Wiesent K, Barth K, Navab N, Durlak P, Brunner T, Schuetz O, Seissler W
Medical Engineering Group, Siemens AG, Erlangen/Forchheim, Germany.
IEEE Trans Med Imaging. 2000 May;19(5):391-403. doi: 10.1109/42.870250.
Increasingly, three-dimensional (3-D) imaging technologies are used in medical diagnosis, for therapy planning, and during interventional procedures. We describe the possibilities of fast 3-D-reconstruction of high-contrast objects with high spatial resolution from only a small series of two-dimensional (2-D) planar radiographs. The special problems arising from the intended use of an open, mechanically unstable C-arm system are discussed. For the description of the irregular sampling geometry, homogeneous coordinates are used thoroughly. The well-known Feldkamp algorithm is modified to incorporate corresponding projection matrices without any decomposition into intrinsic and extrinsic parameters. Some approximations to speed up the whole reconstruction procedure and the tradeoff between image quality and computation time are also considered. Using standard hardware the reconstruction of a 256(3) cube is now possible within a few minutes, a time that is acceptable during interventions. Examples for cranial vessel imaging from some clinical test installations will be shown as well as promising results for bone imaging with a laboratory C-arm system.
三维（3-D）成像技术越来越多地应用于医学诊断、治疗规划以及介入手术过程中。我们描述了仅从一小系列二维（2-D）平面X射线照片中以高空间分辨率快速三维重建高对比度物体的可能性。讨论了使用开放式、机械不稳定的C形臂系统所产生的特殊问题。为了描述不规则采样几何形状，充分使用了齐次坐标。对著名的费尔德坎普算法进行了修改，以纳入相应的投影矩阵，而无需将其分解为内参数和外参数。还考虑了一些加速整个重建过程的近似方法以及图像质量和计算时间之间的权衡。使用标准硬件，现在可以在几分钟内重建一个256(3)的立方体，这在介入手术期间是可以接受的时间。将展示一些临床测试设备的颅血管成像示例以及实验室C形臂系统在骨成像方面的 promising results。（注：“promising results”直译为“有前景的结果”，这里保留英文更合适，因为在专业语境中可能有特定含义，若强行翻译可能影响专业性和准确性）
