骶前间隙肿瘤的MRI诊断

目的：了解骶前间隙肿瘤的MRI表现特征。方法：分析73例骶前间隙肿瘤的MRI表现，包括纤维脂肪血管瘤、未分化癌和淋巴瘤各1例，畸胎瘤和骨巨细胞瘤各3例，神经源性肿瘤18例，骶尾部脊索瘤22例，转移瘤24例。结果：畸胎瘤含脂肪、纤维和液体等成分；纤维脂肪血管瘤含有粗大血管；骨巨细胞瘤呈溶骨性破坏，1例在T2WI有液－液平面；神经源性肿瘤通过骶孔与骶管内病变相连，神经节母细胞瘤和神经外胚层瘤破坏孔；9例脊索瘤在T2WI有条状低信号纤维结构和高信号粘液基质；未分化癌和淋巴瘤T1WI呈略低信号，T2WI呈略高和较高信号；19例转移瘤有多处骨骼破坏，5例只有骶椎侵犯。结论：MRI可清楚地显示骶前间 隙肿瘤的部位和范围，其中多数肿瘤可以定性。

MR diagnosis of the tumors of presacral space

Objective:To study the MRI characteristics of tumors of presacral space. Methods: MR appearances of 73 cases of presacral tumors were retrospectively analysed,including fibrolipomatous angioma(n= 1) ,undifferentiated carcinoma (n=l) ,lymphoma(n=1),teratoma(n= 3),giant cell tumor(n= 3) ,neurogenic tumor(n= 18) ,chordoma(n = 22) ,and metastasis(n=24). Results; MRI showed such components as fat,fibre,and liquid in teratoma,and large vessels in fibrolipomatous angioma;lytic bone destruction in giant cell tumor(n= 3), with fluid-fluid level on T1 WI in 1 cases. Neurogcnic tumors in presacral space were connected with those in the spinal canal through the sacral foramen, in ganglioneuroblastoma and primitive neuroectodermal tumor the sacral foramen was destructed. Low signal fibrous septum and high signal mucus material were shown on T2 WI in 9 cases of chordomas. The undifferentiated carcinoma and lymphoma showed low signal on T1 WI and slightly high signal on T2WI. Multiple bone destruction occurred in 19 cases of metastasis, whereas only sacral destruction were found in another 5. Conclusion: The location and extent of the presacral tumors can by clearly delineated on MRI,and most tumors can be correctly diagnosed accrding to their MRI features.