Imaging of nontraumatic mediastinal and pulmonary processes

Thoracic complaints including cough, shortness of breath, and pleuritic chest pain are common but nonspecific presenting symptoms in the emergency department, and as many as 5 % of visits are due to acute chest pain (19). Acute chest pain in the absence of trauma remains a diagnostic challenge because of extensive etiology that ranges from benign to potentially lethal. After cardiac and aortic etiologies are ruled out, three main categories of disease origin should be considered: mediastinum (including pulmonary vasculature only), lung, and pleura. Nontraumatic, noncardiac mediastinal processes which can present with chest symptoms include, but are not limited to, pulmonary embolism (technically lung but will be considered with mediastinum), esophageal perforation, mediastinitis, and abscess. Pulmonary pathology also tends to affect the pleural space so these two categories will be considered together. Pneumonia and pulmonary edema are the most common pulmonary diagnoses in the emergency room. It is equally important to delineate any associated complications including pulmonary abscess and empyema. Pneumothorax can also be nontraumatic in etiology and present with acute thoracic symptoms (18).