title: Noninvasive measurement of pulmonary vascular resistances by assessment of cardiac output and pulmonary transit time.
abstract: OBJECTIVE
  Pulmonary vascular resistance is of special interest in many diseases. Usually it is determined invasively by catheterization, but cardiac output and pulmonary transit time can be ascertained by several noninvasive methods.
  
  
  METHODS
  Fourteen heart recipients (age 34-71 years) were examined by electron-beam CT of the heart. Cine and flow studies were performed using a total of 60 mL of contrast and a breath-hold of 20 seconds.
  
  
  RESULTS
  A mathematical model for calculating pulmonary vascular resistances from noninvasively measured cardiac outputs and pulmonary transit times was developed. Right-sided heart catheterization served as the reference method.
  
  
  CONCLUSIONS
  The formula created seems to allow a clinically valid estimate of pulmonary vascular resistance from noninvasively acquired data.
authors.affiliation: Department of Surgery, Karl-Franzes-University, Graz, Austria. helmut.muller@kfunigraz.ac.at
authors.forename: H M
authors.initials: HM
authors.lastname: Müller
authors.forename: M B
authors.initials: MB
authors.lastname: Tripolt
authors.forename: P H
authors.initials: PH
authors.lastname: Rehak
authors.forename: R
authors.initials: R
authors.lastname: Groell
authors.forename: R
authors.initials: R
authors.lastname: Rienmüller
authors.forename: K H
authors.initials: KH
authors.lastname: Tscheliessnigg
mesh_terms: D000465:Algorithms; D002302:Cardiac Output; D005260:Female; D016027:Heart Transplantation / Q000000981:diagnostic imaging* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011652:Pulmonary Circulation / Q000502:physiology*; D011667:Pulmonary Veins / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014655:Vascular Resistance / Q000502:physiology*