Thyroid lymphosonography: a novel method for evaluating lymphatic drainage.
OBJECTIVE
We evaluated lymphosonography, or contrast-enhanced, ultrasonography (US)-guided sentinel lymph node (SLN) detection, as a technique for demonstrating the lymphatic drainage of the thyroid gland.


METHODS
In this prospective animal study, four 50-kg Yorkshire swine underwent transcutaneous injection of a US contrast agent and methylene blue dye into the thyroid gland. Contrast-enhanced US was used to identify draining lymphatic channels and SLNs. Sentinel node biopsy was conducted. Subsequently, bilateral neck and upper mediastinal dissection was carried out.


RESULTS
In 3 of 4 cases, a blue dye-positive and US contrast-positive SLN was identified. We identified SLNs in level IV in 2 cases. One case revealed 2 adjacent nodes in the superior mediastinum. In 1 case, a lymphatic channel was identified traveling into the mediastinum, but exposure of the SLN could not be obtained. No residual blue dye-positive or US contrast-positive nodes were identified on subsequent dissection.


CONCLUSIONS
Lymphosonography of the thyroid gland in a porcine model correlates well with blue dye-guided sentinel node biopsy and is technically feasible, although in some cases access to the SLN may be difficult. This technique could potentially enable a detailed analysis of thyroidal lymphatic drainage if applied to humans.
Curry
Joseph M
JM
Department of Otolaryngology-Head and Neck Surgery, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Ezzat
Waleed H
WH
Merton
Daniel A
DA
Goldberg
Barry B
BB
Cognetti
David M
DM
Rosen
David
D
Pribitkin
Edmund A
EA
D000818:Animals; D008196:Lymph / Q000502:physiology*; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008208:Lymphatic System / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy; D013552:Swine; D013961:Thyroid Gland / Q000000981:diagnostic imaging*; D014463:Ultrasonography