128层螺旋CT在正常模型测量中的可靠性研究

摘要

Objective To verify the reliability, repeatability and accuracy of 128-slice spiral CT through comparing the measurement results of 128-slice spiral CT of 20 normal chin models with those of traditional manual measurement results.Methods The volume scanning with its data collection of normal chin models were conducted with 128-slice spiral CT. Then the images whose slice thicknesses were 0.6 mm were obtained through function reconstruction and then were transferred to various softwares including the 3D workstation, Dental and Inspace. The related indicators including the teeth width, dental arch length and dental arch width of maxillary and mandibular teeth were measured with axial images, MPR (Multiplanar Reconstruction), CPR (Curve Planar Reconstruction) and VR (Volume Reconstruction) while these indicators were also measured with vernier caliper manually. The measurement data collected from those two methods were analyzed and compared.Results The parallel validity of manual measurement was similar to CT measurement whose measurement error was-0.02~0.02 mm.Conclusion 128-slice spiral CT can meet the clinical orthodontic requirements.%目的：通过对20副正常模型的128层螺旋CT测量结果与传统手工测量结果进行比较，验证128层螺旋CT系统的可靠性、可重复性、精确性。方法应用128层螺旋CT机对正常模型进行容积扫描、数据采集，并进行函数重建得到0.6 mm层厚图像，传送至配套3D工作站、Dental（齿科软件）、Inspace（4D无间断实时互动三维成像技术）等软件，利用轴位图像、MPR（多平面重建）、CPR （曲面重建）、VR（容积重建）等方法测量正常模型的上、下颌牙的牙齿宽度，牙弓长度、宽度等相关指标；同时用游标卡尺手工测量上述指标，将两种测量方法所得数据进行比较。结果两种测量方法具有相似的平行效度。CT系统的测量误差为-0.02～0.02 mm，精确度较高。结论128层螺旋CT可以满足临床正畸需要。