PICTORIAL ESSAY Spectrum of Blunt Chest Injuries

IMAGING FOR BLUNT CHEST TRAUMA The chest radiograph remains the initial study for assessing patients sustaining blunt trauma to the chest, and many common injuries can be identified by the chest radiograph alone. However, in severely injured patients, the ideal upright, full inspiratory PA chest radiograph cannot be obtained. Portable supine radiographs, often suffering from poor positioning, poor inspiration, or artifact from an underlying backboard or overlying monitoring equipment, are generally the rule rather than the exception, and many injuries may be difficult to detect on these suboptimal studies. It is essential to identify on the chest radiograph life threatening conditions such as pneumothorax, hemothorax, abnormal mediastinum (possibly indicating aortic or other great vessel injury), and thoracic spine fracture, as well as malpositioned life support devices. The technical limitations of a chest radiograph should be declared when it is difficult or impossible to exclude a life-threatening injury, and alternative imaging studies should be suggested. CT of the chest, particularly with the development multidetector-row CT (MDCT) scanners, has become a common examination for imaging the trauma patient with known or suspected thoracic injury, as CT scanners are available in almost all trauma centers. The fast scanning time of MDCT allows for single-breath-hold scanning, fewer motion artifacts, and improved contrast bolus imaging. Additionally, thinner collimation provides isotropic voxels, allowing for multiplanar reformations while maintaining spatial resolution. Magnetic resonance imaging (MRI) has many advantages for imaging the chest, including no need for iodinated contrast material, lack of ionizing radiation, and multiplanar imaging capabilities. However, scan times can be lengthy, and monitoring critically ill patients can be difficult, limiting the role of MRI for evaluating trauma patients. This pictorial essay will review the spectrum of injuries that occur in the chest following blunt trauma, focusing on the radiographic and CT findings.