Volumetric Image Projection Super-Resolution Ultrasound (VIP-SR) with a 1D Unfocused Linear Array

TL;DR

This paper introduces VIP-SR, a novel volumetric super-resolution ultrasound technique using a 1D unfocused linear array, enabling high-resolution 3D microvascular imaging with simpler hardware and reduced costs.

Contribution

The study demonstrates the feasibility of VIP-SR with a 1D array for volumetric super-resolution imaging, achieving similar coverage to 2D arrays at a fraction of the hardware complexity.

Findings

VIP-SR captures significantly more volumetric information than focused 1D probes.

VIP-SR achieves similar volumetric coverage as 2D arrays with 32 times fewer elements.

Bubble concentration and vascular density affect VIP-SR imaging performance.

Abstract

Super-Resolution Ultrasound (SRUS) through localizing spatially isolated microbubbles has been demonstrated to overcome the wave diffraction limit and reveal the microvascular structure and flow information at the microscopic scale. However, 3D SRUS imaging remains a challenge due to the fabrication and computational complexity of 2D matrix array probes and connections. Inspired by X-ray radiography which can present volumetric information in a single projection image with much simpler hardware than X-ray CT, this study investigates the feasibility of volumetric image projection super-resolution (VIP-SR) ultrasound using a 1D unfocused linear array. Both simulation and experiments were conducted on 3D microvessel phantoms using a 1D linear array with or without an elevational focus, and a 2D matrix array as the reference. Results show that, VIP-SR, using an unfocused 1D array probe can capture significantly more volumetric information than the conventional 1D elevational focused probe. Compared with the 2D projection image of the full 3D SRUS results using the 2D array probe with the same aperture size, VIP-SR has similar volumetric coverage using 32 folds less independent elements. The impact of bubble concentration and vascular density on the VIP-SR US was also investigated. This study demonstrates the ability of high-resolution volumetric imaging of microvascular structures at significantly reduced costs with VIP-SR.