[Visualization of brain perfusion by contrast-enhanced ultrasonography: preliminary study in rabbits].

Purpose: We evaluated the usefulness of an agent for contrast-enhanced ultrasonography (galactose parmitine acid: Levovist) in visualizing brain perfusion in rabbits.

Materials And Methods: Six rabbits were involved in this study. A hole in the skull bone was made under anesthesia and used as an acoustic window. An ischemic model (3 of 6 rabbits) was made by surgically occluding the M1 portion of the middle cerebral artery. Power Doppler images (PDI) and B-mode Harmonic images (HI) before and after intravenous injections of the contrast medium (150 mg/body) were obtained using the HDI5000 (ATL) equipped with a linear-type 5-12 Mhz probe.

Results: Smaller arteries were clearly visualized by contrast-enhanced PDI. However, enhancement of brain parenchyma was not clear on PDI. Enhancement of brain parenchyma was observed clearly on contrast-enhanced HI. Enhancement was strong during the first pass and then diminished quickly. In ischemic models, hypoperfusion in the right cerebral hemisphere (the occluded side) were clearly observed on contrast-enhanced HI.

Conclusion: Brain perfusion in rabbits can be observed on contrast-enhanced Harmonic ultrasonographic imaging. It is suggested to be useful for human clinical cases, including hypoxic ischemic brain injury in infants.