Ultrasonographic Criteria to Define the Lower Limits of Neck Node Levels 2 and 3

To find ultrasonographic landmarks to define the lower limits of neck node levels 2 and 3.

Data were collected prospectively between February 2014 and January 2015. In total, 103 patients were recruited (50 men and 53 women), and the mean age was 50.9 years (range: 18-89). At the lower level of the hyoid, we classified ultrasonographic findings as hyoid type (HT)1 when the internal and external carotid arteries were visualized separately, HT2 when the internal and external carotid arteries joined together, and HT3 when the common carotid artery was visualized. At the lower border of the cricoid cartilage, we classified ultrasonographic findings as cricoid type (CT)1 when the omohyoid reached the medial half of the common carotid artery, CT2 when the omohyoid reached the lateral half of the common carotid artery, CT3 when the omohyoid reached the medial half of the internal jugular vein, and CT4 when the omohyoid reached the lateral half of the internal jugular vein.

At the lower border of the hyoid, HT1 was most commonly observed in 59.2%, whereas HT2 and HT3 were observed in 31.3% and 9.7%, respectively. At the lower border of the cricoid cartilage, CT3 was most commonly observed in 52.9%, whereas CT2, CT4, and CT1 were observed in 20.4%, 14.1%, and 12.6%, respectively.

HT1 and CT3 can be suggested ultrasonographic landmarks for the lower limits of levels 2 and 3, respectively.

2. Laryngoscope, 129:2487-2490, 2019.