title: Spatial versus temporal laser speckle contrast analyses in the presence of static optical scatterers.
abstract: Previously published data demonstrate that the temporal processing algorithm for laser speckle contrast imaging (LSCI) can improve the visibility of deep blood vessels and is less susceptible to static speckle artifacts when compared with the spatial algorithm. To the best of our knowledge, the extent to which the temporal algorithm can accurately predict the speckle contrast associated with flow in deep blood vessels has not been quantified. Here, we employed two phantom systems and imaging setups (epi-illumination and transillumination) to study the contrast predicted by the spatial and temporal algorithms in subsurface capillary tubes as a function of the camera exposure time and the actual flow speed. Our data with both imaging setups suggest that the contrast predicted by the temporal algorithm, and therefore the relative flow speed, is nearly independent of the degree of static optical scattering that contributes to the overall measured speckle pattern. Collectively, these results strongly suggest the potential of temporal LSCI at a single-exposure time to assess accurately the changes in blood flow even in the presence of substantial static optical scattering.
authors.affiliation: Instituto Nacional de Astrofisica, Optica y Electronica, Departamento de Optica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840, MexicobUniversity of California, Irvine, Beckman Laser Institute and Medical Clinic, Department of Surgery, 1002 Health S.
authors.forename: Julio C
authors.initials: JC
authors.lastname: Ramirez-San-Juan
authors.affiliation: University of California, Irvine, Beckman Laser Institute and Medical Clinic, Department of Surgery, 1002 Health Sciences Road East, Irvine, California 92612, United StatescUniversity of California, Irvine, Department of Biomedical Engineering, 3120 Natur.
authors.forename: Caitlin
authors.initials: C
authors.lastname: Regan
authors.affiliation: Instituto Nacional de Astrofisica, Optica y Electronica, Departamento de Optica, Luis Enrique Erro No. 1, Tonantzintla, Puebla 72840, Mexico.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Coyotl-Ocelotl
authors.affiliation: University of California, Irvine, Beckman Laser Institute and Medical Clinic, Department of Surgery, 1002 Health Sciences Road East, Irvine, California 92612, United StatescUniversity of California, Irvine, Department of Biomedical Engineering, 3120 Natur.
authors.forename: Bernard
authors.initials: B
authors.lastname: Choi
mesh_terms: D000328:Adult; D000465:Algorithms; D006801:Humans; D007834:Lasers; D061848:Optical Imaging / Q000379:methods*; D019047:Phantoms, Imaging; D012867:Skin / Q000737:chemistry; D014070:Tooth / Q000737:chemistry