Abstract: The purpose of this study was to investigate the value of superb micro-vascular imaging (SMI) combined with ultrasound elastography (UE) in the differential diagnosis of benign and malignant thyroid nodules. Ultrasound, SMI and UE examination were performed in patients with thyroid nodules and the diagnosis results were analyzed. Among the 122 nodules in 80 patients, The proportion of malignant nodules with blood flow classification of grade Ⅱ to Ⅲ by SMI was significantly higher than that of benign nodules (P<0.05). The proportion of malignant nodules with regular shape and internal cystic lesions was significantly lower than that of benign nodules (P<0.05), while the proportion of unclear boundary, aspect ratio ≥1, hypoechoic and internal calcification was significantly higher than that of benign nodules (P<0.05). The strain rate ratio ≥3.79, and the proportion of elastic score 4-5 of malignant nodules were significantly higher than those of benign nodules (P<0.05). The sensitivity and negative predictive value of SMI combined with UE in the diagnosis of thyroid malignant nodules were significantly higher than that of color ultrasound combined with UE (P<0.05). SMI combined with UE can improve the differentiation ability of benign and malignant thyroid nodules, which is worthy of clinical use.

Key words: superb micro-vascular imaging, ultrasonic elastography, thyroid nodule, benign and malignant