Tolerance of iotrolan 190 and cerebrospinal fluid-diluted iotrolan 300 at the same iodine concentration in lumbar myelography.

Iotrolan, the radiologically effective ingredient of the contrast medium Isovist, has so little osmotic activity that only solutions of about 300 mg I/ml are isotonic to cerebrospinal fluid (CSF). The osmolality of the contrast medium at lower iodine concentrations has to be increased through additives. Theoretically, iotrolan 300 diluted with CSF is the most physiologic. Therefore, the commercial preparation iotrolan 190 (adaptation of the osmolality through the addition of saline and sodium bicarbonate) was tested in a randomized, single-blind study against a diluted contrast medium solution, iotrolan 190 (produced from iotrolan 300). The dilution was performed with the patient's own CSF. The test was carried out in lumbar myelography in two groups of 50 patients each. There were neither statistical nor tendency differences between the two preparations in either the opacification or the tolerance. Therefore, there is no suggestion that a contrast medium solution prepared with the patient's own CSF is better tolerated.