不同CT层厚下3D打印颅骨的精准度

Accuracy of 3D printing skull under different CT layer thickness

目的对比不同CT扫描层厚下颅骨3D打印模型与标本的测量数据,探讨不同层厚对打印模型精准度的影响。方法收集8例(标记为1~8号)正常颅骨标本(N组),分别以0.625 mm(A组)、1.25 mm(B组)、2.5 mm(C组)、3.75 mm(D组)、5 mm(E组)层厚进行CT扫描、三维重建与3D打印,测量各层厚下3D打印颅骨模型枕骨大孔前后径、前床突间距、蝶翼间距3个尺寸数值进行解剖还原度对比分析。结果根据解剖标志量化对比结果,随着CT层厚增加3D打印颅骨模型解剖标志数量逐渐减少。各层厚对打印3D模型造成的精度差异无统计学意义,A、B、C 3组与N组成高度相关性(r>0.85,P<0.05),A、B、C 3组的误差分析结果中偏差度<2.6%,与实体标本(N组)偏差较小。结论薄层CT数据(0.625~2.5 mm)下的3D打印模型精准度较高,且差异较小,可为临床应用提供高精度3D打印模型。

Objective To compare the measurement differences between the skull 3D printed model and the real specimen under different CT scan slice thicknesses,and to explore the effect of slice thickness on the accuracy of the 3D printed model.Methods Eight normal skull specimens(marked as Nos.1-8)(group N)were used for CT scanning with different slice thicknesses,specifically 0.625 mm(group A),1.25 mm(group B),and 2.5 mm(group C),3.75 mm(group D),and 5 mm(group E),and then carried out 3D reconstruction and 3D printing respectively,and compared the anatomical reduction degree of the foramen magnum diameter,anterior clinoid distance,and butterfly wing distance of the 3D printed skull model.Results The reduction degree of anatomical structure of 3D printed skull model decreased with the increase of CT slice thickness.There was no significant difference in the accuracy of 3D model among groups A,B and C(P>0.05).There was a high correlation between group A,B and C and group N(P<0.05).The size indexes and statistical values of group A,B and C were similar.Conclusion CT slice thickness has a significant effect on the accuracy and reduction of the 3D printed skull model.The 3D printed model with thin slice data(0.625 mm,1.25 mm,2.5 mm)has higher accuracy and less difference.