新型肝脏管道模型的数字化制造研究

目的　设计并制作内部管道与肝实质外形兼备的新型肝脏管道模型。  方法　选取一具新鲜的人体肝脏标本，肝静脉及门静脉灌注后行64排螺旋CT扫描，利用Mimics软件重建门静脉、肝静脉及肝实质三维模型。在Magic4.0软件中设计肝脏管道与肝实质外壳模具的装配结构。将设计好的模型通过快速成型机进行模型的三维打印，并进行组装形成管道铸模模具。将融化的透明果冻蜡注入铸模模具内，待蜡凝固后，除去肝实质壳模具，获得新型肝脏管道模型。  结果　本研究通过三维重建、快速成型及模具技术成功地制作了内部管道与肝实质外形兼备的新型肝脏管道模型。模型清晰地显示肝内管道的分布情况，位置关系，分支关系，管道直径等，快速成型管道的最小直径约为1.2 mm。由透明果冻蜡制作的肝实质外形良好，清晰透明，质地与肝实质相近。   结论　新型肝脏管道模型表现力丰富，容易保存。它拓展了铸型标本在医学教育，科研，临床上的应用。

Digital production of a novel liver casts using rapid prototyping and mold technologies

Objectives　To explore a novel hepatic duct cast with transparent liver parenchyma and internal ducts.    Methods   A fresh human liver was harvested and the hepatic and portal veins were perfused. And the sectional images were obtained by a 64-slice spiral CT. The three-dimensional (3D) models of the portal vein, hepatic vein and liver parenchyma were reconstructed using Mimics software. The shell molds of the liver parenchyma and its connection with ducts were designed in software Magic 4.0. The 3D models were then uploaded into a rapid prototype 3D printer to physically duplicate the models. After assembling the cast and the shell structures, the mold was manufactured. Melted transparent jelly wax was then poured into the mold. After wax solidification, the shell molds were removed. And the novel RP(rapid prototype) hepatic cast was produced.    Result    The novel RP cast of human liver with transparent parenchyma and internal ducts was successfully produced. It had a fine morphology and a good hand feeling with the transparent jelly wax. And the duct structures of the portal vein and hepatic vein were clearly displayed in different colors with their intimate relationship demonstrated. The smallest branch of the RP cast of hepatic ducts was about 1.2 mm in diameter.     Conclusion    The RP cast of human liver can demonstrate the details of the liver structure and is convenient at reservation It can expand the application of the duct cast in medical education, research and clinical trials.