Mediastinum

Abstract

The mediastinal space is located between the right and left mediastinal pleura which is a continuation of the costal parietal pleura and marks the medial border of the left and right pleural sacs, respectively. As for any radiographic study of the thorax, the mediastinum should be evaluated on orthogonal views. This chapter discusses mediastinal shift, mediastinal fluid accumulation, masses, lymphadenopathy, pneumomediastinum, and esophageal and tracheal disorders. The normal esophagus is not visible on survey radiographs of the thorax in dogs and cats. The imaging modalities commonly used to evaluate a patient for suspected esophageal disorders are survey radiographs and positive contrast esophagography. The trachea extends from the cricoid cartilage of the larynx to its bifurcation into the mainstem bronchi dorsal to the heart base. A tracheal rupture or tear is usually traumatic in etiology, although other causes, including iatrogenic injury, are possible.