Development and Validation of a Predictive Nomogram for Cervical Lymph Node Metastasis in Aspect Ratio ≥1 Papillary Thyroid Carcinoma Using Ultrasonic Features and Serum Calcitonin

Yan Liu, Yuchen He, Jianwei He, Zhenhao Zheng, Xichen Yao, Tianxin Liu, Ziyu Liu, Ruyan Zhou, Wen Liu, Jun Li