This paper presents a unit free-form deformation (FFD) method applied to rapid three-dimensioanl (3D) bone reconstruction, which was based on traditional FFD. With the femur as an example, we reconstructed a 3D model of femur from two X-ray images and a standardized model by taking advantage of unit FFD algorithm. The X-ray images and its parameters were taken by C-arm device. Those parameters and X-ray contour are contributed to 3D reconstruction. The out contours of X-ray image and standard model were connected by point matching algorithm. The unit-FFD lattice was built to reconstruct standard model and finally made the contour of X-ray image and standard model exactly the same. Experiments on shape accuracy, robustness and time consuming, carried out by 35 specimen from cadaver, showed that mean error of shape (0. 52 mm) and mean construction time (112 s) were lower than those using traditional method (0.7-2.6 mm, 8-20 min). The method proposed in this paper shows a good prospect in clinical application and related research.
Algorithms ; Femur ; anatomy & histology ; diagnostic imaging ; Humans ; Imaging, Three-Dimensional ; Models, Anatomic ; Radiography

A whole technical way of reconstructing 3D model of the scoliotic spine from two X-ray images was proposed. From the experimental results of 30 patients with mild to severe scoliosis, we can conclude that the accuracy of locating vertebrae is 0.5 mm, the orientation accuracy was 1.5. After comparing the results with those using the previous methods, we found that the method proposed in this paper can get higher resolution with less computational time, making it suitable for clinical routine use.
Humans ; Imaging, Three-Dimensional ; methods ; Models, Statistical ; Radiography ; Scoliosis ; diagnostic imaging ; Spine ; diagnostic imaging