Preoperative prediction of lymph node metastasis in nonfunctioning pancreatic neuroendocrine tumors from clinical and MRI features: a multicenter study - Hai-bin Zhu; Pei Nie; Liu Jiang; Juan Hu; Xiao-Yan Zhang; Xiao-Ting Li; Ming Lu; Ying-Shi Sun (Insights into Imaging, 2022)