Thyroid abnormalities by ultrasonography in neonates with congenital hypothyroidism

Objectives To investigate the usefulness of thyroid ultrasonography for neonates with congenital hypothyroidism. Study design Patients (n = 66) were evaluated by ultrasonography at age 15.2 +/- 12 days. Results Thyroid scanning was more sensitive for the identification of ectopic tissue as ultrasonography showed ectopic thyroid tissue in only 9 of 42 cases. In cases for which no iodine uptake was demonstrated by thyroid scanning (n = 12), ultrasonography showed normally located thyroid tissue in 2 patients. Therefore, on the basis of both thyroid scanning and ultrasonography, 10 cases were classified as athyreosis, and 14 cases were classified as showing normal location of the thyroid gland. Among the latter 14 cases, 5 showed a developmental abnormality. Ultrasonography also revealed additional phenotypic abnormalities in patients with thyroid dysgenesis, with cysts (n = 6) and thymus tissue (n = 4) within the empty thyroid area, which are novel observations in these patients. Conclusions Ultrasonography may reveal additional findings with regard to those obtained by scintigraphy such as information regarding the anatomy of the thyroid gland, presence of cysts, and presence of additional thymic tissue within the empty thyroid area.