Anatomy and Anomalies

Real-time ultrasound was introduced in the 1980’s and rapidly proved to be the most sensitive and efficient method to evaluate thyroid anatomy. The superficial location of the soft tissue structures in the anterior neck also allows the physician to study the anatomy of the entire area and detect anatomic variations as well as identify extra thyroidal masses (1,2). Often patients present with a neck mass thought to be of thyroid origin, but ultrasound quickly and easily identifies it of extrathyroidal origin. This use of ultrasound to define the anatomy of the neck provides an excellent teaching tool in medical education to augment the physical examination. In this chapter we review the normal anatomy along with some common anomalies one might encounter in performing ultrasound.