腹膜后肾周肿瘤的CT、MRI诊断价值研究

Study on value of CT and MRI in diagnosis of retroperitoneal tumors in perirenal space

目的探讨CT、MRI对腹膜后肾周肿瘤的诊断价值。方法 18例经手术或穿刺病理证实的腹膜后肾周肿瘤均行多排螺旋CT或MRI检查,回顾性分析其CT及MRI征象。结果肾周淋巴瘤6例,4例CT表现为肾周软组织肿块,增强扫描动脉期轻-中度强化,门脉期及延迟期呈渐进性强化;2例MRI表现为T1WI上呈稍等信号,在T2WI上呈等低信号,增强扫描呈渐进性强化。肾周转移瘤5例,CT、MRI表现为周围巨大肿块,密度(信号)不均匀,增强后动脉期不均匀强化,毗邻大血管被包绕或侵犯,邻近肾脏受侵。肾周脂肪肉瘤3例,肾周肿块以脂肪密度或信号为主,内见团片状软组织密度,增强后实性部分强化。肾周脂肪瘤2例,表现为肾周脂肪密度或信号肿块。副神经节细胞瘤1例,肿块信号不均,增强后动脉期明显强化。肾周神经节细胞瘤1例,表现为肾周囊性肿块,内见分隔,包绕毗邻血管,增强后分隔及边缘强化。结论 CT、MRI能对腹膜后肾周肿瘤精确定位,显示肿块与邻近脏器、血管的关系,CT、MRI对脂肪类肿瘤、淋巴瘤及部分神经源性肿瘤具有定性诊断价值。

Objective To investigate the value of CT and MRI in the diagnosis of retroperitoneal tumors in perirenal space. Methods Retrospective analysis of characteristic for CT or MRI was made for 18 cases proved by pathology of surgery or biopsy. Results Six cases of perirenal lymphoma were confirmed. CT showed pefirenal soft tissue mass of 4 cases with slight to moderate enhancement in arterial phase and progressive enhancement in venous and delayed phase. MRI showed 2 cases with isointense mass lesion on T1WI, low intense lesion on T2WI and progressive enhancement after contrast medium injection. Five cases of perirenal metastatic tumor were confirmed. CT （MRI） showed perirenal mass with uneven density （ signal）, uneven enhancement in arterial phase,adjacent vascular invasion or encasement and renal invasion. Three cases of perirenal liposarcoma were confirmed. CT （MRI） showed perirenal mass with fat density （ signal）, internal patchy soft tissue and partial enhancement of solid. Two cases of perirenal lipoma presented as mass of fatty density（signal）. One case of paraganglioma presented as mass with inhomogeneous density and high enhancement in arterial phase. One case of gangliocytoma presented as perirenal cyst-solid mass with internal septation, adjacent vascular encasement,enhancement of septation and margin after contrast medium injection. Conclusions CT and MRI can accurately localize retroperitoneal tumors in perirenal space and show relationship between mass and adjacent organ or vessel. CT and MRI have great value in the diagnosis of lipomatous tumors,lymphoma and part of neurogenic turnouts.