低剂量CT扫描获取颌面部软硬组织三维模型的初步研究

摘要

目的:评价低剂量CT扫描获取颌面部软硬组织三维模型的可行性,为低剂量CT在颜面赝复体计算机辅助设计制作中的应用提供研究依据.方法:征集20例需要接受颌面部CT检查的患者,分别进行常规剂量(280 mAs)和低剂量(35 mAs)CT扫描,记录扫描时容积剂量指数(CTDIvol)和剂量长度乘积(DLP)；应用Mimics 10.01软件重建软硬组织三维模型；利用Geomagic 11.0软件进行三维比较,评价不同扫描剂量下重建软硬组织三维模型表面形态的差异.结果:常规剂量和低剂量扫描条件下,2组间CTDIvol值和DLP值的差异均具有统计学意义(P＜0.05)；软硬组织三维模型配准后3D比较生成彩虹图显示其表面形态的差异不大于0.5 mm,软硬组织三维模型对应各标记点坐标值无统计学差异(P＞0.05).结论:低剂量(35mAs) CT扫描可用于获取颌面部软硬组织的三维模型.%Objective: To study the feasibility of low-dose CT (LDCT) in the construction of three-dimensional(3D) model of the maxillofacial hard and soft tissues. Methods: The craniofacial CT examination was conducted by conventional dose(280 mAs) and low dose (35 mAs) in 20 patients, the scanning volume CT dose index (CTDIvol) and dose-length product(DLP) were recorded. The 3D model of the hard and soft tissues were reconstructed with Mimics 10. 01 software, and 3D comparison of the morphologic data between LDCT and conventional dose CT was carried out with Geomagic 11.0 software. Results: There was statistical significance(P <0. 05)in CTDIvol and DLP values, rainbow diagram generated by 3D comparison of the models of the hard and soft tissues showed that the differences of the surface morphology was not greater than 0. 5 mm, there was no statistical significance (P>0.05)in coordinate values(X, Y and Z values) of each corresponding marked points of the hard and soft tissues. Conclusion: The low-dose (35 mAs) CT can be used to obtain three-dimensional model of the maxillofacial hard and soft tissues.