目的:探讨MicroCT在新生儿单侧完全性腭裂模型线距测量方面的信度和效度。方法:随机选取10个新生儿单侧完全性腭裂石膏模型,设置标志点。用MicroCT对石膏模型进行三维数据采集、逆向工程软件重建,由2名检测者b、C独立进行2次(间隔1周)MicroCT模型测量,1名检测者a用游标卡尺对模型做相同线距测量2次(间隔1周)作为对照。采用组内相关系数(ICC)评价手工石膏测量者和MicroCT测量者组内测量结果的一致性。用差值平均值、配对t检验、相对误差评估MicroCT模型测量值的信度和效度。结果:通过MicroCT扫描系统获得新生儿单侧完全性腭裂三维模型,模型形态清晰,范围完整。实验者a、b、c的组内ICC均大于0.99,呈高度一致性;MicroCT检测者自身和检测者之间线距最大差值平均数为0.052mm;MicroCT组与石膏模型组线距测量最大差值平均数为0.361mm,相对误差最大值1.97%,配对比较的数据P〉0.05。结论:MicroCT能够用于获得精确的腭裂数字化三维模型,在测量模型线距方面具有较高信度和效度。
Objective: To built up a 3-D model of unilateral complete cleft palate of neonate by Micro CT and to investigate the validi- ty and reliability of liner measurements on the model. Methods: Ten plaster models of unilateral complete cleft palate of neonate were scanned by Micro CT. The 3-D digital models were reconstructed by the reversed engineering software, and the linear measurements were taken on the models by experimenter b and c for two times with a interval of one week. As control, the same measurements were taken on the plaster models using calipers by experimenter a for two times with a interval of one week. lntraclass correlation coefficient (ICC) was used to analyze the intra-observation reliability of the measurements obtained by experimenter a, b and e, respectively. Va- lidity and reliability were assessed by average of the deviation, paired Student t tests and relative error. Results: The ICCs in the same observer were beyond 0.99. The 3- D digital models by Micro CT were intact and clear. Of Micro CT models, between intraexaminers and interexaminers the highest average of the deviation was 0. 052mm. , between digital models and the plaster models the maximum av- erage of the deviation was 0.361 1, the maximum of the Relative Error was only 1.97% (P 〉0.05, for each pair of compared data). Conclusion : The Micro CT can be used as an ideal method to built up digital entity model of unilateral complete cleft palate of the neo- natus with high Validity and reliability for the liner measurements.