. Invitro testing, organ specific toxicity studies and overall systemic toxicity assessments such as LD50 measurements all point to an excellent toxicity profile. This justify their application in high dose procedures where their low toxicity may be distinctly advantageous. Their iso-osmolality, possibly combined with a slower diffusion of the larger molecules across vessel walls and out of the vascular space, may play a significant role in producing better quality venous phase images following arteriography and arterial phase images following venous injection. This may have implications for the quality of IV-DSA, the venous phase of arteriograms, CT-portography and spiral CT arteriography.