title: Quantitative analysis of lung perfusion in patients with primary pulmonary hypertension.
abstract: The aim of this study was to evaluate quantitatively the heterogeneity of lung perfusion scans in patients with primary pulmonary hypertension (PPH) and to compare it with the severity of disease.
  
  
  METHODS
  Lung perfusion scans were obtained on 22 patients with PPH and 12 age-matched control subjects. The perfused area rates (PARs) were calculated by dividing the lung area in each 10% threshold width from 10% to 100% of maximal counts by total lung area. The total absolute difference in the PAR between each patient and the mean control value was assumed as the perfusion index of the lung (P index). The P index was compared with hemodynamic parameters and the right ventricular ejection fraction (RVEF), including 7 patients who received long-term vasodilator therapy.
  
  
  RESULTS
  The P index correlated significantly with mean pulmonary arterial pressure (P < 0.001) and RVEF (P < 0.05). In patients with vasodilator therapy, the P index was improved significantly after therapy (P < 0.05) and was associated with a reduction in pulmonary arterial pressure.
  
  
  CONCLUSIONS
  Quantitative assessment of lung perfusion irregularity might provide useful information about the severity of disease and the effect of therapy in addition to the routine visual representation.
authors.affiliation: Department of Radiology, National Cardiovascular Center, Suita, Osaka, Japan. kfukuchi@hsp.ncvc.go.jp
authors.forename: Kazuki
authors.initials: K
authors.lastname: Fukuchi
authors.forename: Kohei
authors.initials: K
authors.lastname: Hayashida
authors.forename: Norifumi
authors.initials: N
authors.lastname: Nakanishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inubushi
authors.forename: Shingo
authors.initials: S
authors.lastname: Kyotani
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Nagaya
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Ishida
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008168:Lung / Q000000981:diagnostic imaging*; D008297:Male; D011652:Pulmonary Circulation / Q000502:physiology; D019275:Radiopharmaceuticals; D013318:Stroke Volume; D013668:Technetium Tc 99m Aggregated Albumin; D016278:Ventricular Function, Right; D015646:Ventriculography, First-Pass
chemical_list: D019275:Radiopharmaceuticals; D013668:Technetium Tc 99m Aggregated Albumin