title: High-resolution optical Doppler tomography for in vitro and in vivo fluid flow dynamics.
abstract: BACKGROUND
  The objective of our research was to use a noninvasive tomographic imaging technique with high spatial resolution (2-15 microm) to characterize and monitor fluid flow and the microvasculature in highly scattering biological tissues at user-specified discrete locations.
  
  
  METHODS
  The technique of optical Doppler tomography (ODT) combines laser Doppler flowmetry (LDF) with optical coherence tomography to obtain high-resolution tomographic velocity and structural images of static and moving constituents in highly scattering biological tissues. We present ODT structural and velocity images using in vitro turbid samples of a circular conduit infused with a suspension of polymer microspheres. At a thin rectangular cross-section of the conduit, the Intralipid flow was measured. Blood flow velocity was measured in vivo in the ear of rodent skin.
  
  
  RESULTS
  In first model, the ODT velocity images demonstrated beads near the center of the conduit moving faster than those near the circular wall. In the second model, the ODT velocity images indicated that laminar flow was fastest along the central axis of the conduit. Blood flow in 2 small veins with diameters of 70 and 40 microm, respectively, and an artery with diameter of 25 microm, was clearly identified in a rodent model.
  
  
  CONCLUSIONS
  In our preliminary in vitro and in vivo studies on turbid samples and model vasculatures, we determined that the application of ODT to characterize and image blood flow with high spatial resolution at discrete user-specified locations in highly scattering biological tissues is feasible.
authors.affiliation: Department of Plastic Surgery, Chang Gung Memorial Hospital, Taipei. chengjen@cgmh.org.tw
authors.forename: Cheng-Jen
authors.initials: CJ
authors.lastname: Chang
authors.forename: Kuang-Hua
authors.initials: KH
authors.lastname: Hou
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology*; D003935:Diagnostic Techniques, Cardiovascular; D066298:In Vitro Techniques; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008833:Microcirculation / Q000502:physiology*; D008863:Microspheres; D008962:Models, Theoretical; D051381:Rats; D012867:Skin / Q000098:blood supply; D014054:Tomography