CT扫描层厚参数对骨组织3D打印模型精度影响的研究

摘要

目的:通过对比研究,探讨CT层厚参数是否对3D打印模型的精度存在影响.方法:以10段带有完整软组织层次的家猪骨为研究对象.分别以0.6 mm(A组)、1 mm(B组)、2 mm(C组)及3 mm(D组)厚度进行CT扫描,通过Mimics 16.0重建猪骨的3D数字模型文件,并导入3D打印机中,获得猪骨模型.测量各段猪骨及相应猪骨3D模型的近端、远端处的外径及高度,统计分析各组数值是否存在差异.结果:通过采用不同扫描厚度获得的数据重建出三维骨骼实物模型,外观存在差异,扫描层厚越薄,模型与实物相似程度越高;采用不同扫描厚度时除A组、B组扫描厚度外,其他各组均与研究对象实体存在差异,其中的差异具有显著性意义(P<0.05);B组与A组在外径上差异不明显(P>0.05),而B组与C组及D组外径差异具有显著性意义(P<0.05).结论:CT层厚参数对3D打印模型精度存在影响,层厚越薄,精度越高,但层厚过薄对精度的提高作用不明显.%Objective: In order to study whether the CT scanning thickness affects the precision of the 3D model printed by 3D technology. Methods: We took 10 pieces of domestic pig femur with the complete soft tissue levels as our research object. By scanning the femur in thicknesses of 0.6mm, 1mm, 2mm and 3mm with CT respectively, importing the collected images in DICOM format files into the software Mimics 16.0 , we obtained the 3D digital model file, then imported it into the 3D rapid prototyping machine. We then printed out the bone model. We conducted a pair-matched study respectively on each measurement and research object and the corresponding model of bones at the proximal and distal ends about the outer diameter and height (taking the longest diameter), so as to know whether the thickness of the CT scan made an impact on the precision of the 3D model. Results: In the 3D model of bones created by data through adopting different scanning thicknesses, we found differences in appearance, the thinner the scanning layer is, the more similarities that exist between the model and the physical object. Meanwhile, by measuring each research object, the corresponding research object, and the corresponding model of bones at the proximal and distal ends. The outer diameter and height (taking the longest diameter) were measured, and making Paired Samples T-test, the result shows that when adopting different scanning thicknesses, apart from the samples with 0.6 mm and 1mm scanning thickness of Group A and B, other groups of samples show deviations from the research physical object. Among them, the deviation of Group C makes a statistically significant difference (P<0.05). The differences of the outer diameter between Group A and B is not significant (P>0.05), while the outer diameters of Group B, C and D are statistically significant (P<0.05). Conclusion: The thickness of CT scanning makes significant impact on the precision of 3D printed model (the thinner the layer is, the higher the precision is), but the affection is not obvious when the layer thickness is too thin.