Fig. 5

A 45-year-old female patient with nodular goiter in the left lobe of the thyroid underwent US-guided MWA. (A) The relationship between the RLN (asterisk) and the ZTTN (white arrow). The distance from the farthest outside of ZTTNs (white arrow) to the outer edge of thyroid is 4.0 mm (ZTTN grade 1). The RLN (asterisk) is located at the side of ZTTN (white arrow), and the relationship between ZTTN and RLN is Type D. (B) shows the relationship between the ZTTN (white arrow) with the RLN (asterisk) in the long axial section after the hydrodissection. (C) After the physiological saline solution was injected, the distance between the RLN and ZTTN significantly widened in the short-axis section. (D) The ablation antenna (double short white arrow) was placed inside the ZTTN (white arrow), and the injection needle (long white arrow) was placed between the ZTTN (white arrow) and RLN (asterisk). During the microwave ablation, the physiological saline solution could be continuously injected between the ZTTN (white arrow) and RLN (asterisk) to protect the RLN. (E) After MWA, the contrast-enhanced ultrasonography showed no enhancement in arterial and venous phase of ZTTN (white arrow), but high enhancement in RLN (asterisk), suggesting that RLN was not damaged during ablation