The effects of different ionic and non-ionic X-ray contrast media on the morphological and rheological properties of human red blood cells

Contrast media (CM) widely used in medicine are hyperosmotic, have a higher plasma viscosity, density and different ionic strength than ordinary blood plasma. Therefore, a bolus administration of such CM for X-ray diagnostics should alter the physico-chemical properties of blood and among these its rheological behaviour. To address this question, blood samples were incubated with ionic and non-ionic X-ray CM (75 mg I/ml). In order to quantify the complex rheological behavior we studied the whole blood apparent viscosity (0.05s⁻¹–100s⁻¹), sedimentation/packing ability of RBC and RBC aggregation by light back scattering in addition to microscopic examination of samples. The shape qual i ty index was lowest for ionic monomeric CM meglumineamidotrizoate and the non-ionic CM metrizamid. These CM also alter in a drastic manner the rheological behaviour of blood. Whereas most non-ionic monomeric CM (iopamidol, iohexol, iopromide, ioversol and iotriside) have shown an intermediate influence, the ionic dimeric ioxaglate and the non-ionic dimeric iotrolan deteriorate the morphology as well as the rheology of RBC in a less pronounced way.