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Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents

Photoacoustic (PA) imaging systems are spreading in the biomedical community, and the development of new PA contrast agents is an active area of research. However, PA contrast agents are usually characterized with spectrophotometry or uncalibrated PA imaging systems, leading to partial assessment of...

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Autores principales: Lucas, Théotim, Sarkar, Mitradeep, Atlas, Yoann, Linger, Clément, Renault, Gilles, Gazeau, Florence, Gateau, Jérôme
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9460656/
https://www.ncbi.nlm.nih.gov/pubmed/36081006
http://dx.doi.org/10.3390/s22176543
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author Lucas, Théotim
Sarkar, Mitradeep
Atlas, Yoann
Linger, Clément
Renault, Gilles
Gazeau, Florence
Gateau, Jérôme
author_facet Lucas, Théotim
Sarkar, Mitradeep
Atlas, Yoann
Linger, Clément
Renault, Gilles
Gazeau, Florence
Gateau, Jérôme
author_sort Lucas, Théotim
collection PubMed
description Photoacoustic (PA) imaging systems are spreading in the biomedical community, and the development of new PA contrast agents is an active area of research. However, PA contrast agents are usually characterized with spectrophotometry or uncalibrated PA imaging systems, leading to partial assessment of their PA efficiency. To enable quantitative PA spectroscopy of contrast agents in vitro with conventional PA imaging systems, we have developed an adapted calibration method. Contrast agents in solution are injected in a dedicated non-scattering tube phantom imaged at different optical wavelengths. The calibration method uses a reference solution of cupric sulfate to simultaneously correct for the spectral energy distribution of excitation light at the tube location and perform a conversion of the tube amplitude in the image from arbitrary to spectroscopic units. The method does not require any precise alignment and provides quantitative PA spectra, even with non-uniform illumination and ultrasound sensitivity. It was implemented on a conventional imaging setup based on a tunable laser operating between 680 nm and 980 nm and a 5 MHz clinical ultrasound array. We demonstrated robust calibrated PA spectroscopy with sample volumes as low as 15 μL of known chromophores and commonly used contrast agents. The validated method will be an essential and accessible tool for the development of new and efficient PA contrast agents by improving their quantitative characterization.
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spelling pubmed-94606562022-09-10 Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents Lucas, Théotim Sarkar, Mitradeep Atlas, Yoann Linger, Clément Renault, Gilles Gazeau, Florence Gateau, Jérôme Sensors (Basel) Article Photoacoustic (PA) imaging systems are spreading in the biomedical community, and the development of new PA contrast agents is an active area of research. However, PA contrast agents are usually characterized with spectrophotometry or uncalibrated PA imaging systems, leading to partial assessment of their PA efficiency. To enable quantitative PA spectroscopy of contrast agents in vitro with conventional PA imaging systems, we have developed an adapted calibration method. Contrast agents in solution are injected in a dedicated non-scattering tube phantom imaged at different optical wavelengths. The calibration method uses a reference solution of cupric sulfate to simultaneously correct for the spectral energy distribution of excitation light at the tube location and perform a conversion of the tube amplitude in the image from arbitrary to spectroscopic units. The method does not require any precise alignment and provides quantitative PA spectra, even with non-uniform illumination and ultrasound sensitivity. It was implemented on a conventional imaging setup based on a tunable laser operating between 680 nm and 980 nm and a 5 MHz clinical ultrasound array. We demonstrated robust calibrated PA spectroscopy with sample volumes as low as 15 μL of known chromophores and commonly used contrast agents. The validated method will be an essential and accessible tool for the development of new and efficient PA contrast agents by improving their quantitative characterization. MDPI 2022-08-30 /pmc/articles/PMC9460656/ /pubmed/36081006 http://dx.doi.org/10.3390/s22176543 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Lucas, Théotim
Sarkar, Mitradeep
Atlas, Yoann
Linger, Clément
Renault, Gilles
Gazeau, Florence
Gateau, Jérôme
Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents
title Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents
title_full Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents
title_fullStr Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents
title_full_unstemmed Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents
title_short Calibrated Photoacoustic Spectrometer Based on a Conventional Imaging System for In Vitro Characterization of Contrast Agents
title_sort calibrated photoacoustic spectrometer based on a conventional imaging system for in vitro characterization of contrast agents
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9460656/
https://www.ncbi.nlm.nih.gov/pubmed/36081006
http://dx.doi.org/10.3390/s22176543
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