Lung torsion: radiographic findings in nine cases.

Torsion of the lung, although relatively rare, can occur under three sets of circumstances: spontaneously, usually in association with some other pulmonary abnormality; following traumatic pneumothorax; and as a complication of thoracic surgery. Nine cases of pulmonary torsion were analyzed. The radiographic findings are a collapsed or consolidated lobe that occupies an unusual position at plain radiography, at plain or computed tomography, at angiography, or at bronchography; hilar displacement in a direction inappropriate for that lobe; alteration in the normal position and sweep of the pulmonary vasculature; rapid opacification of an ipsilateral lobe following trauma or thoracic surgery; marked change in position of an opacified lobe on sequential radiographs; bronchial cutoff with no evidence of a mass; or lobar air trapping. Mortality is high if the torsion goes unrecognized and surgical fixation is delayed.