Nonvascular, nontraumatic mediastinal emergencies in adults: a comprehensive review of imaging findings.

Given their high frequency, mediastinal emergencies are often perceived as being a result of external trauma or vascular conditions. However, there is a group of nonvascular, nontraumatic mediastinal emergencies that are less common in clinical practice, are less recognized, and that represent an important source of morbidity and mortality in patients. Nonvascular, nontraumatic mediastinal emergencies have several causes and result from different pathophysiologic mechanisms including infection, internal trauma, malignancy, and postoperative complications, and some may be idiopathic. Some conditions that lead to nonvascular, nontraumatic mediastinal emergencies include acute mediastinitis; esophageal emergencies such as intramural hematoma of the esophagus, Boerhaave syndrome, and acquired esophagorespiratory fistulas; spontaneous mediastinal hematoma; tension pneumomediastinum; and tension pneumopericardium. Although clinical findings of nonvascular, nontraumatic mediastinal emergencies may be nonspecific, imaging findings are often definitive. Awareness of various nonvascular, nontraumatic mediastinal emergencies and their clinical manifestations and imaging findings is crucial for making an accurate and timely diagnosis to facilitate appropriate patient management.