[Determination of hematocrit and iodine concentrations following intravenous bolus administration of ionic and nonionic monomeric and dimeric contrast media--an animal experimental study].

A monomeric ionic (meglumine diatrizoate), a monomeric non-ionic (iopromide) and a dimeric non-ionic contrast medium were intravenously administered (V. jugularis) to 15 rabbits. Blood iodine concentration as well as haematocrit were determined from blood samples taken from the femoral artery immediately after injection until the 90th second p.i. The contrast media showed clear differences concerning the haematocrit, i.e. the isotonic non-ionic dimer induced its lowest decrease. The direct determination of the blood iodine concentration revealed no significant deviations between the contrast media studied. Only non-ionic dimers are iso-osmolar with plasma at the iodine concentrations employed in diagnostic radiology. Compared with monomeric compounds this study provides fundamental evidence that isotonic, non-ionic dimeric contrast media cause only slight effects on blood cells. This confirms experimentally the clinically reported good tolerance of dimeric contrast media in patients.