title: Diagnostic accuracy of a novel software technology for detecting pneumothorax in a porcine model.
abstract: BACKGROUND
  Our objective was to measure the diagnostic accuracy of a novel software technology to detect pneumothorax on Brightness (B) mode and Motion (M) mode ultrasonography.
  
  
  METHODS
  Ultrasonography fellowship-trained emergency physicians performed thoracic ultrasonography at baseline and after surgically creating a pneumothorax in eight intubated, spontaneously breathing porcine subjects. Prior to pneumothorax induction, we captured sagittal M-mode still images and B-mode videos of each intercostal space with a linear array transducer at 4cm of depth. After collection of baseline images, we placed a chest tube, injected air into the pleural space in 250mL increments, and repeated the ultrasonography for pneumothorax volumes of 250mL, 500mL, 750mL, and 1000mL. We confirmed pneumothorax with intrapleural digital manometry and ultrasound by expert sonographers. We exported collected images for interpretation by the software. We treated each individual scan as a single test for interpretation by the software.
  
  
  RESULTS
  Excluding indeterminate results, we collected 338M-mode images for which the software demonstrated a sensitivity of 98% (95% confidence interval [CI] 92-99%), specificity of 95% (95% CI 86-99), positive likelihood ratio (LR+) of 21.6 (95% CI 7.1-65), and negative likelihood ratio (LR-) of 0.02 (95% CI 0.008-0.046). Among 364 B-mode videos, the software demonstrated a sensitivity of 86% (95% CI 81-90%), specificity of 85% (81-91%), LR+ of 5.7 (95% CI 3.2-10.2), and LR- of 0.17 (95% CI 0.12-0.22).
  
  
  CONCLUSIONS
  This novel technology has potential as a useful adjunct to diagnose pneumothorax on thoracic ultrasonography.
authors.affiliation: Department of Emergency Medicine, San Antonio Military Medical Center, JBSA Fort Sam Houston, TX, USA.
authors.forename: Shane M
authors.initials: SM
authors.lastname: Summers
authors.affiliation: Department of Emergency Medicine, San Antonio Military Medical Center, JBSA Fort Sam Houston, TX, USA.
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Chin
authors.affiliation: Department of Emergency Medicine, San Antonio Military Medical Center, JBSA Fort Sam Houston, TX, USA. Electronic address: Michael.D.April@post.harvard.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: April
authors.affiliation: United States Army Institute of Surgical Research, JBSA Fort Sam Houston, TX, USA.
authors.forename: Ronald D
authors.initials: RD
authors.lastname: Grisell
authors.affiliation: Department of Emergency Medicine, San Antonio Military Medical Center, JBSA Fort Sam Houston, TX, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Lospinoso
authors.affiliation: United States Army Institute of Surgical Research, JBSA Fort Sam Houston, TX, USA.
authors.forename: Bijan S
authors.initials: BS
authors.lastname: Kheirabadi
authors.affiliation: United States Army Institute of Surgical Research, JBSA Fort Sam Houston, TX, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Salinas
authors.affiliation: United States Army Medical Department Center and School (AMEDD C&S), JBSA Fort Sam Houston, TX, USA.
authors.forename: Lorne H
authors.initials: LH
authors.lastname: Blackbourne
mesh_terms: D000818:Animals; D015505:Chest Tubes; D005260:Female; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D011030:Pneumothorax / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D012984:Software; D013552:Swine; D035441:Thoracic Wall / Q000000981:diagnostic imaging*; D014463:Ultrasonography
keywords: Diagnosis; Pneumothorax; Software; Swine; Ultrasonography