乏血供与富血供胰腺神经内分泌肿瘤影像学表现比较

Comparison of Imaging Features of Hypovascular and Hypervascular Pancreatic Neuroendocrine Neoplasm

摘要: 目的：探讨乏血供与富血供胰腺神经内分泌肿瘤(pancreatic Neuro Endocrine, pNEN)的计算机体层成像(Computed Tomography, CT)和磁共振成像(Magnetic Resonance Imaging, MRI)征象。方法：回顾性分析经手术病理证实为pNEN的161例患者的影像学资料，术前所有患者均行上腹部CT或(和)MRI平扫及增强扫描；以动脉晚期病变强化程度为标准，将病变分为乏血供与富血供病变；重点观察病变位置(头颈、体尾)、数目(单发、多发)、形态(类圆形、不规则形)、最大径、病变的密度、信号特点及增强特征，有无囊变坏死、脂质、钙化、包膜是否完整、胰管是否扩张(>3 mm)、胰体尾部萎缩、是否有恶性征象(侵袭邻近组织器官、淋巴结转移及肝转移)；采用t检验、Mann-Whitney U检验、卡方检验及Fisher确切概率法比较乏血供与富血供pNEN在患者年龄、性别、是否存在内分泌功能、病灶形态特征、病理分级方面的差异。结果：乏血供与富血供pNEN在部位、数目、形态、边界、包膜、囊变坏死、出血、钙化、脂质、胰管扩张、胰腺体尾部萎缩、恶性征象(病灶侵袭邻近组织器官、淋巴结转移)、T1加权成像(T1-Weighted Imaging)信号、T1预扫信号相对强度、病灶延迟期增强百分比及动脉晚期、延迟期增强指数)上均无统计学意义(P > 0.05)；在病变功能状态(p < 0.001)、病变最大径(p = 0.001)、肝转移(p = 0.001)、T2加权成像(T2-Weighted Imaging, T2WI, χ² = 19.678, p < 0.001)、弥散加权成像(Diffusion-Weighted Imaging, DWI, p = 0.032)、病灶动脉晚期、实质期及延迟期相对信号强度、病灶动脉晚期及实质期增强百分比、实质期病灶增强指数(p < 0.05)、病理分级(χ² = 7.063, p = 0.029)上有统计学意义。结论：乏血供与富血供的pNEN在CT、MRI征象上大致相同，乏血供pNEN更常表现为病变最大径较大、T2WI信号及DWI信号更低、病灶动脉晚期、实质期强化程度低，并易出现肝转移，且病理分级为G3级神经内分泌肿瘤或神经内分泌癌；通过认识pNEN影像学表现，有助于病变治疗前的准确诊断及临床治疗方案的制定。

Abstract: Objective: To investigate the imaging features of hypovascular and hypervascular pancreatic neuroendocrine neoplasm (pNEN). Methods: Retrospective analysis of imaging data from 161 patients with pNEN confirmed by surgical pathology. All patients underwent upper abdominal CT or MRI plain scan and dynamic contrast scan before operation. According to the late arterial phase enhancement pattern, the lesions were divided into hypovascular and hypervascular pNEN. The following imaging parameters were evaluated: the location (head and neck, body and tail), number (single, multiple), shape (round, irregular), maximum diameter, density or signal intensity and the enhancement characteristics of the lesions, cystic change or necrosis (present or absent), lipid, calcification, whether the capsule was intact, whether were associated with a dilated main pancreatic duct (>3 mm), atrophy of the pancreatic body and tail, malignant signs (invasion of adjacent tissues and organs, lymph node metastasis and liver metastasis). T-test, Mann-Whitney U test, Chi-square test and Fisher exact probability method were used to compare the differences of age, gender, endocrine function, morphological characteristics and pathological grade and lesion enhancement characteristics between patients with with hypovascular and hypervascular lesions. Results: There were no statistical differences in the location, number, shape, margin, capsule, cystic change or necrosis, hemorrhage, calcification, lipid, pancreatic duct dilatation, pancreatic body and tail atrophy, lesion invasion of adjacent tissues and organs, lymph node metastasis, T1-weighted imaging, T1 signal relative intensity on pre-scan, enhancement percentage of delayed phase and late arterial phase, delayed phase enhancement index of pNEN patients with hypovascular and hypervascular lesions (p > 0.05). There were statistical differences in lesion functional status (p < 0.001), lesion maximum diameter (p = 0.001), liver metastasis (p = 0.001), T2-weighted imaging (T2WI, χ² = 19.678, p < 0.001), diffusion-weighted imaging (DWI, p = 0.032), relative signal intensity of late arterial phase, parenchymal phase and delayed phase of lesion, enhancement percentage of late arterial phase and parenchymal phase of lesion, enhancement index of parenchymal phase of lesion (p < 0.05), pathological grade (χ² = 7.063, p = 0.029) of pNEN patients with hypovascular and hypervascular lesions. Conclusion: The CT and MRI signs of pNEN patients with hypovascular and hypervascular lesions are mostly the same. Hypovascular pancreatic neuroendocrine tumors are more often characterized by larger lesion diameter, lower T2WI signal and DWI signal, lower enhancement degree of late arterial phase and parenchymal phase of lesion, and prone to liver metastasis, and the pathological grade is G3 neuroendocrine tumor or neuroendocrine carcinoma; understanding the imaging manifestations of pancreatic neuroendocrine tumors is helpful to the accurate diagnosis and clinical treatment plan before treatment.