颈椎间盘突出症的磁共振表现及其临床意义

对86例经过手术治疗的颈椎间盘突出症患者的MRI表现进行了分析，并提出了分型。根据T1加权像结合横断面分为中央型及后外侧型突出；根据T1加权像结合矢状面分为Ⅰ型、Ⅱ型、Ⅲ型及Ⅳ型突出。并就分型与临床的关系，特别是对手术治疗的指导意义进行了阐述。     

Kinematic evaluation of cervical sagittal balance and thoracic inlet alignment in degenerative cervical spondylolisthesis using kinematic magnetic resonance imaging

Background Context

T1 slope is a novel thoracic parameter used to assess cervical spine sagittal balance. Thoracic index (TI) parameters including T1 slope and cervical sagittal alignment parameters may play an important role in degenerative cervical spondylolisthesis (DCS). Current literature regarding the relationship between TI and cervical sagittal alignment parameters in patients with DCS is limited.

脊髓型颈椎病伴发育性椎管狭窄患者的脊髓储备空间

【摘要】 目的：观察脊髓型颈椎病伴发育性椎管狭窄患者颈椎MRI上脊髓在硬膜囊内的储备空间。方法：2006年2月~2010年7月,以脊髓型颈椎病就诊于北京大学第三医院骨科的患者123例,其中66例不伴后纵韧带或黄韧带骨化、椎体后缘骨赘或椎间盘突出的椎管侵占不超过50%的患者被纳入研究,其中男性41例,女性25例;年龄34~84岁,平均57岁。依据颈椎中立位X线平片上中矢径比值将所有患者分为伴发育性椎管狭窄组（狭窄组,中矢径比值≤0.75,n=38）和不伴发育性椎管狭窄组（非狭窄组,中矢径比值>0.75,n=28）,在MRI T2矢状位像上测量C3~C7硬膜囊中矢径和椎体中矢径,在MRI T2横断位像上测量脊髓横截面积和硬膜囊横截面积,计算并比较两组患者MRI中矢径比值（硬膜囊中矢径/椎体中矢径）和硬膜囊占有率（脊髓横截面积/硬膜囊横截面积）。结果：狭窄组C3~C7各节段MRI中矢径比值均显著小于非狭窄组（P<0.001）;C3~C6节段硬膜囊占有率与非狭窄组无显著性差异（P>0.05）,而C7节段有显著性差异（P<0.05）。结论：脊髓型颈椎病患者中,伴有发育性颈椎管狭窄的患者硬膜囊矢状径明显减小,但C3~C6节段脊髓在硬膜囊内的储备空间并未显著减小,呈现“小椎管小脊髓”的特点。     

Placement of pedicle screws in thoracic idiopathic scoliosis: a magnetic resonance imaging analysis of screw placement relative to structures at risk

In posterior pedicle screw instrumentation of thoracic idiopathic scoliosis, screw malposition might cause significant morbidity in tems of possible pleural, spinal cord, and aorta injury. Preoperative axial magnetic resonace images (MRI) in 12 consecutive patients with right thoracic adolescent scoliosis, all with King type 3 curves, were analyzed in order to evaluate the relationship between the inserted pedicle screw position to pleura, spinal cord, aorta. Axial vertebral images for each thoracic level were scanned and the simulation of pedicle screw insertion was performed using a digital measurement programme. The angular contact value for each parameter regarding the pleura and spinal cord was measured on both sides of the curve. The aorta-vertebral distance was also measured. Aorta-vertebral distance was found to be decreasing gradually from the cephalad to the caudad with the shortest distance being measured at T12 with a mean of 1.2 mm. Concave-sided screws on T5–T9 and convex-sided screws on T2–T3 had the greatest risk to spinal cord injury. Pleural injury is most likely on T4–T9 segments by the convex side screws. T4–T8 screws on the concave side and T11–T12 screws on the convex side may pose risk to the aorta. This MRI-based study demonstrated that in pedicle instrumentation of thoracic levels, every segment deserves special consideration, where computer scanning might be mandatory in immature spine and in patients with severe deformity.     

Evaluation of intervertebral disc cartilaginous endplate structure using magnetic resonance imaging

Purpose

The cartilaginous endplate (CEP) is a thin layer of hyaline cartilage positioned between the vertebral endplate and nucleus pulposus (NP) that functions both as a mechanical barrier and as a gateway for nutrient transport into the disc. Despite its critical role in disc nutrition and degeneration, the morphology of the CEP has not been well characterized. The objective of this study was to visualize and report observations of the CEP three-dimensional morphology, and quantify CEP thickness using an MRI FLASH (fast low-angle shot) pulse sequence.

Methods

MR imaging of ex vivo human cadaveric lumbar spine segments (N = 17) was performed in a 7T MRI scanner with sequence parameters that were selected by utilizing high-resolution T1 mapping, and an analytical MRI signal model to optimize image contrast between CEP and NP. The CEP thickness at five locations along the mid-sagittal AP direction (center, 5 mm, 10 mm off-center towards anterior and posterior) was measured, and analyzed using two-way ANOVA and a post hoc Bonferonni test. For further investigation, six in vivo volunteers were imaged with a similar sequence in a 3T MRI scanner. In addition, decalcified and undecalcified histology was performed, which confirmed that the FLASH sequence successfully detected the CEP.

Results

CEP thickness determined by MRI in the mid-sagittal plane across all lumbar disc levels and locations was 0.77 ± 0.24 mm ex vivo. The CEP thickness was not different across disc levels, but was thinner toward the center of the disc.

Conclusions

This study demonstrates the potential of MRI FLASH imaging for structural quantification of the CEP geometry, which may be developed as a technique to evaluate changes in the CEP with disc degeneration in future applications.     

Pedicle morphology of the thoracic spine in preadolescent idiopathic scoliosis: magnetic resonance supported analysis

Although several studies have been reported on the adult vertebral pedicle morphology, little is known about immature thoracic pedicles in patients with idiopathic scoliosis. A total of 310 pedicles (155 vertebrae) from T1 to T12 in 10–14 years age group were analyzed with the use of magnetic resonance imaging and digital measurement program in 13 patients with right-sided thoracic idiopathic scoliosis. Each pedicle was measured in the axial and sagittal planes including transverse and sagittal pedicle width and angles, chord length, interpedicular distance and epidural space width on convex and concave sides of the curve. The smallest transverse pedicle widths were in the periapical region and the largest were in the caudal region. No statistically significant difference in transverse pedicle widths was detected between the convex and concave sides. The transverse pedicle angle measured 15.56° at T1 and decreased to 6.32° at T12. Chord length increased gradually from the cephalad part of the thoracic spine to the caudad part as the shortest length was seen at T1 convex level with a mean of 30.45 mm and the largest length was seen at T12 concave level with a mean of 41.73 mm. The width of epidural space on the concave side was significantly smaller than that on the convex side in most levels of the curve. Based on the anatomic measurements, it may be reasonable to consider thoracic pedicle screws in preadolescent idiopathic scoliosis.     

High-intensity zone (HIZ) of lumbar intervertebral disc on T2-weighted magnetic resonance images: spatial distribution, and correlation of distribution with low back pain (LBP)

Objectives

To analyze the three-dimensional distribution of high-intensity zone (HIZ) in lumbar disks and to assess the correlation between low back pain (LBP) and spatial distribution of HIZs.

Methods

Clinical records and lumbar MRIs of 623 patients (337 males and 286 females, age 50.10 ± 15.38 years) were selected and reviewed. Baseline characteristics and 3D localization were performed and recorded by two radiologists in a blind fashion.

Results

Among the 623 patients, 200 exhibited an HIZ in at least one disk. HIZs were more frequently seen in the inferior part of annulus fibrosus (superior–middle–inferior ratio 39:59:140, P < 0.001). One hundred and eighty-one HIZs (76.1%) occurred at L4/5 and/or L5/S1. The prevalence of multi-segmental HIZ was 16.5%. Among the 33 patients with multi-segmental HIZs, 24 exhibited HIZs in adjacent disks. The LBP rate of HIZ patients was significantly higher than that of patients who exhibited no HIZ (57.5 vs. 47.8%, P < 0.05). There was no evidence for a correlation between LBP and spatial distribution of HIZ in disk (P > 0.05). The incidence of LBP was slightly higher when the HIZ disk level was lower or when there were HIZs exhibited in more disks; however, the difference was statistically insignificant (P > 0.05).

Conclusions

High-intensity zones occurred frequently at lower segments, inferior part of annulus fibrosus, and single disk.     

无骨折脱位型颈髓损伤的核磁共振成像诊断

对２０例无骨折脱位型颈髓损伤的ＭＲＩ检查结果做分析，将无骨折脱位颈髓损伤分为不伴有颈椎疾病组和伴有颈椎疾病组。两组在年龄、致伤原因、ＭＲＩ图像、治疗方法及治疗效果上存在着差异。ＭＲＩ是诊断无骨折型颈髓损伤的一种有效检查手段，并有助于制订外科治疗计划和预后判断。     

Tophaceous gout causing thoracic spinal cord compression: Case report and review of the literature

Objective

To improve neurologists’ awareness of spine gout by showing a rare case of tophaceous gout in thoracic spine and a summary of vertebral gout in order.

Kinematics of the lumbar spine in trunk rotation: in vivo three-dimensional analysis using magnetic resonance imaging

In vivo three-dimensional (3D) kinematics of the lumbar spine has not been well evaluated by the conventional methods because of their methodological limitations, while 3D intervertebral motions have been quantitatively determined by cadaver studies. We thus developed a novel 3D analyzing system for the relative motions of individual vertebrae using 3D magnetic resonance imaging (MRI) and analyzed in vivo 3D intervertebral motions of the lumbar spine during trunk rotation. Ten healthy volunteers underwent 3D MRI of the lumbar spine in nine positions with 15° increments during trunk rotation (0°, 15°, 30°, 45°, and maximum). Relative motions of the lumbar spine were calculated by automatically superimposing a segmented 3D MRI of the vertebra in the neutral position over images of each position using the voxel-based registration method. These 3D motions were represented with 6 degrees of freedom by Euler angles and translations on the coordinate system. The mean axial rotation of ten healthy volunteers of each lumbar spinal segment in 45° trunk rotation to each side ranged from 1.2° to 1.7°. Coupled flexion with axial rotation was observed at the segments from L1/2 to L5/S1. Coupled lateral bending of the segments from L1/2 to L4/5 was in the opposite direction of the trunk rotation, while that of T12/L1 and L5/S1 was in the same direction. The direction of the coupled lateral bending in the present study was different from that in the previous cadaver study only at L4/5. This difference might result from the non-load state of the supine position in the current study and/or the non-physiological state in the cadaver study. Our system has two limitations: (1) the study was conducted with each volunteer in the supine position, and (2) because the rotation device regulated trunk rotation, trunk rotation might not have been physiological. In vivo 3D intervertebral motions of the lumbar spine during trunk rotation were evaluated using our novel motion analysis system. These data may be useful for the optimal orthopaedic management of lumbar spinal disorders. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Dorsal thoracic spinal cord herniation: report of an unusual case and review of the literature

Background context

Spinal cord herniation is a rare but well-documented condition that has been associated with tethering through the dural defect. Both spinal cord herniation and cord tethering result in progressive myelopathy that can be improved or stabilized with surgical intervention. Most cases of herniation are caused by dural defects in the ventral or ventrolateral thoracic spine, rarely occurring through the dorsal dura. This is the first reported case of a spontaneous dorsal herniation.

Purpose

To describe a unique case of thoracic tethered cord resulting from a dorsal dural defect through which there is spinal cord herniation.

Study design

A case report and review of the literature.

Methods

A 55-year-old man presented with progressive low back pain, paresthesias, and weakness in his left lower extremity that was exacerbated by walking. Imaging revealed a dorsal dural defect with tethering and herniation of the spinal cord at T7.

Results

The patient underwent a T6–T7 laminoplasty to release the tethered cord and repair the dural defect. At 1-year follow-up, the patient noted improvement in strength and back spasticity.

Conclusions

Spinal cord herniation through a dural defect is an uncommon but important cause of symptomatic tethered cord in adults. Surgical intervention can significantly alter the course and prevent further disability.     

Analysis of the clinical picture in patients with osteoarthritis of the spine depending on the type and severity of lesions on magnetic resonance imaging

Objectives

Spondyloarthritis is the most common pathological change in the spine. In a significant number of cases, it leads to compression of the nervous structures of the spinal canal, causing pain and neurological symptoms. Intervertebral disc pathology is a common cause of root deficits in neurological examination of all types of degenerative changes of the spine structures. Disc herniation is pathologically divided into 4 stages of herniated nucleus pulposus: 1) bulging, 2) protrusion, 3) extrusion, 4) sequestration. The aim of this study is to analyze the correlation between the type and severity of degenerative changes in the spine and the incidence of neurological deficits.

Material and methods

The study included 100 patients: 74 men and 26 women aged 50.2 ±10.43 years with pain of the spine in the cervical and/or lumbosacral segments and with degenerative changes in the plain radiographs. The mean value of body mass index (BMI) was 27.8 ±3.95 kg/m². Each patient underwent neurological examinations and 1.5 T magnetic resonance imaging MRI of the cervical and/or lumbar spine.

Results

Every patient was diagnosed with herniated nucleus pulposus affecting on average 4 ±2 segments of the spine. The most frequently observed degree of severity of disc herniation was the second (protrusion, 71.9% of all disc disease in 89 patients). Much less frequently found was the third degree (extrusion, 45 patients, 20.1% slipped disc), the first (bulging, 14 patients, 6.3% slipped disc), and least often only a small percentage of fourth degree (sequestration, 4 patients, 1.7% slipped disc). Neurological symptoms (deficits) were observed in 34 patients. They were accompanied by disc herniations in 23.7% of patients. In remaining patients with neurological deficits there was spinal stenosis. No correlation was observed between neurological deficits and stage 1 of disc herniation.

Conclusions

The incidence rate of neurological deficits is correlated with the degree of changes in the spine, as visualized by MRI.     

Thoracic disc herniation leads to anterior spinal artery syndrome demonstrated by diffusion-weighted magnetic resonance imaging (DWI): a case report and literature review

BackgroundThoracic disc herniation rarely causes acute ischemic events involving the spinal cord. Few reports have suggested this as a mechanism leading to anterior spinal artery syndrome, and none with illustration through diffusion-weighted magnetic resonance imaging (DWI).PurposeThe purpose of this study was to report a case of anterior spinal artery syndrome secondary to thoracic disc herniation and demonstrate the first use of DWI to aid in diagnosis of this rare myelopathy.Study designCase report.MethodsA 36-year-old woman developed sudden onset of back pain followed by evolving paraparesis and sensory loss consistent with anterior spinal artery distribution ischemia. T2-weighted magnetic resonance imaging (MRI) demonstrated an acute herniated nucleus pulposus at the T7–T8 disc, which produced a focal indentation of the adjacent anterior spinal cord without cord displacement or canal stenosis. T2-weighted hyperintensities were seen at T4–T7 levels with corresponding brightness on DWI and reduction of the apparent diffusion coefficient, consistent with cord ischemia.ResultsRemarkably, within just a few days and following conservative treatment, including heparin and steroids, this patient's neurologic status began to show improvement. Within 3 weeks, she was ambulating with assisted devices, and at the 10-month follow-up, the patient had nearly complete neurological improvement. A follow-up MRI at 10 months showed normal T2-weighted imaging except for a 1×2-mm area of anterior-left lateral cord myelomalacia at T4–T5.ConclusionsAcute thoracic disc herniation with cord contact but without canal stenosis is able to disrupt blood flow to the cord leading to anterior spinal artery distribution ischemia. This case represents the first demonstrated use of DWI in diagnosing this rare cause of anterior spinal artery ischemia.     

“菱形”截骨切除脊髓前方致压物治疗硬化性胸及胸腰段椎间盘突出症

目的:探讨经后路"菱形"截骨切除脊髓前方致压物治疗硬化性胸及胸腰段椎间盘突出症的临床疗效。方法:2009年8月~2014年7月,共收治26例硬化性胸及胸腰段椎间盘突出症患者,男19例,女7例;年龄平均43.8±23.3岁(18~70岁)。19例为胸椎间盘突出,包括胸椎间盘突出并钙化14例,胸椎后缘骨赘5例;7例为胸腰段椎间盘突出并钙化。术前神经功能Frankel分级:B级3例,C级14例,D级9例。手术均采用经后路"菱形"截骨切除脊髓前方致压物。手术疗效评价参照改良Macnab疗效评定标准及Frankel分级,随访观察治疗效果。结果:手术均顺利完成,术后X线片显示内固定位置良好,CT显示突出物切除彻底。1例患者(T10/11)术后出现症状加重(Frankel分级由D级变为C级),经甲强龙、脱水剂、营养神经药物治疗后恢复至术前水平。随访5~36个月,平均19.8个月。24例患者术后神经功能获不同程度恢复(2例Frankel D级患者无变化)。根据改良Macnab疗效评定标准,本组优15例,良8例,可2例,差1例,优良率88.46%(23/26),总有效率96.15%(25/26)。所有患者均获得骨性融合,无内固定松动断裂等并发症发生。结论:经后路"菱形"截骨切除脊髓前方致压物治疗硬化性胸及胸腰段椎间盘突出症可获得满意疗效。     

Thoracic disc herniation. Improved diagnosis with computed tomographic scanning and a review of the literature

Thoracic disc herniation is uncommon. One of the main problems in the treatment of thoracic disc herniation has been the lack of accuracy of diagnostic tests. Now, with the use of computed tomographic scanning with and without metrizamide in the subarachnoid space, this accuracy has greatly improved. Computed tomography scanning can demonstrate the type and level of the lesion even when the myelographic study is negative. We have reviewed 280 cases; a peak incidence was noted in the fourth decade with 75% of the protruded discs occurring below T-8. Back pain was the most common presenting symptom followed by sensory disturbances. By the time of diagnosis, 70% of the patients had signs of spinal cord compression. A small group of patients could be identified that invariably had a good prognosis. They had a history of trauma, symptoms lasting less than a month, and soft disc herniation. Regarding the results of surgical treatment, there was a success rate ranging from 57% for decompressive laminectomy to over 80% for the posterolateral, lateral, and transthoracic approaches.     

大段复合骨移植修复胸腰椎椎体肿瘤切除后骨缺损的临床应用

目的:评价胸腰椎椎体肿瘤切除后应用大段复合骨移植修复脊柱骨缺损的效果。方法:对36例胸腰椎椎体肿瘤患者行病椎全切或部分切除,采用大段复合骨(异体皮质骨段复合重组合异种骨)移植填充骨缺损,并结合内固定系统重建脊柱稳定性,评价其临床治疗效果。结果:33例患者获5~100个月(平均47个月)随访,植骨后无排异、感染、植骨塌陷等并发症,其中31例术后3~7个月(平均4.3个月)获骨性愈合,2例内植物松动。结论:胸腰椎椎体肿瘤椎体全切或部分切除后,采用大段复合骨移植结合内固定系统行脊椎前柱稳定性重建可达到早期脊柱稳定支撑和后期植骨融合固定的效果。     

胸椎后纵韧带骨化症术后临床疗效及其相关因素分析

目的：探讨胸椎后纵韧带骨化症减压融合术后的临床疗效及其相关因素。方法：2000年1月一2011年1月,我院共收治胸椎后纵韧带骨化症患者64例,其中男39例,女25例,年龄42。67岁,平均54．1岁。采用后路椎板广泛切除、减压、植骨融合治疗者36例,采用前路减压、植骨融合治疗者12例,后外侧经关节突减压植骨融合者9例,前后路联合减压植骨融合者7例。评估患者的年龄、病程、影像学表现、病变类型、手术方式、术前合并疾患,及术后并发症和手术疗效的关系。手术疗效采用JOA评分及其改善率进行判定。结果：所有患者均获得随访,平均随访时间4．6年（1—12年）。术前平均JOA评分为（4．5±1．9）分,末次随访时（7．8±2．1）分,平均改善率为（48．4±38．1）％。后路椎板广泛切除、减压、植骨融合组为（37．6±36．8）％,前路减压、植骨融合组为（62．9±32．6）％,后外侧经关节突减压植骨组为（30．8±29．2）％,前后路联合减压植骨融合组为（59．5±39．1）％。患者的术前病程、年龄、手术方式,、MRI检查T2WI信号改变,及是否合并糖尿病对术后疗效有显著影响（P〈0．05）。30例（46．9％）患者合并术后1种或多种并发症：17例患者术后神经功能恶化,12例患者合并脑脊液漏,3例患者硬膜外血肿形成,5例合并肺部感染。结论：对于胸椎后纵韧带骨化症外科治疗可以获得较好的疗效,患者术前病程、年龄、手术方式、MRI检查T2WI信号改变,及是否合并糖尿病是影响手术疗效的主要因素。     

Familial ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine: case report

BACKGROUND

Ossification of the posterior longitudinal ligament (OPLL) of the spine is most common in the Japanese population and in the cervical spine. We present a case of OPLL of the lower thoracic spine in two Caucasian siblings.

CASE DESCRIPTION

A 58-year-old female presented with lower extremity dysesthesia and urinary hesitancy. Family history was significant for a brother who had OPLL of the lower thoracic spine removed surgically. Magnetic resonance imaging and computed tomography scan of the thoracic spine demonstrated OPLL at T10–11 causing cord compression and abnormally high T2 signal in the cord. The patient underwent posterior decompression with improvement of her symptoms.

CONCLUSION

A genetic predisposition to develop OPLL has been suggested by previous linkage and biochemical studies. While OPLL is an increasingly recognized diagnosis in North America, this is the first reported case of familial thoracic OPLL in Caucasian siblings.     

Normal morphology, age-related changes and abnormal findings of the cervical spine. Part II: magnetic resonance imaging of over 1,200 asymptomatic subjects

Purpose

The aim of this study is to establish standard MRI values for the cervical spinal canal, dural tube, and spinal cord, to evaluate age-related changes in healthy subjects, and to assess the prevalence of abnormal findings in asymptomatic subjects.

Methods

The sagittal diameter of the spinal canal and the sagittal diameter and cross-sectional area of the dural tube and spinal cord were measured on MRIs of 1,211 healthy volunteers. These included at least 100 men and 100 women in each decade of life between the third (20s) and eighth (70s). Abnormal findings such as spinal cord compression and signal changes in the spinal cord were recorded.

Results

The sagittal diameter of the spinal canal was 11.2 ± 1.4 mm [mean ± standard deviation (SD)]/11.1 ± 1.4 mm (male/female) at the mid-C5 vertebral level, and 9.5 ± 1.8/9.6 ± 1.6 mm at the C5/6 disc level. The cross-sectional area of the spinal cord was 78.1 ± 9.4/74.4 ± 9.4 mm² at the mid-C5 level and 70.6 ± 11.7/68.9 ± 11.3 mm² at the C5/6 disc level. Both the sagittal diameter and the axial area of the dural tube and spinal cord tended to decrease with increasing age. This tendency was more marked at the level of the intervertebral discs than at the level of the vertebral bodies, especially at the C5/6 intervertebral disc level. The spinal cord occupation rate in the dural tube at the C5 vertebral body level averaged 58.3 ± 7.0%. Spinal cord compression was observed in 64 cases (5.3%) and a T2 high-signal change was observed in 28 cases (2.3%).

Conclusions

Using MRI data of 1,211 asymptomatic subjects, the standard values for the cervical spinal canal, dural tube, and spinal cord for healthy members of each sex and each decade of life and the age-related changes in these parameters were established. The relatively high prevalence of abnormal MRI findings of the cervical spine in asymptomatic individuals emphasizes the dangers of predicating operative decisions on diagnostic tests without precisely correlating these findings with clinical signs and symptoms.