title: Quantitative mapping of hemodynamics in the lung, brain, and dorsal window chamber-grown tumors using a novel, automated algorithm.
abstract: OBJECTIVE
  Hemodynamic properties of vascular beds are of great interest in a variety of clinical and laboratory settings. However, there presently exists no automated, accurate, technically simple method for generating blood velocity maps of complex microvessel networks.
  
  
  METHODS
  Here, we present a novel algorithm that addresses the problem of acquiring quantitative maps by applying pixel-by-pixel cross-correlation to video data. Temporal signals at every spatial coordinate are compared with signals at neighboring points, generating a series of correlation maps from which speed and direction are calculated. User-assisted definition of vessel geometries is not required, and sequential data are analyzed automatically, without user bias.
  
  
  RESULTS
  Velocity measurements were validated against the dual-slit method and against in vitro capillary flow with known velocities. The algorithm was tested in three different biological models in order to demonstrate its versatility.
  
  
  CONCLUSIONS
  The hemodynamic maps presented here demonstrate an accurate, quantitative method of analyzing dynamic vascular systems.
authors.affiliation: Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA.
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Fontanella
authors.forename: Thies
authors.initials: T
authors.lastname: Schroeder
authors.forename: Daryl W
authors.initials: DW
authors.lastname: Hochman
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Chen
authors.forename: Gabi
authors.initials: G
authors.lastname: Hanna
authors.forename: Michael M
authors.initials: MM
authors.lastname: Haglund
authors.forename: Narasimhan
authors.initials: N
authors.lastname: Rajaram
authors.forename: Amy E
authors.initials: AE
authors.lastname: Frees
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Secomb
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Palmer
authors.forename: Mark W
authors.initials: MW
authors.lastname: Dewhirst
mesh_terms: D000465:Algorithms; D000818:Animals; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply*; D005260:Female; D008168:Lung / Q000098:blood supply*; D008325:Mammary Neoplasms, Experimental / Q000098:blood supply*; D051379:Mice; D008819:Mice, Nude; D008955:Models, Cardiovascular
keywords: blood flow; computational; image processing; tumor microcirculation