Initial experience of transcranial contrast-enhanced ultrasonography with Sonazoid in the evaluation of microvascular brain anatomy.

PURPOSE: The aim of this study is to visualize the microvascular anatomy of the brain parenchyma using transcranial contrast-enhanced ultrasonography (TCEUS) with Sonazoid. METHODS: TCEUS was performed in 14 subjects using the transtemporal and transnuchal approach (two patients with cerebral infarction and 12 healthy volunteers). An ultrasound system equipped with a 2- to 4-MHz sector probe set to coded phase inversion mode with a mechanical index of 0.4 was used. An intravenous bolus of Sonazoid (0.01 ml/kg) was injected. First-pass perfusion images were recorded from injection to 50 s after injection, and flush-replenishment (FR) images were recorded three times on both sides of the head from 1 to 5 min after injection. RESULTS: Real-time perfusion images of the brain parenchyma could be observed in all cases. At first pass, the main cerebral arteries began to be visualized at 10-20 s after injection, followed by the microvasculature at 15-30 s. The microvasculature reconstructed by the FR method could be observed on both sides of the head. CONCLUSION: TCEUS with Sonazoid allows effective, noninvasive evaluation of brain parenchyma microvasculature.