MEDIC序列在MR腰骶脊神经根成像中的临床应用

目的探讨Siemens 3T磁共振多回波数据图像重合(multiecho data image combination,MEDIC)序列在腰骶脊神经根显示的技术及病变诊断的应用价值。方法用Siemens 3TVerio磁共振成像仪,对35例腰痛患者行腰椎MRI常规序列(矢状位T1W,T2W,横轴位T2W)、冠状位MEDIC序列及MR脊髓造影MRM序列扫描,MEDIC序列及MRM序列的所有图像均用3D最大信号强度投影(MIP)后处理。由2位高级职称MRI影像诊断医师对MIP重建后图像所显示的腰骶脊神经根长度、形态及病变的影像表现,评价MEDIC序列的应用价值。结果 MEDIC序列显示腰骶脊神经根长度达节后段,MRM未显示节后段。MEDIC序列用MIP软件行神经根曲面容积重建能清晰显示神经根鞘受压移位、神经根病变及与神经根关系的全貌。结论 MEDIC序列能诊断神经根病变,且图像质量优于MRM,是常规MRI的重要补充;用MIP软件行神经根曲面容积重建图像可提供直观的解剖形态信息。     

MR选择性激励技术在腰椎间盘突出患者神经根显示中的价值

目的:探讨MR选择性激励技术(PROSET)在腰椎间盘突出患者中显示神经根的应用价值.方法:正常志愿者15例,腰椎间盘突出患者47例,进行常规扫描和PROSET冠状面腰骶部神经根成像,所有图像均经3D最大信号强度投影(MIP)后处理,观察脊神经根形态、走行及与突出椎间盘的关系.结果:15例志愿者PROSET成像均清楚显示硬膜囊、硬脊膜鞘外形及脊神经根、神经节和部分节后段的走行.47例腰椎间盘突出患者PROSET成像全部清楚显示突出椎间盘对神经根压迫及其程度.结论:PROSET序列对显示腰骶神经根解剖具有独特优势,可以为腰椎间盘突出时神经根受压情况的诊断提供依据.     

MR选择性激励技术(PROSET)在诊断脊神经根病变中的应用

目的：探讨选择性激励技术（PROSET）在诊断腰骶部脊神经根病变中的临床应用价值。方法：将正常志愿者15例作为对照组,脊神经根病变47例作为观察组,进行常规扫描和PROSET冠状面腰骶部神经根成像,所有图像均经3D最大信号强度投影（MIP）后处理,观察脊神经根形态、走行及与病变的关系。结果：对照组PROSET成像均能清楚显示硬膜囊、硬脊膜鞘外形及脊神经根、神经节和部分节后段的走行,MIP重建图像能多方位观察神经根走行。观察组PROSET成像可以清楚显示病变对神经根压迫和侵犯程度。结论：PROSET序列对显示腰骶神经根解剖具有独特优势,结合常规磁共振图像,为临床诊治腰骶神经根病变提供较好的依据。     

MR PROSET序列在正常腰骶部脊神经根成像中的应用

目的：观察磁共振PROSET序列对正常腰骶部脊神经根的显示,探讨磁共振PROSET序列在正常腰骶部脊神经根成像中的价值。方法：对30例正常健康志愿者采用PROSET序列做冠状面扫描,获得正常腰骶部脊神经根影像,所得原始图像经3D最大信号强度投影（MIP）处理。结果：30例PROSET成像及mMIP重建图像多方位旋转均清楚显示腰骶部硬脊膜囊、神经根鞘、脊神经根、神经节和部分节后段。结论：PROSET序列能清晰显示腰骶部神经根,结合常规磁共振图像,为临床诊治腰骶神经根病变提供影像学依据。     

腰骶脊神经根MR成像术在腰椎间盘突出中的应用

目的 探讨腰骶脊神经根MR成像术在腰椎间盘突出中的应用价值. 资料与方法 分析65例椎间盘突出患者腰骶脊神经根MR成像术表现. 结果 在神经根成像术上所有病例腰骶部脊神经根及神经节呈高信号.64.9%的椎间盘突出单根神经根受累,17.0%的椎间盘突出2根神经根同时受累,7.4%的椎间盘突出多根神经根受累;10.7%的椎间盘突出仅见硬膜囊受压. 结论 腰骶脊神经根MR成像术能直观地显示腰骶部脊神经根走行及受压情况.     

磁共振PROSET技术在诊断脊神经根病变中的价值

目的　探讨磁共振PROSET技术在显示和诊断脊神经根病变中的价值。方法　收集可疑腰骶部脊神经根病变 10例 ,正常志愿者 5例 ,观察PROSET的原始图像和MIP重建图像对脊神经根的显示情况。结果　PROSET的原始图像更有利于神经根的显示。 10例可疑患者中发现有 4例神经根鞘膜囊肿 ;2例脊神经根损伤 ;1例神经纤维瘤 ;其余 3例和 5例志愿者的腰骶脊神经根正常结构显示良好 ,能清晰地显示硬膜囊、马尾神经、神经根、脊神经节及节后一段脊神经纤维。结论　PROSET对脊神经根的显示完整清晰 ,对脊神经根的病变诊断和鉴别诊断具有较高价值。     

三叉神经根、Meckel腔内半月神经节及其分支与断层标本对比的解剖学研究

目的:获得三叉神经根、Meckel腔内半月神经节及其分支的正常MR影像和断层解剖资料.方法:57名正常体检者和1例伴有下颌神经痛的患者进行3D-CISS序列扫描、多平面重组(MPR)成像,对三叉神经根、Meckel腔内半月神经节及其分支的走行进行最大程度的显示,将正常MR成像结果与尸体断层切片、尸体头颅标本3D-CISS序列成像进行对照分析.结果:①三叉神经感觉根在斜横断位、斜矢状位和冠状位重组图像上全部以100%(114/114)的几率显示;三叉神经运动根在斜横断位、斜矢状位及冠状位重组图像分别以59%(67/114)、61%(70/114)及46%(52/114)的几率显示;Meckel腔内半月神经节及其分支在斜横断位、斜矢状位及冠状位重组图像的显示率均为100%(114/114);②31%(35/114)的三叉神经根束在进入Meckel腔之前呈聚拢状,其内未见明显脑脊液信号;69%(79/114)的三叉神经根束在进入Meckel腔之前呈分离状,其内可见明显脑脊液信号;③同一被检查者的双侧三叉神经根束走行基本一致;60%(68/114)正常体检者的三叉神经根束呈水平状进入Meckel腔,24%(27/114)正常体检者的三叉神经根束呈前、上方向走行进入Meckel腔,16%(18/114)正常体检者的三叉神经根束呈前、下方向走行进入Meckel腔;④在三叉神经根断面的外下1/3区域分布着下颌神经纤维束,在断面的中内1/3区域主要分布着上颌神经纤维束,在断面的头侧1/3区域主要分布着眼神经纤维束;在连于脑桥部位,部分与三叉神经呈分离状态的三叉神经运动根位于感觉根的内侧;⑤将正常体检者的三叉神经根、Meckel腔内半月神经节及其分支成像显示结果与尸体头颅3D-CISS MR成像、断层切片标本所显示的三叉神经相对照,显示良好的对应关系.结论:3D-CISS MR成像可以清晰显示三叉神经根、Meckel腔内半月神经节及其分支.     

SPACE在诊断腰骶神经根病变的临床应用

目的：探讨磁共振 SPACE 技术在显示和诊断腰骶神经根病变中的价值。方法：搜集可疑腰骶部脊神经根病变31例,正常志愿者8例,观察 SPACE 的原始图像和 MIP 重建图像对脊神经根的显示情况。进行常规扫描和 SPACE冠状面腰骶部神经根成像,所有图像均经3D 最大信号强度投影（MIP）后处理,观察脊神经根形态、走行及与病变的关系。结果：SPACE 成像可以清楚显示病变对神经根压迫和侵犯程度。观察组31例可疑患者中发现15例腰椎间盘突出,4例神经根鞘膜囊肿,3例神经根变异,3例神经根损伤,3例原发神经源性肿瘤,3例肿瘤转移累及神经根。结论：SPACE 序列对显示腰骶神经根解剖具有独特优势,能为临床诊治腰骶神经根病变提供较满意的依据。     

CUBE-FLEX序列显示全脊柱神经根的可行性研究

目的：探讨CUBE-FLEX序列全脊柱神经根成像技术的可行性.方法：采用GE Signa HDxt 3.OT超导磁共振成像系统,对20例健康志愿者及6例神经根病变患者行MR全脊柱神经根成像检查,利用一次定位、自动进床和水脂分离技术的三维容积采集（CUBE-FLEX）序列,分3段行冠状面扫描,即颈段、胸段、腰骶段,将原始图像传至图像后处理工作站,再利用Pasting软件将3段扫描图像自动无缝拼接显示全脊柱神经根图像,全面显示神经根及其病变.结果：20例健康志愿者中,17例的CUBE-FLEX图像能全面、直观、清晰显示周围神经根,2例脊柱侧弯者部分神经根显示不佳,1例因两段脊神经根扫描中体位发生变动,致使脊髓正中层面发生错位,从而影响全视野神经根的观察.6例患者CUBEFLEX能完整显示周围神经根病变及其空间关系,其中臂丛神经损伤1例,骶管神经根囊肿2例,神经纤维瘤病3例.结论：CUBE-FLEX全脊柱神经根成像技术能全面清楚显示全脊柱神经根的空间信息及神经根病变,有利于空间定位,具有较好的整体观和临床应用价值.     

3.0T磁共振全身神经根成像在神经纤维瘤病中的应用价值

目的：探讨3.0T磁共振三维容积采集水脂分离技术（CUBE-FLEX）序列全身神经根成像在神经纤维瘤病中的应用价值。方法：采用GE SIGNA HDxt 3.0T超导磁共振成像系统,对20例神经纤维瘤病患者行MRI全身神经根成像检查,利用一次定位,自动进床和水脂分离技术三维容积采集,分4段行冠状面扫描,即颈段、胸段、腰骶段、下肢段,将原始图像传至工作站行后处理,将4段扫描图像自动无缝拼接显示全身神经根图像,评估图像质量及病变的空间位置。结果：本组20例神经纤维瘤病患者中19例的CUBE-FLEX序列后处理图像能整体、直观、全面、清晰地显示周围神经根、神经纤维瘤以及两者的空间关系;1例因原始图像分段扫描过程中患者体位发生变动,致使脊髓正中层面发生错位导致拼接失败,从而影响全视野神经根的观察。神经纤维瘤病在全身神经根成像中表现为沿神经纤维走行分布的均匀或不均匀高信号影,病变多发、弥漫且大小不一,呈圆形或者椭圆形,边界清楚。结论：3.0T MRI CUBE-FLEX序列全身神经根成像能整体、全面、清楚地显示神经根、神经纤维瘤及两者的空间关系,且有利于发现小的神经纤维瘤病灶,具有较高的临床应用价值。     

3T MRI腰骶部脊神经根扩散张量成像在腰椎间盘突出症中的应用价值

目的 探索扩散张量成像(diffusion tensor imaging,DTI)和纤维示踪成像(fibre tracking,FT)显示腰骶脊神经根的可行性,并评估椎间盘突出症患者L4及L5脊神经根各向异性分数(fractional anisotropy,FA)和表观扩散系数(apparent diffusion coefficient,ADC)值的差别.方法 20例由于后外侧或椎间孔椎间盘突出引起单侧坐骨神经痛的患者和20例健康志愿者纳入研究.所有检查均在Philips Achieve 3.0 T TX MRI上进行,纤维示踪成像参数:FA阈值＝0.15;最小纤维束长度=10mm;最大角度=27°.应用横轴位T2解剖融合图像序列评估重建图像的相关性.对所有被检者的L4、L5和S1脊神经根行扩散张量和纤维示踪成像,并在FA图和ADC图上测量L4和L5脊神经根的平均FA值和ADC值.结果 腰椎间盘突出症患者和健康志愿者腰骶部脊神经根纤维束成像在T2解剖融合图像上完全匹配.在纤维示踪图像上可以清晰地辨别腰骶部脊神经根受压位置.所有患者和健康志愿者的FA值和ADC值可以从FA图和ADC图上获得.受压侧脊神经根的FA值显著低于对侧神经根(P＜0.01)和健康志愿者的(P＜0.01); ADC值显著高于对侧神经根(P＜0.01)和健康志愿者的(P＜0.01).结论 3T MRI腰骶部脊神经根扩散张量和纤维示踪成像是可行的.腰椎间盘突出症患者受压L4和L5脊神经根的FA值和ADC值有显著性的变化.     

Coronal MR imaging of the normal 3rd, 4th, and 5th lumbar and 1st sacral nerve roots

Seven healthy volunteers underwent coronal MR imaging at 1.5 tesla of the normal 3rd, 4th, and 5th lumbar, and 1st sacral nerve roots. Coronal slices, 3-mm-thick with a 0.3-mm gap between the slices were obtained (TR/TE 600/22) through the lumbar spinal canal. All the nerve roots were visible on at least one image. One can routinely expect to demonstrate the 3rd, 4th, and 5th lumbar, and 1st sacral nerve roots on T1-weighted, 3-mm-thick coronal MR scans. We found no correlation between the degree of lumbar lordosis and the lengths of the visible nerve roots. Five patients with one of the following spinal problems: anomaly, tumor, disk herniation, and failed back surgery syndrome were examined according to our protocol. In all these cases coronal MR imaging gave the correct diagnosis.     

Role of stenosis of spinal canal in L4-L5 nerve root compression assessed by flexion-extension myelography

Summary Myelographic flexion-extension studies were performed in four groups of 10 patients each, with (A) normal myelogram; (B) bilateral nerve root compression at L4-L5; (C) unilateral nerve root compression at L4-L5 and (D) nerve root compression at L5-S1. The aim of the investigation was to assess the role of spinal stenosis in contributing to nerve root compression. The results indicate that a form of stenosis of the spinal canal plays an important role in bilateral nerve root compression at L4-L5, and to a lesser extent in unilateral nerve root compression at L4-L5. It does not appear to play a role in L5-S1 nerve root compression (stenosis of the lateral recess left aside). It is advocated that in myelographic L4-L5 nerve root compression additional flexion-extension studies should be performed in order to evaluate the possible role of stenosis of the spinal canal contributing to this compression. Even in nerve root compression by disc extrusion, concomitant spinal stenosis may necessitate additional decompressive laminectomy.     

Lumbosacral transitional vertebra and S1 radiculopathy: the value of coronal MR imaging

Introduction

The association of a lumbosacral transitional vertebra with accelerated degeneration of the disc above has been described. Lumbosacral transitional vertebrae have also been reported as a cause of extraforaminal entrapment of the L5 nerve root between the transverse segment of the transitional vertebra and the sacral ala optimally demonstrated by coronal MRI. The association of the lumbosacral transitional vertebra pseudoarthroses and S1 nerve root entrapment due to degenerative stenosis of the nerve root canal has never been described.

Methods

We present 12 patients with lumbosacral transitional vertebrae that were referred for symptoms and signs of S1 nerve root radiculopathy in which the sagittal and axial MRI sequences failed to identify a plausible cause for the patients’ S1 nerve root symptoms. A coronal T1-weighted imaging (T1WI) MRI sequence was consequently added to the investigation.

Results

The coronal T1WI MRI sequence demonstrated hypertrophic degenerative stenosis of the S1 nerve root canal at the level of the lumbosacral transitional vertebra pseudoarthrosis, with entrapment of the respective S1 nerve root in all patients.

Conclusion

We emphasize the value of coronal T1WI MRI of the lumbosacral junction and sacrum if the cause for S1 radicular symptoms was not identified on conventional sagittal and axial MRI sequences in patients with lumbosacral transitional vertebrae.     

DTI在腰椎间盘突出引起腰骶神经根压迫症中的应用价值

目的：探讨腰骶神经根扩散张量成像（DTI）及纤维示踪成像（FT）的可行性,同时评定健康志愿者及腰椎间盘突出引起单侧坐骨神经痛患者的腰骶神经根 DTI 参数不同层面数值的连续性变化。方法：将20例腰椎间盘突出引起单侧坐骨神经痛的患者及20例与患者年龄相仿的健康志愿者同时纳入研究。所有检查均在 Siemens 3．0T MR 上进行,采用3D T1-VIBE 及 DTI 融合图像,分别在神经根（L5和 S1）的三个不同层面测量左右两侧神经根的各向异性分数（FA）值和 ADC 值,同时进行 L4、L5、S1神经根 FT。结果：20例健康志愿者 L5和 S1神经根左、右两侧 FA 值分别为0．319±0．019和0．320±0．019,ADC 值分别为1．427±0．171和1．416±0．185,左右两侧差异无统计学意义（P ＞0．05）;不同层面神经根两两之间的 FA 及 ADC 值差异无统计学意义（P ＞0．05）。20例患者的患侧神经根 FA 值低于健侧,分别为0．285±0．026和0．319±0．019,差异有统计学意义（P ＜0．05）;患侧神经根近端至远端 FA 值逐层递减（P ＜0．05）,ADC值逐层递增（P ＜0．05）;健侧不同层面 FA 值无明显差异（P ＞0．05）。结论：DTI 结合常规 MRI 对定量评价病变神经根及定位诊断腰骶神经根卡压有一定的应用价值。     

Feasibility and limitation of constructive interference in steady-state (CISS) MR imaging in neonates with lumbosacral myeloschisis

Introduction The aim of this study was to evaluate three-dimensional Fourier transformation-constructive interference in steady-state (CISS) imaging as a preoperative anatomical evaluation of the relationship between the placode, spinal nerve roots, CSF space, and the myelomeningocele sac in neonates with lumbosacral myeloschisis. Methods Five consecutive patients with lumbosacral myeloschisis were included in this study. Magnetic resonance (MR) CISS, conventional T1-weighted (T1-W) and T2-weighted (T2-W) images were acquired on the day of birth to compare the anatomical findings with each sequence. We also performed curvilinear reconstruction of the CISS images, which can be reconstructed along the curved spinal cord and neural placode. Results Neural placodes were demonstrated in two patients on T1-W images and in three patients on T2-W images. T2-W images revealed a small number of nerve roots in two patients, while no nerve roots were demonstrated on T1-W images. In contrast, CISS images clearly demonstrated neural placodes and spinal nerve roots in four patients. These findings were in accordance with intraoperative findings. Curvilinear CISS images demonstrated the neuroanatomy around the myeloschisis in one slice. The resulting images were degraded by a band artifact that obstructed fine anatomical analysis of the nerve roots in the ventral CSF space. The placode and nerve roots could not be visualized in one patient in whom the CSF space was narrow due to the collapse of the myelomeningocele sac. Conclusion MR CISS imaging is superior to T1-W and T2-W imaging for demonstrating the neural placode and nerve roots, although problems remain in terms of artifacts.     

Differentiation between Symptomatic and Asymptomatic Extraforaminal Stenosis in Lumbosacral Transitional Vertebra: Role of Three-Dimensional Magnetic Resonance Lumbosacral Radiculography

Objective

To investigate the role of lumbosacral radiculography using 3-dimentional (3D) magnetic resonance (MR) rendering for diagnostic information of symptomatic extraforaminal stenosis in lumbosacral transitional vertebra.

Materials and Methods

The study population consisted of 18 patients with symptomatic (n = 10) and asymptomatic extraforaminal stenosis (n = 8) in lumbosacral transitional vertebra. Each patient underwent 3D coronal fast-field echo sequences with selective water excitation using the principles of the selective excitation technique (Proset imaging). Morphologic changes of the L5 nerve roots at the symptomatic and asymptomatic extraforaminal stenosis were evaluated on 3D MR rendered images of the lumbosacral spine.

Results

Ten cases with symptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. On 3D MR lumbosacral radiculography, indentation of the L5 nerve roots was found in two cases, while swelling of the nerve roots was seen in eight cases at the exiting nerve root. Eight cases with asymptomatic extraforaminal stenosis showed hyperplasia and degenerative osteophytes of the sacral ala and/or osteophytes at the lateral margin of the L5 body. Based on 3D MR lumbosacral radiculography, indentation or swelling of the L5 nerve roots was not found in any cases with asymptomatic extraforaminal stenosis.

Conclusion

Results from 3D MR lumbosacral radiculography Indicate the indentation or swelling of the L5 nerve root in symptomatic extraforaminal stenosis. Based on these findings, 3D MR radiculography may be helpful in the diagnosis of the symptomatic extraforaminal stenosis with lumbosacral transitional vertebra.