Spectral crosstalk in photoacoustic computed tomography

Hongzhi Zuo; Manxiu Cui; Xuanhao Wang; Cheng Ma

doi:10.1016/j.pacs.2022.100356

Spectral crosstalk in photoacoustic computed tomography

Photoacoustics. 2022 Apr 13:26:100356. doi: 10.1016/j.pacs.2022.100356. eCollection 2022 Jun.

Authors

Hongzhi Zuo¹, Manxiu Cui¹, Xuanhao Wang¹, Cheng Ma^{1

2

3}

Affiliations

¹ Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
² Center for Clinical Big Data Research, Institute of Precision Medicine, Tsinghua University, Beijing 100084, China.
³ Photomedicine Laboratory, Institute of Precision Medicine, Tsinghua University, Beijing 100084, China.

Abstract

Multispectral photoacoustic (PA) imaging faces two major challenges: the spectral coloring effect, which has been studied extensively as an optical inversion problem, and the spectral crosstalk, which is basically a result of non-ideal acoustic inversion. So far, there is no systematic work to analyze the spectral crosstalk because acoustic inversion and spectroscopic measurement are always treated as decoupled. In this work, we theorize and demonstrate through a series of simulations and experiments how imperfect acoustic inversion induces inaccurate PA spectrum measurement. We provide detailed analysis to elucidate how different factors, including limited bandwidth, limited view, light attenuation, out-of-plane signal, and image reconstruction schemes, conspire to render the measured PA spectrum inaccurate. We found that the model-based reconstruction outperforms universal back-projection in suppressing the spectral crosstalk in some cases.

Keywords: Multispectral photoacoustic imaging; Optoacoustic computed tomography; Photoacoustic computed tomography; Photoacoustic image reconstruction; Quantitative photoacoustic imaging; Spectral crosstalk.