US image acquisition
TUMOR RECURRENCE
Before RFA, the ultrasound features of PTMC typically included a hypoechoic nodule with well-defined margins, a taller-than-wide shape, and intranodular vascularity on Doppler ultrasound. After RFA, the ultrasound features of the treated area would vary based on the degree of ablation. Ideally, the treated area should show non-enhancement in the entire ablation zone, indicating complete ablation. However, in cases of incomplete ablation or tumor recurrence, there may be areas of enhancement within the ablation zone. It is important to monitor these ultrasound features during follow-up to evaluate the effectiveness of the RFA treatment