To establish a predictive model based on contrast-enhanced ultrasound (CEUS) to evaluate the risk of central cervical lymph node metastasis (CLNM) in patients with thyroid papillary carcinoma (PTC), and to evaluate the diagnostic efficacy of the model.

A retrospective analysis was performed on 108 patients with single PTC who were examined by conventional ultrasonography and contrast-enhanced ultrasonography before operation at the Beijing Friendship Hospital of Capital Medical University from January 2017 to December 2019. The patients were divided into either a CLNM group or a non-CLNM group according to whether CLNM occurred, and the differences in clinical, conventional ultrasound, and CEUS characteristics between the two groups were compared. A predictive model was established according to multivariate regression analysis, and the diagnostic efficacy of the model was evaluated by receiver operating characteristic (ROC) curve analysis.

Univariate analysis indicated significant differences between the CLNM and non-CLNM groups in age, maximum tumor diameter, contact with capsule, degree of enhancement, and uniformity of enhancement (P＜0.05). Multivariate logistic regression analysis showed that age≤42 (odds ratio [OR]=4.783, P=0.002), contact with capsule (OR=4.833, P=0.006), Hyper- or isoechoic enhancement (OR=3.696, P=0.013), and heterogeneous enhancement (OR=5.264, P=0.004) were independent risk factors for CLNM. ROC curve analysis showed that the area under the curve (AUC), sensitivity, and specificity of the predictive model were 0.800, 70.8%, and 78.3%, respectively. The AUC of the predictive model was greater than that of any single independent risk predictor (P＜0.05).

The prediction model based on CEUS combined with conventional ultrasound and clinical factors has good diagnostic efficiency and can be used for the risk assessment of CLNM in PTC patients.