基于二维三维配准的股骨三维模型重建

3D reconstruction of femur based on 2D /3D registration

介绍了一种利用两张常规X光照片和标准骨模型对股骨三维模型进行快速重建的方法。从两个正交方向拍摄X光片,并记录X光片拍摄的参数信息;利用二维/三维配准算法建立了二维X光片与三维标准模型之间的对应关系。提出了基于FFD算法的单位自由变形方法对标准模型进行重建,最终使得X光片外轮廓与标准模型模拟投影轮廓一致,从而获得个性化的股骨三维模型。针对35个样本设计了全面的实验,最终得到全骨的二维点配对平均时间为20s,平均重建时间为112s;三维模型的外形平均误差为0.52mm,且精度和速度均保持稳定,具有良好的鲁棒性。该快速长骨重建方法减少了重建时间,具有较高的重建精度,同时具有良好的稳定性,在临床应用和相关科学研究中具有很好的应用前景。

This paper described a rapid method for reconstructing 3D modds of femur using a standard shape model and two conventional X-ray images. The X-ray images were taken at two orthogonal directions and documented X-ray source and sensor configurations. A direct correspondence building method was proposed for linking 2D images with 3I） projections of a Standard Shape Model （SSM）. A silhouette-based unit Free-Form Deformation （FFD） method was evaluated for its suitability as an adaption of the standard model for projection images. The reconstruction method proposed in this study was accomplished by deforming the template bone shape until its silhouette boundary approximated the X-ray image as closely as possible for correspondence of the two silhouettes. Comprehensive experiments were designee and conducted with 35 specimens. The mean time for creating full bone correspondence is 20 s and 92 s for 3D model reconstruction. The mean error of reconstructed model is 0.52 ram. With a reduced reconstruction time, improved precision, and a good robustness, the proposed method is efficient for routine clinical and research purposes.