title: Photoacoustic imaging of valves in superficial veins.
abstract: OBJECTIVE
  In intravenous access to veins there is a risk of puncturing venous valves or blocking of the catheter by the valves. Therefore, we have investigated whether and how photoacoustic imaging (PAI), which visualizes the lumen of blood vessels, can be used to detect these valves.
  
  
  METHODS
  Venous valves in superficial veins on the dorsal side of the hand of human volunteers were located by palpation and visual inspection. Next, this location was imaged using PAI.
  
  
  RESULTS
  In 16 of 21 human volunteers venous valves that were found by palpation could be observed by PAI as local discontinuities in the imaged vessel. From these images, four characteristic features by which venous valves can be recognized in photoacoustic images were identified.
  
  
  CONCLUSIONS
  PAI has the potential to be applied in the detection of venous valves.
authors.affiliation: Biophysical Engineering, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands. r.g.m.kolkman@utwente.nl
authors.forename: Roy G M
authors.initials: RG
authors.lastname: Kolkman
authors.forename: Nienke
authors.initials: N
authors.lastname: Bosschaart
authors.forename: Ben
authors.initials: B
authors.lastname: Kok
authors.forename: Ton G
authors.initials: TG
authors.lastname: van Leeuwen
authors.forename: Wiendelt
authors.initials: W
authors.lastname: Steenbergen
mesh_terms: D000162:Acoustics; D000293:Adolescent; D000328:Adult; D002648:Child; D004867:Equipment Design; D005260:Female; D006225:Hand / Q000098:blood supply*; D006801:Humans; D007834:Lasers; D008297:Male; D010173:Palpation; D014463:Ultrasonography / Q000295:instrumentation*; D014680:Veins / Q000033:anatomy & histology*