Isotonicity
Characteristic of a fluid that has the same osmolality as blood or other body fluids. Often used synonymously with isosmolar. All ionic and non-ionic monomeric contrast media are hypertonic compared to blood, ionic contrast media having osmolalities of up to 7 times that of blood, non-ionic monomers up to 2.5-3 times. Non-ionic dimers are supplied as isotonic with blood in all iodine concentrations. This gives a very low osmotoxicity. Non-ionic dimers are also called iso-osmolar contrast media (IOCM).
GE Healthcare Glossary