title: Utility of cervical spinal and abdominal computed tomography in diagnosing occult pneumothorax in patients with blunt trauma:  Computed tomographic imaging protocol matters.
abstract: BACKGROUND
  Small pneumothoraces (PXs), which are not initially recognized with a chest x-ray film and diagnosed by a thoracic computed tomography (CT), are described as occult PX (OCPX). The objective of this study was to evaluate cervival spine (C-spine) and abdominal CT (ACT) for diagnosing OCPX and overt PX (OVPX).
  
  
  METHODS
  All patients with blunt trauma who presented consecutively to the emergency department during a 26-months period were included. Among all the chest CTs (CCTs) (6,155 patients) conducted during that period, 254 scans were confirmed to have a true PX. The findings in their C-spine CT and ACT were compared with the findings in CCTs.
  
  
  RESULTS
  Among these patients, 254 had a diagnosis of PX confirmed with CCT. OCPXs were identified on the chest computed tomographic scan of 128 patients (70.3%), whereas OVPXs were evident in 54 patients (29.7%). Computed tomographic imaging of the C-spine was performed in 74% of patients with OCPX and 66.7% of patients with OVPX trauma. Only 45 (35.2%) cases of OCPX and 42 (77.8%) cases of OVPX were detected by C-spine CT. ACT was performed in almost all patients, and 121 (95.3%) of 127 of these correctly identified an existing OCPX. Sensitivity of C-spine CT and ACT was 35.1% and 96.5%, respectively; specificity was 100% and 100%, respectively.
  
  
  CONCLUSIONS
  Almost all OCPXs, regardless of intrathoracic location, could be detected by ACT or by combining C-spine and abdominal computed tomographic screening for patients. If the junction of the first and second vertebra is used as the caudad extent, C-spine CT does not have sufficient power to diagnose more than a third of the cases.
  
  
  METHODS
  Diagnostic study, level III.
authors: Department of Emergency Medicine, Dr. Lütfi Kırdar Kartal Education and Research Hospital, Istanbul, Turkey. drhaldun@gmail.com
authors: Haldun
authors: H
authors: Akoglu
authors: Ebru Unal
authors: EU
authors: Akoglu
authors: Serdar
authors: S
authors: Evman
authors: Tayfun
authors: T
authors: Akoglu
authors: Arzu
authors: A
authors: Denizbasi
authors: Ozlem
authors: O
authors: Guneysel
authors: Ozge
authors: O
authors: Onur
authors: Ender
authors: E
authors: Onur
mesh_terms: D000293:Adolescent; D000328:Adult; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries*; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000000981:diagnostic imaging* / Q000209:etiology; D012372:ROC Curve; D011860:Radiography, Abdominal; D013902:Radiography, Thoracic; D015203:Reproducibility of Results; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000150:complications / Q000000981:diagnostic imaging*; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014949:Wounds, Nonpenetrating / Q000150:complications / Q000000981:diagnostic imaging*; D055815:Young Adult