数字化仪定点X线头影测量可靠性的研究

A Study on Reliability of Digitizing Analysator on Cephalometric Measurement

目的：评价数字化仪定点X线头影测量的可靠性。方法：将30张X线头颅侧位片描图标记标志点，对标志点进行数字化仪定点并获取各点的坐标值，使用计算机软件计算出测量结果。通过两次数字化仪定点测量结果近似程度的比较，评价数字化仪定点X线头影测量的可靠性。结果：所有测量项目重复测量结果无显著性差异，两次测量结果差值范围为每度0～0．59mm、由短线段组合的测量项目测量误差偏大。结论：数字化仪虽然具有较高的精确性，但是用于头影测量时其定点精度并非都很高，因而可能出现一定程度的测量误差，使用数据时要注意避免这种误差的影响。

Objective： To evaluate the reliability of digitizing analysator on cephalometric measurement. Methods： 30 cephalometric radiographs were selected randomly, The marked points were fixed and their parameters were measured through digitizing analysator. The results were calculated with computer software, The difference between repetitive measurements were compared to evaluate the reliability of digitizing analysator on cephalometric measurement. Result：There was no statistical difference in repetitive measurements. The error between twice measurements was 0 - 0.59mm every degree, while that of short line segment was maximal. Conclusion： Though the digitizing analysator is accurate, there are certain errors of measurement. It should be avoided from errors of numerical value.