Computed tomography of the thyroid attenuation (80–100 Hounsfield Units). The presence of thyroiditis can be suggested by a diffusely enlarged and hypo-attenuating (around 45 Hounsfield Units) thyroid gland. This is probably due to follicular cell destruction and reduced thyroid iodine concentration. Marked homogenous enhancement is typically expected. Therefore, moderate thyroid enhancement in a case of thyroiditis suggests a diffuse inflammatory process. It is essential to clinically correlate this with a thyroid function test and serum autoantibody levels. During embryogenesis, the bi-lobed thyroid migrates inferiorly from the foramen cecum of the tongue to the lower neck. Initially, the thyroid primordium passes anterior to the primordial hyoid
Computed tomography of the thyroid region, or within the parotid gland substance (Fig. 17). The origin of lateral ectopic thyroid tissue is not fully understood. Although this is controversial, some authors suggest that it might have originated from lateral thyroid anlagen (ultimobranchial bodies) that failed to fuse with the median anlage during caudal migration. A thyroglossal duct cyst (TDC) is a duct remnant between the foramen cecum and thyroid isthmus. Most TDCs are located below the hyoid bone and in the midline. The more caudal the cyst, the more likely it will be off midline within 2 cm (Fig. 19 and and20).20). On a CT