MR imaging of the thyroid

The thyroid gland was evaluated with MR imaging in six normal subjects and 32 patients with thyroid disease. The purpose was to evaluate signal characteristics of normal and diseased thyroid tissue; determine the contrast between normal and diseased tissue on T1- and T2-weighted images; compare relaxation times of normal thyroid, adenomas, and carcinoma; and assess the capability of MR for showing the extent of large thyroid masses. Adenomas and carcinomas were frequently isointense with normal thyroid tissue on T1-weighted images but had markedly higher intensity on T2-weighted images. The mean T1 (1202 +/- 717 msec) and T2 (118 +/- 48 msec) relaxation times of adenomas were markedly longer than the T1 (721 +/- 97 msec) and T2 (59 +/- 10 msec) times of normal thyroid tissue. Likewise, the T1 and T2 values of carcinomas were markedly prolonged compared with normal thyroid but the values overlapped with those of the adenomas. Sagittal and coronal images effectively depicted the extent of large goiters, ade...