Title
Enhanced Linear-array Photoacoustic Beamforming using Modified Coherence Factor.
Abstract
Photoacoustic imaging (PAI) is a promising medical imaging modality providing the spatial resolution of ultrasound imaging and the contrast of optical imaging. For linear-array PAI, a beamformer can be used as the reconstruction algorithm. Delay-and-sum (DAS) is the most prevalent beamforming algorithm in PAI. However, using DAS beamformer leads to low-resolution images as well as high sidelobes due to nondesired contribution of off-axis signals. Coherence factor (CF) is a weighting method in which each pixel of the reconstructed image is weighted, based on the spatial spectrum of the aperture, to mainly improve the contrast. We demonstrate that the numerator of the formula of CF contains a DAS algebra and propose the use of a delay-multiply-and-sum beamformer instead of the available DAS on the numerator. The proposed weighting technique, modified CF (MCF), has been evaluated numerically and experimentally compared to CF. It was shown that MCF leads to lower sidelobes and better detectable targets. The quantitative results of the experiment (using wire targets) show that MCF leads to for about 45% and 40% improvement, in comparison with CF, in the terms of signal-to-noise ratio and full-width-half-maximum, respectively. (c) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Year
DOI
Venue
2017
10.1117/1.JBO.23.2.026005
JOURNAL OF BIOMEDICAL OPTICS
Keywords
Field
DocType
photoacoustic imaging,beamforming,linear-array imaging,noise suppression,contrast improvement
Aperture,Beamforming,Weighting,Medical imaging,Optics,Coherence (physics),Reconstruction algorithm,Pixel,Image resolution,Medicine
Journal
Volume
Issue
ISSN
23
2
1083-3668
Citations 
PageRank 
References 
2
0.43
11
Authors
3
Name
Order
Citations
PageRank
Moein Mozaffarzadeh1132.62
Mohammad Mehrmohammadi221.10
Bahador Makkiabadi3538.92