Figure 2

The ultrasound-guided capsule-sheath space block (CSSB) in imaging study: ultrasonogram of the thyroid gland before and after local anesthetic injection. (A) The juncture of internal jugular vein and thyroid gland was identified and placed in the center of the optimal image with minor adjustment of scanning planes; (B) In-plane view of a block needle inserted under color Doppler guidance; (C) Intermittent changes in needle direction to maintain a uniform distribution of contrast medium, especially at isthmus of thyroid. CA, carotid artery; IJV, internal jugular vein; LA, local anesthetics; SCM, sternocleidomastoid muscle.