甲状腺癌是近年来发病率增长最快的恶性肿瘤。美国近10年增长了4.99倍，我国增长了2.24倍，其中主要为甲状腺乳头状癌（PTC）。由于高频超声分辨率的提高，越来越多≤1cm的甲状腺微小癌得以发现，已超过甲状腺癌总患病人数的50%。文献报告甲状腺微小癌颈部淋巴结转移的发生率约2.0%～43% 。相对高发的淋巴结转移机制是什么？影响因素有哪些？超声影像对淋巴结转移能否早期预警？尚无相关研究报道。本课题运用高分辨率超声结合靶向超声造影、弹性成像技术，与组织病理和分子病理对照研究，探索有或无淋巴结转移的甲状腺乳头状癌的超声影像特征，建立甲状腺乳头状癌早期淋巴结转移的预警系统。对于不易转移的甲状腺乳头状癌，可避免甲状腺全切和颈部淋巴结清扫等过度手术治疗，减少甲状旁腺及喉反神经损伤等术后并发症的发生。同时，该研究也为甲状腺微小乳头状癌局部经皮射频消融治疗奠定了理论基础。

In recent years, the incidence of thyroid cancer is the fastest-growing malignancy. It grew 4.99 times by nearly 10 years in United States , 2.24 times in our country .In which it is mainly differentiated thyroid carcinoma (DTC). Since the resolution of high-frequency ultrasound to be improved , more and more thyroid cancer smaller than 1cm could be found , and it more than 50% of the total. The incidence of thyroid cancer lymph node metastasis reported in the literature tiny approximately 2.0% to 43 %. What mechanism of relatively high incidence of lymph node metastasis is ? Factors affecting lymph node metastasis have? Could ultrasound imaging as early warning for lymph node metastasis ? No related research reports. This topic through targeted ultrasound imaging and ultrasound elastography technology, research and differentiated thyroid carcinoma with lymph node metastasis and without lymph node metastasis their imaging features , the establishment of early warning systems early differentiated thyroid cancer lymph node metastasis . For easy transfer of differentiated thyroid cancer can be avoided by total thyroidectomy and neck lymph node dissection , such as excessive surgical treatment to reduce the incidence of parathyroid and laryngeal nerve damage and other anti postoperative complications . Meanwhile, the study also tiny thyroid cancer topical percutaneous radiofrequency ablation laid a theoretical foundation.