Factors related to the failure of radiographic recognition of occult posttraumatic pneumothoraces.
OBJECTIVE
Although posttraumatic pneumothoraces (PTXs) are common and potentially life threatening, the supine chest radiograph (CXR) is an insensitive test for their detection. Computed tomography (CT) often identifies occult pneumothoraces (OPTXs). Previous descriptions of OPTX topography have been poor. Our purpose was to define their distribution and aid in the targeting of thoracic ultrasound.


METHODS
Posttraumatic supine CXRs and CTs were reviewed for occult, overt, and residual PTXs. PTXs were compared according to their apical, basal, anterior, lateral, medial, and posterior components. A comparative size index was calculated.


RESULTS
Among 761 patients, 338 CT scans revealed 103 PTXs in 89 patients; 55% were OPTXs. OPTXs were apical (57%), basal (41%), anterior (84%), lateral (24%), and medial (27%), with 0% posterior.


CONCLUSIONS
CXR missed over half of all PTXs. OPTXs had a greater anterior versus lateral (nearly 4-fold) and both basal and apical versus lateral (2-fold) distribution. OPTXs are often located at easily accessible sonographic windows.
Ball
Chad G
CG
Department of Surgery, Foothills Medical Centre, Room EG23, 1403-29 Street NW, Calgary, Alberta, Canada.
Kirkpatrick
Andrew W
AW
Laupland
Kevin B
KB
Fox
Dan L
DL
Litvinchuk
Stacey
S
Dyer
Dianne M M
DM
Anderson
Ian B
IB
Hameed
S Morad
SM
Kortbeek
John B
JB
Mulloy
Rob
R
D005260:Female; D006801:Humans; D015601:Injury Severity Score; D008297:Male; D011030:Pneumothorax / Q000000981:diagnostic imaging*; D013902:Radiography, Thoracic / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D016683:Supine Position; D013898:Thoracic Injuries / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D014949:Wounds, Nonpenetrating / Q000000981:diagnostic imaging*