title: In vivo flow mapping in complex vessel networks by single image correlation.
abstract: We describe a novel method (FLICS, FLow Image Correlation Spectroscopy) to extract flow speeds in complex vessel networks from a single raster-scanned optical xy-image, acquired in vivo by confocal or two-photon excitation microscopy. Fluorescent flowing objects produce diagonal lines in the raster-scanned image superimposed to static morphological details. The flow velocity is obtained by computing the Cross Correlation Function (CCF) of the intensity fluctuations detected in pairs of columns of the image. The analytical expression of the CCF has been derived by applying scanning fluorescence correlation concepts to drifting optically resolved objects and the theoretical framework has been validated in systems of increasing complexity. The power of the technique is revealed by its application to the intricate murine hepatic microcirculatory system where blood flow speed has been mapped simultaneously in several capillaries from a single xy-image and followed in time at high spatial and temporal resolution.
authors.affiliation: Università degli Studi di Milano-Bicocca, Physics Department, Piazza della Scienza 3, I-20126, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Sironi
authors.affiliation: Università degli Studi di Milano-Bicocca, Physics Department, Piazza della Scienza 3, I-20126, Milan, Italy.
authors.forename: Margaux
authors.initials: M
authors.lastname: Bouzin
authors.affiliation: 1] Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, I-20132, Milan, Italy [2] Vita-Salute San Raffaele University, I-20132, Milan, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: Inverso
authors.affiliation: Università degli Studi di Milano-Bicocca, Physics Department, Piazza della Scienza 3, I-20126, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: D'Alfonso
authors.affiliation: Università degli Studi di Milano-Bicocca, Physics Department, Piazza della Scienza 3, I-20126, Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pozzi
authors.affiliation: Università degli Studi di Milano, Department of Life Sciences, Via Celoria 26, I-20133, Milan, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Cotelli
authors.affiliation: Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, I-20132, Milan, Italy.
authors.forename: Luca G
authors.initials: LG
authors.lastname: Guidotti
authors.affiliation: 1] Division of Immunology, Transplantation and Infectious Diseases, IRCCS San Raffaele Scientific Institute, I-20132, Milan, Italy [2] Vita-Salute San Raffaele University, I-20132, Milan, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Iannacone
authors.affiliation: Università degli Studi di Milano-Bicocca, Physics Department, Piazza della Scienza 3, I-20126, Milan, Italy.
authors.forename: Maddalena
authors.initials: M
authors.lastname: Collini
authors.affiliation: Università degli Studi di Milano-Bicocca, Physics Department, Piazza della Scienza 3, I-20126, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Chirico
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D002196:Capillaries / Q000033:anatomy & histology / Q000502:physiology*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D051379:Mice; D008833:Microcirculation / Q000502:physiology*; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods*; D015203:Reproducibility of Results; D012212:Rheology / Q000379:methods*; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D015027:Zebrafish