Ultrasonography of Various Thyroid Diseases in Children and Adolescents: A Pictorial Essay

Abstract

Thyroid imaging is indicated to evaluate congenital hypothyroidism during newborn screening or in cases of a palpable thyroid mass in children and adolescents. This pictorial essay reviews the ultrasonography (US) of thyroid diseases in children and adolescents, including normal thyroid gland development, imaging features of congenital thyroid disorders (dysgenesis, [aplasia, ectopy, hypoplasia], dyshormonogenesis, transient hypothyroidism, thyroglossal duct cyst), diffuse thyroid disease (Grave's disease, Hashimoto's thyroiditis, and suppurative thyroiditis), and thyroid nodules. The primary imaging modalities for evaluating thyroid diseases are US and radionuclide scintigraphy. Additionally, US can be used to guide aspiration of detected nodules.

Thyroid Ultrasound: State of the Art Part 1 – Thyroid Ultrasound reporting and Diffuse Thyroid Diseases

“…Scintigraphy provides functional information of the thyroid which is not available based on ultrasound examination alone. The thyroid gland appears normal on US in patients with hypoplasia; however, scintigraphy reveals decreased isotope uptake [20].…”

“…Hashimoto's thyroiditis or chronic lymphocytic thyroiditis (CLT) is the most common form of organ-specific autoimmune diseases [20]. It is the commonest cause of hypothyroidism in the United States [27].…”

“…Ectopic thyroid tissue most commonly appears in the midline in the cervical region (90 % of the cases) [24]. Appearance varies on US, but the tissue is generally located close to the hyoid bone (fig 3) [20]. Its prevalence is approximately 1/100,000 -1/300,000 [25].…”

“…It is characterized by diffuse interstitial lymphocytic infiltration and a variable degree of fibrosis [43]. Diagnosis is made by detecting anti-thyroid antibodies, including anti-thyroid peroxidase and anti-thyroglobulin antibodies [20]. Patients with the acute form present with painless, lobular, diffusely enlarged thyroid gland (classical Hashimoto´s) or -much more common -an atrophic thyroid (historically named as Ord´s thyroiditis) [27].…”

“…Congenital hypothyroidism is a relatively common endocrine disorder [20]. Approximately 80% of congenital hypothyroidism is caused by thyroid dysgenesis due to absence, hypoplasia or ectopia of the gland, which is almost always sporadic in nature [21].…”