1990 Volvo Award in Clinical Sciences: The Consistency and Accuracy of Roentgenograms for Measuring Sagittal Translation in the Lumbar Vertebral Motion Segment: An Experimental Model
1990 Volvo Award in Clinical Sciences: The Consistency and Accuracy of Roentgenograms for Measuring Sagittal Translation in the Lumbar Vertebral Motion Segment: An Experimental Model
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1990 年沃尔沃临床科学奖：用于测量腰椎运动节段矢状平移的 X 线图的一致性和准确性：实验模型
DOI：
10.1097/00007632-199008010-00003
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发表时间：
1990
期刊：
影响因子：
3
通讯作者：
V. Goel
中科院分区：
文献类型：
--
作者：
W. Shaffer;K. Spratt;J. Weinstein;T. Lehmann;V. Goel
开发了L4-L5腰椎运动节段的实验模型，该模型允许精确操作矢状平移、L5相对于L4的旋转、L4在L5上的倾斜以及通过在管和椎体之间放置水浴来控制X线片质量（图像清晰度）。设计了一系列实验，系统地评估矢状面平移测量的一致性和准确性，从不同质量的X线片，使用不同的测量协议和各种评级组合的模型与不同程度的伴随运动（旋转和倾斜）。研究1评估了X线片质量、评分员和7种测量方法对矢状面平移评价的一致性和准确性的影响。结果表明，非常高的可靠性，在X线片质量，评分员和测量。正如预期的那样，高质量的X线片比低质量的X线片更准确地评估。然而，对测量翻译中错误后果的仔细检查表明，假阳性和假阴性率高得惊人，测量方法之间存在显着差异。研究2评估了伴随运动和测量方法对评估一致性和准确性的影响。评估者内一致性和准确性指数非常高，并且在测量方法和伴随运动程度之间相似。然而，再次观察到假阳性和假阴性率的重要差异。Morgan和King描述的方法2证明了整体最佳性能和伴随运动引起的干扰最小。研究3评估了评定者和测量方法对临床X线片中测量平移一致性的影响，其中可能存在伴随的运动因素，但未明确考虑。结果表明，相对于从模型中获得的平均值，评分者内和评分者间的一致性估计值明显较低，尽管这些幅度与其他评估临床X线片的报告相似。相对于增加的假阳性和假阴性率，较低的一致性估计的影响必须更仔细地检查。这些研究提供的证据表明，高一致性和准确性指数并不能确保可接受的假阳性和假阴性率，因此，提供了经验证据支持的观点，即使用X线片作为诊断不稳定的基础，往往会导致错误的分类。当在相对清晰的X线照片上观察到的平移相对较大（± 5+ mm）时，这种情况较少，并且伴随运动最小。然而，当X线片质量较低时，平行度问题明显，并且涉及伴随运动，即使是±6 mm或更大的相对较大的测量平移也可能发生，而实际平移实质上更小。在这些设置中，使用X线片将患者分类为具有过度平移可能导致较大的假阳性率。
An experimental model of the L4–L5 lumbar motion segment was developed that allowed precise manipulation of sagittal translation, rotation of L5 relative to L4, tilt of L4 on L5, and control of roentgenogram quality (image clarity) by placing a water bath between the tube and the vertebral body. A series of experiments were designed to systematically assess the consistency and accuracy of sagittal translation measurements from roentgenograms of varying quality, using different measurement protocols and various rater combinations on models with varying degrees of concomitant motions (rotations and tilts). Study 1 assessed the effects of roentgenogram quality, raters, and seven measurement methods on the consistency and accuracy of evaluating translations in the sagittal plane. Results indicated very high reliabilities across roentgenogram quality, raters, and measurement. As expected, high-quality roentgenograms were more accurately evaluated than lower-quality roentgenograms. However, closer inspection of the consequences of errors in measured translations indicated surprisingly high false-positive and false-negative rates, with significant differences observed between measurement methods. Study 2 assessed the effects of concomitant motions and measurement methods on the consistency and accuracy of evaluations. Within-rater consistency and accuracy indices were remarkably high and similar across measurement methods and degrees of concomitant motions. However, important differences in the false-positive and false-negative rates were again observed. Method 2, described by Morgan and King, demonstrated the overall best performance and the least interference due to concomitant motions. Study 3 assessed the effects of raters and measurement methods on the consistency of measuring translation in clinical roentgenograms, where concomitant motion factors may be present, but not explicitly considered. Results indicated substantially lower within-and between-rater consistency estimates relative to consistencies obtained from the model, although these magnitudes were similar to those reported by others evaluating clinical roentgenograms. The implications of lower consistency estimates relative to increased false-positive and false-negative rates must be more closely examined. These studies present evidence suggesting that high consistency and accuracy indices do not ensure acceptable false-positive and false-negative rates and, thus, provide empirical evidence supporting the view that using roentgenograms as a basis for diagnosing instability often can lead to errors in classification. This is less so when observed translations are relatively large ( ± 5+ mm) on roentgenograms that are relatively clear, with little obliquity, and when concomitant motions are minimal. However, when roentgenogram quality is lower, obliquity problems are apparent, and concomitant motions are involved, even relatively large measured translations of ±6 mm or more may occur when actual translations are substantially less. In these settings, using roentgenograms to classify patients as having excessive translation may result in large false-positive rates.