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Sudakou A, Wabnitz H, Liemert A, Wolf M, Liebert A. Two-layered blood-lipid phantom and method to determine absorption and oxygenation employing changes in moments of DTOFs. BIOMEDICAL OPTICS EXPRESS 2023; 14:3506-3531. [PMID: 37497481 PMCID: PMC10368065 DOI: 10.1364/boe.492168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/29/2023] [Accepted: 05/29/2023] [Indexed: 07/28/2023]
Abstract
Near-infrared spectroscopy (NIRS) is an established technique for measuring tissue oxygen saturation (StO2), which is of high clinical value. For tissues that have layered structures, it is challenging but clinically relevant to obtain StO2 of the different layers, e.g. brain and scalp. For this aim, we present a new method of data analysis for time-domain NIRS (TD-NIRS) and a new two-layered blood-lipid phantom. The new analysis method enables accurate determination of even large changes of the absorption coefficient (Δµa) in multiple layers. By adding Δµa to the baseline µa, this method provides absolute µa and hence StO2 in multiple layers. The method utilizes (i) changes in statistical moments of the distributions of times of flight of photons (DTOFs), (ii) an analytical solution of the diffusion equation for an N-layered medium, (iii) and the Levenberg-Marquardt algorithm (LMA) to determine Δµa in multiple layers from the changes in moments. The method is suitable for NIRS tissue oximetry (relying on µa) as well as functional NIRS (fNIRS) applications (relying on Δµa). Experiments were conducted on a new phantom, which enabled us to simulate dynamic StO2 changes in two layers for the first time. Two separate compartments, which mimic superficial and deep layers, hold blood-lipid mixtures that can be deoxygenated (using yeast) and oxygenated (by bubbling oxygen) independently. Simultaneous NIRS measurements can be performed on the two-layered medium (variable superficial layer thickness, L), the deep (homogeneous), and/or the superficial (homogeneous). In two experiments involving ink, we increased the nominal µa in one of two compartments from 0.05 to 0.25 cm-1, L set to 14.5 mm. In three experiments involving blood (L set to 12, 15, or 17 mm), we used a protocol consisting of six deoxygenation cycles. A state-of-the-art multi-wavelength TD-NIRS system measured simultaneously on the two-layered medium, as well as on the deep compartment for a reference. The new method accurately determined µa (and hence StO2) in both compartments. The method is a significant progress in overcoming the contamination from the superficial layer, which is beneficial for NIRS and fNIRS applications, and may improve the determination of StO2 in the brain from measurements on the head. The advanced phantom may assist in the ongoing effort towards more realistic standardized performance tests in NIRS tissue oximetry. Data and MATLAB codes used in this study were made publicly available.
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Affiliation(s)
- Aleh Sudakou
- Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | - André Liemert
- Institut für Lasertechnologien in der Medizin und Meßtechnik an der Universität Ulm, Germany
| | - Martin Wolf
- Department of Neonatology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Adam Liebert
- Nałęcz Institute of Biocybernetics and Biomedical Engineering Polish Academy of Sciences, Warsaw, Poland
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2
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Hacker L, Wabnitz H, Pifferi A, Pfefer TJ, Pogue BW, Bohndiek SE. Criteria for the design of tissue-mimicking phantoms for the standardization of biophotonic instrumentation. Nat Biomed Eng 2022; 6:541-558. [PMID: 35624150 DOI: 10.1038/s41551-022-00890-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 02/07/2022] [Indexed: 01/08/2023]
Abstract
A lack of accepted standards and standardized phantoms suitable for the technical validation of biophotonic instrumentation hinders the reliability and reproducibility of its experimental outputs. In this Perspective, we discuss general criteria for the design of tissue-mimicking biophotonic phantoms, and use these criteria and state-of-the-art developments to critically review the literature on phantom materials and on the fabrication of phantoms. By focusing on representative examples of standardization in diffuse optical imaging and spectroscopy, fluorescence-guided surgery and photoacoustic imaging, we identify unmet needs in the development of phantoms and a set of criteria (leveraging characterization, collaboration, communication and commitment) for the standardization of biophotonic instrumentation.
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Affiliation(s)
- Lina Hacker
- Department of Physics, University of Cambridge, Cambridge, UK.,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany
| | | | | | - Brian W Pogue
- Thayer School of Engineering, Dartmouth, Hanover, NH, USA
| | - Sarah E Bohndiek
- Department of Physics, University of Cambridge, Cambridge, UK. .,Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK.
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3
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Amendola C, Lacerenza M, Buttafava M, Tosi A, Spinelli L, Contini D, Torricelli A. A Compact Multi-Distance DCS and Time Domain NIRS Hybrid System for Hemodynamic and Metabolic Measurements. SENSORS 2021; 21:s21030870. [PMID: 33525488 PMCID: PMC7866011 DOI: 10.3390/s21030870] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/22/2021] [Accepted: 01/24/2021] [Indexed: 01/17/2023]
Abstract
In this work, we present a new multi-distance diffuse correlation spectroscopy (DCS) device integrated with a compact state-of-the-art time domain near infrared spectroscopy (TD-NIRS) device. The hybrid DCS and TD-NIRS system allows to retrieve information on blood flow, tissue oxygenation, and oxygen metabolic rate. The DCS device performances were estimated in terms of stability, repeatability, ability in retrieving variations of diffusion coefficient, influence of the tissue optical properties, effect of varying count rates and depth sensitivity. Crosstalk between DCS and TD-NIRS optical signals was also evaluated. Finally, in vivo experiments (venous and arterial cuff occlusions on the arm) were conducted to test the ability of the hybrid system in measuring blood flow variations.
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Affiliation(s)
- Caterina Amendola
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan, Italy; (M.L.); (D.C.)
- Correspondence: (C.A.); (A.T.)
| | - Michele Lacerenza
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan, Italy; (M.L.); (D.C.)
| | - Mauro Buttafava
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, via Ponzio 34/5, 20133 Milan, Italy; (M.B.); (A.T.)
| | - Alberto Tosi
- Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, via Ponzio 34/5, 20133 Milan, Italy; (M.B.); (A.T.)
| | - Lorenzo Spinelli
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, piazza Leonardo da Vinci 32, 20133 Milan, Italy;
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan, Italy; (M.L.); (D.C.)
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, piazza Leonardo da Vinci 32, 20133 Milan, Italy; (M.L.); (D.C.)
- Consiglio Nazionale delle Ricerche, Istituto di Fotonica e Nanotecnologie, piazza Leonardo da Vinci 32, 20133 Milan, Italy;
- Correspondence: (C.A.); (A.T.)
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4
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Yang L, Wabnitz H, Gladytz T, Sudakou A, Macdonald R, Grosenick D. Space-enhanced time-domain diffuse optics for determination of tissue optical properties in two-layered structures. BIOMEDICAL OPTICS EXPRESS 2020; 11:6570-6589. [PMID: 33282509 PMCID: PMC7687957 DOI: 10.1364/boe.402181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/18/2020] [Accepted: 09/28/2020] [Indexed: 05/05/2023]
Abstract
A novel methodology for solving the inverse problem of diffuse optics for two-layered structures is proposed to retrieve the absolute quantities of optical absorption and reduced scattering coefficients of the layers simultaneously. A liquid phantom with various optical absorption properties in the deep layer is prepared and experimentally investigated using the space-enhanced time-domain method. Monte-Carlo simulations are applied to analyze the different measurements in time domain, space domain, and by the new methodology. The deviations of retrieved values from nominal values of both layers' optical properties are simultaneously reduced to a very low extent compared to the single-domain methods. The reliability and uncertainty of the retrieval performance are also considerably improved by the new methodology. It is observed in time-domain analyses that for the deep layer the retrieval of absorption coefficient is almost not affected by the scattering properties and this kind of "deep scattering neutrality" is investigated and overcome as well.
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Affiliation(s)
- Lin Yang
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
| | - Thomas Gladytz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
| | - Aleh Sudakou
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Trojdena 4, 02-109 Warsaw, Poland
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
- Institute of Optics and Atomic Physics, Technical University of Berlin, Strasse des 17. Juni 135, 10623 Berlin, Germany
| | - Dirk Grosenick
- Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany
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5
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Di Sieno L, Contini D, Lo Presti G, Cortese L, Mateo T, Rosinski B, Venturini E, Panizza P, Mora M, Aranda G, Squarcia M, Farina A, Durduran T, Taroni P, Pifferi A, Mora AD. Systematic study of the effect of ultrasound gel on the performances of time-domain diffuse optics and diffuse correlation spectroscopy. BIOMEDICAL OPTICS EXPRESS 2019; 10:3899-3915. [PMID: 31452983 PMCID: PMC6701515 DOI: 10.1364/boe.10.003899] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 07/01/2019] [Accepted: 07/01/2019] [Indexed: 05/06/2023]
Abstract
Recently, multimodal imaging has gained an increasing interest in medical applications thanks to the inherent combination of strengths of the different techniques. For example, diffuse optics is used to probe both the composition and the microstructure of highly diffusive media down to a depth of few centimeters, but its spatial resolution is intrinsically low. On the other hand, ultrasound imaging exhibits the higher spatial resolution of morphological imaging, but without providing solid constitutional information. Thus, the combination of diffuse optical imaging and ultrasound may improve the effectiveness of medical examinations, e.g. for screening or diagnosis of tumors. However, the presence of an ultrasound coupling gel between probe and tissue can impair diffuse optical measurements like diffuse optical spectroscopy and diffuse correlation spectroscopy, since it may provide a direct path for photons between source and detector. A systematic study on the effect of different ultrasound coupling fluids was performed on tissue-mimicking phantoms, confirming that a water-clear gel can produce detrimental effects on optical measurements when recovering absorption/reduced scattering coefficients from time-domain spectroscopy acquisitions as well as particle Brownian diffusion coefficient from diffuse correlation spectroscopy ones. On the other hand, we show the suitability for optical measurements of other types of diffusive fluids, also compatible with ultrasound imaging.
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Affiliation(s)
- Laura Di Sieno
- Politecnico di Milano - Dipartimento di Fisica, Milano, Italy
| | - Davide Contini
- Politecnico di Milano - Dipartimento di Fisica, Milano, Italy
| | - Giuseppe Lo Presti
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | - Lorenzo Cortese
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
| | | | | | - Elena Venturini
- Scientific Institute (IRCCS) Ospedale San Raffaele - Breast Imaging Unit, Milano, Italy
| | - Pietro Panizza
- Scientific Institute (IRCCS) Ospedale San Raffaele - Breast Imaging Unit, Milano, Italy
| | - Mireia Mora
- IDIBAPS, Fundació Clínic per la Recerca Biomèdica, Barcelona, Spain
| | - Gloria Aranda
- IDIBAPS, Fundació Clínic per la Recerca Biomèdica, Barcelona, Spain
| | - Mattia Squarcia
- IDIBAPS, Fundació Clínic per la Recerca Biomèdica, Barcelona, Spain
| | - Andrea Farina
- Consiglio Nazionale delle Ricerche - Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | - Turgut Durduran
- ICFO - Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Castelldefels (Barcelona), Spain
- Instituciò Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Paola Taroni
- Politecnico di Milano - Dipartimento di Fisica, Milano, Italy
- Consiglio Nazionale delle Ricerche - Istituto di Fotonica e Nanotecnologie, Milano, Italy
| | - Antonio Pifferi
- Politecnico di Milano - Dipartimento di Fisica, Milano, Italy
- Consiglio Nazionale delle Ricerche - Istituto di Fotonica e Nanotecnologie, Milano, Italy
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6
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Martelli F, Binzoni T. Heuristic model for ballistic photon detection in collimated transmittance measurements. OPTICS EXPRESS 2018; 26:744-761. [PMID: 29401955 DOI: 10.1364/oe.26.000744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/10/2017] [Indexed: 06/07/2023]
Abstract
An heuristic model for ballistic photon detection in continuous-wave measurements of collimated transmittance through a slab is presented. The model is based on the small angle approximation and the diffusion equation and covers all the ranges of optical thicknesses of the slab from the ballistic to the diffusive regime. The performances of the model have been studied by means of comparisons with the results of gold standard Monte Carlo simulations for a wide range of optical thicknesses and two types of scattering functions. For a non-absorbing slab and field of view of the receiver less than 3° the model shows errors less than 15% for any value of the optical thickness. Even for an albedo value of 0.9, and field of view of the receiver less than 3° the model shows errors less than 20%. These results have been verified for a large set of scattering functions based on the Henyey-Greenstein model and Mie theory for spherical scatterers. The latter has also been used to simulate the scattering function of Intralipid, a diffusive material widely used as reference standard for tissue simulating phantoms. The proposed model represents an effective improvement compared to the existing literature.
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7
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Binzoni T, Sassaroli A, Torricelli A, Spinelli L, Farina A, Durduran T, Cavalieri S, Pifferi A, Martelli F. Depth sensitivity of frequency domain optical measurements in diffusive media. BIOMEDICAL OPTICS EXPRESS 2017; 8:2990-3004. [PMID: 28663921 PMCID: PMC5480444 DOI: 10.1364/boe.8.002990] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/13/2017] [Accepted: 04/18/2017] [Indexed: 05/03/2023]
Abstract
The depth sensitivity functions for AC amplitude, phase (PH) and DC intensity signals have been obtained in the frequency domain (where the source amplitude is modulated at radio-frequencies) by making use of analytical solutions of the photon diffusion equation in an infinite slab geometry. Furthermore, solutions for the relative contrast of AC, PH and DC signals when a totally absorbing plane is placed at a fixed depth of the slab have also been obtained. The solutions have been validated by comparisons with gold standard Monte Carlo simulations. The obtained results show that the AC signal, for modulation frequencies < 200 MHz, has a depth sensitivity with similar characteristics to that of the continuous-wave (CW) domain (source modulation frequency of zero). Thus, the depth probed by such a signal can be estimated by using the formula of penetration depth for the CW domain (Sci. Rep.6, 27057 (2016)). However, the PH signal has a different behavior compared to the CW domain, showing a larger depth sensitivity at shallow depths and a less steep relative contrast as a function of depth. These results mark a clear difference in term of depth sensitivity between AC and PH signals, and highlight the complexity of the estimation of the actual depth probed in tissue spectroscopy.
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Affiliation(s)
- Tiziano Binzoni
- Département de Neurosciences Fondamentales, University of Geneva, Switzerland
- Département de l'Imagerie et des Sciences de l'Information Médicale, University Hospital, Geneva, Switzerland
| | - Angelo Sassaroli
- Tufts University, Department of Biomedical Engineering, 4 Colby Street, Medford, MA 02155 USA
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Andrea Farina
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Turgut Durduran
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, Av. Carl Friedrich Gauss, 3, Castelldefels (Barcelona), 08860, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA) (Barcelona, Spain)
| | - Stefano Cavalieri
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Milano, Italy, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
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Martelli F, Del Bianco S, Spinelli L, Cavalieri S, Di Ninni P, Binzoni T, Jelzow A, Macdonald R, Wabnitz H. Optimal estimation reconstruction of the optical properties of a two-layered tissue phantom from time-resolved single-distance measurements. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:115001. [PMID: 26524677 DOI: 10.1117/1.jbo.20.11.115001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 09/25/2015] [Indexed: 05/02/2023]
Abstract
In this work, we have tested the optimal estimation (OE) algorithm for the reconstruction of the optical properties of a two-layered liquid tissue phantom from time-resolved single-distance measurements. The OE allows a priori information, in particular on the range of variation of fit parameters, to be included. The purpose of the present investigations was to compare the performance of OE with the Levenberg–Marquardt method for a geometry and real experimental conditions typically used to reconstruct the optical properties of biological tissues such as muscle and brain. The absorption coefficient of the layers was varied in a range of values typical for biological tissues. The reconstructions performed demonstrate the substantial improvements achievable with the OE provided a priori information is available. We note the extreme reliability, robustness, and accuracy of the retrieved absorption coefficient of the second layer obtained with the OE that was found for up to six fit parameters, with an error in the retrieved values of less than 10%. A priori information on fit parameters and fixed forward model parameters clearly improves robustness and accuracy of the inversion procedure.
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Affiliation(s)
- Fabrizio Martelli
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Samuele Del Bianco
- Istituto di Fisica Applicata Nello Carrara del Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, Sesto Fiorentino 50019, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, Milano 20133, Italy
| | - Stefano Cavalieri
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Paola Di Ninni
- Università degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Via G. Sansone 1, Sesto Fiorentino 50019, Firenze, Italy
| | - Tiziano Binzoni
- University of Geneva, Département de Neurosciences Fondamentales, 1, rue Michel-Servet 1211 Genève 4, SwitzerlandeUniversity Hospital, Département de l'Imagerie et des Sciences de l'Information Médicale, 1, 4 rue Gabrielle-Perret-Gentil, 1211 Geneva 14, S
| | - Alexander Jelzow
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
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Wabnitz H, Jelzow A, Mazurenka M, Steinkellner O, Macdonald R, Milej D, Żołek N, Kacprzak M, Sawosz P, Maniewski R, Liebert A, Magazov S, Hebden J, Martelli F, Di Ninni P, Zaccanti G, Torricelli A, Contini D, Re R, Zucchelli L, Spinelli L, Cubeddu R, Pifferi A. Performance assessment of time-domain optical brain imagers, part 2: nEUROPt protocol. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:086012. [PMID: 25121480 DOI: 10.1117/1.jbo.19.8.086012] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/21/2014] [Indexed: 05/18/2023]
Abstract
The nEUROPt protocol is one of two new protocols developed within the European project nEUROPt to characterize the performances of time-domain systems for optical imaging of the brain. It was applied in joint measurement campaigns to compare the various instruments and to assess the impact of technical improvements. This protocol addresses the characteristic of optical brain imaging to detect, localize, and quantify absorption changes in the brain. It was implemented with two types of inhomogeneous liquid phantoms based on Intralipid and India ink with well-defined optical properties. First, small black inclusions were used to mimic localized changes of the absorption coefficient. The position of the inclusions was varied in depth and lateral direction to investigate contrast and spatial resolution. Second, two-layered liquid phantoms with variable absorption coefficients were employed to study the quantification of layer-wide changes and, in particular, to determine depth selectivity, i.e., the ratio of sensitivities for deep and superficial absorption changes. We introduce the tests of the nEUROPt protocol and present examples of results obtained with different instruments and methods of data analysis. This protocol could be a useful step toward performance tests for future standards in diffuse optical imaging.
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Affiliation(s)
- Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Alexander Jelzow
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Mikhail Mazurenka
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Oliver Steinkellner
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany
| | - Daniel Milej
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Norbert Żołek
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Michal Kacprzak
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Piotr Sawosz
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Roman Maniewski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Adam Liebert
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland
| | - Salavat Magazov
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Jeremy Hebden
- University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom
| | - Fabrizio Martelli
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Paola Di Ninni
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Giovanni Zaccanti
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Alessandro Torricelli
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Davide Contini
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Rebecca Re
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lucia Zucchelli
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Rinaldo Cubeddu
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalyfIstituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Antonio Pifferi
- Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, ItalyfIstituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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Martelli F, Di Ninni P, Zaccanti G, Contini D, Spinelli L, Torricelli A, Cubeddu R, Wabnitz H, Mazurenka M, Macdonald R, Sassaroli A, Pifferi A. Phantoms for diffuse optical imaging based on totally absorbing objects, part 2: experimental implementation. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:076011. [PMID: 25023415 DOI: 10.1117/1.jbo.19.7.076011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 06/05/2014] [Indexed: 05/19/2023]
Abstract
We present the experimental implementation and validation of a phantom for diffuse optical imaging based on totally absorbing objects for which, in the previous paper [J. Biomed. Opt.18(6), 066014, (2013)], we have provided the basic theory. Totally absorbing objects have been manufactured as black polyvinyl chloride (PVC) cylinders and the phantom is a water dilution of intralipid-20% as the diffusive medium and India ink as the absorber, filled into a black scattering cell made of PVC. By means of time-domain measurements and of Monte Carlo simulations, we have shown the reliability, the accuracy, and the robustness of such a phantom in mimicking typical absorbing perturbations of diffuse optical imaging. In particular, we show that such a phantom can be used to generate any absorption perturbation by changing the volume and position of the totally absorbing inclusion.
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Affiliation(s)
- Fabrizio Martelli
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Paola Di Ninni
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Giovanni Zaccanti
- Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy
| | - Davide Contini
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Lorenzo Spinelli
- Istituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Alessandro Torricelli
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Rinaldo Cubeddu
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, ItalycIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Heidrun Wabnitz
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - Mikhail Mazurenka
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - Rainer Macdonald
- Physikalisch-Technische Bundesanstalt (PTB), Abbestrasse 2-12, 10587 Berlin, Germany
| | - Angelo Sassaroli
- Tufts University, Department of Biomedical Engineering, 4 Colby Street, Medford, Massachusetts 02155, United States
| | - Antonio Pifferi
- Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, ItalycIstituto di Fotonica e Nanotecnologie, Consiglio Nazionale delle Ricerche, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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11
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Torricelli A, Contini D, Pifferi A, Caffini M, Re R, Zucchelli L, Spinelli L. Time domain functional NIRS imaging for human brain mapping. Neuroimage 2014; 85 Pt 1:28-50. [DOI: 10.1016/j.neuroimage.2013.05.106] [Citation(s) in RCA: 294] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 04/25/2013] [Accepted: 05/21/2013] [Indexed: 02/02/2023] Open
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12
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Re R, Contini D, Turola M, Spinelli L, Zucchelli L, Caffini M, Cubeddu R, Torricelli A. Multi-channel medical device for time domain functional near infrared spectroscopy based on wavelength space multiplexing. BIOMEDICAL OPTICS EXPRESS 2013; 4:2231-46. [PMID: 24156079 PMCID: PMC3799681 DOI: 10.1364/boe.4.002231] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 09/12/2013] [Accepted: 09/17/2013] [Indexed: 05/03/2023]
Abstract
We have designed a compact dual wavelength (687 nm, 826 nm) multi-channel (16 sources, 8 detectors) medical device for muscle and brain imaging based on time domain functional near infrared spectroscopy. The system employs the wavelength space multiplexing approach to reduce wavelength cross-talk and increase signal-to-noise ratio. System performances have been tested on homogeneous and heterogeneous tissue phantoms following specifically designed protocols for photon migration instruments. Preliminary in vivo measurements have been performed to validate the instrument capability to monitor hemodynamic parameters changes in the arm muscle during arterial occlusion and in the adult head during a motor task experiment.
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Affiliation(s)
- Rebecca Re
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Davide Contini
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Massimo Turola
- Division of Optometry and Visual Sciences, City University London, Northampton Square, EC1V 0HB London, UK
| | | | - Lucia Zucchelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Matteo Caffini
- Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Via Golgi 39, 20133 Milan, Italy
| | - Rinaldo Cubeddu
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
| | - Alessandro Torricelli
- Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milan, Italy
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Hallacoglu B, Sassaroli A, Fantini S. Optical characterization of two-layered turbid media for non-invasive, absolute oximetry in cerebral and extracerebral tissue. PLoS One 2013; 8:e64095. [PMID: 23724023 PMCID: PMC3660388 DOI: 10.1371/journal.pone.0064095] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Accepted: 04/09/2013] [Indexed: 11/18/2022] Open
Abstract
We introduce a multi-distance, frequency-domain, near-infrared spectroscopy (NIRS) method to measure the optical coefficients of two-layered media and the thickness of the top layer from diffuse reflectance measurements. This method features a direct solution based on diffusion theory and an inversion procedure based on the Levenberg-Marquardt algorithm. We have validated our method through Monte Carlo simulations, experiments on tissue-like phantoms, and measurements on the forehead of three human subjects. The Monte Carlo simulations and phantom measurements have shown that, in ideal two-layered samples, our method accurately recovers the top layer thickness (L), the absorption coefficient (µ a ) and the reduced scattering coefficient (µ' s ) of both layers with deviations that are typically less than 10% for all parameters. Our method is aimed at absolute measurements of hemoglobin concentration and saturation in cerebral and extracerebral tissue of adult human subjects, where the top layer (layer 1) represents extracerebral tissue (scalp, skull, dura mater, subarachnoid space, etc.) and the bottom layer (layer 2) represents cerebral tissue. Human subject measurements have shown a significantly greater total hemoglobin concentration in cerebral tissue (82±14 µM) with respect to extracerebral tissue (30±7 µM). By contrast, there was no significant difference between the hemoglobin saturation measured in cerebral tissue (56%±10%) and extracerebral tissue (62%±6%). To our knowledge, this is the first time that an inversion procedure in the frequency domain with six unknown parameters with no other prior knowledge is used for the retrieval of the optical coefficients and top layer thickness with high accuracy on two-layered media. Our absolute measurements of cerebral hemoglobin concentration and saturation are based on the discrimination of extracerebral and cerebral tissue layers, and they can enhance the impact of NIRS for cerebral hemodynamics and oxygenation assessment both in the research arena and clinical practice.
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Affiliation(s)
- Bertan Hallacoglu
- Department of Biomedical Engineering, Tufts University, Medford, Massachusetts, USA.
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Di Ninni P, Martelli F, Zaccanti G. Effect of dependent scattering on the optical properties of Intralipid tissue phantoms. BIOMEDICAL OPTICS EXPRESS 2011; 2:2265-78. [PMID: 21833363 PMCID: PMC3149524 DOI: 10.1364/boe.2.002265] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 06/29/2011] [Accepted: 07/06/2011] [Indexed: 05/21/2023]
Abstract
The calibration of optical tissue-simulating phantoms remains an open question in spite of the many techniques proposed for accurate measurements of optical properties. As a consequence, a reference phantom with well known optical properties is still missing. As a first step towards a reference phantom we have recently proposed to use dilutions of Intralipid 20%. In this paper we discuss a matter that is commonly ignored when dilutions are prepared, i.e., the possibility of deviations from the simple linear relationships between the optical properties of the dilution and the Intralipid concentration due to the effects of dependent scattering. The results of an experimental investigation showed that dependent scattering does not affect absorption. As for the reduced scattering coefficient the effect can be described adding a term proportional to the square of the concentration. However, for concentrations of interest for tissue optics deviations from linearity remain within about 2%. The experimental investigation also showed that the microphysical properties of Intralipid are not affected by dilution. These results show the possibility to easily obtain a liquid diffusive phantom whose optical properties are known with error smaller than about 1%. Due to the intrinsic limitations of the different techniques proposed for measuring the optical properties it seems difficult to obtain a similar accuracy for solid phantoms.
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Vedantham S, Karellas A. Modeling the performance characteristics of computed radiography (CR) systems. IEEE TRANSACTIONS ON MEDICAL IMAGING 2010; 29:790-806. [PMID: 20199915 PMCID: PMC5228607 DOI: 10.1109/tmi.2009.2036995] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Computed radiography (CR) using storage phosphors is widely used in digital radiography and mammography. A cascaded linear systems approach wherein several parameter values were estimated using Monte Carlo methods was used to model the image formation process of a single-side read ;;flying spot'' CR system using a granular phosphor. Objective image quality metrics such as modulation transfer function and detective quantum efficiency were determined using this model and show good agreement with published empirical data. A model such as that addressed in this work could allow for improved understanding of the effect of storage phosphor physical properties and CR reader parameters on objective image quality metrics for existing and evolving CR systems.
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Affiliation(s)
- Srinivasan Vedantham
- Department of Radiology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
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Pifferi A, Torricelli A, Bassi A, Taroni P, Cubeddu R, Wabnitz H, Grosenick D, Möller M, Macdonald R, Swartling J, Svensson T, Andersson-Engels S, van Veen RLP, Sterenborg HJCM, Tualle JM, Nghiem HL, Avrillier S, Whelan M, Stamm H. Performance assessment of photon migration instruments: the MEDPHOT protocol. APPLIED OPTICS 2005; 44:2104-14. [PMID: 15838951 DOI: 10.1364/ao.44.002104] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We propose a comprehensive protocol for the performance assessment of photon migration instruments. The protocol has been developed within the European Thematic Network MEDPHOT (optical methods for medical diagnosis and monitoring of diseases) and is based on five criteria: accuracy, linearity, noise, stability, and reproducibility. This protocol was applied to a total of 8 instruments with a set of 32 phantoms, covering a wide range of optical properties.
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Affiliation(s)
- Antonio Pifferi
- Laboratorio Nazionale per l'Ottica Ultra-rapida e Ultra-intensa, Dipartimento di Fisica e Istituto di Fotonicae Nanotecnologie, Consiglio Nazionale delle Ricerche, Politecnico di Milano, I-20133 Milan, Italy.
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