Tongtong Zhou,1,2,* Li Tan,1,* Yang Gui,1 Jing Zhang,1 Xueqi Chen,1 Menghua Dai,3 Mengsu Xiao,1 Qing Zhang,1 Xiaoyan Chang,4 Qun Xu,5 Chunmei Bai,6 Yuejuan Cheng,6 Qiang Xu,3 Xue Wang,7 Hua Meng,1 Wanying Jia,1 Ke Lv,1 Yuxin Jiang1 1Department of Ultrasound, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 2Department of Ultrasound, China-Japan Friendship Hospital, Beijing, People’s Republic of China; 3Department of General Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 4Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 5Department of Epidemiology and Biostatistics, Institute of Basic Medical Sciences Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, People’s Republic of China; 6Department of Medical Oncology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of China; 7Key Laboratory of Endocrinology of National Health Commission, Department of Endocrinology, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, People’s Republic of China*These authors contributed equally to this workCorrespondence: Ke Lv; Yuxin JiangDepartment of Ultrasound, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People’s Republic of ChinaTel/Fax +86 10-69155493; +86 10-69155491Email lvke@163.com; yuxinjiangxh@163.comObjective: Investigate the CEUS enhancement patterns of PDAC and analyse correlations between the CEUS enhancement pattern and both the degree of tumour tissue differentiation and overall survival (OS).Methods: The study included 56 patients with locally advanced PDAC, performed conventional ultrasound and CEUS, and analysed characteristics of the CEUS enhancement patterns. In addition, clinical data, such as serum level of CA19-9, TNM stage were collected, and patients’ survival times were followed up. TICs of dynamic CEUS images were acquired using image processing software to obtain the peak, TP, sharpness, and AUC. Correlations of the CEUS enhancement patterns of PDAC with the degree of differentiation of tumour tissue and OS were quantitatively analysed, as were the correlations of the TIC parameters and CEUS enhancement patterns with OS.Results: Enhancement in the arterial phase included iso-enhancement (30.3%) and hypo-enhancement (69.6%), and was not significantly correlated with sex, age at disease onset, or lesion size. Also was not significantly correlated with tumour tissue differentiation. Clear survival times were obtained for 50 patients during follow-up, and the median survival time was significantly longer for the patients with iso-enhancement than hypo-enhancement. Among the TIC parameters, peaktumour, sharpnesstumour, AEsharpness, and REsharpness differed significantly between the group with iso-enhancement and hypo-enhancement (p < 0.05).Conclusion: The CEUS enhancement patterns of PDAC in the arterial phase include iso-enhancement and hypo-enhancement. Enhancement pattern was not significantly correlated with the degree of differentiation of tumour tissue, but patient survival time differed significantly between the two enhancement patterns, with longer survival for patients with iso-enhancement.Keywords: contrast-enhanced ultrasound, pancreatic ductal adenocarcinoma, survival time, enhancement pattern, time-intensity curve