An in vitro comparison of ultrasonic contrast agents in solutions with varying air levels

The performance, in particular, the stability of ultrasound (US) contrast a gents has yet to be assessed. An in vitro system has been set up to investi gate the properties of ultrasonic contrast agents under different suspensio n conditions. This is designed to contribute to the optimal use of agents i n clinical practice. In this study, the contrast agents were introduced int o solutions of different oxygen concentration levels, as might be encounter ed in blood, and their relative performance was assessed in terms of decay in the solution environment, The partial pressures of oxygen in those solut ions ranged between 1.5 and 26 kPa, Three IV and one arterial contrast agen ts were used: Levovist(R), DMP115, Quantison(TM) and Myomap(TM). Levovist(R ) showed the highest sensitivity to oxygen concentration in the solution, a nd the other three proved tolerant for the above values of oxygen concentra tions. (C) 2000 World Federation for Ultrasound in Medicine & Biology.