3-D Super-Resolution Ultrasound Imaging With a 2-D Sparse Array.

Sevan Harput,Enrico Boni,Matthieu Toulemonde,Alessandro Ramalli,Robert J Eckersley,Meng-Xing Tang,Jiaqi Zhu,Piero Tortoli,Chris Dunsby,Kirsten Christensen-Jeffries,Chee Hau Leow,Ge Zhang,Jemma Brown

doi:10.1109/tuffc.2019.2943646

Abstract

High-frame-rate 3-D ultrasound imaging technology combined with super-resolution processing method can visualize 3-D microvascular structures by overcoming the diffraction-limited resolution in every spatial direction. However, 3-D super-resolution ultrasound imaging using a full 2-D array requires a system with a large number of independent channels, the design of which might be impractical due to the high cost, complexity, and volume of data produced. In this study, a 2-D sparse array was designed and fabricated with 512 elements chosen from a density-tapered 2-D spiral layout. High-frame-rate volumetric imaging was performed using two synchronized ULA-OP 256 research scanners. Volumetric images were constructed by coherently compounding nine-angle plane waves acquired at a pulse repetition frequency of 4500 Hz. Localization-based 3-D super-resolution images of two touching subwavelength tubes were generated from 6000 volumes acquired in 12 s. Finally, this work demonstrates the feasibility of 3-D super-resolution imaging and super-resolved velocity mapping using a customized 2-D sparse array transducer.

Highlights

V ISUALIZATION of the microvasculature beyond the diffraction-limited resolution has been achieved by localizing spatially isolated microbubbles through multiple frames
Researchers demonstrated the use of 2-D super-resolution ultrasound (SR-US) imaging in many different controlled experiments and preclinical studies using microbubbles [4]–[11] and nanodroplets [12]–[15]
We demonstrate the feasibility of 3-D superresolution imaging and super-resolved flow velocity mapping using a density-tapered sparse array instead of a full 2-D array to reduce the number of channels and the amount of data while maintaining the volumetric imaging rate

Summary

Introduction

V ISUALIZATION of the microvasculature beyond the diffraction-limited resolution has been achieved by localizing spatially isolated microbubbles through multiple frames. Researchers demonstrated the use of 2-D super-resolution ultrasound (SR-US) imaging in many different controlled experiments and preclinical studies using microbubbles [4]–[11] and nanodroplets [12]–[15]. These studies generated super-resolved images of 3-D structures using 1-D ultrasound arrays where super-resolution cannot be achieved in the elevational direction. With the implementation of 3-D SR-US imaging using a 2-D array, diffraction-limited resolution can be overcome in every direction and there is the potential for 3-D motion tracking and correction

Methods

Results

Discussion

Conclusion