Fig. 1.

Normal transverse US of thyroid gland. Cross-sectional US shows normal thyroid glands and surrounding structures. Both thyroid glands show homogeneous parenchymal echogenicity higher than anterior strap muscles. Both CCAs run laterally adjacent to both thyroid lobes and infrahyoid strap muscles overlie thyroid gland. Both SCM muscles are located antero-laterally and longus colli muscles are seen posterolaterally to thyroid gland. US = ultrasonography, SCM = sternocleidomastoid muscle, CCA = common carotid artery, IJV = internal jugular vein, Ant. Strap m = anterior strap muscle, Longus Colli m = longus colli muscle