Transcranial volumetric imaging using a conformal ultrasound patch.

Area of Science:

• Biomedical Engineering
• Neuroscience
• Medical Imaging

Background:

• Accurate cerebral blood flow monitoring is crucial for neurocritical care and research.
• Conventional Transcranial Doppler (TCD) has limitations in 3D vascular imaging and prolonged monitoring due to its rigid design.

Purpose of the Study:

• To develop and evaluate a conformal ultrasound patch for hands-free, volumetric, and continuous cerebral blood flow imaging.
• To overcome the limitations of traditional TCD for complex vascular networks and long-term recordings.

Main Methods:

• Utilized 2 MHz ultrasound waves for reduced skull attenuation and a copper mesh shielding layer for improved signal-to-noise ratio.
• Employed ultrafast ultrasound imaging with diverging waves for 3D rendering of the circle of Willis and focused waves for continuous spectral recording.
• Compared the conformal patch's accuracy against a conventional TCD probe in 36 participants.

Main Results:

• The conformal patch demonstrated high accuracy, with small mean differences in peak systolic velocity (-1.51 ± 4.34 cm/s), mean flow velocity (-0.84 ± 3.06 cm/s), and end diastolic velocity (-0.50 ± 2.55 cm/s) compared to TCD.
• Achieved a measurement success rate of 70.6%, comparable to conventional TCD (75.3%).
• Successfully demonstrated continuous blood flow monitoring during interventions and identified intracranial B waves during drowsiness.

Conclusions:

• The conformal ultrasound patch offers a practical and accurate solution for hands-free, continuous, and volumetric cerebral blood flow monitoring.
• This technology has the potential to enhance neurocritical care and neurovascular research by providing more detailed and accessible hemodynamic data.