In transverse view, which round anechoic structure is lateral to each thyroid lobe?

In transverse view, which round anechoic structure is lateral to each thyroid lobe?

• A. Internal Jugular Vein
• B. Trachea
• C. Common Carotid Artery
• D. Esophagus

Answer: (C)

In transverse neck ultrasound, the thyroid lobes sit on either side of the trachea, with the carotid sheath running lateral to them. The round anechoic structure you see just lateral to each thyroid lobe is the internal jugular vein. It appears dark (anechoic) on gray-scale and is compressible, which helps confirm it as a vein. The carotid artery sits medial to the vein and shows a pulsatile lumen with thicker walls on gray-scale and Doppler. The trachea is midline, and the esophagus lies posterior to the trachea rather than lateral to the thyroid.

In transverse neck ultrasound, the thyroid lobes sit on either side of the trachea, with the carotid sheath running lateral to them. The round anechoic structure you see just lateral to each thyroid lobe is the internal jugular vein. It appears dark (anechoic) on gray-scale and is compressible, which helps confirm it as a vein. The carotid artery sits medial to the vein and shows a pulsatile lumen with thicker walls on gray-scale and Doppler. The trachea is midline, and the esophagus lies posterior to the trachea rather than lateral to the thyroid.