Partner: Heidrun Wabnitz

Physikalisch-Technische Bundesanstalt (DE)

Recent publications
1.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 timedomain optical brain imagers, part 2: nEUROPt protocol, JOURNAL OF BIOMEDICAL OPTICS, ISSN: 1083-3668, DOI: 10.1117/1.JBO.19.8.086012, Vol.19, No.8, pp.086012-1-12, 2014
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.

Affiliations:
Wabnitz H.-Physikalisch-Technische Bundesanstalt (DE)
Jelzow A.-Physikalisch-Technische Bundesanstalt (DE)
Mazurenka M.-Physikalisch-Technische Bundesanstalt (DE)
Steinkellner O.-Physikalisch-Technische Bundesanstalt (DE)
Macdonald R.-Physikalisch-Technische Bundesanstalt (DE)
Milej D.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Żołek N.-other affiliation
Kacprzak M.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Sawosz P.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Maniewski R.-other affiliation
Liebert A.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Magazov S.-University College London (GB)
Hebden J.-University College London (GB)
Martelli F.-University of Florence (IT)
Di Ninni P.-University of Florence (IT)
Zaccanti G.-University of Florence (IT)
Torricelli A.-Politecnico di Milano (IT)
Contini D.-Politecnico di Milano (IT)
Re R.-Politecnico di Milano (IT)
Zucchelli L.-Politecnico di Milano (IT)
Spinelli L.-Consiglio Nazionale delle Ricerche–Istituto di Fotonica e Nanotecnologie (IT)
Cubeddu R.-Politecnico di Milano (IT)
Pifferi A.-Consiglio Nazionale delle Ricerche–Istituto di Fotonica e Nanotecnologie (IT)
2.Spinelli L., Botwicz M., Żołek N., Kacprzak M., Milej D., Sawosz P., Liebert A., Weigel U., Durduran T., Foschum F., Kienle A., Baribeau F., Leclair S., Bouchard J.P., Noiseux I., Gallant P., Mermut O., Farina A., Pifferi A., Torricelli A., Cubeddu R., Ho H.C., Mazurenka M., Wabnitz H., Klauenberg K., Bodnar O., Elster C., Bénazech-Lavoué M.Y., Bérubé-Lauzière Y., Lesage F., Khoptyar D., Subash A.A., Andersson-Engels S., Di Ninni P., Martelli F., Zaaccanti G., Determination of reference values for optical properties of liquid phantoms based on Intralipid and India ink, BIOMEDICAL OPTICS EXPRESS, ISSN: 2156-7085, DOI: 10.1364/BOE.5.002037, Vol.5, No.7, pp.2037-2053, 2014
Abstract:

A multi-center study has been set up to accurately characterize the optical properties of diffusive liquid phantoms based on Intralipid and India ink at near-infrared (NIR) wavelengths. Nine research laboratories from six countries adopting different measurement techniques, instrumental set-ups, and data analysis methods determined at their best the optical properties and relative uncertainties of diffusive dilutions prepared with common samples of the two compounds. By exploiting a suitable statistical model, comprehensive reference values at three NIR wavelengths for the intrinsic absorption coefficient of India ink and the intrinsic reduced scattering coefficient of Intralipid-20% were determined with an uncertainty of about 2% or better, depending on the wavelength considered, and 1%, respectively. Even if in this study we focused on particular batches of India ink and Intralipid, the reference values determined here represent a solid and useful starting point for preparing diffusive liquid phantoms with accurately defined optical properties. Furthermore, due to the ready availability, low cost, long-term stability and batch-to-batch reproducibility of these compounds, they provide a unique fundamental tool for the calibration and performance assessment of diffuse optical spectroscopy instrumentation intended to be used in laboratory or clinical environment. Finally, the collaborative work presented here demonstrates that the accuracy level attained in this work for optical properties of diffusive phantoms is reliable.

Affiliations:
Spinelli L.-Consiglio Nazionale delle Ricerche–Istituto di Fotonica e Nanotecnologie (IT)
Botwicz M.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Żołek N.-other affiliation
Kacprzak M.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Milej D.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Sawosz P.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Liebert A.-Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences (PL)
Weigel U.-ICFO, Institut de Ciències Fotòniques (ES)
Durduran T.-ICFO, Institut de Ciències Fotòniques (ES)
Foschum F.-Universit at Ulm (DE)
Kienle A.-Universit at Ulm (DE)
Baribeau F.-National Optics Institute (CA)
Leclair S.-National Optics Institute (CA)
Bouchard J.P.-National Optics Institute (CA)
Noiseux I.-National Optics Institute (CA)
Gallant P.-National Optics Institute (CA)
Mermut O.-National Optics Institute (CA)
Farina A.-Consiglio Nazionale delle Ricerche–Istituto di Fotonica e Nanotecnologie (IT)
Pifferi A.-Consiglio Nazionale delle Ricerche–Istituto di Fotonica e Nanotecnologie (IT)
Torricelli A.-Politecnico di Milano (IT)
Cubeddu R.-Politecnico di Milano (IT)
Ho H.C.-Industrial Technology Research Institute (TW)
Mazurenka M.-Physikalisch-Technische Bundesanstalt (DE)
Wabnitz H.-Physikalisch-Technische Bundesanstalt (DE)
Klauenberg K.-Physikalisch-Technische Bundesanstalt (DE)
Bodnar O.-PTB, Physikalisch-Technische Bundesanstalt (DE)
Elster C.-Physikalisch-Technische Bundesanstalt (DE)
Bénazech-Lavoué M.Y.-Université de Sherbrooke (CA)
Bérubé-Lauzière Y.-Université de Sherbrooke (CA)
Lesage F.-Polytechnique Montreal (CA)
Khoptyar D.-Lund University (SE)
Subash A.A.-Lund University (SE)
Andersson-Engels S.-Lund University (SE)
Di Ninni P.-University of Florence (IT)
Martelli F.-University of Florence (IT)
Zaaccanti G.-University of Florence (IT)