骶丛、坐骨神经盆腔段在磁共振神经成像术的解剖特征

Anatomical characteristics of sacral plexus and pelvic segment of sciatic nerve in magnetic resonance neurography

[目的]应用磁共振神经成像序列,探讨骶丛、坐骨神经盆腔段MRI表现及解剖学特点。[方法]观察40例(80侧)健康成年志愿者骶丛、坐骨神经盆腔段在磁共振图像上的表现,并利用GE公司AW4.6工作站对磁共振3D-BRAVO序列、3D-FIESTA序列图像进行多平面重建(MPR),取得最佳显示层面,观察其影像学解剖特点。[结果] 3D-BRAVO序列、3D-FIESTA序列能够完成骶丛、坐骨神经盆腔段的显示,并且可以通过多平面重建清晰显示其与周围结构的毗邻关系。在MRI神经成像序列上测量双侧骶丛神经的长度,二者差异无统计学意义(P>0.05)。测量双侧坐骨神经、梨状肌下孔的前后径、左右径,二者差异无统计学意义(P>0.05)。[结论]利用MRI神经成像及多平面重建同层显示技术可以理想地显示骶丛、坐骨神经盆腔段的解剖特征,清晰地描述梨状肌下孔的形态及其毗邻结构组成。3D-BRAVO序列结合3D-FIESTA序列可以应用于外周神经的显示,对骶丛、坐骨神经正常解剖、相关病变的影像学诊断具有重要意义。

[Objective] To evaluate the MRI findings and anatomical features of sacral plexus and sciatic nerve in pelvic cavity by using magnetic resonance neurography(MRN). [Methods] The magnetic resonance imaging(MRI) of the sacral plexus and sciatic pelvic segments in 40 healthy adult volunteers(80 sides) were observed and multiplanar reconstruction(MPR)was performed on GE AW4.6 workstation by using 3 D-BRAVO sequence and 3 D-FIESTA sequence images. The best display level obtained and the imaging anatomy displayed by the two sequences were compared. [Results] Both the 3 D-BRAVO sequence and 3 D-FIESTA sequence did clearly reveal the sacral plexus, the pelvic segment of sciatic nerve, and the adjacent structure by multiplanar reconstruction. There were no significant differences regarding to the length of bilateral sacral plexus in the MRI nerve imaging sequence between the two groups(P>0.05). In addition, there were no significant differences in anteroposterior diameter, left and right diameter of bilateral inferior sciatic nerve, as well as piriformis foramen between the two groups(P>0.05). [Conclusion] MRN can ideally display the anatomical features of the of the sacral plexus and sciatic nerves pelvic segment by multiplanar reconstruction of the same layer, it can clearly describe the morphology and adjacent structure of the piriformis foramen. Both 3 D-BRAVO sequence and 3 D-FIESTA sequence can be applied to display the peripheral nerve, which can be established for the normal anatomy and imaging diagnosis of the sacral plexus and sciatic nerve related lesions.