多种MR成像技术在胰腺癌诊断及其可切除性探讨

目的 探讨多种MR成像技术对胰腺癌诊断及其手术可切除性判断的价值。 方法 18例经手术和/或病理证实的胰腺癌患者进行了磁共振检查,采用的磁共振序列分别为:GRE T_1WI,TSE T_2WI,脂肪抑制GRE T_1WI,延迟增强GRE T_1WI,磁共振胰胆管造影(MRCP)和三维动态对比增强MRA(3D DCE MRA)。肿瘤累及胰周血管根据程度依次分为0～4级。 结果 18例胰腺癌肿瘤病灶,在GRE T_1WI上均呈稍低信号,TSE T_2WI上均呈稍高信号。脂肪抑制GRE T_1WI上所有肿瘤均呈明 显低信号,延迟增强GRE T_1WI上肿瘤表现环形不规则强化14例,均匀强化4例,但均低于正常胰腺强化。MRCP显示胆总管与主胰管均扩张表现为典型“双管征”8例。在3D DCE MRA上,根据肿瘤与血管周径接触面>1/2为不能切除的标准,则门静脉受累56％(10/18),脾静脉受累39％(7/18),肠系膜上静脉受累67％(12/18),腹腔干及主要分支受累22％(4/18)及肠系膜上动脉受累17％(3/18)。MRI判断2例可完全手术切除,与手术结果相符。 结论 MRI快速扫描序列、脂肪抑制技术、MRCP及3D DCE MRA四大MR成像技术的综合应用能提供胰腺癌诊断及手术可切除性判断的必需信息,可以达到一步到位的诊断目标。

Multiple MR imaging techniques in the diagnosis and assessment of resectability in pancreatic carcinoma

Objective: To study the value of multiple MR imaging techniques in the diagnosis of pancreatic carcinoma and the assessment of resectbility of the lesion. Methods: MR imaging was performed in 18 patients with surgically and/or pathologically proven pancreatic carcinoma. GRE T1WI, TSE T2WI, GRE TlWI with fat suppression, delayed enhancement GRE T1WI, MRCP and 3D DCE MRA were used in MR scanning. Tumor involvement of the celiac trunk and its main branches, superior mesenteric artery, the portal, splenic and superior mesenteric veins were prospectively graded on a 0-4 scale based on circumferential contiguity of tumor to vessel. Results: On GRE T1WI and TSE T2WI all the lesions showed slightly hypointense and hyperintense, respectively; On GRE T1WI with fat suppression, all the tumors obviously appeared hypointense; On delayed enhancement GRE T1WI, the lesions displayed irregularly circular enhancement in 14 patients and well-distributed enhancement in 4 patients. MRCP showed extensive bile and main pancreatic duct dilatation with typical "double-duct" sign in 8 patients. On 3D DCE MRA, we thought it was unresectable with more than half circumferential involvement of tumor to vessel, so that the portal, splenic and superior mesenteric veins were involved with 56% (10/18), 39% (7/18) and 67% (12/18), respectively. The celiac trunk and its main branches and superior mesenteric arteries were involved with 22% (4/18) and 17% (3/18), respectively. The pancreatic lesions in 2 cases could be completely resected in the evaluation of MR imaging, which was fitted to the findings of operation by pancreatoduodenectomy. The pancreatic lesions in other 2 cases were partly, resected because there was tumor extension to superior mesenteric vein and/or artery. The tumors in the remaining 14 patients were too large and involved peripancreatic vessels or there were stomach or liver metastases, so these patients were only treated by choledochojejunostomy and gastrojejunstomy. Conclusion: The "all-in-one" MR approach including fast scanning sequences, fat suppression, MRCP and 3D DCE MRA provides the surgeon with diagnosis and assessment of resectability of the lesion prior to surgery of pancreatic carcinoma.