A Novel Computer-Aided Method to Evaluate Scoliosis Curvature using Polynomial Math Function

Background: Scoliosis is a health problem that causes a side-to-side curvature in the spine. The curvature may have an “S” or “C” shape. To evaluate scoliosis, the Cobb angle has been commonly used. However, digital image processing allows the Cobb angle to be obtained easily and quickly, several researchers have determined that Cobb angle contains high variations (errors) in the measurements. Therefore, a more reproducible computer aided-method to evaluate scoliosis is presented. Material and Methods: In this analytical study, several polynomial curves were fitted to the spine curvature (۴th to ۸th order) of thirty plain films of scoliosis patients to obtain the Curvature-Length of the spine. Each plain film was evaluated by ۳ physician observers. Curvature was measured twice using the Cobb method and the proposed Curvature-Length Technique (CLT). Data were analyzed by a paired-sample Student t-test and Pearson correlation method using SPSS Statistics ۲۵. Results: The curve of ۷th order polynomial had the best fit on the spine curvature and was also used for our proposed method (CLT) obtaining a significant positive correlation when compared to Cobb measurements (r=۰.۸۶۳, P<۰.۰۰۱). The Intraclass Correlation (ICC) was between ۰.۸۶۳ and ۰.۹۴۸ for Cobb method and۰.۹۷۴ to ۰.۹۸۴ for CLT method. In addition, mean measurement of the inter-observer COV (Coefficient of Variation) for Cobb method was of ۰.۱۸۵, that was significantly greater than the obtained with CLT method of ۰.۱۵۵, this means that CLT method is ۱۶.۲% more repeatable than Cobb Method. Conclusion: Based on results, it was concluded that CLT method is more reproducible than the Cobb method for measuring spinal curvature.

Keywords:

scoliosis , Spinal Curvatures , Polynomial , Methods , Cobb-Angle