title: Absorption and scattering perturbations in homogeneous and layered diffusive media probed by time-resolved reflectance at null source-detector separation.
abstract: We characterize the capability of time-resolved reflectance measurements at small source-detector separation (less than 5 mm) to localize small inhomogeneities embedded in an otherwise homogeneous or layered diffusive medium. By considering both absorption and scattering inhomogeneities, we demonstrate the improvement of this approach in terms of contrast and spatial resolution, as compared to more typical set-ups involving larger source-detection separations (few centimeters). Simulations are performed exploiting an analytical perturbation approach to diffusion theory and a four-layer heterogeneous time-resolved Monte Carlo code, considering realistic tissue geometries. Exhaustive investigation in the parameters space is reported.
authors.affiliation: INFM-Dipartimento di Fisica and IFN-CNR, Politecnico di Milano, piazza L. da Vinci 32, I-20133 Milan, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Spinelli
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Martelli
authors.forename: Samuele
authors.initials: S
authors.lastname: Del Bianco
authors.forename: Antonio
authors.initials: A
authors.lastname: Pifferi
authors.forename: Alessandro
authors.initials: A
authors.lastname: Torricelli
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Cubeddu
authors.forename: Giovanni
authors.initials: G
authors.lastname: Zaccanti
mesh_terms: D000042:Absorption; D003198:Computer Simulation; D008027:Light; D008954:Models, Biological; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010783:Photometry / Q000379:methods*; D012542:Scattering, Radiation