Fast Acoustic Steering Via Tilting Electromechanical Reflectors (FASTER): A Novel Method for High Volume Rate 3-D Ultrasound Imaging.

Zhijie Dong,Jun Zou,Pengfei Song,Shuangliang Li,Jason Pan,Matthew R Lowerison

doi:10.1109/tuffc.2020.3020871

Abstract

The 3-D ultrasound imaging is essential for a wide range of clinical applications in diagnostic and interventional cardiology, radiology, and obstetrics for prenatal imaging. 3-D ultrasound imaging is also pivotal for advancing technical developments of emerging imaging technologies, such as elastography, blood flow imaging, functional ultrasound (fUS), and super-resolution microvessel imaging. At present, however, existing 3-D ultrasound imaging methods suffer from low imaging volume rate, suboptimal imaging quality, and high costs associated with 2-D ultrasound transducers. Here, we report a novel 3-D ultrasound imaging technique, fast acoustic steering via tilting electromechanical reflectors (FASTER), which provides both high imaging quality and fast imaging speed while at low cost. Capitalizing upon unique water immersible and fast-tilting microfabricated mirror to scan ultrafast plane waves in the elevational direction, FASTER is capable of high volume rate, large field-of-view (FOV) 3-D imaging with conventional 1-D transducers. In this article, we introduce the fundamental concepts of FASTER and present a series of calibration and validation studies for FASTER 3-D imaging. In a wire phantom and tissue-mimicking phantom study, we demonstrated that FASTER was capable of providing spatially accurate 3-D images with a 500-Hz imaging volume rate and an imaging FOV with a range of 48° (20 mm at 25-mm depth) in the elevational direction. We also showed that FASTER had comparable imaging quality with conventional mechanical translation-based 3-D imaging. The principles and results presented in this study establish the technical foundation for the new paradigm of high volume rate 3-D ultrasound imaging based on ultrafast plane waves and fast-tilting, water-immersible microfabricated mirrors.

Highlights

U LTRASOUND has become the most commonly used clinical imaging modality due to its safety, low cost, and portability
3-D ultrasound imaging is challenged by various technical limitations of existing techniques, such as limited volume rate for 1-D transducer-based 3-D scanning, high complexity and costs associated with 2-D ultrasound transducers, and suboptimal spatial resolution and imaging quality for emerging techniques, such as RCA transducers and sparse arrays
We introduced a new method of conducting high volume rate 3-D imaging—fast acoustic steering via tilting electromechanical reflectors (FASTER)— which is based on a fast-tilting, water-immersible microfabricated mirror and conventional 1-D ultrasound transducers

Summary

Introduction

U LTRASOUND has become the most commonly used clinical imaging modality due to its safety, low cost, and portability. Conventional ultrasound can only provide a 2-D image for 3-D tissue structures. This leads to a high degree of operator dependence and uncertainty in image-guided procedures because radiological assessment, targeting, and image quantifications are dependent on transducer placement and patient positioning. With the capabilities of volumetric data acquisition, visualization, and quantification, 3-D ultrasound can mitigate the issues of operator dependence and uncertainties of imaging guidance associated with 2-D imaging. These features facilitate more reliable radiological evaluations and interpretations as well as more robust interventional planning with ultrasound. 3-D ultrasound has the potential of offering more accurate quantitative measurements with improved repeatability, accuracy, and reproducibility over 2-D imaging [3]

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Discussion

Conclusion