4D Wide-Field Ultrafast Ultrasound of the Human Carotid Using a Multi-Lens Probe

To extend the use of a large multi-lens probe technology to 4D ultrafast Doppler imaging and validate its performance both in vitro using a flow phantom and in vivo on the human carotid artery.

Radio-frequency data were acquired using a 1MHz large-aperture multi-lens probe on a tilted flow phantom with two tubes perfused by a water-cellulose mixture, and on a human carotid artery in vivo with contrast agents. 3D delay-and-sum beamforming with coherent compounding of 10 to 12 diverging waves, lens correction, and dynamic focusing was performed, followed by singular value decomposition (SVD) filtering to obtain Power Doppler data, Color and spectral Doppler data. Tube diameters were measured from Power Doppler volumes and compared with reference measurements taken with a conventional linear probe.

Tube diameters measured with the probe were consistent with those using a premium image quality commercial echographic device (Aixplorer, Supersonic Imagine), demonstrating the capability to retrieve structural information. The multi-lens system showed sensitivity to flow orientation and successfully detected opposite flow directions within the phantom. Doppler spectra captured carotid pulsatility, illustrating the ability to quantify physiologically relevant flow dynamics. The large-aperture design achieved an extended field of view of 41 × 69 × 41 mm³ in the phantom and 39 × 103 × 32 mm³ in vivo, with penetration depths of up to 8 cm and 6 cm, respectively.

The large multi-lens probe enables a wide-field of view 4D ultrafast Doppler imaging of the carotid in humans and holds strong potential to improve vascular mapping in a clinical setting.