In vitro and in vivo studies on continuous echo-contrast application strategies using SonoVue in a newly developed rotating pump setup.

ABSTRACT

With emerging imaging strategies for contrast sonography (CS), there is a rising demand for the precise control of ultrasound (US) contrast agent delivery. Constant delivery minimizes artefacts and improves efficacy. The aim of this study was to evaluate the physical properties of the new contrast agent SonoVue and to evaluate the feasibility and accuracy of a new infusion approach using an automated infusion system for contrast agitation and delivery of echo-contrast agents. In vitro testing of infusion properties of SonoVue were performed in a capillary phantom mimicking tissue perfusion. Nonagitated standard infusion setups were compared with hand agitation and the new pump system with respect to possible artefacts, constancy of contrast effect and efficacy. In three volunteers, the new pump system was tested for constancy of contrast in large vessels. Without continuous agitation, continuous infusion of SonoVue resulted in bolus-like signal-intensity curves, along with substantial imaging artefacts. Additionally, homogenization of SonoVue significantly improved efficacy (p < 0.0001). No significant differences were found between hand agitation and homogenization by the new pump. In clinical settings, constant agitation using the new pump resulted in constant signal conditions in the carotid artery 3.72 +/- 0.46 units (U) after 5 min. Continuous agitation of SonoVue is mandatory for quantitative approaches. By the new infusion technique, CS could be performed for a reasonably long time period and efficacy is significantly improved (p < 0.0001). The new infusion technique might thereby allow routine application of constant infusion scenarios in clinical CS.