MR image-based grading of lumbar nerve root compromise due to disk herniation: reliability study with surgical correlation

A system for grading lumbar nerve root compromise (no compromise, contact of disk material with nerve root, deviation of nerve root, and compression of nerve root) was tested in the interpretation of routine magnetic resonance images of 500 lumbar nerve roots in 250 symptomatic patients. Intra- and interobserver reliability was assessed for three independent observers. In the 94 nerve roots evaluated at surgery, surgical grading was correlated with image-based grading. kappa statistics indicated substantial agreement between different readings by the same observer and between different observers (for intraobserver agreement, kappa = 0.72-0.77; for interobserver agreement, kappa = 0.62-0.67). Correlation of image-based grading with surgical grading was high (r = 0.86). The image-based grading system enabled reliable evaluation and reporting of nerve root compromise.     

Observer variation in MRI evaluation of patients suspected of lumbar disk herniation

OBJECTIVE: Our objective was to assess observer variation in MRI evaluation in patients suspected of lumbar disk herniation. SUBJECTS AND METHODS: Two experienced neuroradiologists independently evaluated 59 consecutive patients with lumbosacral radicular pain. Per patient, three levels (L3-L4 through L5-S1) and the accompanying roots were evaluated on both sides. For each segment, the presence of a bulging disk or a herniation and compression of the root was reported. Images were interpreted twice: once before and once after disclosure of clinical information. Interobserver agreement was expressed as unweighted kappa values. RESULTS: Without clinical information, interobserver agreement for the presence of herniation or bulging disk was moderate (full agreement, 84%; kappa = 0.63; 95% confidence interval [CI], 0.53-0.72). Of a total of 352 segments evaluated, there was disagreement on 58 segments (17%): bulging disk versus no defect in 26 (7.4%), bulging disk versus herniation in five (1.4%), and hernia versus no defect in 27 (7.7%). With clinical information, twice as many bulging disks were reported but no new herniations were detected. Agreement slightly decreased, but not significantly (full agreement, 77%; kappa = 0.59; 95% CI, 0.49-0.69; p = 0.12). CONCLUSION: On average, more than 50% of interobserver variation in MRI evaluation of patients with lumbosacral radicular pain is caused by disagreement on bulging disks. Knowledge of clinical information does not influence the detection of herniations but lowers the threshold for reporting bulging disks.     

螺旋CT多层面重建(MPR)在腰椎间盘病变诊断中的应用价值

目的　探讨螺旋CT多层面重建 (MPR)对腰椎间盘病变的诊断价值。方法　经常规扫描和螺旋扫描MPR重建腰椎间盘病变患者共 41例 ,对L3～ 4 、L4～ 5和L5～S1扫描所得结果进行对比观察。结果　 41例经常规扫描患者中有 35例表现为椎间盘膨出或/和突出 ,经螺旋CT扫描MPR重建示有 36例表现为神经根受压、硬膜囊受压或椎间孔骨性狭窄 ,其中常规扫描无异常发现的 6例患者 ,经MPR示椎间盘压迫神经根或椎间孔骨性狭窄致神经根受压。结论　MPR重建在诊断腰椎间盘病变、显示腰椎疾病的原因以及腰椎疾病的鉴别诊断等方面具有重要价值     

Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

ObjectiveTo assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI).ResultsThe interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI.ConclusionMultidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI.     

直立位椎管造影对腰椎间盘突出的诊断价值

目的　评价直立位椎管造影对腰椎间盘突出的诊断价值。方法　经CT或MRI诊断的腰椎间盘突出 196例术前进行直立位椎管造影检查。结果　直立位椎管造影的诊断结果与CT或MRI基本符合 ,但有 7例直立位椎管造影发现L4～ 5椎间盘突出并伴有神经根受压 ,而CT或MRI未能显示。结论　直立位椎管造影对腰椎间盘突出的诊断可能优于CT或MRI ,尤其对L4 5椎间盘突出伴有神经根受压的病例。     

Low-field magnetic resonance imaging of the lumbar spine: reliability of qualitative evaluation of disc and muscle parameters

Purpose: To determine the intra- and interobserver reliability in grading disc and muscle parameters using low-field magnetic resonance imaging (MRI).

Material and Methods: MRI scans of 100 subjects representative of the general population were evaluated blindly by two radiologists. Criteria for grading lumbar discs were based on the spinal nomenclature of the Combined Task Force and the literature. Consensus in rating was achieved by evaluating 50 MRI examinations in tandem. The remaining 50 examinations were evaluated independently by the observers to determine interobserver agreement and re-evaluated by one of the observers to determine intra-observer agreement.

Results: Intra- and interobserver agreement was substantial when grading changes in the lumbar discs. Interobserver agreement was fair to moderate in grading the lumbar muscles, whereas intra-observer agreement was almost perfect.

Conclusion: Convincing reliability was found in the evaluation of disc- and muscle-related MRI variables.     

Traumatic extra-axial hemorrhage: correlation of postmortem MSCT, MRI, and forensic-pathological findings

PURPOSE: To evaluate the diagnostic accuracy of in situ postmortem multislice computed tomography (MSCT) and magnetic resonance imaging (MRI) in the detection of primary traumatic extra-axial hemorrhage. MATERIALS AND METHODS: Thirty forensic neurotrauma cases and 10 nontraumatic controls who underwent both in situ postmortem cranial MSCT and MR imaging before autopsy were retrospectively reviewed. Both imaging modalities were analyzed in view of their accuracy, sensitivity, and specificity concerning the detection of extra-axial hemorrhage. Statistical significance was calculated using the McNemar test. kappa values for interobserver agreement were calculated for extra-axial hemorrhage types and to quantify the agreement between both modalities as well as MRI, CT, and forensics, respectively. RESULTS: Analysis of the detection of hemorrhagic localizations showed an accuracy, sensitivity, and specificity of 89%, 82%, and 92% using CT, and 90%, 83%, and 94% using MRI, respectively. MRI was more sensitive than CT in the detection of subarachnoid hemorrhagic localizations (P = 0.001), whereas no significant difference resulted from the detection of epidural and subdural hemorrhagic findings (P = 0.248 and P = 0.104, respectively). Interobserver agreement for all extra-axial hemorrhage types was substantial (CT kappa = 0.76; MRI kappa = 0.77). The agreement of both modalitites was almost perfect (readers 1 and 2 kappa = 0.88). CONCLUSION: CT and MRI are of comparable potential as forensic diagnostic tools for traumatic extra-axial hemorrhage. Not only of forensic, but also of clinical interest is the observation that most thin blood layers escape the radiological evaluation.     

Diffusion-weighted magnetic resonance imaging of symptomatic nerve root of patients with lumbar disk herniation

Introduction

Diffusion-weighted imaging (DWI) can provide valuable structural information that may be useful for evaluating pathological changes of the lumbar nerve root. Diffusion-weighted magnetic resonance (MR) neurography has recently been introduced as an alternative way to visualize nerves, but to date, quantitative DWI and MR neurography have not been applied to evaluate the pathology of lumbar nerve roots.

Methods

Our purpose was to visualize lumbar nerve roots and to analyze their morphology by MR neurography, and to measure the apparent diffusion coefficient (ADC) of lumbar nerve roots compressed by herniated disks using 1.5-T MR imaging. Ten consecutive patients (median age, 48.0 and range, 20?C72?years) with monoradicular symptoms caused by a lumbar herniated disk and 14 healthy volunteers were studied. Regions of interests were placed on the lumbar roots at dorsal root ganglia (DRG) and distal spinal nerves on DWI to quantify mean ADC values. The spinal nerve roots were also visualized by MR neurography.

Results

In the patients, mean ADC values were significantly greater in the compressed DRG and distal spinal nerves than in intact nerves. MR neurography also showed abnormalities such as nerve swelling at and below the compression in the symptomatic nerve root. Increased ADC values were considered to be because of edema and Wallerian degeneration of compressed nerve roots.

Conclusion

DWI is a potential tool for analysis of the pathophysiology of lumbar nerve roots compressed by herniated disks.     

Correlation between the MRI changes in the lumbar multifidus muscles and leg pain

AIM: In the assessment of the lumbar spine by magnetic resonance imaging (MRI), changes in the paraspinal muscles are frequently overlooked. In this study, our objective was to investigate the relationships between lumbar multifidus (MF) muscle atrophy and low back pain (LBP), leg pain and intevertebral disc degeneration. METHODS: A retrospective study of 78 patients (aged 17-72) with LBP presenting with back pain with or without associated leg pain was undertaken. Their MR images were visually analysed for signs of lumbar MF muscle atrophy, disc degeneration and nerve root compression. The clinical history in each case was obtained from their case notes and pain drawing charts. RESULTS: MF muscle atrophy was present in 80% of the patients with LBP. The correlation between MF muscle atrophy and leg pain was found to be significant (P < 0.01). However, the relationships between muscle atrophy and radiculopathy symptoms, nerve root compression, herniated nucleus pulposus and number of degenerated discs were statistically not significant.CONCLUSION: Examination of the paraspinal muscles looking for atrophy of MF muscle should be considered when assessing MR images of lumbar spine. This may explain the referred leg pain in the absence of other MR abnormalities.     

腰椎退变性滑脱症的CT诊断及临床意义

目的：探讨腰椎退变性滑脱症的ＣＴ诊断依据和对硬膜囊、神经根的影响。材料和方法：回顾性分析了５８例腰椎退变性滑脱症（前滑脱４６例，后滑脱１２例）的ＣＴ表现、好发部位及其原因。结果：滑椎下缘相邻间盘均显示有相对性前、后膨出，椎小关节均有半脱位，硬膜囊均有受压，另外，在前滑脱中因１６例椎间盘向后上方突出，２３例椎小关节突明显增生肥大而压迫神经根。结论：ＣＴ不仅能诊断腰椎退变性滑脱症，而且还能显示硬膜囊和神经根的改变。     

Asbestos-related pleural disease: value of dedicated magnetic resonance imaging techniques

OBJECTIVES: We sought to compare respiratory-gated high-spatial resolution magnetic resonance imaging (MRI) and radial MRI with ultra-short echo times with computed tomography (CT) in the diagnosis of asbestos-related pleural disease. METHODS: Twenty-one patients with confirmed long-term asbestos exposure were examined with a CT and a 1.5-T MR unit. High-resolution respiratory-gated T2w turbo-spin-echo (TSE), breath-hold T1w TSE, and contrast-enhanced fat-suppressed breath-hold T1w TSE images with an inplane resolution of less than 1 mm were acquired. To visualize pleural plaques with a short T2* time, a pulse sequence with radial k-space-sampling was used (TE = 0.5 milliseconds) before and after administration of Gd-DTPA. CT and MR images were assessed by 4 readers for the number and calcification of plaques, extension of pleural fibrosis, extrapleural fat, detection of mesothelioma and its infiltration into adjacent tissues, and detection of pleural effusion. Observer agreement was studied with the use of kappa statistics. RESULTS: The MRI protocol allowed for differentiation between normal pleura and pleura with plaques. Interobserver agreement was comparable for MRI and CT in detecting pleural plaques (median kappa = 0.72 for MRI and 0.73 for CT) and significantly higher with CT than with MRI for detection of plaque calcification (median kappa 0.86 for CT and 0.72 for MRI; P = 0.03). Median sensitivity of MRI was 88% for detection of plaque calcification compared with CT. For assessment of pleural thickening, pleural effusion, and extrapleural fat, interobserver agreement with MRI was significantly higher than with CT (median kappa 0.71 and 0.23 for pleural thickening, 0.87 and 0.62 for pleural effusion, and 0.7 and 0.56 for extrapleural fat, respectively; P < 0.05). For detection of mesothelioma, median kappa was 0.63 for MRI and 0.58 for CT. CONCLUSION: High-resolution MR sequences and radial MRI achieve a comparable interobserver agreement in detecting pleural plaques and even a higher interobserver agreement in assessing pleural thickening, pleural effusion, and extrapleural fat when compared with CT.     

Metrizamide myelography in conjoined lumbosacral nerve roots

Conjoined lumbosacral nerve roots are a congenital anomaly found at 1% of lumbar disc operations. They are usually present at the L5-S1 level and may or may not be associated with herniated intervertebral discs. Previously it had been thought that the preoperative myelogram was not helpful in diagnosis but using metrizamide myelography the diagnosis should be made more often by observing: (a) an asymmetric subarachnoid space, (b) a common axillary pouch exiting between opposite upper and lower nerve root sheaths, (c) a widened axillary pouch, and (d) two or more individual nerve roots in the axillary pouch.     

Traumatic lumbosacral nerve root meningoceles

Summary A case of traumatic lumbar meningoceles at four levels in combination with total and partial nerve root avulsion and with perservation of a nerve root is reported. Several diagnostic imaging techniques (myelography, CT, myelo-CT and MRI) are compared and their value in demonstrating the continuity of the nerve roots is discussed. MRI could assess the continuity of a nerve root in a traumatic meningocele, not demonstrable by myelography or myelo-CT. The combination of myelography, myelo-CT and MRI is likely to provide a complete diagnostic evaluation of nerve root lesions.     

Transfemoral lumbar epidural venography.

Lumbar epidural venography performed in 107 patients with normal or nondiagnostic myelograms resulted in correct preoperative diagnosis in 25 of 27 patients (92%) with herniated disc disease and three of six patients (50%) with nerve root compression without associated disc herniation. Compression or occlusion of an epidural and/or radicular vein at the disc level is the most significant venographic abnormality. Potentially confusing venographic findings such as flow defects, extravertebral veins mimicking epidural veins, and occlusion of radicular veins by the catheter must be recognized to prevent false diagnoses. Lumbar epidural venography is valuable for the diagnoses of herniated lumbar discs not demonstrated by myelography.     

螺旋CT多平面重建对极外侧型腰椎间盘突出症的诊断

目的 探讨极外侧型腰椎间盘突出症(ELLDH)在螺旋CT多平面重建(MPR)的特征表现，提高对该病的诊断率。方法 对25例ELLDH进行常规CT扫描 薄层螺旋扫描和冠状面、矢状面的MPR；25例中男18例，女7例，均经手术证实。结果 25例ELLDH MPR显示椎间盘突出部位及压迫同位节段脊神经根情况与手术所见基本相符，其中椎间孔内突出15例，椎间孔外侧突出4例，椎间孔内外突出3例，椎间孔内并同节段椎管内后外侧突出3例。其MPR特征为突入椎间孔内和椎间孔外的软组织块影，压迫同位节段脊神经根，形态多呈丘状、圆形或三角形。25例ELLDH中有7例常规CT扫描未发现ELLDH，病人再行MPR均发现ELLDH；8例常规CT扫描显示ELLDH可疑，通过MPR得到明确诊断；10例常规CT扫描虽发现ELLDH，但不能清楚显示神经根受压情况；25例ELLDH通过MPR均直接显示了神经根受压情况。结论 MPR在ELLDH的诊断中具有重要价值，能准确地提供椎间盘突出的部位、形态、大小以及与神经根的关系等解剖学信息，有助于临床医师选择手术方式。     

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.     

CT diagnosis of lumbosacral conjoined nerve roots

Summary The authors report the observations derived from CT evaluation of 19 cases of lumbosacral conjoined nerve roots; 11 of these have been confirmed by lumbar myelography and/or at surgery. They conclude that CT without intrathecal metrizamide allows the recognition in most cases of the presence of conjoined nerve roots and to differentiate them from a herniated disk fragment; this is especially useful to avoid surgical damage of anomalous roots.     

腰椎间孔镜术后复发的原因分析及对策

目的 探讨腰椎间盘突出症术后复发与腰椎间孔镜手术操作的关系,以便改进技术,减少复发概率.方法 复发的24例再次行椎间孔镜手术治疗,结合患者症状体征、术前影像检查及术中镜下情况分析复发原因.术前及术后分别进行视觉模拟评分(visual analogue scales,VAS)和Oswestry功能障碍指数(oswestry disability index,ODI)测定,比较手术前后评分变化情况.结果 24例复发率为0.86％,复发原因有纤维环医源性损伤、髓核摘除不彻底、关节突骨屑残留、终板损伤、血肿形成和神经根粘连.所有病例术后1年VAS评分2.61 ±0.19,低于术前的7.40 ±0.23,差异有统计学意义(P＜0.05);术后1年ODI评分8.53 ±0.35,低于术前的67.90±3.47,差异有统计学意义(P＜0.05).结论 术中准确定位、镜下严格按照微创理念操作,术后严密观察病情发展,及时处理有关并发症,可以有效降低腰椎间孔镜术后复发概率.     

退变性腰椎滑脱的CT分折

目的 探讨退变性腰椎滑脱的病因和CT诊断价值。方法 回顾性分析了50例退变性腰椎滑脱的CT表现，好发部位及其原因。结果 滑椎下缘相邻间盘均显示有“假性间盘脱出”征，椎间盘及椎小关节退变，椎小关节半脱位，硬膜囊受压。结论 椎间盘及椎小关节退变及韧带的松弛是本病的重要诱因，CT不仅能诊断退变性腰椎滑脱症，还能显示硬膜囊和神经根的改变。     

Observer variability based on the strength of MR scanners in the assessment of lumbar degenerative disc disease

OBJECT: aim of this study was to analyse the observer variability in the diagnosis and definition of disc pathologies with low and high-field strength MR scanners. MATERIAL AND METHODS: 95 patients with low back pain or radicular pain who were referred from two different centers were included in the study. Fifty-seven patients were scanned with 0.3 T MR (group 1) and 38 patients with 1.5 T (group 2). The intraobserver and interobserver reliability were assessed with the cappa coefficient which was characterised as follows: values less than 0.0 = 'poor' agreement, values 0.01-0.2 = 'slight' agreement beyond chance, 0.21-0.4 = 'fair' agreement, 0.41-0.60 = 'moderate' agreement, 0.61-0.80 = 'substantial' agreement and 0.81-1.00 = 'almost perfect' agreement. RESULTS: intraobserver agreement in group 1 and group 2 for both readers was 'almost perfect' in differentiating normal and pathological discs; 'substantial-almost perfect' in defining the disc pathologies, 'moderate-substantial' in root compression, and 'moderate-substantial' in spinal stenosis. Interobserver agreement was 'almost perfect' in differentiating normal and pathological discs, 'substantial' in defining disc pathologies, 'moderate' in root compression and 'moderate' in spinal stenosis in the group 1, whereas in group 2, it was 'almost perfect' in differentiating normal and pathological discs, 'almost perfect' in defining disc pathologies, 'slight-substantial' in root compression and 'moderate' in spinal stenosis. CONCLUSION: in the diagnosis of root compression and spinal stenosis, the intra and interobserver agreements were relatively poor with both high and low-strength field MRIs, indicating a need for more objective criteria. In differentiating normal and pathologic appearance of disc, the interobserver agreement was considerably better with high-field compared to low-field strength MRI. In cases where this definition is important, high-field strength scanners should be preferred.