胰腺内分泌肿瘤的MRI诊断

目的 探讨MRI在胰腺内分泌肿瘤诊断中韵价值。资料与方法 15例胰腺内分泌肿瘤患者均行MRI检查。扫描序列包括SE T1WI、FS T1WI、FSE T2WI、FMPSPGR平扫及动态增强扫描。结果 15例患者共16个病灶。多数肿瘤呈长T1（9／15）长T2（11／15）信号，FS T1WI及FMPSPGR平扫序列多为低信号（分别为8／11和13／16），且显示肿瘤较常规SE T1WI更清晰，动态增强后肿瘤可有多种强化方式，8个动脉期中度或明显均匀强化，门脉和延迟期有所下降但仍高于周围正常胰腺实质；2个动脉期边缘结节样强化，进行性向中心填充；2个表现为均匀轻中度强化；2个呈均一渐进性强化；2个明显囊变，囊变区无强化，周围呈持续环状强化。动态增强扫描不仅有助于肿瘤的检出、定性，而且可以了解血管受累程度及有无肝脏、淋巴结转移。结论 MRI多序列扫描及动态增强扫描对胰内分泌肿瘤诊断具有较高价值。

MRI Diagnosis of Pancreatic Neuroendocrine Tumors

Objective To assess the value of MRI in the diagnosis of endocrine tumors of pancreas. Materials and Methods 15 patients with pancreatic endocrine tumors confirmed pathologically were examined by 1.5T MRI. Scan sequences included SE T_1WI, Fat-suppressed T_1WI (T_1WI FS), FSE T_2WI, Fast multiplanar spoiled gradient recalled technique(FMPSPGR) with contrast of Gd-DTPA.Results 15 patients with 16lesions, most of them were detected as hypointensity on T_1WI (9/15), T_1WI FS(8/11), FMPSPGR(13/16)and hyperintensity on FSE T_2WI (11/15) . Lesions contour on images of T_1WI FS and FMPSPGR were more clear than those of T_1WI. On dynamic contrast-enhancement scanning, 8 tumors were moderate to marked homogenous enhancement in the arterial phase, in portal venous and delayed phase ,the intensity of the tumors was still higher than that of normal pancreatic parenchyma; 2 tumors were demonstrated peripheral nodulated enhancement with gradual centripetal enhancement; 2 tumors were manifested mild to moderate homogenous enhancement; 2 tumors were detected delayed enhancement. 2 tumors had cystic changes with ring enhancement. Dynamic contrast-enhanced scan not only improved the detection and characterization of pancreatic lesion, but also depicted the invasion of vessels and metastasis of liver and lymph nodules.Conclusion Multi-sequences and dynamic contrast-enhanced MRI have considerable value for diagnosis of pancreatic endocrine tumors.