title: Performance assessment of time-domain optical brain imagers, part 2: nEUROPt protocol.
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.
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Heidrun
authors.initials: H
authors.lastname: Wabnitz
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Jelzow
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Mazurenka
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Steinkellner
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Macdonald
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Milej
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Norbert
authors.initials: N
authors.lastname: Żołek
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Michal
authors.initials: M
authors.lastname: Kacprzak
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Piotr
authors.initials: P
authors.lastname: Sawosz
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Roman
authors.initials: R
authors.lastname: Maniewski
authors.affiliation: Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, ul. Trojdena 4, 02-109 Warsaw, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Liebert
authors.affiliation: University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: Salavat
authors.initials: S
authors.lastname: Magazov
authors.affiliation: University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Hebden
authors.affiliation: Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Martelli
authors.affiliation: Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Di Ninni
authors.affiliation: Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, 50019 Sesto Fiorentino, Firenze, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Zaccanti
authors.affiliation: Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Torricelli
authors.affiliation: Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Contini
authors.affiliation: Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Re
authors.affiliation: Politecnico di Milano-Dipartimento di Fisica, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Zucchelli
authors.affiliation: Istituto di Fotonica e Nanotecnologie, CNR, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Spinelli
authors.affiliation: 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.
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Cubeddu
authors.affiliation: 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.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pifferi
mesh_terms: D000465:Algorithms; D001921:Brain / Q000166:cytology*; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D005060:Europe; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008853:Microscopy / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041622:Tomography, Optical / Q000295:instrumentation*