In children ultrasound is the best tool we have to evaluate any change in the neck, high
resolution ultrasound allows excellent details of the anatomy, it¥s possible to asses vessels,
muscles and glands as the thyroid gland, Which begins it¥s formation 24 days after
fecundation, it begins at the floor of the larynx and migrates through the thyroglossal duct, by
the 7 th week it completes this process, and starts functioning during the 3rd month of
intrauterine life, this knowledge of the embryology of the gland is important due to the fact that
in the evaluation of the neck ultrasound will allow to differentiate congenital abnormalities that
will behave like a mass. Among other pathology we have in the neck, are those related to that of the
sternocleidomastoid muscle congenital or acquired. Vascular lesions such as the
hemangioma, or masses which have its origin in the fatty tissue such as lipomas, are very well
defined by ultrasound. The aid of Doppler to let us know not only the relationship to vessels
but to know if it¥s a vascular mass or not.