3D Reconstruction Of Scoliosis Spine X-ray Films And Auxiliary Measurement

Three-dimensional reconstruction of medical image which is an importantapplication of visualization technology in the medical field has been an indispensableadjunct to clinical diagnosis and treatments.Currently, many young people have beenaffected spine lesions owing to influence of various factors. The spinal diseases,whose treatments are complicated and tough, have become a difficult problem inorthopedic surgeries.3D reconstruction of the spine based on CT slices needs a lot ofcomplete CT spinal slices. Adolescents whose bodies have been immature will betreated with X-Rays for a long time to get CT slices. This process will bring bodytissues a great loss. In that case, taking3D reconstruction of spinal column asresearch object, this paper proposed two approaches which are point’s reconstructionand shape matching reconstruction on the basis of studying algorithms of medicalthree-dimensional image reconstruction.Both methods only need two frontal andlateral X-Ray images. By calculating every vertebra, we can obtain three-dimensionalparameters which will be used to fit the normal spinal column model in order to getthe diseased spine model. Throng human-computer interaction toward the distortedspine model and analyses of computer-aided measurement data of Cobb angel, thedoctors can diagnose and cure accurately.This paper is mainly focused on three points as follows:1. This paper put forward a method for the3D reconstruction based onbarycenter points. Firstly, after getting the barycenter position of every vertebra, ituses cubic spline interpolation to fit these points to a curve. Secondly, it calculatesoffsets and angles between the tangent and the normal of each point on the curve.Lastly, it combines these offsets and angles to3D translation and rotation parametersto fit the normal spinal model to obtain the scoliosis model.2. A new approach of three-dimensional reconstruction based on shape matchingis presented in this paper. This method is based on Marching Cubes algorithm. At firstby rotating and prospectively projecting the3D model of every vertebra it can reformthe projection picture that is similar to the corresponding vertebral block in the X-Rayslice, and then it matches the projection picture with the corresponding vertebralblock in the X-Ray slice by adjusting the rotation parameters until the matching resultis successful. At last, it records rotation parameters α, β and translation parameters h,v. By adjusting corresponding parameters of every vertebral block in the standard model of spine with the help of rotation and translation parameters of every vertebra,the3D model of final spine can be reconstructed throng visualization techniques.Theexperimental results show that there are preferable matching and corking accuracybetween the reconstructed3D spinal model and the real spinal model. Even the qualityof the X-Ray film is relatively poor, it can still match well and rebuild the model ofspine. Compared to the three-dimensional reconstruction method based on barycenterpoints, this method which has controllable three-dimensional parameters is moreintuitive and has relatively simple calculation.3. The two computer aided measurements of Cobb angle which are three-pointmethod and straight-line method are proposed in this article. The main idea ofthree-point is introduced as follows. The first step is to draw a point respectively onthe starting position, intermediate position and end position of scoliosis spine, andthen it fits these three points to a curve. By computing the tangent slopes to this curveat both points, the normal slopes of these points can be calculated. Throng themathematical principle the Cobb angle can be counted.Straight-line method needs todraw a line respectively on both spinal blocks, and it is the lines that are parallel tothe lateral edges of the spinal blocks. The Cobb angle can be calculated with theprinciple of mathematics.