title: Characterization of a time-resolved non-contact scanning diffuse optical imaging system exploiting fast-gated single-photon avalanche diode detection.
abstract: We present a system for non-contact time-resolved diffuse reflectance imaging, based on small source-detector distance and high dynamic range measurements utilizing a fast-gated single-photon avalanche diode. The system is suitable for imaging of diffusive media without any contact with the sample and with a spatial resolution of about 1 cm at 1 cm depth. In order to objectively assess its performances, we adopted two standardized protocols developed for time-domain brain imagers. The related tests included the recording of the instrument response function of the setup and the responsivity of its detection system. Moreover, by using liquid turbid phantoms with absorbing inclusions, depth-dependent contrast and contrast-to-noise ratio as well as lateral spatial resolution were measured. To illustrate the potentialities of the novel approach, the characteristics of the non-contact system are discussed and compared to those of a fiber-based brain imager.
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Di Sieno
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: Heidrun
authors.initials: H
authors.lastname: Wabnitz
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pifferi
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Mazurenka
authors.affiliation: Department of Biomedical Optics, Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Hoshi
authors.affiliation: Politecnico di Milano, Dipartimento di Fisica, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Dalla Mora
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 Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Boso
authors.affiliation: Becker and Hickl GmbH, Nahmitzer Damm 30, 12277 Berlin, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Becker
authors.affiliation: Dipartimento di Fisica e Astronomia dell'Università degli Studi di Firenze, Via G. Sansone 1, Sesto Fiorentino, Firenze 50019, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Martelli
authors.affiliation: Politecnico di Milano, Dipartimento di Elettronica, Informazione e Bioingegneria, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Tosi
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Abbestr. 2-12, 10587 Berlin, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Macdonald
mesh_terms: D001921:Brain / Q000502:physiology; D004566:Electrodes; D007834:Lasers; D055100:Optical Fibers; D061848:Optical Imaging / Q000295:instrumentation*; D019047:Phantoms, Imaging; D017785:Photons; D013997:Time Factors