Degenerative diseases of the cervical spine: comparison of a multiecho data image combination sequence with a magnetisation transfer saturation pulse and cervical myelography and CT

Assessing degenerative disease in the cervical spine remains a challenge. There is much controversy about imaging the cervical spine using MRI. Our aim in this prospective study was to compare a T2*-weighted 2D spoiled gradient-echo multiecho sequence (MEDIC) with a magnetisation transfer saturation pulse with cervical myelography and postmyelographic CT. Using an assessment scale we looked at the vertebral bodies, intervertebral discs, neural foramina, anterior and posterior nerve roots, grey matter, ligamenta flava, oedema in the spinal cord and stenosis of the spinal canal. We also evaluated postmyelography CT and the MEDIC sequence for assessing narrowing of the neural foramina in a cadaver cervical spine. We examined 67 disc levels in 18 patients, showing 18 disc prolapses and 21 osteophytes narrowing the spinal canal or the neural foramina. All MRI studies showed these abnormalities findings equally well. Postmyelography CT was significantly better for showing the bony structures and the anterior and posterior nerve roots. The MEDIC sequence provided excellent demonstration of soft-tissue structures such as the intervertebral disc and ligamentum flavum. No statistical differences between the imaging modalities were found in the assessment of narrowing of the neural foramina or the extent of spinal stenosis. The cadaver measurements showed no overestimation of abnormalities using the MEDIC sequence.     

Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading.

PURPOSETo measure the effect of extension, flexion, lateral bending, and axial rotation loads applied to the spine on the anatomic relationship of the spinal nerves in the neural foramen to the ligamentum flavum and the intervertebral disk, anc to determine the effect of disk degeneration on the response to loading.METHODSCadaveric lumbar motion segments were examined with CT and MR imaging, loaded with pure moment forces, frozen in situ, reexamined with CT, and sectioned with a cryomicrotome. The morphology of the intervertebral disks was classified on the basis of the appearance of the cryomicrotome sections. The neural foramina were classified as having no evident stenosis, as being stenotic, as having occult stenosis, or as showing resolved stenosis on the basis of the images and sections before and after loading. The stenotic and nonstenotic foramina were stratified by disk level, intervertebral disk classification, and type of loading applied. The effect of spinal level, disk type, and load type on the prevalence of stenosis was studied.RESULTSOn average, extension, flexion, lateral bending, and axial rotation resulted in the ligamentum flavum or intervertebral disk contacting or compressing the spinal nerve in 18% of the neural foramina. Extension loading produced the most cases of nerve root contact, and lateral bending produced the fewest cases. Each of the loading types resulted also in diminished contact between the spinal nerve and the intervertebral disk or ligamentum flavum in some cases. Disk degeneration significantly increased the prevalence of spinal stenosis. All foramina associated with advanced disk degeneration and half of the foramina associated with disks having radial tears of the annulus fibrosus either developed occult stenosis or were stenotic before loading.CONCLUSIONSThe study supports the concept of dynamic spinal stenosis; that is, intermittent stenosis of the neural foramina. Flexion, extension, lateral bending, and axial rotation significantly changed the anatomic relationships of the ligamentum flavum and intervertebral disk to the spinal nerve roots.     

Changes in cross-sectional measurements of the spinal canal and intervertebral foramina as a function of body position: in vivo studies on an open-configuration MR system

OBJECTIVE: The purpose of this study was to evaluate physiologic changes of the cross-sectional area of the spinal canal and neural foramina in young asymptomatic volunteers. SUBJECTS AND METHODS: Twelve asymptomatic volunteers were examined in a 0.5-T open-configuration MR system. T2-weighted fast spin-echo sequences were obtained in upright neutral, upright flexed, upright extended, and supine extended positions. The cross-sectional area of the spinal canal and the thickness of the ligamentum flavum were measured on angled axial images at the L4-L5 level. The anteroposterior diameter of the spinal canal and cross-sectional areas of the neural foramina were measured on sagittal images from L1 to S1. RESULTS: At disk level, the cross-sectional area of the spinal canal varied significantly between body positions, most notably between the upright flexed (mean, 268 mm2) and the upright extended (mean, 224 mm2) positions (p < .0001). The maximum thickness of the ligamenta flava increased in the extended positions (p < .0001). The cross-sectional area of the neural foramina underwent position-dependent variations of as much as 44.4%. The smallest cross-sectional areas were found in the extended positions. CONCLUSION: In asymptomatic volunteers, MR imaging is able to show position-dependent changes in the cross-sectional areas of the spinal canal and the intervertebral foramina. The extended positions best reveal important findings.     

Neural foraminal ligaments of the lumbar spine: appearance at CT and MR imaging.

Axial and parasagittal computed tomographic (CT) scans and magnetic resonance (MR) images and exactly corresponding sections obtained with the freezing microtome in 18 human cadavers were examined to characterize the radiologic appearance of the lumbar neural forminal ligaments, which have been thought to contribute to nerve root compression. In the CT component of this study, 114 neural foramina at 57 spinal levels were studied; in the MR component, 27 neural foramina were studied. The ligaments originated from the posterolateral margin of the intervertebral disk and attached to the inferior pedicle, superior articular process, transverse process, or ligamentum flavum. On CT scans, they appeared as linear structures with higher attenuation coefficients than those of the adjacent fat and areolar tissue; on MR images, as linear structures with lower signal intensities than those of the adjacent fat and areolar tissue in the neural foramina. It is concluded that the ligaments in the neural foramen can be effectively depicted with CT or MR imaging.     

Foraminal spurs: a normal variant in the lumbar spine

A normal variant, the foraminal spur, is described in five patients. It was seen on computed tomographic studies as a bony process extending from either the pars or the pedicle into the neuroforamen dorsal to the nerve root. In four of the cases it was seen bilaterally. None of the patients had any symptoms related to these spurs. No associated disease of the neuroforamen or facet was present. These spurs most likely represent ossification of the ligamentum flavum at its point of insertion and should not be mistaken for osteophytes, free disk fragments that have calcified, or fracture fragments. Sagittal reformations are helpful in visualizing the extent of the foraminal spurs.     

Normal and degenerative posterior spinal structures: MR imaging

A retrospective study of the magnetic resonance (MR) images of the lumbar spines of 13 healthy subjects and 30 patients with degenerative changes was done. In the healthy subjects, the vertebral facets, thickness of the cartilage and ligamentum flavum, signal characteristics of the bone marrow, and size of the spinal canal were studied. In the patients with degenerative changes in one of these structures, MR images in the sagittal plane were useful in demonstrating hypertrophy of the ligamentum flavum or the vertebral facets, in grading the degree of foraminal stenosis, and in measuring the sagittal diameter of the spinal cord. MR images in the axial plane facilitated detailed analysis of the facet joint and more accurate measurements of the thickness of the ligamentum flavum and spinal canal diameter. MR images were compared with computed tomography scans in 12 patients.     

50例腰椎管狭窄症临床及影像学研究

目的 探讨影像学在椎管狭窄诊断中的价值。方法 对50例腰椎管狭窄的X线、CT、MRI表现进行回顾性分析。腰椎管狭窄分为四度：0度、I度(轻度)、Ⅱ度(中度)、Ⅲ度(重度)。结果 椎管狭窄位于L3，4平面6例，L4，5水平者29例，位于L5，S1平面者15例。CT及MRI显示单纯黄韧带肥厚者12例；椎间盘突出并黄韧带肥厚致腰盘黄间隙狭窄13例；椎体后缘骨质增生突入椎管者8例，椎体后缘增生并小关节突增生肥大16例，后纵韧带骨化1例。椎管狭窄I度26例，Ⅱ度10例，Ⅲ度14例。结论 腰椎管狭窄是临床常见病和多发病。传统X线检查有其局限性，CT和MRI无创，能够准确显示腰椎管狭窄的解剖学和部分组织学改变。     

人工体神经-内脏神经反射弧建立术前MRI检查的价值

目的 评价MRI在人工体神经-内脏神经反射弧建立术前的诊断价值。资料与方法 对73例神经源性膀胱．拟行人工体神经-内脏神经反射弧建立术的患者进行术前MRI检查。结果 脊髓栓系综合征57例．骨折并脊髓损伤10例,椎管内占位3例．马尾神经粘连3例。结论 神经源性膀胱患者人工体神经-内脏神经反射弧建立术前应进行MRI检查。MRI对于发现脊髓栓系综合征、骨折并脊髓损伤、椎管内占位性病变以及马尾神经粘连有重要意义。     

使用U-Net深度学习网络对腰椎矢状T2WI图像自动分割的可行性研究

目的:研究训练U-Net模型自动分割腰椎矢状面T₂WI图像中各结构的可行性。方法:回顾性搜集腰椎矢状面T2WI图像数据,共获得80个矢状面T₂WI序列。由2位影像医师手工标注矢状面腰椎椎体、椎间盘、椎间孔、椎管/硬膜囊、脊髓及马尾神经。将数据随机分为训练集、调优集和测试集,使用U-Net网络分两步(coarse-to-fine)训练腰椎矢状T₂WI分割模型。模型评价指标包括客观评估(Dice系数)和主观评估。结果:11例测试集数据中U-Net模型预测腰椎5个解剖部位分割的Dice值分别为椎体0.82~0.9(平均0.864)、椎间盘0.86~0.92(平均0.898)、椎管/硬膜囊0.76~0.87(平均0.837)、椎间孔0.6~0.76(平均0.67)、脊髓及马尾神经0.55~0.9(平均0.669)。主观评估各解剖部位分割满意率分别为椎体97.5%、椎间盘97.9%、椎管/硬膜囊86.4%、椎间孔76.7%、脊髓及马尾神经78.6%。结论:基于U-Net深度学习网络对腰椎矢状T₂WI图像的解剖结构进行自动分割是可行的。     

马尾和终丝部黏液乳头状室管膜瘤的MR征象分析

目的:探讨马尾、终丝部黏液乳头状室管膜瘤MRI特征.万法:回顾性分析经于术病理正实的12例马尾、终丝部黏液乳头状室管膜瘤的临床、病理及MRI资料,所有患者均行MRI平扫和增强扫描,分析肿瘤的长度、生长方式、信号特点.结果:马尾、终丝部黏液乳头状室管膜瘤累及2～9个椎体单位;肿瘤生长方式可分为椎体受累型(n=3)和椎体无...     

老年人腰椎椎管狭窄的CT评估

目的：描述６０岁以上老年人脊椎狭窄的有关ＣＴ表现及测量,探讨老年人脊椎狭窄的特征。方法：采用ＣＴ横断而簿层扫描,并测量硬膜囊矢状径、黄韧带前间隙、侧隐窜宽度,分析他们与脊央和／或神经根受压的关系。结果：硬膜囊矢状径≤１０ｍｍ、黄韧带前间隙〈５ｍｍ,侧陷窝宽度≤３ｍｍ,常提示压迫脊髓或神经根。结论：老年人椎管狭窄多有椎骨小关节及侧隐窝狭窄,而黄韧带前间隙〈５ｍｍ是神经根压迫较为可靠的依据。     

CT对腰椎退行性变的诊断价值

目的探讨ＣＴ在诊断腰椎退行性变中的价值。方法回顾分析３００例腰椎退行性变的ＣＴ检查资料,找出其影像变化的特征。结果在３００例ＣＴ诊断为腰椎退行性变的病例中,表现为：（１）椎体骨质增生１９４例,占６４７％;（２）椎间盘膨出１１０例,占３６７％;（３）椎间盘突出９７例,占３２３％;（４）椎小关节病９７例,占３２３％;（５）椎间盘膨出和突出６１例,占２０３％;（６）退变性骨性椎管狭窄中央型２３例,占７７％;侧隐窝狭窄１９例,占６３％;（７）黄韧带肥厚１８例,占６０％;（８）退变性脊椎滑脱６例,占２０％;（９）真空现象５例,占１７％。结论ＣＴ检查不仅能明确腰椎退行性变的诊断,而且能为临床表现的解释和治疗提供更多的信息和依据。     

成人下腰椎骨折合并马尾神经损伤的手术治疗

目的探讨成人下腰椎骨折合并马尾神经损伤的手术治疗方法及疗效。方法回顾性分析2004年1月—2010年10月在我科进行手术治疗并随访1.5年以上的34例下腰椎骨折合并马尾神经损伤患者,比较手术前后影像学资料、ASIA功能评分等指标。结果术后随访1.5年以上,ASIA神经损伤评分明显改善,无加重病例发生,术后X线示:脊柱后凸畸形矫正,椎体高度恢复至正常椎体高度80%～95%,磁共振(MR)检查:椎管无明显狭窄,伤椎局部硬膜囊无明显致压物存在。结论椎体爆裂骨折伴马尾神经损伤的患者,通过早期行后路椎板减压、马尾神经回纳、硬膜修补、椎弓根钉内固定植骨融合可取得较好疗效。     

腰椎退行性变和腰椎间盘突出致黄韧带增厚的原因分析

 目的 分析腰椎退行性变和腰椎间盘突出致黄韧带增厚的原因.方法 通过对58例健康人与100例腰椎退行性变患者及100例腰椎间盘突出患者的MRI资料研究,测量黄韧带厚度.结果 58例健康人组中,黄韧带增厚2例,占3.4％;100例腰椎退行性变组巾,黄韧带增厚26例,占26.0％;100例腰椎间盘突出组(L3～4、L4～5及L5/S1)中,黄韬带不同程度增厚24例,占24％,显示腰椎退行性变和椎间盘突出与黄韧带增厚有显著的相关性(P＜0.01).结论 腰椎退行性变和腰椎间盘突出容易造成黄韧带增厚.     

Volume fast spin-echo imaging of the cervical spine

RATIONALE AND OBJECTIVES: The authors prospectively evaluated a T2-weighted, three-dimensional (3D) volume, fast spin-echo (SE) pulse sequence in assessment of the cervical spine and compared it with standard imaging protocol. MATERIALS AND METHODS: Eighteen patients with neck pain underwent magnetic resonance (MR) imaging at 1.5 T with two-dimensional (2D) fast SE and axial 3D gradient-echo (GRE) protocols and with an additional sagittal T2-weighted volume fast SE protocol. The spinal cord and canal, neural foramina, and intervertebral disks were assessed by two neuroradiologists, and the results were compared with reports from the standard protocol. The quality of the partition (direct sagittal) and reconstructed images were evaluated. RESULTS: No differences existed in the assessment of spinal cord disease or disk herniation with 2D fast SE and volume fast SE imaging. Some mild variation occurred in assessment of the neural foramina. Partition images demonstrated a high level of resolution and contrast, while reconstructed images had consistently lower quality. However, this did not impede detection and grading of disk or spinal abnormalities, which were adequately shown on volume fast SE sagittal images. Neural foramina were well demonstrated on axial reconstructions from volume fast SE imaging. CONCLUSION: Volume fast SE imaging provides information about the spinal cord, canal, disks, and neural foramina that is comparable to the information provided by routine imaging. Its thinner sections and multiplanar reconstruction capability are advantages over 2D imaging. Its greater tissue contrast with better visualization of the cervical cord, greater signal-to-noise ratio, and less susceptibility artifact are advantages over 3D GRE imaging.     

Sagittal splitting laminoplasty for spinal canal enlargement for ossification of the spinal ligaments (OPLL and OLF)

Patients have been followed up radiologically after sagittal splitting laminoplasty (SSL) for ossification of the posterior longitudinal ligament (OPLL) and ligamentum flavum. The enlarged spinal canal was maintained satisfactorily in all the cases, and the posterior spinal elements were also almost completely restored. In most cases, the range of the vertebral motion was good with more than 50% of the preoperative status. Postoperative instability of the vertebral column was not identified in any case. Mild cervical kyphosis was noted in 6% of cervical OPLL patients. There were no patients with neurological deterioration. Using SSL, reconstruction and restoration of the posterior spinal elements and retention of the enlarged spinal canal were accomplished safely and adequately.     

Paravertebral ligamentous ossification: DISH,OPLL and OLF

This is an overview of paravertebral ligamentous ossification based on our 5-year experience in ossification of posterior longitudinal ligament (109 cases) and ossification of ligamentum flavum (18 cases). Paravertebral ligamentous ossification is designated as the disorder caused by frequently coexisting ossification of paravertebral ligaments, DISH, OPLL, and OLF. The frequency of the occurrence of isolated ossification of PLL and OLF in Japan is still uncertain. DISH, which is not rare in Europe or North America, is frequently associated with ossification of the posterior aspect of the vertebral bodies, but it may be less symptomatic. The major cause of the probably higher incidence of symptomatic patients in Japan may be due to associated narrowing of the spinal canal.     

腰椎管狭窄104例与黄韧带的关系

目的　探讨形成腰椎管狭窄症的原因及与黄韧带的关系。方法　对我院 1990年以来手术的 10 4例腰椎管狭窄症进行分析。结果　腰椎管狭窄可由骨性椎管因素造成 ,也可由非骨性物退变增生导致的椎管内占位所造成。结论　腰椎黄韧带钙化、骨化及肥厚是引起腰椎管狭窄的常见原因 ,特别是骨性椎管已有狭窄或有椎间盘突出等病变存在时更会加重症状     

Effect of axial loading on neural foramina and nerve roots in the lumbar spine

The hypothesis that the neural foramina in some patients are critically narrowed by axial compression of the spine has not been studied with direct imaging techniques. Frozen cadaveric motion segments of the lumbar spine (intervertebral disk and contiguous vertebrae) were imaged with computed tomography (CT). The segments were thawed and compressed in a hydrostatic press to simulate axial loading, and then the segments were frozen and imaged again. The motion segments were subsequently sectioned with a cryomicrotome, and the chronic degenerative changes present in the disks were classified. Pre- and post-compression CT images were compared, and anatomic relationships were studied. In 41 randomly selected segments (some with preexisting radial, transverse, and concentric annular tears), compression diminished the diameters and cross-sectional areas of the spinal canal and neural foramina. In no cases were nerve roots displaced, distorted, or compressed by axial loading. This study suggests that axial loading, such as that produced by ordinary weight bearing, does not critically compromise the neural foramina even in the presence of chronic degenerative disk changes.     

脊髓马尾区神经鞘瘤的MRI诊断分析

目的:探讨马尾神经鞘瘤的MRI诊断价值。方法:回顾性分析18例经手术病理证实的马尾神经鞘瘤的MRI平扫和增强后的形态及信号特点,以及受累马尾神经的形态及信号特点。结果:18例马尾神经鞘瘤中16例为单发,2例为多发(共5个病灶),肿瘤长径平均30mm。14例位于硬膜内,肿瘤为圆形、卵圆形,相邻脊髓圆锥受压或马尾神经推压移位;3例跨硬膜内外生长,肿瘤为哑铃形,沿椎间孔向外生长,椎间孔扩大,椎体后缘压迫性骨吸收。1例位于硬膜外,肿瘤呈哑铃状,自椎管沿椎间孔向外延伸,相邻蛛网膜下腔受压变窄。病灶T1WI等或(和)低信号,T2WI等或(和)高信号,2例T2WI混杂斑点状低信号,13例内部见囊变区,增强扫描肿瘤呈明显均匀或不均匀强化,13例可见肿瘤上、下方或侧方有增粗强化的马尾神经。结论:MRI能清楚显示马尾神经鞘瘤的大小、形态、内部情况及与邻近马尾神经、硬膜囊的关系,对于临床诊断及制定手术方案具有非常重要的意义。