胰腺神经内分泌瘤的MRI特点

MRI features of pancreatic neuroendocrine tumours

目的分析胰腺神经内分泌瘤的MR影像特点,并对MRI在胰腺神经内分泌瘤诊断中的价值进行评估。方法对18名经病理证实的胰腺神经内分泌瘤患者的MR扫描进行回顾性分析。扫描系列包括SET1WI、脂肪抑制T1WI、FSET2WI、快速多层面干扰梯度回波(FMPSPGR)Gd-DTPA造影剂增强前和增强后。结果多数在T1WI(66.7%,12/18)、脂肪抑制T1WI(78.6%,11/14)和未增强的FMPSPGR(84.2%,16/19)影像上为低信号,在T2WI上为高信号(66.7%,12/18)。脂肪抑制T1WI和FMPSPGR影像上的病变轮廓比常规T1WI和T2WI的更清晰。在动态造影剂增强扫描中,10例肿瘤在动脉期、门静脉期和延迟期呈中到强的均匀性增强,肿瘤信号强度仍然高于正常胰腺实质;3例肿瘤呈周边结节性增强和逐渐的向心性增强;2例肿瘤呈轻度到中度均匀性增强;2例肿瘤呈延迟增强;2例肿瘤呈囊性改变伴环状增强;1例局限于胰体内的病变伴有肝转移。结论多序列和动态造影剂增强MRI对胰腺神经内分泌瘤的诊断具有重要价值。

Objective To analyze the MR imaging features and to assess the role of MRI in the diagnosis of pancreatic neuroendocrine tumors. Methods MR imaging features of 18 patients with pathologically-confirmed pancreatic neuroendocrine tumors were retrospectively analyzed. MR scanning included SE T1WI, fat-suppressed TIWI, FSE T2WI, and fast multiplanar spoiled gradient recalled （FMPSPGR） wave before and after the contrast medium, Gd-DTPA, was used. Results Most lesions were detected at T1WI （66.7%, 12/18） and fat-suppressed T1WI （78.6%, 11/14）. Lesions found at FMPSPGR （84.2%, 16/19 ） had low signals, and lesions found at T2WI （66.7%, 12/18） had high signals. Lesions found at FMPSPGR and fat-suppressed T1WI were clearer than those found at routine T1WI and T2WI. Dynamic contrast-enhancement scanning showed moderate and intense homogenous enhancement signals in 10 tumors at the arterial, portal venous and delayed phases. The intensity of tumor signals was still higher than that of normal pancreatic parenchyma. Peripheral nodule enhancement with gradual centripetal enhancement, moderate homogenous enhancement, delayed homogenous enhancement, and cystic changes with ring enhancement were observed in 3, 2, 2, and 2 tumors, respectively. One tumor located in the pancreatic body had hepatic metastasis. Conclusion Multi-sequence and dynamic contrast-enhanced MR/ plays an important role in the diagnosis of pancreatic neuroendocrine tumors.