Alhilali L M, Fakhran S
Department of Radiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
AJNR Am J Neuroradiol. 2013 Dec;34(12):2399-404. doi: 10.3174/ajnr.A3585. Epub 2013 Jun 13.
The anterior diskoligamentous complex is important for cervical spinal stability. Subjective widening of the disk space after trauma has been used to gauge disruption of the anterior diskoligamentous complex on CT scanning, but no quantitative CT measurements exist to evaluate injury. The purpose of our study was to evaluate if an increased intervertebral disk angle could serve as a more sensitive, reproducible indicator of disruption of the anterior diskoligamentous complex compared with subjective assessment.
The intervertebral disk angle was retrospectively measured on CT scanning for 122 disk levels with disruption of the anterior diskoligamentous complex by MR imaging and 1095 disk levels with an intact anterior diskoligamentous complex by MR imaging. The intervertebral disk angle was measured between the anterior superior endplate and anterior inferior endplate, with angle apex at the midposterior disk. Area under the receiver operating characteristic curves for subjective disk widening and specific angle values were obtained. Intervertebral disk angle reproducibility was also evaluated.
Intervertebral disk angle measurements were "substantially reproducible." No disk with an intact anterior diskoligamentous complex had an intervertebral disk angle greater than 18° or 2 standard deviations from the average intervertebral disk angle of the remaining disks. The area under the receiver operating characteristic curve for a criterion of subjective disk widening was 0.58. The area under the receiver operating characteristic curve for objective criteria, an intervertebral disk angle greater than 13 or above 1 standard deviation from normal values, was 0.85. The maximal area under the receiver operating characteristic curve was achieved if an intervertebral disk angle greater than 2 SD from the average angle of the other disks was used (0.86).
Subjective disk widening does not accurately detect disruption of the anterior diskoligamentous complex on CT scanning; an elevated intervertebral disk angle provides a more sensitive and objective measurement to help direct further imaging in trauma patients.
前侧椎间盘韧带复合体对颈椎稳定性至关重要。创伤后椎间盘间隙主观上的增宽已被用于在CT扫描时判断前侧椎间盘韧带复合体的断裂情况，但尚无定量CT测量方法来评估损伤。我们研究的目的是评估与主观评估相比，椎间盘角度增加是否可作为前侧椎间盘韧带复合体断裂更敏感、可重复的指标。
回顾性测量了122个经磁共振成像显示前侧椎间盘韧带复合体断裂的椎间盘层面以及1095个经磁共振成像显示前侧椎间盘韧带复合体完整的椎间盘层面的CT扫描图像上的椎间盘角度。椎间盘角度是在前上终板和前下终板之间测量，角顶位于椎间盘后中部。获得了主观椎间盘增宽和特定角度值的受试者操作特征曲线下面积。还评估了椎间盘角度的可重复性。
椎间盘角度测量“具有高度可重复性”。前侧椎间盘韧带复合体完整的椎间盘，其椎间盘角度均未大于18°或比其余椎间盘的平均椎间盘角度超出2个标准差。以主观椎间盘增宽为标准的受试者操作特征曲线下面积为0.58。以客观标准，即椎间盘角度大于13°或高于正常值1个标准差为标准的受试者操作特征曲线下面积为0.85。如果采用比其他椎间盘平均角度超出2个标准差的椎间盘角度，则可获得最大的受试者操作特征曲线下面积（0.86）。
在CT扫描时，主观椎间盘增宽不能准确检测前侧椎间盘韧带复合体的断裂；椎间盘角度升高提供了一种更敏感和客观的测量方法，有助于指导创伤患者的进一步影像学检查。
