In vitro study of high-pressure catheters and various contrast agents.

The versatility of angiography has been expanded by the introduction of low-osmolality contrast agents; high-pressure, high-flow catheters with small outer diameters; and the use of contrast agents with low iodine concentrations. These changes have resulted in the need for a review of the physical factors that influence the flow of contrast agents through flush catheters. Various contrast agents were injected through several types of high-pressure, high-flow catheters with small outer diameters, and the flow rates were measured. Great differences in the viscosities of contrast agents resulted in proportionately smaller differences in maximum flow rates, and warming the contrast agent from room to body temperature had little effect on the maximum flow rate, except for the most viscous contrast agents. The maximum flow rates of the new low-osmolality contrast agents did not differ significantly from those of conventional ionic contrast agents of similar iodine concentration. With unheated contrast agents, iodine delivery was more rapid for contrast agents with iodine concentrations of 280-300 mg/mL.