Continuous-infusion contrast-enhanced US: In vitro studies of infusion techniques with different contrast agents

PURPOSE: To evaluate the infusion properties of three ultrasonographic (US) contrast agents and to compare different infusion techniques for achieving constant signals during harmonic power Doppler US. MATERIALS AND METHODS: In vitro studies were performed in a flow phantom. S H U 508A, NC100100, or FS069 was continuously infused at clinically usable doses and infusion rates. To assess agent-specific physical properties, the se agents were administered by using a vertically fixed infusion pump and v arying infusion start times. The contrast agents were administered by also using a horizontally oriented infusion pump that was either fixed or contin uously rotated to homogenize the agent in the syringe. RESULTS: With SH U 508A and NC100100, constant signals were achieved, regar dless of the infusion modality used. Compared with conventional infusion, t he continuous homogenization of SH U 508A, although not necessary for signa l constancy, increased the agent's usefulness (P < .05). With FS069, only c ontinuous homogenization yielded constant signals (P < .001). CONCLUSION: Continuous infusion of SH U 508A or NC100100 provided constant harmonic power Doppler US signals, regardless of the infusion modality used . Because of the special physical properties of FS069, only homogenization produced constant harmonic power Doppler US signals during continuous infus ion of this agent.