The Application of an Iterative Structure to the Delay-and-Sum and the Delay-Multiply-and-Sum Beamformers in Breast Microwave Imaging.

Tyson Reimer,Mario Solis-Nepote,Stephen Pistorius

doi:10.3390/diagnostics10060411

Tyson Reimer, Mario Solis-Nepote + Show 1 more

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https://doi.org/10.3390/diagnostics10060411

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Abstract

Breast microwave imaging (BMI) is a potential breast cancer screening method. This manuscript presents a novel iterative delay-and-sum (DAS) based reconstruction algorithm for BMI. This iterative-DAS (itDAS) algorithm uses a forward radar model to iteratively update an image estimate. A variation of the itDAS reconstruction algorithm that uses the delay-multiply-and-sum (DMAS) beamformer was also implemented (the itDMAS algorithm). Both algorithms were used to reconstruct images from experimental scans of an array of 3D-printed MRI-based breast phantoms performed with a clinical BMI system. The signal-to-clutter ratio (SCR) and signal-to-mean ratio (SMR) were used to compare the performance of the itDAS and itDMAS methods to the DAS and DMAS beamformers. While no significant difference between the itDAS and itDMAS methods was observed in most images, the itDAS algorithm produced reconstructions that had significantly higher SMR than the non-iterative methods, increasing contrast by as much as 19 dB over DAS and 13 dB over DMAS. The itDAS algorithm also increased the SCR of reconstructions by up to 5 dB over DAS and 4 dB over DMAS, indicating that both high-intensity and background clutter are reduced in images reconstructed by the itDAS algorithm.

Highlights

IntroductionBreast microwave imaging (BMI) has emerged as a potential breast cancer detection technique [1]
Breast microwave imaging (BMI) has emerged as a potential breast cancer detection technique [1].This modality uses non-ionizing microwave radiation to interrogate the breast tissues, and measurements of the resultant field produced after scattering from the tissues can be used to reconstruct an image of the breast
The dielectric properties of the tissues govern the interaction of the microwave signal within the breast, and the contrast in the properties of malignant and healthy tissues [4,5] allows for the detection of malignant lesions by BMI systems

Summary

Introduction

Breast microwave imaging (BMI) has emerged as a potential breast cancer detection technique [1]. This modality uses non-ionizing microwave radiation to interrogate the breast tissues, and measurements of the resultant field produced after scattering from the tissues can be used to reconstruct an image of the breast. Because BMI systems use non-ionizing microwave radiation and are relatively low-cost, the modality has been proposed as a potential breast cancer screening method [1,3]. The dielectric properties of the tissues govern the interaction of the microwave signal within the breast, and the contrast in the properties of malignant and healthy tissues [4,5] allows for the detection of malignant lesions by BMI systems

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