神经根性腿痛是一种退行性腰椎疾病的典型症状，由多种不同的病理引起的神经根压迫或刺激所致，准确地了解病理损害神经根是获得较好的治疗措施。
Radicular pain inthe leg, a representative symptom of degenerative lumbar spine diseases,results from nerve root compression or irritation at various locations bydiverse pathologies. An accurate understanding of the pathology compromisingthe nerve root is essential to obtain good surgical outcomes5).
磁共振成像(MRI)无创、无辐射，对软组织分析的优越，通常用于诊断腿部疼痛的诊断，计算机断层摄影(CTM)可提供高质量的骨或钙化病灶图像，并在较薄的影像切片中提供高分辨率的影像，不受金属植入物的影响，但可能存在腰椎穿刺、静脉造影剂注射和辐射暴露有关并发症;目前认为CTM比MRI更不精确。
Magneticresonance imaging (MRI) is commonly used for diagnostic imaging of radicularpain in the leg because of its noninvasiveness, no radiation exposure, andsuperiority of soft tissue analysis. MRI is also recognized as the mostaccurate imaging study7,8,15). Computed tomography-myelography (CTM),another common imaging modality, can provide good quality images of bone orcalcified lesions, and deliver an image with high spatial and contrastresolution in thinner imaging slices even when metallic implants are present10,23). Currently, its use has been limitedbecause it entails potential complications related to lumbar puncture,intrathecal contrast injection, and radiation exposure; it is considerably moreinvasive and risky than MRI; and it is recognized as a less accurate imagingstudy than MRI.
MRI通常用于外科治疗退行性脊髓疾病的最终决策。然而，一些临床医生认为，CTM比MRI更有价值，用于鉴别单纯的钙和骨化的椎间盘的鉴别诊断，以确认各种腰退行性疾病的骨化变化，以及诊断为一腿骨疼痛的主要病理的诊断)。从手术的角度看，了解哪种方法更准确、更有效地确认病理是很重要的。作者认为CTM的临床意义不被重视，并对CTM的诊断价值进行了回顾性的评估，与MRI在临床意义上的主要症状的临床表现的主要症状相比，由于保守的治疗失败而需要手术治疗。
MRI is routinelyused in final decision making for surgical treatment of degenerative spinaldiseases. However, some clinicians believe that CTM is more valuable than MRIfor differential diagnosis between pure and calcified/ossified disc materials,to confirm bony changes in various lumbar degenerative diseases and in thediagnosis of the main pathology of radicular pain in a leg23). From a surgical standpoint, it isimportant to know which method is more accurate and efficient in confirming thepathology. The authors considered the possibility that the clinicalsignificance of CTM has been underemphasized and retrospectively evaluated thediagnostic value of CTM in comparison with that of MRI in patients with themain symptom of clinically significant radiculopathy that required surgicalmanagement because of conservative treatment failure.
91名由退化性腰脊髓疾病引起的长期单侧性腿疼痛的患者，患有椎间盘突出症的患者(n=73)和侧隐窝狭窄(n=18)。所有的患者均采用术前测定肌电图(EMG)、疼痛评分、MRI和CTM，术中证实神经根病变。
The studyincluded 91 consecutive patients presenting with intractable unilateralradicular leg pain caused by degenerative lumbar spinal disease who fulfilledthe inclusion criteria between February 2012 and January 2013. The studyincluded only patients with herniated nucleus pulposus (n=73) and lateralrecess stenosis (n=18). All the patients were evaluated by using preoperativeelectromyography (EMG) study, visual analog scale (VAS) score for pain, MRI,and CTM, and nerve root compromise was confirmed in the operative field. Duringthe above-mentioned period, CTM was routinely used for patients who werescheduled to undergo surgery for degenerative lumbar spinal disease in theauthors’ institute. This study was approved by the institutional review boardof the authors’ institute, and because of the retrospective nature of thestudy, the need for informed consent was waived.
排除标准：1椎管狭窄和椎间孔狭窄的病人，椎间孔狭窄的诊断是基于T1矢状图上的脂肪信号的丢失，对矢状面和轴向图像的分级不具有统计学意义，对轴向图像的根压缩程度进行了分类，中央管狭窄的主要症状是间歇性跛行，而特定的神经根不能代表一种主要的致病性结构。2感染病例，3硬膜外注射史的病例。因为这些可能会导致影像的改变，而不是退化性的变化。表1列出了患者的人口统计数据。
Patients with central canal stenosispresenting with claudication as the major symptom and patients withintervertebral foraminal stenosis were excluded. Generally, intervertebralforaminal stenosis is diagnosed based on a loss of fat signal on T1 sagittalimages rather than on axial images3,24). As a comparison between gradingsagittal and axial images cannot be given statistical significance and thedegree of root compression on axial images was classified in the present study,cases with intervertebral foraminal stenosis were excluded. Patients withcentral canal stenosis were also excluded because the main symptom in centralcanal stenosis is claudication, and a specific nerve root cannot represent amajor causative structure for claudication. Infection cases, revision cases, andcases with an epidural injection history were also excluded, as these can causechanges in imaging other than degenerative changes. The demographic data of thepatients are listed in Table 1.
一般情况
术前症状侧的神经根的轴位MRI和CTM扫描，根据严重程度病理程度分为四级0级：没有神经根受压(根映像是可视化); I级：神经根被激惹;II级：神经根移位或变形;III级：确定的神经根被压缩。
The root imageson the preoperative axial MRI and CTM scans of the symptomatic side at thepathological level were classified into four grades according to the severityof nerve root compression by modifying a previous grading system as follows:grade 0, no nerve root compression (root image is well visualized); grade I, nerveroot is abutted or contacted; grade II, nerve root is displaced or deformed;and grade III, definite root compression or completely nonvisualized (flattenedor obliterated) root image1
MRI神经根图像的分级
脊髓造影断层摄影神经根图像的分级
突出的髓核和侧隐窝狭窄神经根图像的分级。
A：不激惹神经根(0)级。B:神经根毗邻但不显示任何激惹或变形的迹象(I级)。C:神经根移位,压缩变形(II级)。D:明确的神经根受压的神经根(III级)。E: 侧隐窝无激惹神经根(0)级。F:三侧隐窝三叶草形态变化 (I级)。G: 侧隐窝变尖(II级)。H: 侧隐窝三叶草形缩小, 神经根移位及变形(II级)。I: 侧隐窝夹角变尖, 神经根移位机变形 (II级)。J:严重的侧隐窝夹角变尖,扁平的神经根(III级)。K: 侧隐窝不见神经根(III级)。
Gradingof nerve root images in the herniated nucleus pulposus and lateral recessstenosis. A: No compromise of the nerve root (grade 0). B: The nerve root isabutted but does not show any signs of deviation or deformation (grade I). C:The nerve root is displaced (deviated) and deformed by compression (grade II).D: Definite nerve root compression with the nerve root completely nonvisualized(grade III). E: No compromise of the nerve root in the lateral recess (grade0). F: Trefoil-shape change of the lateral recess (grade I). G: Early acuteangular narrowing of the lateral recess (grade I). H: Trefoil-shape narrowingof the lateral recess, and displaced (deviated) and deformed nerve root (gradeII). I: Angular pinch-like narrowing of the lateral recess, and displaced(deviated) and deformed nerve root (grade II). J: Severe angular pinch-likenarrowing of the lateral recess and flattened nerve root (grade III). K: Theroot image is completely nonvisualized in the lateral recess (grade III).
两名经验丰富的盲临床信息神经外科医生评估所有影像学资料，其中一位外科医生在两周后对图像进行了重新评估。以避免其记忆效应。对两种不同的观测结果进行了比较，统计观察者之间及同一观察者之间的差异。
Two experienced neurosurgeons evaluated theresults of all the imaging studies while blinded to the patients’ clinicalinformation. One of the surgeons performed a retest of the images after 2weeks. Any bias that might have occurred because of the memory effect shouldhave been minimized by the delay of 2 weeks between the two readings. Theresults of each imaging modality by two different observers were compared, andthe interobserver and intraobserver variances were calculated.
分析术前VAS评分和EMG以比较核磁共振成像和CTM的神经根压缩评分的相关性，使用接收-操作特性(ROC)曲线在核磁共振的根压缩等级与临床特征进行回顾性分析。VAS评分和EMG作为临床参数。同样对CTM的根压缩等级与临床特征(VAS和EMG)进行相关性分析。
Preoperative VAS scores and EMG results wereanalyzed to compare their relationships with the nerve root compression gradesmeasured on MRI and CTM. For this purpose, the receiver-operatingcharacteristic (ROC) curve was used. Correlation analyses between rootcompression grades on MRI and clinical features were performed retrospectivelyby using a ROC curve. VAS score and EMG result were used as clinicalparameters. In the same way, Correlation analyses between root compressiongrades on CTM and clinical features (VAS score and EMG result) were performed.
ROC曲线的相关性分析中与临床特征一致的EMG结果为1，与临床特征不匹配的结果为0。肌电图的结果由神经生理学家记录和临床评估。当观察到在休息异常肌电活动(纤维性颤动，正波，或高频率重复放电)或在高水平下神经原性模式 (运动单元动作电位更少)，可确定神经根病变。
For the correlation analyses using ROC curves, EMGresults that were congruent with clinical features were set at 1, and theresults that did not match the clinical features were set at 0. EMG (MedelecSynergy; Cardinal Health, Surrey, UK) results were recorded and clinicallyassessed by a neurophysiologist. When abnormal activity on EMG at rest (fibrillation,positive sharp waves, or high-frequency repetitive discharge) or neurogenicpatterns at maximum effort (fewer motor unit action potentials at high levels)were observed, radiculopathy was defined6,19).
VAS评分小于6设为0，VAS评分大于5设为1。作者为神经根病的诊断标准设定大于6VAS评分标准，并将其划分为在ROC分析中获得最佳的诊断值(在曲线下的曲线0.691，灵敏度77.6，特异性62.5)。
VASscores of <6 were set at 0, and VAS scores of >5 were set at 1. Theauthors set a VAS score of ≥6 as the diagnostic criterion for radiculopathy, and the divisionwas made to achieve the optimal diagnostic value (area under the curve [AUC]0.691, sensitivity 77.6, specificity 62.5) in the ROC analysis11,17).
我们通过图表回顾来确定并发症的发生率和并发症细节。记录患者年龄、性别、诊断、手术治疗、神经根受压原因、并存症和与手术相关的并发症。采用3-特斯拉系统MRI;西门子CT，采用200*200毫米的视野和4毫米厚的薄片厚度，得到T2加权MRI扫描。
Weidentified the complication rate and details of the complications by performinga chart review. Patient age, sex, diagnosis, surgical treatment, the cause ofroot compression, comorbidities, and procedure-related complications wererecorded. For MRI, 3-Tesla systems (Magnetom Verio 3T; Siemens, Berlin, Germany)were used; for CT, Somatom Definition AS (Siemens, Berlin, Germany) was used.T2-weighted axial MRI scans (TR/TE/NEX/FA, 4700/71 ms/2.0/160°) obtained byusing a 200×200-mm field of view and 4-mm slice thickness were used for thisanalysis.
2位神经外科医生采用22-25号穿刺针使用12毫升的非离子水溶性造影剂，在X线引导下于L4-5水平实施脊髓造影术，在脊髓造影术后，立即进行CT成像。
Themyelography procedure was performed by 2 neurosurgeons with a 22- to 25-gaugestyletted spinal needle using 12 mL of nonionic water-soluble contrast medium(Visipaque; GE Healthcare, Cork, Ireland) at the L4–L5 level under fluoroscopicguidance. CT imaging was performed as soon as possible after the myelographyprocedure.
统计验证是由PASW统计版本18.0，p值小于0.05，在统计学差异有显著意义。患者群体的一般特征采用卡方试验和t-检验法进行了析。McNemar用于检查CTM和MRI等级之间的相关性。同时记录相关的并发症。
Statisticalverification was determined using PASW Statistics version 18.0 (SPSS Inc.,Chicago, IL, USA) and MedCalc version 12.0 (MedCalc, Mariakerke, Belgium). Ap-value of <0.05 was considered statistically significant. The chi-squaretest and t-test were used to analyze the general characteristics of the patientgroups. McNemar’s test was utilized to check for an association between CTM andMRI grades. Procedure-related complications were also recorded.
结果
核磁共振轴位扫描的神经根压分级显示0%为0级，30.8%为I级，38.5%为II级，30.8%为III级。而CTM轴向扫描的神经根压分级显示，0%为0，2.2%为I级，30.8%为II级，67%为III级。从统计学意义上来说，组内和组间平均系数都是显著的差异(表3)。
RESULTS
Gradingof the nerve root compression on the MRI axial scans showed that among thecases, 0% was grade 0, 30.8% were grade I, 38.5% were grade II, and 30.8% weregrade III. On the other hand, grading of the nerve root compression on the CTMaxial scans showed that among the cases, 0% was grade 0, 2.2% were grade I,30.8% were grade II, and 67% were grade III. The mean intraclass coefficientsof both intrarater and interrater reliability were statistically significant(Table 3).
在54%的病例,两个不同的评分结果发现在相同的病人,1个从核磁共振和其他的从CTM(表4)。使用McNemar检验法的测试CTM与MRI的一致性,结果显示两种诊断方法并没有显示诊断的一致性(p < 0.0001)。CTM比MRI更容易识别出更高等级的神经根受压。
In 54% of the cases, two different grading resultswere found in the same patient, one from MRI and the other from CTM (Table 4). The diagnostic concurrence betweenCTM and MRI grades was confirmed by using McNemar’s test, which revealed thatthe two diagnostic modalities did not show diagnostic concurrence of the studyresults (p<0.0001). CTM tended toidentify higher grades of nerve root compression than did MRI.
ROC曲线分析MRI /CTM的等级和肌电图相关性，结果表明,肌电图结果与MRI等级或CTM等级之间无相关性(图4)。曲线之间的分析基于疼痛程度评分的MRI /CTM与疼痛程度显示CTM等级变化的相关性明显优于核磁共振(p = 0.0007;图5)。
The ROC curves for analyses between MRI/CTM gradesand EMG results revealed that EMG results did not correlate with changes in MRIor CTM grades (Fig. 4). The ROC curves for analyses betweenMRI/CTM grades and pain severity based on VAS score revealed that VAS severitywas more highly correlated with changes of the grades on CTM than with those onMRI (p=0.0007; Fig. 5).
A: Receiver-operating characteristic (ROC) curve for electromyography(EMG)-computed tomography-myelography (CTM) grading; the area under the curve(AUC) is 0.497, indicating no association between the EMG results and grades onCTM. B: ROC curve for EMG-magnetic resonance imaging (MRI) grading; the AUC is0.567, indicating no association between the EMG results and grades on MRI.
A: Receiver-operating characteristic (ROC) curve for visual analog scale(VAS) score-computed tomography-myelography (CTM) grading; the area under thecurve (AUC) was 0.691, indicating an moderate association between VAS score andgrade on CTM. B: The ROC curve for VAS score-magnetic resonance imaging (MRI)grading; the AUC is 0.598, indicating less association between VAS score andgrade on MRI.
A:Preoperative magnetic resonance imaging (MRI) T2 and computedtomography-myelography (CTM) axial scans showing differences in rootcompression finding. While the finding is grade I on the MRI axial scan, thefinding is grade III on CTM. Grade I on MRI generally means less significantradicular pain that does not require surgical intervention. However, grade IIIon CTM generally means severe root compression that requires decompressivesurgery. B: CTM axial scan showing severe left L5 root compression byobliteration of the nerve root not detectable on MRI axial scan. While grade IIon MRI generally indicates a moderate degree of root compression, grade III onCTM generally means severe root compression that requires decompressivesurgery. Grade III on CTM is congruent with the patients’ clinical symptoms(severe radicular pain with a VAS score of 8).
结论
研究表明CTM与临床症状更密切相关，并且在同一病人身上表现出比MRI更有积极的意义，在神经根性病变患者CTM在发现神经根受压的程度可能比MRI更有价值。当MRI不能提供足够的信息来确定腰神经根病患者的根性疼痛的确切原因时，CTM可能是诊断性诊断的有用工具。虽然CTM的大部分并发症都是轻微和短暂性的，但CTM的创伤性和潜在的并发症，如低颅内压综合征，应该进一步研究。
CONCLUSION
Thepresent study demonstrates that CTM correlated more closely with clinicalsymptoms and tended to demonstrate more aggressive findings in the same patientthan MRI. The results indicated that CTM might be more valuable than MRI indefining the severity of nerve root compression in patients with radiculopathy.In this regard, CTM can be a useful tool for confirmative diagnosis when MRIdoes not provide sufficient information to define an exact cause of radicularpain in patients with lumbar radiculopathy. Although most of the complicationsof CTM were mild and transient, with clinically insignificant symptoms, theinvasiveness and potential complications of CTM, such as low intracranialpressure syndrome, should be investigated further.
References