Zhang Junhua, Lou Edmond, Shi Xinling, Wang Yuanyuan, Hill Douglas L, Raso James V, Le Lawrence H, Lv Liang
Department of Electronic Engineering, Yunnan University, Yunnan, China.
J Spinal Disord Tech. 2010 Aug;23(6):383-7. doi: 10.1097/BSD.0b013e3181bb9a3c.
Development of a computer-aided Cobb measurement method and evaluation of its reliability.
To reduce the variability of Cobb angle measurement by developing the computer-aided method and to investigate if the developed method is sensitive to observer skill levels or experiences.
Therapeutic decisions for scoliosis heavily rely on the Cobb angle measured from consecutive radiographs. The manual Cobb measurement is subject to human errors. The observer error is 3 to 10 degrees resulted from different end-vertebrae selection and/or manually drawing variable best-fit lines to the endplates of the end-vertebrae.
A fussy Hough transform technique was used to develop a computer-aided method to detect the vertebral endplates. The Cobb angle, upper end-vertebra, and lower end-vertebra were then measured automatically. The computer-aided method was tested twice by each of 3 observers in 84 posteroanterior radiographs from patients with adolescent idiopathic scoliosis. The intraobserver and interobserver errors were analyzed.
Both the intraobserver and interobserver reliability analyses resulted in the intraclass correlation coefficients higher than 0.9 for the Cobb angle. The average intraobserver and interobserver errors were less than 3 degree for the Cobb angle, and less than 0.3 levels for both the upper and lower end-vertebral identification. There were no significant differences in the measurement variability between groups of curve location (thoracic, thoracolumbar, and lumbar), curve direction (right and left), curve magnitude (curves less than 25 degree, between 25 and 45 degrees, and more than 45 degree), and observer experience (experienced observer and inexperienced observers).
Compared with the documented results, variability of the Cobb measurement is reduced by using the developed computer-aided method. This method can help orthopedic surgeons measure the Cobb angle more reliably during scoliosis clinics.
一种计算机辅助Cobb测量方法的开发及其可靠性评估。
通过开发计算机辅助方法来减少Cobb角测量的变异性，并研究所开发的方法是否对观察者的技能水平或经验敏感。
脊柱侧弯的治疗决策严重依赖于从连续X线片测量得到的Cobb角。手动Cobb测量容易出现人为误差。由于不同的终椎选择和/或手动绘制到终椎终板的可变最佳拟合线，观察者误差为3至10度。
使用模糊霍夫变换技术开发一种计算机辅助方法来检测椎体终板。然后自动测量Cobb角、上端椎和下端椎。3名观察者分别在84张青少年特发性脊柱侧弯患者的正位X线片中对计算机辅助方法进行了两次测试。分析了观察者内和观察者间的误差。
观察者内和观察者间可靠性分析得出Cobb角的组内相关系数均高于0.9。Cobb角的平均观察者内和观察者间误差小于3度，上下端椎识别的误差均小于0.3个椎体水平。在曲线位置（胸椎、胸腰段和腰椎）、曲线方向（右和左）、曲线大小（小于25度、25至45度和大于45度的曲线）和观察者经验（经验丰富的观察者和经验不足的观察者）组之间的测量变异性没有显著差异。
与已记录的结果相比，使用所开发的计算机辅助方法可降低Cobb测量的变异性。该方法可帮助骨科医生在脊柱侧弯门诊中更可靠地测量Cobb角。
