Evaluation of intrathoracic goiter with I-123 scintigraphy and nuclear magnetic resonance imaging.

Iodine-123 thyroid scintigraphy allows the diagnosis of a functioning retrosternal goiter in a patient with a mediastinal mass. The case report of a 60-yr-old lady demonstrates this. The correlative values of nuclear magnetic resonance imaging and thyroid scintigraphy in the initial evaluation and continued management of patients with thyroid mediastinal mass are presented. In addition, this observation demonstrates the ability of nuclear magnetic resonance to identify retrosternal thyroid tissue. This may obviate the need for TCT evaluation, which involves both ionizing radiation and iodinated contrast enhancement.