Thyroid Imaging in Infants.

Congenital hypothyroidism is the most common preventable cause of mental retardation. It is important to know the cause of each patient's thyroid dysfunction to foresee the course of therapy and outcomes. Imaging methods, such as ultrasound and thyroid scan, help determine the anatomy and function of the thyroid gland. Although thyroid scan is considered superior in detecting ectopic thyroid tissue, ultrasound is able to detect the presence of thyroid tissue not otherwise visualized in 15% of patients.