Development and validation of a nomogram model based on pretreatment ultrasound and contrast-enhanced ultrasound to predict the efficacy of neoadjuvant chemotherapy in patients wit... oleh Xiaoyi Yan, Xianshui Fu, Yang Gui, Xueqi Chen, Yuejuan Cheng, Menghua Dai, Weibin Wang, Mengsu Xiao, Li Tan, Jing Zhang, Yuming Shao, Huanyu Wang, Xiaoyan Chang, Ke Lv