Air-filled ultrasound contrast agents do not damage the cerebral microvasculature or brain tissue in rats.

Rationale And Objectives: Air microemboli may damage the cerebral microvasculature. The aim of this study was to evaluate the safety of ultrasound contrast agents composed of air microspheres with regard to cerebral damage when administered into the arterial system (ie, when not filtered by the capillary system of the lungs).

Methods: Three experimental methods were used in 75 rats after injection of either Albunex, Echovist, or Levovist into the left heart ventricle.