title: Speckle variance detection of microvasculature using swept-source optical coherence tomography.
abstract: We report on imaging of microcirculation by calculating the speckle variance of optical coherence tomography (OCT) structural images acquired using a Fourier domain mode-locked swept-wavelength laser. The algorithm calculates interframe speckle variance in two-dimensional and three-dimensional OCT data sets and shows little dependence to the Doppler angle ranging from 75 degrees to 90 degrees . We demonstrate in vivo detection of blood flow in vessels as small as 25 microm in diameter in a dorsal skinfold window chamber model with direct comparison with intravital fluorescence confocal microscopy. This technique can visualize vessel-size-dependent vascular shutdown and transient vascular occlusion during Visudyne photodynamic therapy and may provide opportunities for studying therapeutic effects of antivascular treatments without on exogenous contrast agent.
authors.affiliation: Department of Medical Biophysics, University of Toronto, Toronto, M5G 2M9, Canada.
authors.forename: Adrian
authors.initials: A
authors.lastname: Mariampillai
authors.forename: Beau A
authors.initials: BA
authors.lastname: Standish
authors.forename: Eduardo H
authors.initials: EH
authors.lastname: Moriyama
authors.forename: Mamta
authors.initials: M
authors.lastname: Khurana
authors.forename: Nigel R
authors.initials: NR
authors.lastname: Munce
authors.forename: Michael K
authors.initials: MK
authors.lastname: Leung
authors.forename: James
authors.initials: J
authors.lastname: Jiang
authors.forename: Alex
authors.initials: A
authors.lastname: Cable
authors.forename: Brian C
authors.initials: BC
authors.lastname: Wilson
authors.forename: I Alex
authors.initials: IA
authors.lastname: Vitkin
authors.forename: Victor X D
authors.initials: VX
authors.lastname: Yang
mesh_terms: D000465:Algorithms; D000818:Animals; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D051379:Mice; D008819:Mice, Nude; D008833:Microcirculation / Q000166:cytology*; D018613:Microscopy, Confocal / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*