title: Can cervical spine computed tomography assist in detecting occult pneumothoraces?
abstract: BACKGROUND
  Screening CT often detects posttraumatic pneumothoraces that were not diagnosed on a preceding supine anteroposterior chest radiograph (occult pneumothoraces (OPTXs)). Because abdominal CT imaging misses OPTXs in the upper thorax, the objective of this study was to evaluate the utility of cervical spine (C-spine) CT screening for diagnosing OPTXs.
  
  
  METHODS
  A dual-institution (Foothills Medical Centre and Grady Memorial Hospital) retrospective review of consecutive OPTXs was performed. The accuracy of various CT screening protocols in detecting OPTXs was compared.
  
  
  RESULTS
  OPTXs were detected in 75 patients. Patient demographics and injury characteristics were similar between centres (65% male; 97% blunt mechanism; 29% hemodynamically unstable; mean ISS=27; mean length of stay=22 days; mortality=9%)(p>0.05). Patients received either abdominal (41%) or thoraco-abdominal (59%) CT imaging. Most patients (89%) also underwent C-spine CT imaging. OPTXs were evident on thoracic CT in 100% (44/44), abdominal CT in 83% (62/75), and C-spine CT in 82% (55/67) of cases. All patients with OPTXs identified solely on thoracic CT (i.e. not abdominal) who also underwent imaging of their C-spine could have had their OTPXs diagnosed by using the pulmonary windows setting of their C-spine CT series. Combining C-spine and abdominal CT screening diagnosed all OPTXs (67/67) detected on thoracic CT, for patients who also underwent these investigations.
  
  
  CONCLUSIONS
  OPTXs were evident on thoracic (and not abdominal) CT in 17% of severely injured patients. For patients who also underwent C-spine imaging, all OPTXs isolated to thoracic CT could be diagnosed by using the pulmonary windows setting of their C-spine CT imaging protocol. All OPTXs, regardless of intra-thoracic location, could also be detected by combining C-spine and abdominal CT screening.
authors: Department of Surgery, The University of Calgary, Trauma Services Foothills Medical Centre, 1403-29 Street N.W., T2N 2T9 Calgary, Alberta, Canada. ball.chad@gmail.com
authors: Chad G
authors: CG
authors: Ball
authors: Derek J
authors: DJ
authors: Roberts
authors: Andrew W
authors: AW
authors: Kirkpatrick
authors: David V
authors: DV
authors: Feliciano
authors: John B
authors: JB
authors: Kortbeek
authors: Indraneel
authors: I
authors: Datta
authors: Kevin B
authors: KB
authors: Laupland
authors: Mantaj
authors: M
authors: Brar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000000981:diagnostic imaging* / Q000209:etiology; D013902:Radiography, Thoracic; D012189:Retrospective Studies; D013898:Thoracic Injuries / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014193:Trauma Centers; D016896:Treatment Outcome; D055815:Young Adult