Improving Minimum Variance Beamforming with Sub-Aperture Processing for Photoacoustic Imaging.
Improving Minimum Variance Beamforming with Sub-Aperture Processing for Photoacoustic Imaging.
复制标题
DOI：
10.1109/embc46164.2021.9630278
复制
发表时间：
2021-11
期刊：
影响因子：
--
通讯作者：
Varghese T
中科院分区：
文献类型：
--
作者：
Al Mukaddim R;Ahmed R;Varghese T
与用于光声成像（派）的延迟求和（DAS）波束形成相比，最小方差（MV）波束形成提高了分辨率并减少了旁瓣。然而，一定程度的旁瓣信号和非相干杂波持续降低MV派质量。本文提出了一种结合MV公式和子孔径处理的自适应波束形成算法。在PSAPMV中，接收到的信道数据被分成两个互补的不重叠的子孔径，并使用MV进行波束成形。基于子孔径波束形成图像之间的相似性，推导出一个加权矩阵，并与全孔径MV图像相乘，从而抑制了PA图像中的旁瓣和非相干杂波。点目标、弥散夹杂和微血管网络的数值模拟实验验证了PSAPMV的有效性。定量评价指标包括主副瓣比、半高宽、对比度和广义对比噪声比。PSAPMV定性和定量地证明了改进的波束形成性能。在点靶模拟中，PSAPMV的分辨率（FWHM =0.19 mm）高于MV（0.21 mm）和DAS（0.22 mm），对于弥漫性夹杂物，PSAPMV的靶检测能力（gCNR =0.99）优于MV（0.89）和DAS（0.84），并且对比度得到改善（微血管模拟中的CR，DAS = 15.38，MV = 22.42，PSAPMV = 51.74 dB）。
Minimum variance (MV) beamforming improves resolution and reduces sidelobes when compared to delay-and-sum (DAS) beamforming for photoacoustic imaging (PAI). However, some level of sidelobe signal and incoherent clutter persist degrading MV PAI quality. Here, an adaptive beamforming algorithm (PSAPMV) combining MV formulation and sub-aperture processing is proposed. In PSAPMV, the received channel data are split into two complementary nonoverlapping sub-apertures and beamformed using MV. A weighting matrix based on similarity between sub-aperture beamformed images was derived and multiplied with the full aperture MV image resulting in suppression of sidelobe and incoherent clutter in the PA image. Numerical simulation experiments with point targets, diffuse inclusions and microvasculature networks are used to validate PSAPMV. Quantitative evaluation was done in terms of main-lobe-to-side-lobe ratio, full width at half maximum (FWHM), contrast ratio (CR) and generalized contrast-to-noise ratio (gCNR). PSAPMV demonstrated improved beamforming performance both qualitatively and quantitatively. PSAPMV had higher resolution (FWHM =0.19 mm) than MV (0.21 mm) and DAS (0.22mm) in point target simulations, better target detectability (gCNR =0.99) than MV (0.89) and DAS (0.84) for diffuse inclusions and improved contrast (CR in microvasculature simulation, DAS = 15.38, MV = 22.42, PSAPMV = 51.74 dB).