不同磁共振腰骶丛神经成像序列的临床研究

目的:比较周围神经背景信号抑制弥散加权成像(diffusion-weighted neuroimag ing with background signal suppression,DWIBS)、选择性激励技术(principle of selective excitation technique,PROSET)及三维短时反转恢复(3D Short Term Inversion Recovery,3D STIR)序列在腰骶部脊神经成像中的不同表现,探讨其对腰骶部病变的临床应用价值。方法:对29名正常志愿者及42例腰骶丛病变损伤患者行磁共振腰骶丛神经成像,包括DWIBS序列,PROSET及3D STIR序列。对DWIBS及3D STIR原始图像行最大信号强度投影(MIP)后处理重建,对志愿者组及病变组所得图像质量分级并分别进行统计分析,评价三种高场强磁共振腰骶丛神经成像序列在正常组及病变组的显示效果。结果:在正常志愿者组中,三种高场强磁共振腰骶丛神经成像序列均可显示脊神经根、神经节等解剖细节,对于腰4、5脊神经的显示,三者的图像分级差异不具有统计学意义。在腰2、3脊神经成像中,三者图像质量分级的差异具有统计学意义(P0.05)。在病例组中,经秩和检验三组组间显示效果不完全相同,P0.05,差异有统计学意义。进行两两比较,DWIBS与3D SITR序列,其差异具有统计学意义(P0.01)。PROSET与3D STIR序列,差异具有统计学意义(P0.01)。而DWIBS与PROSET图像质量分级差异无明显统计学差异。结论:DWIBS、PROSET、3DSTIR序列作为常规序列的补充,均可完整的显示腰骶神经的解剖细节,而DWIBS及PROSET序列对背景组织的抑制更加充分,更利于观察神经的走行变化、判断神经受损部位及范围。DWIBS序列MIP后处理图像实现了对腰骶神经的多方位多角度旋转观察,为术前制定手术方案提供可靠的影像学依据,弥补了常规磁共振序列的不足。

Controlled Study on Diverse MRI Sequences for Lumbosacral Plexus

Objective:To investigate the value of three sequences in depicting normal lumbosacral nerve roots as well as in patients with lumbosacral disease.Methods:29 volunteers and 42 patients with lumbosacral plexus lesions were enrolled in this study. Diffusion-weighted neuroimaging with background signal suppression (DWIBS) sequence, principle of selective excitation technique (PROSET) sequence and 3D short term inversion recovery (3D STIR) sequence scanning were performed in all subjects. Maximum intensity projection (MIP) of reconstruction was used for images in DWIBS sequence. Images of all subjects were observed and divided into three classes of resolution. The three methods of scanning in two groups were evaluated statistically for the imaging quality.Results:In group of volunteers, all of three MRI sequences can be implemented to show the detail of the lumbosacral plexus nerves. Chi-square test proved that there was no significant difference between the methods in L4-5 spinal nerve roots, but there were obvious differences in L2-3 spinal nerve roots. In patients, Friedman test showed that there were obvious differences among the imaging quality of three sequences. DWIBS as well as PROSET seemed superior to 3DSTIR and their difference had obvious statistical significance (P<0.05). There was no obvious statistical significance between DWIBS and PROSET.Conclusion:Further technical developments of MRI sequences provide more information in detecting nerves. Excellent depiction of 3D nerve anatomy and pathology is currently possible. By the combination of routine sequences, DWIBS and PROSET, 3D STIR can clearly display the relevant anatomy details and traumatic signs of the Lumbosacral Plexus. Furthermore, the technique of background suppression that displays high specific signal of nerves is more superior in DWIBS and PROSET than in 3DSTIR. The MIP reconstruction of DWIBS can show the multiaspect of the Lumbosacral plexus and observe nerves by different dimensions. DWIBS provide a reliable imaging data for preoperative plan, and make up for the deficiency of conventional magnetic resonance imaging.