Ultrasonographic study of the incidence of pyramidal lobe and agenesis of the thyroid isthmus in Nnewi population.

Ultrasound is the most reliable imaging modality for thyroid evaluation due to the limitations in the clinical examination of this gland. Thyroid gland developmental anomalies are rare. Most of its variations are due to the persistence of the thyroglossal duct and the absence of the isthmus.