Identification and removal of laser-induced noise in photoacoustic imaging using singular value decomposition.

Emma R Hill,Adrien E Desjardins,Wenfeng Xia,Matthew J Clarkson

doi:10.1364/boe.8.000068

Abstract

Singular value decomposition (SVD) was used to identify and remove laser-induced noise in photoacoustic images acquired with a clinical ultrasound scanner. This noise, which was prominent in the radiofrequency data acquired in parallel from multiple transducer elements, was induced by the excitation light source. It was modelled by truncating the SVD matrices so that only the first few largest singular value components were retained, and subtracted prior to image reconstruction. The dependency of the signal amplitude and the number of the largest singular value components used for noise modeling was investigated for different photoacoustic source geometries. Validation was performed with simulated data and measured noise, and with photoacoustic images acquired from the human forearm and finger in vivo using L14-5/38 and L40-8/12 linear array clinical imaging probes. The use of only one singular value component was found to be sufficient to achieve near-complete removal of laser-induced noise from reconstructed images. This method has strong potential to increase image quality for a wide range of photoacoustic imaging systems with parallel data acquisition.

Highlights

Photoacoustic (PA) imaging couples the molecular contrast of optical absorption with the structural contrast and spatial resolution of ultrasound (US) imaging [1]
Singular value decomposition (SVD) was used to identify and remove laserinduced noise in photoacoustic images acquired with a clinical ultrasound scanner
Validation was performed with simulated data and measured noise, and with photoacoustic images acquired from the human forearm and finger in vivo using L14-5/38 and L40-8/12 linear array clinical imaging probes

Summary

Introduction

Photoacoustic (PA) imaging couples the molecular contrast of optical absorption with the structural contrast and spatial resolution of ultrasound (US) imaging [1]. With this hybrid imaging modality, tissue is irradiated with pulsed or modulated excitation light that is scattered in tissue and absorbed by chromophores. From the standpoint of clinical translation, the use of clinical US imaging probes for reception can be advantageous as it allows for inherently co-registered PA and B-mode US images. Dedicated hardware modules allow for parallel data acquisition from all transducer elements in an imaging probe [2,3,4,5,6,7,8,9,10,11,12,13,14]

Methods

Results

Conclusion