RELATIONSHIP BETWEEN VISCOSITY AND DETERMINED INJECTION PRESSURE IN ANGIOGRAPHY CATHETERS FOR COMMON ROENTGEN CONTRAST-MEDIA

The viscosity of 8 commercially available contrast media (CM) at 2 or 3 concentrations were measured as a function of concentration and temp erature, using a rotational viscosimeter. Further on, by use of an aut omated injector, injection pressures were measured for 3 of the CM at various concentrations, temperatures, catheter lengths, catheter diame ters and flow rates. The experiments were performed as fractional fact orial designs. The correlation between the injection pressure and the viscosity was found to be log-linear, and an empiric equation was esta blished for this relationship. The relative reduction of viscosity - a nd thereby injection pressure - with increasing injection temperature, was largest for the most concentrated CM. Iodixanol and iotrolan, the 2 nonionic dimers investigated, demonstrated an increased viscosity c ompared to the nonionic monomers at equal concentrations. However, all CM investigated could be used with an acceptable injection pressure e ither by relatively small changes in catheter conditions or by adjustm ent of injection temperature closer to body temperature.