Computed tomography and magnetic resonance imaging of vascular rings and other things: a pictorial review.

Compression of the airway, esophagus or both by aortic and pulmonary vessels can be caused by a variety of anatomical situations. Vascular rings are the most commonly encountered entity; however, compression can also occur from less common anomalies such as a left pulmonary artery sling or innominate artery compression. Vascular rings and other vascular compression abnormalities can be challenging to visualize and image and often require advanced imaging by CT or MRI to better understand the cause and extent of compression. Atretic vascular structures, such as the ligamentum arteriosum or atretic arch, play a key role in creating a vascular ring and do not enhance with contrast agent in a typical fashion. Despite these imaging challenges, classic and useful signs can indicate the presence or absence of a vascular ring or compression.