A proposal for using active contour parametrical models in Cobb angle determination

Scoliosis is a spinal deformity that affects a large number of patients in its different modalities. One of the most-used characterizing metrics for scoliosis is known as the Cobb angle, which quantifies the degree of severity in the curvature of the patient's spine. This angle has been traditionally calculated by hand, and while nowadays that calculation is computer-assisted, it is not free of the variability caused by the measurement procedures. Aiming to solve this issue and to provide an automated approach to the determination of the Cobb angle, in this paper the use of active contour parametric models is proposed for that determination, by combining these models with measurement algorithms. By implementing this combination into a programming environment, a model has been defined that, starting from an X-ray image, after its graphical processing it identifies the active contours associated to the spine and then determines the polynomial function associated to their mean profile, from which it is possible to calculate the Cobb angle by means of simple trigonometrical operations. With that, the usefulness and potential utility of the proposed model have been clearly established, inviting to carry out a deeper comparative case study that will allow to properly assess the use of this measurement methodology.