MRI对腹膜后良性神经源性肿瘤的诊断价值

Diagnostic value of MRI on retroperitoneal benign neurogenic neoplasms

目的探讨MRI常规T1WI、T2WI、弥散加权成像(DWI)结合增强扫描对腹膜后良性神经源性肿瘤的诊断价值。方法回顾性研究34例腹膜后良性神经源性肿瘤的MRI常规T1WI、T2WI、DWI及增强表现,所有病变均经手术病理证实,包括神经鞘瘤15例,副神经节瘤11例,节细胞瘤8例。结果神经鞘瘤、副神经节瘤、节细胞瘤患者发病年龄、肿瘤大小无统计学差异(P>0.05),均易产生囊变,神经鞘瘤囊变多位于病灶中心,副神经节瘤囊变多位于病灶周边,神经鞘瘤出血明显多于其他两者(P<0.05),神经鞘瘤及副神经节瘤呈类圆形或椭圆形,节细胞瘤在形态上呈不规则形;三种病例在DWI上均呈稍高信号,部分囊变出血呈混杂信号,DWI信号强度及ADC值差异无统计学意义(P>0.05)。副神经节瘤强化最明显,神经鞘瘤其次,节细胞瘤轻度强化。结论 MRI增强扫描对腹膜后良性神经源性肿瘤的鉴别诊断具有重要作用,常规T2WI及T1WI对病灶形态、大小显示较好,T2WI对显示囊变、T1WI对显示出血具有优势,DWI鉴别价值不高。

Objective To evaluate the value of MRI T1 WI, T2 WI, diffusion-weighted imaging and enhanced scan on the diagnosis of retroperitoneal benign neurogenic neoplasms. Methods A retrospective study was done in 34 benign neurogenic neoplasms patients. Among them, schwannoma was 15 cases, paraganglioma 11 cases,and ganglioneuroma cystadenoma 8 cases. MRI performance with unenhanced and enhanced scan was studied.Results There was no significant difference in age and size（P〉0.05） among schwannoma cases, paraganglioma cases, and ganglioneuroma cystadenoma cases. Schwannoma cystic lesions were located in the center, and paraganglioma cystic lesions were located in the surrounding of lesion. Hemorrhage in schwannoma cases was significantly more than those patients with other two diseases（P〈0.05）. Schwannomas and paragangliomas were round or oval, gangliocytomas were irregular in shape. Among all patients, DWI demonstrated hyperintensity, but some cystic bleeding demonstrated mixed signal. DWI signal intensity and ADC values were not statistically different（P〈0.05）. Paraganglioma enhancement was most obvious, and gangliocytoma slight enhancement. Conclusion MRI enhancement scanning is important in diagnosis of retroperitoneal benign neurogenic neoplasms. T2 WI displays cystic and T1 WI displays hemorrhage. DWI has no obvious value in differential diagnosis.