Sparse Rectangular and Spiral Array Designs for 3D Medical Ultrasound Imaging.

Hansol Yoon,Tai-Kyong Song

doi:10.3390/s20010173

Abstract

In three-dimensional (3D) medical ultrasound imaging with two-dimensional (2D) arrays, sparse 2D arrays have been studied to reduce the number of active channels. Among them, sparse 2D arrays with regular or uniform arrangements of elements have advantages of low side lobe energy and uniform field responses over the entire field of view. This paper presents two uniform sparse array models: sparse rectangular arrays (SRAs) on a rectangular grid and sparse spiral arrays (SSAs) on a sunflower grid. Both arrays can be easily implemented on the commercially available or the custom-made arrays. To suppress the overall grating lobe levels, the transmit (Tx) and receive (Rx) array pairs of both the array models are designed not to have grating lobes at the same locations in the Tx/Rx beam patterns, for which the theoretical design rules are also proposed. Computer simulation results indicate that the proposed array pairs for both the SRAs and the SSAs achieve peak grating lobe levels below –40 dB using about a quarter of the number of elements in the dense rectangular array while maintaining similar beam widths to that of the dense array pair.

Highlights

Ultrasound two-dimensional (2D) array transducers provide a powerful means of fast and high-resolution three-dimensional (3D) ultrasound imaging
Computer simulation results indicate that the proposed array pairs for both the sparse rectangular arrays (SRAs) and the sparse spiral arrays (SSAs) achieve peak grating lobe levels below –40 dB using about a quarter of the number of elements in the dense rectangular array while maintaining similar beam widths to that of the dense array pair
The continuous wave (CW) responses were calculated from the theoretical models (8,19) presented in Sections 2 and 3, and Field II program [19,20] was used to obtain the pulsed wave (PW) responses

Summary

Introduction

Ultrasound two-dimensional (2D) array transducers provide a powerful means of fast and high-resolution three-dimensional (3D) ultrasound imaging. Dense 2D arrays usually have a large number of elements, causing a tremendous increase in the computational or the hardware complexity for ultrasound beamforming. Such huge computational costs can hinder dense 2D arrays from realizing 3D imaging with desired volume rates and spatial resolutions. Reducing the active elements used for real-time 3D imaging has been a very important research topic in 2D array imaging. Sparse 2D arrays are one of the strategies to reduce the number of active elements by undersampling dense arrays. Placing elements irregularly is a reasonable approach to spread the concentrated grating lobe energy of a regular sparse array over the entire acoustic field [1]

Methods

Results

Discussion

Conclusion