title: Value of digital radiography in expiration in detection of pneumothorax.
abstract: OBJECTIVE
  The purpose of this study was to find out whether pneumothorax detection and exclusion is superior in expiratory digital chest radiography.
  
  
  METHODS
  131 patients with pneumothorax with paired inspiratory and expiratory chest radiographs were analyzed regarding localization and size of pneumothorax. Sensitivity, specificity, negative (npv) and positive predictive value (ppv) as well as the positive (LR+) and negative likelihood ratio (LR-) were determined in a blinded randomized interobserver study with 116 patients. The evaluation was performed by three board-certified radiologists.
  
  
  RESULTS
  In 131 patients, there were 139 pneumothoraces, 135 (97.1 %) were located apical, 88 (63.3 %) lateral and 33 (23.7 %) basal. Sensitivity was 99 % for inspiratory and 97 % for expiratory radiographs. The interobserver study yielded a mean sensitivity of 86.1 %/86.1 %, specificity of 97.3 %/93.4 %, npv of 88.7 %/88.5 % and ppv of 96.7 %/92.1 % for inspiration/expiration. For inspiratory radiographs the LR+/LR- were 40.2/0.14 and for expiration 13.9 and 0.15. McNemar-Test showed no significant difference for the detection of pneumothoraces in in-/exspiration.
  
  
  CONCLUSIONS
  Inspiratory and expiratory digital radiographs are equally suitable for pneumothorax detection. Inspiratory radiographs are recommended as the initial examination of choice for pneumothorax detection, an additional expiratory radiograph is only recommended in doubtful cases.
  
  
  CONCLUSIONS
  • Basal pneumothoraces during inspiration demonstrate a greater width than during expiration. • There is statistically no difference between inspiration/expiration for the diagnosis of pneumothorax. • An image taken during inspiration is recommended to confirm or rule out a pneumothorax.
authors.affiliation: Department of Radiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Thomsen
authors.affiliation: Department of Radiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Natho
authors.affiliation: Department of Radiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Feigen
authors.affiliation: Medical statistics, medistat GmbH, Kiel, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Schulz
authors.affiliation: Department of Radiology, Asklepios Klinik St. Georg, Hamburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Kivelitz
mesh_terms: D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D045853:Exhalation; D005260:Female; D006801:Humans; D001239:Inhalation; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000000981:diagnostic imaging*; D015995:Prevalence; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D013902:Radiography, Thoracic / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult