正常马尾神经的磁共振扩散张量成像研究

The research of diffusion tensor imaging of magnetic resonance imaging in normal cauda equina

目的探讨磁共振扩散张量成像(DTI)显示马尾神经(CE)和腰骶脊神经根(LSNR),测量CE和LSNR的各向异性分数(FA)、平均扩散系数(DCavg)。方法对9例正常青年志愿者,行腰2椎体中上部至骶1椎体下缘T2WI和DTI轴面扫描,层厚3mm,无间隔。重建CE和LSNR,并在腰2至骶1诸椎间孔水平测量CE和LSNR的FA、DCavg。结果从腰2至骶1水平,CE显示良好;可分辨从CE分出的LSNR 60束(83%)。CE的FA和DCavg分别为0.359±0.068;(3.711±0.595)×10-9 mm2/s。LSNR的FA和DCavg分别为0.322±0.040;(3.753±0.647)×10-9 mm2/s。经t检验,CE和LSNR的FA相比较,P<0.001;CE和LSNR的DCavg相比较,P>0.05。结论 DTI可无创伤性显示CE和LSNR,通过测量CE和LSNR的FA、DCavg,能在水分子变化水平认识CE和LSNR。

Objective To explore the demonstration of the cauda equina （CE） and lumbosacral spinal nerve roots （LSNR） using diffusion tensor imaging （DTI） of magnetic resonance imaging （MRI） and measure the values of fractional anisotropy （FA） and average diffusion coefficient （DCavg） of CE and LSNR. Methods For 9 healthy young volunteers, T2 WI and DTI were preformed from the upper middle level of the lumbar 2 and inferior margin of sacral 1 in axial direction in the slice thickness of 3 mm and without interslice gap. The CE and LSNR from lumbar 2 to sacral 1 were reconstructed and the values of FA and DCavg of the CE and LSNR were measured at the sites of each intervertebral foramen. Results From lumbar 2 to sacral 1, the CE had a good display. The LSNR were visualized in 60 bundles （83%）. The values of FA and DCavg of CE were 0. 359±0. 068 and （3. 711±0. 595） X 10-9 mmZ/s and the values of FA and DCavg of LSNR were 0. 322±0. 040 and （3. 753±0. 647））〈 10-9 mmZ/s individually. Based on Student＇s t-test, the values of FA had significant difference between the CE and LSNR, P d0. 001. The values of DCavg had no significant difference between CE and LSNR, P 〉0.05. Conclusion DTI provides a non-invasive method to display the CE. Through the measurement of FA and DCavg in normal CE and LSNR, the insight has been promoted to the level of the changes of water molecular in assessing CE and LSNR.