盆腔段坐骨神经MRI技术初探

MRI technique for imaging pelvic segment of the sciatic nerve

目的 探讨应用MRI显示盆腔段坐骨神经的技术问题。方法 采用GESigna 1.5T超导型磁共振仪对 35例检查者共 48条坐骨神经行二维自旋回波 (2D SE)的双斜面定位后斜矢状面成像和三维破坏性稳态梯度回波 (3D SPGR)的容积采集重建成像 ,并将 2种序列对盆腔段坐骨神经的显示率加以比较。其中 4例肿瘤患者 6条坐骨神经行Gd DTPA增强扫描。结果 2D SE序列和 3D SPGR序列对盆腔段坐骨神经的显示率分别为 75 %和 90 % ,两者间差异具有显著性意义 (P <0 .0 5 )。6条增强后的坐骨神经受病变侵犯呈节段性显示 ,并见神经鞘膜强化。结论 以梨状肌为定位点的MR成像技术能显示行走于梨状肌前缘、并从其下缘穿出的盆腔段坐骨神经。 3D SPGR优于 2D SE。

Objective To study the MR technique for demonstration of pelvic segment of the sciatic nerve. Methods 48 sciatic nerves of 35 cases were imaged by GE Signa 1.5 T superconductive MR scanner with the sequences of 2 dimension spin echo(2D SE) dual oblique sections location oblique sagittal imaging and 3 demension spoiled gradient echo(3D SPGR) with volume acquisition and reconstructive imaging. The displaying rates of pelvic segment of ciatic nerve were compared between 2D SE and 3D SPGR( P 1 <0.05). Six nerves were studed after Gd DTPA enhanced in 4 patients with tumor. Results The displaying rates of sciatic nerve in pelvic segment were 75% and 90% in 2D SE and 3D SPGR sequences respectively. There was significant difference between the two sequences( P <0.05). Six sciatic nerves invaded by pelvic tumors were showed by segments and the sheathes were enhanced. Conclusion MRI using the piriformis muscle as the initial reference point can satisfactorily show the sciatic nerve in pelvic segment runing anterior edge of piriformis muscle. 3D SPGR is better than 2D SE.