腹膜后肾上腺外副神经节瘤的CT、MRI表现

目的:探讨腹膜后肾上腺外副神经节瘤的CT、MRI表现特点,提高其影像学诊断水平.方法:收集经手术病理证实的腹膜后肾上腺外副神经节瘤14例,回顾性分析其CT、MRI表现及病理学特点.结果:右侧5例,左侧9例.大小2.3 cm×2.5 cm×2.6 cm～17.6 cm×23.8 cm×14.5 cm.肿块以囊实性为主,以囊性为主者3例,以实性为主者7例,基本呈实性者4例,未见完全囊性病灶.CT平扫表现为等或等低混杂密度灶,边缘清楚,实性部分密度与腹主动脉相近,CT值约为38.5～49.3 HU,囊性部分CT值平均约为18.9 HU.MR检查囊性部分呈长T1长T2异常信号,实性部分呈等T1长T2异常信号.增强扫描后动脉期表现为明显不均质强化肿块,囊性部分无强化,实性部分CT值约为69.5～117.3 HU.门静脉期CT值峰值略下降,信号降低,实性肿块表现为明显均匀强化,CT值约为64.7～103.5 HU,平均77.8 HU.延迟期实性部分密度、信号逐渐下降.结论:腹膜后肾上腺外副神经节瘤有一定的CT、MRI表现,结合临床及实验室检查能得出比较准确的诊断结果.

CT and MRI manifestations of retroperitoneal extra-adrenal paraganglioma

Objective： To explore the CT, MRI manifestations of retroperitoneal extra-adrenal paraganglioma, in order to improve its imaging diagnosis. Methods： Fourteen cases of retroperitoneal extra-adrenal paraganglioma confirmed by surgery and pathology were collected, and their CT and MRI manifestations were analyzed retrospectively. Results： The retroperitoneal extra-adrenal paraganglioma located in the right side in 5 cases, the left side in 9 cases. Size was about 2. 3 cm× 2.5 cm × 2.6 cm-17.6 cm×23.8 cm× 14.5 cm in size. The masses were mainly cystic and solid, cystic-based in 3 patients, solid-based in 7 cases, almost solid in 4 cases. There were no completely cystic tumors. On the pre-contrast imaging, CT scan showed mixed low- and iso-intensity, the edge of the lesion was clear, CT value of solid part was close to the abdominal aorta, approximately 38.5-49.3 HU, average CT value of the cystic part was about 18.9 HU. MR examination showed low signal on T1WI, high sigal on T2 WI in the cystic part of tumor; iso-signal on T1 WI and hyper-signal on T2 WI in the solid part. On the post-contrast imaging, arterial phase showed clearly a heterogeneous enhanced mass, cystic part had no enhancement, solid part of the CT value was approximately 69.5-117.3 HU. Portal venous phase CT peak and signal slightly decreased, the signal reduction, solid mass showed significantly enhanced uniformity, CT value was approximately 64.7-103.5 HU, average 77.8 HU. Delay phase density and signal was gradually declining of solid part. Conclusion： Retroperitoneal extra-adrenal paraganglioma have a certain CT, MRI manifestations. A accurate diagnosis can be made combined with clinical and laboratory examinations.