Small to moderate-sized goiters are a common problem in patients in the United States, whereas large goiters with or without substernal extension are rare. The overall incidence of goiters has progressively declined in the United States owing to the routine inclusion of iodine in salt, bread, and other foodstuffs and the common medical practice of treating goiters early with thyroid hormone therapy.<sup>20 Newman E., Shaha A.R. Substernal goiter J Surg Oncol 1995 ;  60 : 207-212  [cross-ref]

Cliccare qui per andare alla sezione Riferimenti</sup> The development of large multinodular and substernal goiters throughout the rest of the world, especially in areas of iodine deficiency, remains an important problem.

Advances in medical imaging, including CT and MR imaging, allow a rapid accurate assessment of the size of a goiter, its extension into the mediastinum, and its relationship to and impingement on major structures within the chest and neck (Figure 1). This information is clinically useful in patients with goiters causing symptoms of compression or when surgery is contemplated. CT and MR imaging can also identify mediastinal masses as thyroidal in origin, eliminating the need for further invasive testing. This article reviews the use of these techniques.