中文摘要：

目的通过大体解剖对照，探讨兔坐骨神经纤维束的磁共振显微成像能力。方法对10只兔的坐骨神经在1．5T磁共振成像系统上进行快速自旋回波序列3D T2加权成像（T2-weighted imaging，T2WI）、3D T2WI加频率敏感脂肪抑制技术（SPIR）及T1加权成像（T1—weigthed imaging，T1WI）成像，观察坐骨神经纤维束的表现，在3D T2WI上测量其前后径，并与大体解剖进行对照，另使用多回波序列分别测量T1、T2时间。结果3D T2WI、3D T2WI加SPIR及T1WI均能显示10只兔坐骨神经主干内的胫神经及腓神经，3D T2WI并能显示细小的腓肠神经及股后侧皮神经。坐骨神经的T1、T2分别为（915±41）ms、（40±2）ms。活体及MRI上坐骨神经主干的前后径分别为（3．17±0．21）mm、（3．15±0．19）mm，两者差异无统计学意义（P=0．462）。结论1．5TMRI系统能够实现坐骨神经纤维束显微成像，清晰准确分辨坐骨神经干内的组成神经纤维束。

英文摘要：

Objective To investigate the feasibility and accuracy of magnetic resonance microneurography of sciatic nerve fascicles in rabbit by correlation with the gross anatomy. Methods The 3D T2-weighted imaging（3D-T2 MI）,3D T2-weighted imaging plus spectral presaturation with inversion recovery （SPIR）, T1-weighted imaging（T1WI）of the sciatic nerve in 10 rabbits were performed on a 1.5 Tesla magnetic resonance system. The radiological ananomy and imaging features of sciatic nerve fascicles were observed and the anterior-posterior diameter was measured on 3D T2-weighted imaging. The imaging evaluation was correlated with the gross anatomy. The T1 and T2 relaxation time were determined by multiple echo spin echo and mix sequece, respectively. Results The tibial nerve and peroneal nerve in the main trunk of sciatic nerve in all 10 rabbits could be clearly displayed on the 3D T2WI, 3DT2WI plus SPIR, and T1WI, Strikingly , the 3D T2WI could delineate the fine branches of the sural nerve and posterior femural cutaneous nerves. The T1 and T2 relaxation time were 915 ms, 40 ms, respectively. Grossly, the anterior-posterior diameter of sciatic nerve trunk was （3. 17 ±0. 21 ）mm, while was（3. 15 ± 0. 19）on 3D T2WI. There was no statistically significant difference （ t = 0. 768, P = 0. 462）. Conclusion With 1.5 Telsa MR system the microneurography of the sciatic nerve could be achievable and the individual fascicles of sciatic nerve trunk could be clearly and accurately discriminated.