The Mediastinum and Neck

Abstract

The mediastinum is a space that lies along the midline of the thorax between the lung pleurae, extending from the thoracic inlet to the diaphragm. Although divided academically into cranial, middle, caudal, and ventral or dorsal compartments, it is actually a single space in which fluid and air/gas move freely, and it can be affected by benign and malignant conditions. The mediastinum itself is customarily evaluated during thoracic MDCT examination. As a result of embryological development, however, an anatomical continuum exists between the mediastinum and the neck in mammals. Several structures, such as the thyroid, trachea, and esophagus, may be affected by various conditions, indicating the need for simultaneous assessment of these two body compartments. Moreover, spaces between the organs of the neck communicate directly with the mediastinum, creating a conduit for the extension of a variety of pathological processes. For this reason, the neck and mediastinum are treated together here.