下颈椎前纵韧带与后纵韧带损伤的MRI诊断

MRI determination of subaxial cervical anterior longitudinal ligament and posterior longitudinal ligament injury

中文关键词:  下颈椎  前纵韧带  后纵韧带  损伤  MRI

英文关键词:Subaxial cervical vertebrae  Anterior longitudinal ligament  Posterior longitudinal ligament  Injury  MRI

中文摘要:

  【摘要】　目的：探讨MRI对下颈椎前纵韧带与后纵韧带损伤的诊断标准、诊断价值，以指导临床诊断与治疗。方法：2010年8月~2011年7月87例下颈椎损伤但椎体无骨折脱位患者行前路手术，术前均行颈椎X线、CT及MRI检查。两位诊断医师分别以MRI T1加权像低信号带连续中断（T1D）、T2加权像纵形高信号（T2L）、T2加权像横形高或中等信号（T2T）作为标准诊断前纵韧带、后纵韧带损伤。术中仔细探查韧带损伤（韧带完全或部分断裂）情况，并将不同MRI标准的诊断结果与术中所见进行比较。诊断者间的一致性采用Kappa检验。以术中所见作为金标准，计算不同MRI标准诊断前纵韧带、后纵韧带损伤的敏感性、特异性、准确性、阳性预测值及阴性预测值。结果：以T1D为标准判断前、后纵韧带损伤时，两诊断者间一致程度差（Kappa值分别为0.152、0.238），敏感性（57.4%～67.2%、64.7%～64.7%）、特异性（43.3%～60.8%、56.5%～59.7%）、准确性（48.7%～63.3%、58.2%～60.8%）、阳性预测值（38.9%～51.9%、29.0%～30.6%）及阴性预测值（61.8%～74.7%、81.4%～86.1%）均较低。以T2L为标准诊断前、后纵韧带损伤时，两诊断者间一致程度较好（Kappa值分别为0.657、0.607），特异性也较高（78.4%～80.4%、88.7%～90.4%），但敏感性较低（54.1%～65.8%、29.4%～50%），准确性（70.3%～73.4%、75.9%～84.8%）、阳性预测值（63.5%～65.8%、41.7%～70.8%）及阴性预测值（73.6%～78.4%、82.1%～87.3%）也较低。以T2T为标准诊断前、后纵韧带损伤时，两诊断者间一致程度非常好（Kappa值分别为0.837、0.799），且有较高的敏感性（83.6%～86.9%、82.4%～88.2%）、特异性（91.8%～95.9%、90.3%～91.9%）、准确性（89.9%～91.1%、89.9%～89.9%）、阳性预测值（86.9%～92.7%、71.4%～73.7%）及阴性预测值（90.3%～91.8%、95.0%～96.6%）。结论：以MRI的T2T为标准诊断下颈椎前、后纵韧带完全或部分断裂较准确可靠，有助于评价下颈椎的稳定性。

英文摘要:

  【Abstracts】　Objectives:　To investigate the diagnostic value and criteria of magnetic resonance imaging(MRI) in detecting subaxial cervical anterior longitudinal ligament(ALL) and posterior longitudinal ligament(PLL) injury and responsive management.　Methods: From August 2010 to July 2011, 87 patients with subaxial cervical spinal injury and without vertebral fracture or dislocation underwent anterior surgical stabilization.　X-ray, computed tomography(CT) and MRI were performed in all patients pre-operatively. MRI features of discontinuity on sagittal T1-weighted image(T1D),　longitudinal high signal intensity on sagittal T2-weighted image(T2L),transversal high or intermediate signal intensity on sagittal T2-weighted image(T2T) were used to assess the status of ALL and PLL by two physicians. During the operation, ALL and PLL were carefully examined.　The MRI results were compared with surgical findings.　Inter-observer agreement for each assessment was determined using the Kappa statistic. The sensitivity, specificity, accuracy, positive and negative predictive values of different MRI features in detection of ALL and PLL injury were calculated, and the operative finding was used as the gold standard.　Results:　Inter-observer agreement of T1D for the assessment of ALL and PLL injury was poor or fair(Kappa value =0.152, 0.238), and the sensitivity(57.4%-67.2%, 64.7%-64.7%), specificity(43.3%-60.8%, 56.5%-59.7%), accuracy(48.7%-63.3%, 58.2%-60.8%), positive predictive value(38.9%-51.9%, 29.0%-30.6%) and negative predictive value(61.8%-74.7%, 81.4%-86.1%) of T1D by comparing with the operative finding were low. For T2L, the inter-observer agreement was good(Kappa value =0.657, 0.607), and high specificity by comparing with the operative finding(78.4%-80.4%, 88.7%-90.4%) was noted, however, the sensitivity was only 54.1%-65.8% and 29.4%-50%, and the accuracy(70.3%-73.4%, 75.9%-84.8%), positive predictive value(63.5%-65.8%, 41.7%-70.8%) and negative predictive value(73.6%-78.4%, 82.1%-87.3%) were low. By contrast, the inter-observer agreement of T2T for the assessment of ALL and PLL injury was very good(Kappa value =0.837, 0.799), and high sensitivity(83.6%-86.9%, 82.4%-88.2%), specificity(91.8%-95.9%, 90.3%-91.9%), accuracy(89.9%-91.1%, 89.9%-89.9%), positive predictive value(86.9%-92.7%, 71.4%-73.7%) and negative predictive value(90.3%-91.8%, 95.0%-96.6%) were noted. Conclusions: T2T of MRI is a reliable indicator for ALL and PLL injury and useful in evaluating the stability of cervical spine.