A pictorial review of lung torsion using 3D CT cinematic rendering.

Lung torsion is the abnormal rotation of a lobe or lung around its bronchovascular pedicle. It most commonly occurs in the setting of pulmonary resection, though it has also been described after large-volume thoracentesis and video-assisted thoracic surgery, as well as spontaneously. Resulting ischemia can lead to infarction, making this an emergent diagnosis. As findings are often nonspecific, a high index of suspicion is required, especially in the postsurgical setting. 2D CT angiography findings are subtle and include direct signs of pedicle rotation on CT as well as indirect findings including loss of normal parenchymal enhancement, atelectasis of torsed lobe/lung, and abnormal fissure position. These direct and indirect findings are often appreciated on different window presets and upon review of images in multiple planes, with need to collate the information subsequently. 3D cinematic rendering (CR) using multi-planar light sources can readily highlight spatial relationships of vasculature in the chest and may be able to assist in the confident diagnosis of this sometimes subtle but life-threatening pathology. We have provided the first characterization of common lung torsion findings on 3D CR.