title: Influence of vascular enhancement, age and gender on pulmonary perfused blood volume quantified by dual-energy-CTPA.
abstract: OBJECTIVE
  To determine the influence of technical and demographic parameters on quantification of pulmonary perfused blood volume (PBV) in dual energy computed tomography pulmonary angiography (DE-CTPA).
  
  
  METHODS
  Pulmonary PBV was quantified in 142 patients who underwent DE-CTPA for suspected pulmonary embolism but in whom no thoracic pathologies were detected. Multivariate linear regression analysis was performed to calculate the influence of age, gender, enhancement of pulmonary trunk and enhancement difference between pulmonary trunk and left atrium (as a measure of timing) on PBV values. The resulting regression coefficients were used to calculate age-specific ranges of normal for PBV values adjusted for vascular enhancement and timing.
  
  
  RESULTS
  Enhancement of the pulmonary trunk (β=-0.29, p=0.001) and enhancement difference between pulmonary trunk and left atrium (β=-0.24, p=0.003) were found to significantly influence PBV values. Age (β=-0.33, p<0.001) but not gender (β=0.14, p=0.05) had a significant negative influence on pulmonary PBV values. There was a 20% relative decrease of pulmonary PBV from patients aged <30 to patients over 80 years of age.
  
  
  CONCLUSIONS
  DE-CTPA derived PBV values need to be corrected for age, vascular enhancement and timing but not for gender. The age-specific ranges of normal derived from this study can be used as a reference in future studies of PBV in pulmonary pathologies.
authors.affiliation: Institute for Clinical Radiology, Ludwig-Maximilians-University Hospital Munich, Marchioninistr. 15, 81377 Munich, Germany. felix.meinel@med.uni-muenchen.de
authors.forename: Felix G
authors.initials: FG
authors.lastname: Meinel
authors.forename: Anita
authors.initials: A
authors.lastname: Graef
authors.forename: Wieland H
authors.initials: WH
authors.lastname: Sommer
authors.forename: Kolja M
authors.initials: KM
authors.lastname: Thierfelder
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
authors.forename: Thorsten R C
authors.initials: TR
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001810:Blood Volume / Q000502:physiology*; D001811:Blood Volume Determination / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods* / Q000706:statistics & numerical data; D011651:Pulmonary Artery / Q000000981:diagnostic imaging* / Q000502:physiology*; D011652:Pulmonary Circulation / Q000502:physiology*; D015900:Radiography, Dual-Energy Scanned Projection / Q000379:methods* / Q000706:statistics & numerical data; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods* / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Age; Dual-energy CT; Gender; Norm values; Pulmonary perfusion