目的 研究超声特征在Bethesda Ⅲ/Ⅳ/Ⅴ类甲状腺结节良恶性分层中的临床价值。方法 回顾性分析2023年1月—2025年6月收治的101例经超声引导下细针穿刺细胞学检查评定为Bethesda Ⅲ/Ⅳ/Ⅴ类的甲状腺结节患者临床资料。所有患者均行高频超声检查,记录和统计结节超声特征。以手术病理诊断为金标准分为良性组（50例）、恶性组（51例）,比较两组超声特征差异;采用多因素logistic回归筛选恶性结节的独立危险因素,并分层分析不同Bethesda分级中超声特征的预测效能。结果 恶性组单发结节比例、边界不清、实性结构、纵横比>1、低回声及微钙化的检出率均显著高于良性组（均P<0.05）。多因素回归分析显示,上述6项超声特征均为甲状腺恶性结节的独立危险因素（OR=4.08~5.76,均P<0.05）。分层分析：（1） Bethesda Ⅲ类结节中,低回声及实性结构是恶性的独立预测因子;（2） Bethesda Ⅳ类结节若合并≥2项高危超声特征,恶性风险>80%;（3） Bethesda Ⅴ类结节恶性风险超90％,且微钙化可辅助预测经典乳头状癌亚型。结论 超声特征可有效细化Bethesda Ⅲ/Ⅳ/Ⅴ类甲状腺结节的恶性风险分层,为临床制定个体化治疗方案（如短期随访、分子检测或手术）提供客观依据,有助于减少过度治疗,改善患者预后。

Objective To investigate the clinical value of ultrasound features in differentiation of benign and malignant lesions in Bethesda class Ⅲ/Ⅳ/Ⅴ thyroid nodules. Methods A retrospective analysis was conducted on the clinical data of 101 patients with Bethesda class Ⅲ/Ⅳ/Ⅴ thyroid nodules who underwent ultrasound-guided fine needle aspiration cytology examination from January 2023 to June 2025. All patients underwent high-frequency ultrasound examination, and the ultrasound characteristics of nodules were recorded and statistically analyzed. Using surgical pathology as the gold standard, the patients were divided into a benign group （n=50） and a malignant group （n=51） to compare the differences in ultrasound characteristics. Multiple logistic regression was used to screen independent risk factors for malignant nodules, and stratified analysis was conducted to evaluate the predictive power of ultrasound features in different Bethesda grades. Results The proportion of single nodules, unclear boundaries, solid structures, aspect ratio>1, low echogenicity, and microcalcifications detected in the malignant group were significantly higher than those in the benign group （P<0.05）. Multiple regression analysis showed that the six ultrasound features mentioned above were independent risk factors for thyroid malignant nodules （OR=4.08-5.76, P<0.05）. Stratified analysis showed that： （1） in Bethesda class Ⅲ nodules, hypoechoic and solid structures were independent predictors of malignancy; （2） if Bethesda class Ⅳ nodules were combined with ≥ 2 high-risk ultrasound features, the risk of malignancy was greater than 80%; （3） the malignant risk of Bethesda class Ⅴ nodules exceeded 90%, and microcalcifications could assist in predicting classic papillary carcinoma subtypes. Conclusion Ultrasound features can effectively refine the malignant risk stratification of Bethesda class Ⅲ/Ⅳ/Ⅴ thyroid nodules, providing an objective basis for individualized treatment plans （such as short-term follow-up, molecular testing, or surgery） in clinical practice, helping to reduce overtreatment and improve patient prognosis.