*2.2. Ultrasound Evaluation*

Patients were placed in supine position with their neck in hyperextension. The US was performed with the Philips Epiq Elite machine. For each nodule, the radiologists used real-time clips to measure the major axis and analyzed its composition, echogenicity, shape, margins, and the presence of calcifications, as previously described [3]. The final theoretical indication for FNA execution was formulated according to the ACR and EU-TIRADS algorithms [3,5]. US was performed by three different radiologists (DL, DF, FV) who were experts in thyroid imaging and who contributed equally to the evaluation of the case series.
