Computed tomography of the thyroid bone, before it loops posteriorly and inferiorly to the hyoid bone. Then it continues its descent into the infra-hyoid portion of the neck, anterior to the trachea, thyroid cartilage, and thyroid membrane. Any thyroid residual along the descent course may lead to the development of ectopic thyroid glands. Thyroid carcinomas, thyroiditis, and goiter may develop within any ectopic thyroid tissue. Thyroid scanning with technetium-99 m (Tc99m) plays an important role in detecting orthotopic and ectopic thyroid tissue. Both CT scans and US can help detect ectopic tissue when a lesion demonstrates imaging and enhancement characteristics of thyroid tissue. The absence
Computed tomography of the thyroid high thyroglobulin content is iso-dense to muscle. Thyroid nodules that are detected by an imaging study but have not been previously detected or suspected clinically are considered to be ITNs. ITNs are one of the most common incidental findings on neck imaging. ITNs are reported in up to 25 % of chest CT scans, and in 16–18 % of cervical region cross-sectional imaging, including CT and MRI scans. The rate of malignancy in the detected ITNs on CT and MRI scans varies from 0 % to 11 %. Incidentally detected thyroid carcinomas are more likely to be papillary thyroid carcinomas