title: Sensitivity for detection of patent foramen ovale increased with increasing number of contrast injections: a descriptive study with contrast transesophageal echocardiography.
abstract: OBJECTIVE
  We sought to study the diagnostic yield of increasing numbers of contrast injections for detection of patent foramen ovale (PFO) during transesophageal echocardiography.
  
  
  METHODS
  Contrast was injected twice during each of 10 provocations to 30 patients screened for PFO. Injections were given during quiet respiration, early Valsalva (starting 3-5 seconds before injection), late Valsalva (starting 3-5 seconds after injection), Mueller maneuver, coughing, bed tilt during early Valsalva, after nitroglycerin spray during both quiet respiration, and early Valsalva.
  
  
  RESULTS
  The number of detected PFOs increased as the number of injections increased (r = 0.79, P < .01). Five injections per patient detected all 11 large PFOs. To eventually detect all 14 PFOs among the 30 study patients required a total of 11 injections per patient.
  
  
  CONCLUSIONS
  The sensitivity for PFO detection increased when additional contrast injections were given. At least 5 injections are required to safely detect or rule out the presence of a PFO.
authors.affiliation: Sahlgrenska University Hospital/Ostra, Göteborg, Sweden. Magnus.C.Johansson@vgregion.se
authors.forename: Magnus C
authors.initials: MC
authors.lastname: Johansson
authors.forename: Hrodmar
authors.initials: H
authors.lastname: Helgason
authors.forename: Mikael
authors.initials: M
authors.lastname: Dellborg
authors.forename: Peter
authors.initials: P
authors.lastname: Eriksson
mesh_terms: D000368:Aged; D003287:Contrast Media / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D054092:Foramen Ovale, Patent / Q000000981:diagnostic imaging*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media