Magnetic resonance imaging of the pediatric mediastinum.

The mediastinum, the central anatomical space of the thorax, is divided by anatomical landmarks but not by physical boundaries. The mediastinum is a conduit, a space through which cranial nerves, important nerve branches, the sympathetic chain, vascular structures, and visceral structures, the trachea and esophagus pass. This arrangement allows contiguous extension or communication of disease along facial planes and through potential spaces to and from the head and neck or cervical spine, to and from the superior mediastinum, between superior and inferior mediastinal levels, and between inferior mediastinal spaces into the intra- and retroperitoneal spaces. Magnetic resonance imaging (MRI) of the mediastinum in children poses technical challenges, in particular cardiac and respiratory motion, and diagnostic challenges, including a broad range of tissue types and possible diagnoses. In this paper we review mediastinal anatomy, MRI sequences and protocol choices and include a short discussion of features and MRI findings of some of the congenital and acquired pathologies that are most often encountered in the pediatric mediastinum.