Imaging of the thymus

Technologic advances in imaging, particularly CT and MR imaging, have revolutionized the ability to noninvasively image the thymus. Increasing knowledge of the normal and pathologic states of the thymus has been accompanied by an increasing ability to depict morphologic alterations in this gland with fine spatial resolution and can even provide functional information. This article discusses the role of various imaging modalities in identifying suspected thymic disease, which historically required surgery to visualize. The role of imaging is best understood with an appreciation of the embryology, anatomy, and pathology of the thymus.