目的：探讨胰周血管受侵的影像学表现中的手术可切除性的临界点。方法：收集经手术病理证实或临床治疗证实的胰腺癌无远处转移患者76例，均行术前螺旋CT增强扫描，其中66例行MRI增强扫描并行三维血管重建，显示胰腺癌对周围血管的侵犯情况，根据肿瘤对血管的侵犯程度分为0级、1级、2级、3级、4级。统计各级血管的条数，并与手术结果对照。结果：39例中的138支血管受肿瘤侵犯达2级或以上，放弃手术，另37例术前评估有手术切除可能性，术中25例做了胰腺根治性切除，12例由于术前低估了一支或多支血管的受侵程度，仅做了肿块切除或姑息性治疗。术中综合评估3级、4级的血管手术均无法切除，术中综合评估0级、1级的血管手术均顺利切除，术中综合评估2级的血管受术者水平的影响而有部分切除。以2级受侵为不可切除标准，肿瘤侵犯血管的敏感性为85.5%，特异性为97.1%，阳性预测值105/105=100%，阴性预测值148/191=77.5%。结论：术前用多层螺旋CT及MRI多期增强扫描并进行三维血管重建，可提供可靠的周围血管侵犯情况，对胰腺癌术前可切除性评估有重要的临床意义，动脉2级受侵、静脉1级受侵可作为手术不可切除的最佳界点。

Objective: To explore the critical point of imaging findings, in which the invaded peripancreatic blood vessels could be operability by surgery. Methods: A total of 76 cases of patients with distant metastasis-free pancreatic cancer confirmed by operative pathology or clinical treatment were enrolled, all of them underwent contrast-enhanced CT before operation. Among them, 66 patients underwent enhanced MRI scanning and three-dimensional vascular reconstruction. According to the images, the extents of pancreatic cancer invasion of peripancreatic vessels were divided into grade 0, grade 1, grade 2, grade 3, and grade 4. The numbers of vessels in each grade were counted and compared to the results of operation. Results: There were 138 vessels in 39 cases with invasion extent higher than grade 2, so the operations were given up. A total of 37 cases were assessed with the possibility of operative excision before operation. Among them, 25 cases accepted radical excision of pancreas, however, 12 cases accepted tumor resection or palliative therapy alone because of preoperative underestimate of the invasion extent of one or more vessels. In these 12 cases, the invasion extents of 16 arteries and 21 veins were underestimated. Operative excision could not be executed if the invasion extent was assessed as grade 3 and 4 during operation, while it could be executed if the invasion extent was assessed as grade 0 and 1 during operation. Moreover, operative excision depended on the condition of patients if the invasion extent was assessed as grade 2. Conclusion: Preoperative multi-phase CT, MRI scanning and 3D vascular remodeling, it is very important to evaluate the operability before operation. Level 2 arterial invasion and level 1 vein invasion can be the critical point of resection.