Klein H M, Schneider W, Alzen G, Voy E D, Günther R W
Department of Diagnostic Radiology, University of Technology Medical Center, Aachen, FRG.
Pediatr Radiol. 1992;22(6):458-60. doi: 10.1007/BF02013512.
To improve the planning phase for pediatric craniofacial surgery, 3D reconstructions of CT image series were performed on a personal computer. For construction of true models of the surgical site, two concepts were pursued. CT image data of six patients were used for model manufacturing by a conventional 2 1/2 axis milling system. The material used was polyurethane foam. Alternatively, in one patient a stereolithography was produced on the basis of the 3D reconstructed CT data. This new manufacturing device uses a photocurable monomer, hardened by a UV-laser. The spatial resolution of the system is about 0.1 mm. 3D-reconstructions were performed on a personal computer. Data were then transferred into a surface oriented structure to control a stereolithographic modeling device. Time for transfer was 70 min. The production of the modelled cranium took a total time of 59 h. Accuracy was found to be much higher in stereolithography than in milled models. The model served for surgical planning. The long time for production was caused by inadequate computer capacities, which are configured for much less complex objects in computer aided design. Furthermore the programs for the machine control are optimized for technical purposes. If these conditions are improved, stereolithography could be an attractive alternative to milling of medical models.
为改进小儿颅面外科手术的规划阶段，在个人计算机上对CT图像序列进行了三维重建。为构建手术部位的真实模型，采用了两种方法。使用传统的二点五轴铣削系统，利用六名患者的CT图像数据制作模型。所用材料为聚氨酯泡沫。另外，对一名患者基于三维重建的CT数据制作了立体光刻模型。这种新的制造设备使用一种可光固化的单体，通过紫外激光固化。该系统的空间分辨率约为0.1毫米。在个人计算机上进行三维重建。然后将数据转换为面向表面的结构，以控制立体光刻建模设备。转换时间为70分钟。制作模型颅骨总共耗时59小时。结果发现，立体光刻模型的精度远高于铣削模型。该模型用于手术规划。制作时间长是由于计算机处理能力不足，其在计算机辅助设计中针对的是复杂程度低得多的对象进行配置。此外，机器控制程序是出于技术目的进行优化的。如果这些条件得到改善，立体光刻可能成为医疗模型铣削的一个有吸引力的替代方法。
