[Comparison of the Diagnostic Value of High Frequency Ultrasound and Ultrasound-guided Fine Needle Aspiration Biopsy in Papillary Thyroid Microcarcinoma]

To explore the application value of high frequency ultrasound and ultrasound-guided fine needle aspiration biopsy（US-FNAB） in the diagnosis of papillary thyroid microcarcinoma（PTMC）, and to compare the characteristics and value of the two methods, so as to find a more convenient and non-invasive diagnostic method of PTMC, reduce unnecessary puncture and operation. The data of 190 postoperative pathologically confirmed PTMC patients admitted to Henan Province Cancer Hospital and Henan Provincial Hospital from January to June 2020 were retrospectively analyzed, with a total of 305 nodules, including 198 PTMC nodules and 107 benign thyroid nodules（BTN）. According to the postoperative pathological results, they were divided into groups, and the relationship between the ultrasound appearance of the nodules and whether the cervical lymph nodes could be explored and PTMC was analyzed by chi-square test and logistic regression, and its diagnostic value was evaluated. The Kappa consistency test was used to analyze the consistency between ultrasound, FNAB and surgical pathological diagnosis results. The accuracy, sensitivity and specificity of high-frequency ultrasound and US-FNAB were compared, and the ROC curve was used to calculate the maximum area under the curve to evaluate its effectiveness. The chi-square test showed that there were statistically significant differences in the morphology, margin, internal echo, echo uniformity, calcification, aspect ratio, blood flow signal, and whether the cervical lymph nodes can be detected and other ultrasound signs between the PTMC group and the BTN group. Logistic regression analysis showed that irregular shape, unclear edges, internal hypoechoic, intranodular calcification are independent risk factors for PTMC. By consistency test, the consistency between high-frequency ultrasound, US-FNAB examination and surgical pathological diagnosis was good, Kappa value was 0.802 and 0.893（<0.05）. Each nodule was examined by high-frequency ultrasound, and the diagnostic sensitivity, specificity, accuracy and AUC were 95.45%, 83.18%, 91.15% and 0.877 respectively. US-FNAB was performed on 189 of 305 thyroid nodules, and the diagnostic sensitivity, specificity, accuracy and AUC were 96.03%, 93.65%, 95.24% and 0.948 respectively. High frequency ultrasonic features such as internal hypoechoic, calcification in the nodules, unclear edges, and irregular morphology are of high value for the diagnosis of PTMC. Through data analysis, both high-frequency ultrasound and US-FNAB examination have high diagnostic value for PTMC. Compared with US-FNAB, high-frequency ultrasound has the advantages of low examination cost, non-invasive, simple operation and so on. For some patients with PTMC who do not have high risk factors, ultrasound can be used to actively monitor disease progression to avoid some unnecessary surgery.