EFFICACY OF IMAGENT(R) BP AT 1.5ML KG IN A RABBIT LIVER-TUMOR MODEL/

We have shown using a Vx2 rabbit model that 3 and 5 ml/kg of perflubro n emulsion were highly effective in imaging liver tumors. The results from preliminary clinical trials suggested that should the infusion ra te be increased, a 1.5 ml/kg may be efficacious. This study determined whether 1.5 ml/kg given as a bolus IV would be efficacious to image l iver tumors using a Vx2 rabbit model. Vx2 tumors were implanted in 5 N ZW rabbits, CT of the liver was performed during held expiration at 80 kV and 800mAS, before and shortly after 1.5 ml/kg Imagent(R) BP (ImBP) , again at 30 minutes and 3 days. Regions of interest (ROIs) were draw n over the CT image of the spleen, liver, inferior vena cava, and tumo r, CT# obtained and average enhancement of each tissue calculated at e ach time point. 4 animals had tumors . 5 cm or greater. Precontrast, t umors were faintly seen on CT, Blood was brighter than liver shortly a fter infusion and isointense with liver at 30 minutes. Tumors did not enhance following contrast. Except for the liver and spleen, all tissu es returned to baseline on the 3rd day. Therefore a clinical trial to determine the efficacy of 1.5ml/kg ImBP to image the liver is warrante d.