目的：探索超声造影（CEUS）与常规超声（US）对单发无淋巴结转移甲状腺微小乳头状癌（PTMC）侵袭性的诊断价值。方法：选择经术后病理证实无颈部淋巴结转移的PTMC 92例作为研究对象。分为侵袭性组（13例）和非侵袭性组（79例）。比较两组患者结节的US及CEUS征象的差异，分析US、CEUS诊断单发无淋巴结转移PTMC侵袭性的准确性，并探索两种检查方式联合使用的诊断效能。结果：US征象中，侵袭性组边界不清比例、甲状腺被膜回声中断比例高于非侵袭性组（P＜0.05）。CEUS征象中，侵袭性组增强后边界不清比例、边缘高增强比例以及增强范围形态改变比例高于非侵袭性组（P＜0.05）。US诊断单发无淋巴结转移PTMC侵袭性的敏感性、特异性、准确性为46.15%、79.75%和75.00%，低于CEUS的84.62%、83.54%和83.70%。US联合CEUS诊断单发无淋巴结转移PTMC侵袭性的准确性最佳（AUC=0.929），其最佳诊断点为0.87，其敏感性为100%，特异性为87.74%，拟合方程为Logit（P）=-2.146+0.585×US边界不清+2.796×甲状腺被膜回声中断+0.659×增强后边界不清+3.521×增强后边缘高增强+5.541×增强范围形态改变。结论：US联合CEUS可更好地反映单发无淋巴结转移PTMC浸润生长及被膜侵犯的生物学特征，对判断其侵袭能力具有较高的应用价值。

Objective: To explore the diagnostic value of contrast-enhanced ultrasound(CEUS) and two-dimensional ultrasound in the invasiveness of single papillary thyroid microcarcinoma(PTMC) without lymph node metastasis. Methods: A total of 92 patients with single PTMC but without lymph node metastasis confirmed by surgery pathology were recruited as subjects. They were divided into the invasive group(n=13) and non-invasive group(n=79). The differences of the characteristics in two-dimensional ultrasound and CEUS were compared between the two groups. The accuracy of ultrasound and CEUS in the diagnosis of single PTMC without lymph node metastasis was analyzed. The diagnostic efficacy of the combination of the two methods was explored. Results: In the ultrasound characteristics, the proportion of unclear boundary and the rupture of the thyroid capsule echo in the invasive group were higher than those in the non-invasive group(P<0.05). In the CEUS characteristics, the proportion of unclear boundary after enhancement, marginal high enhancement, and enhancement range morphological changes in the invasive group were higher than those in the non-invasive group(P<0.05). The sensitivity, specificity, and accuracy of ultrasound in the diagnosis of single PTMC without lymph node metastasis were 46.15%, 79.75%, and 75.00%, which were lower than CEUS(84.62%, 83.54%, and 83.70%). The combination of ultrasound and CEUS for the diagnosis of invasiveness of single PTMC without lymph node metastasis was the best(AUC=0.929). The best diagnostic point was 0.87. The sensitivity was 100%, and the specificity was 87.74%. The fitting equation was Logit(P)=-2.146+0.585×Two-dimensional ultrasound boundary unclear+2.796×thyroid capsule echo interruption+0.659×enhanced boundary unclear+3.521×enhanced edge height enhancement+5.541×enhanced range morphological change. Conclusion: CEUS combined with two-dimensional ultrasound can better indicate the invasive growth and capsule invasion of single PTMC without lymph node metastasis, and has high application value in judging its invasive ability.