Perfluoroctylbromide as a blood pool contrast agent for liver, spleen, and vascular imaging in computed tomography

Perfluoroctylbromide (PFOB) in emulsion form was tested as a blood pool imaging agent for computed tomography (CT) in five animals (three dogs and two pigs). Computed tomography of the kidneys, liver, spleen, and mediastinum was performed in the control state and at various time intervals after the end of PFOB infusion. The attenuation coefficient of the vascular space increased by 117 Hounsfield units (HU) (range 105-128 HU), the liver by 54 HU (range 43-70 HU), and the spleen by 77 HU (range 69-86 HU) 30 to 50 min after the end of PFOB infusion, 5 ml/kg. The vascular space enhanced by 25 HU for every g of PFOB/100 ml of blood and remained at almost a constant level for hours after the end of infusion. In conclusion, PFOB emulsion, in addition to hepatosplenic enhancement, produces prolonged and substantial opacification of the vascular space, allowing CT imaging of the heart and vascular structures minutes to hours after the end of infusion.