title: Ventilation-perfusion lung scanning in the evaluation of pulmonary hypertension.
abstract: The objective of this study was to define the sensitivity, specificity and accuracy of ventilation-perfusion (V/Q) lung scanning in distinguishing chronic thromboembolic pulmonary hypertension (PHT) from other nonembolic causes of PHT.
  
  
  METHODS
  The V/Q lung scans from 75 patients in whom a confirmed cause of PHT was established were retrospectively reviewed. Twenty-five patients (33%) had chronic thromboembolic PHT, whereas 35 patients (47%) and 15 patients (20%) suffered from primary PHT and secondary nonthromboembolic PHT, respectively.
  
  
  RESULTS
  A high-probability V/Q scan interpretation had a sensitivity of 96% and a specificity of 94% for detecting patients with thromboembolic PHT. The combination of high- and intermediate-probability V/Q scan interpretations had a sensitivity of 100% for detecting patients with thromboembolic PH; however, the specificity decreased to 86%. Of the 35 patients with primary PHT, all but one patient had low-probability V/Q scan interpretations.
  
  
  CONCLUSIONS
  In this series, a low-probability V/Q scan interpretation effectively excluded the diagnosis of chronic thromboembolic PHT. In patients with an intermediate- or high-probability V/Q scan interpretation, pulmonary angiography was required to confirm the diagnosis of chronic thromboembolic PHT and determine whether surgical intervention was indicated. The V/Q lung scan appears to be a highly sensitive test for chronic thromboembolism in the diagnostic evaluation of patients with PHT. However, its role needs to be defined further by application to a prospectively recruited cohort of patients with PHT.
authors.affiliation: Department of Radiology, University of Pennsylvania Medical Center, Philadelphia.
authors.forename: D F
authors.initials: DF
authors.lastname: Worsley
authors.forename: H I
authors.initials: HI
authors.lastname: Palevsky
authors.forename: A
authors.initials: A
authors.lastname: Alavi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000000981:diagnostic imaging*; D008168:Lung / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000209:etiology; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013668:Technetium Tc 99m Aggregated Albumin; D013923:Thromboembolism / Q000150:complications; D014692:Ventilation-Perfusion Ratio
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin