Transcranial ultrasound brain perfusion assessment with a contrast agent-specific imaging mode: results of a two-center trial.

Background And Purpose: The purpose of this study was to assess brain perfusion with an ultrasound contrast-specific imaging mode and to prove if the results are comparable between 2 centers using a standardized study protocol.

Methods: A total of 32 individuals without known cerebrovascular disease were included in the study. Perfusion studies were performed ipsilaterally in an axial diencephalic plane after intravenous administration of 0.75 mL of Optison. Offline time intensity curves (TIC) were generated in different anatomic regions. Both centers used identical study protocols, ultrasound machines, and contrast agent.

Results: In both centers, the comparison of the parameter time to peak intensity (TPI) revealed significantly shorter TPIs in the main vessel structures compared with any parenchymal region of interest (ROI), whereas no significant differences were seen between the parenchymal ROIs. The parameter peak intensity (PI) varied widely interindividually in both centers, whereas the inter-ROI comparison revealed statistical significance (P < 0.05) in most of the cases according to the following pattern: (1) lentiforme nucleus > thalamus and white matter region, (2) thalamus > white matter region, and (3) main vessel > any parenchymal structure. Similar results were achieved in both centers independently.

Conclusions: The study demonstrates that brain perfusion assessment with an ultrasound contrast-specific imaging mode is comparable between different centers using the same study protocol.