摘要目的:探讨基于CT的皮罗氏序列征患儿喉镜暴露困难的预测模型的建立方法及应用。方法:回顾性分析2016年6月至2018年6月广州市妇女儿童医疗中心行下颌骨牵引术的皮罗氏序列征患儿50例资料，获取术前CT扫描图像进行三维重建，测量相关解剖学参数包括：上中切牙至会厌根部距离(D1)、会厌根部至声门中点距离(D2)、下颌骨下缘至声门中点(D3)、下颌骨长度(D4)、悬雍垂到咽后壁之间的距离(D5)、舌根到咽后壁之间的距离(D6)、会厌到咽后壁之间的距离(D7)、会厌长度(D8)；下颌升支长度(D9)、下颌骨体的长度(D10)、总下颌长度(D11)；上切牙下牙槽嵴、会厌根部、声门中点三者以会厌根部为交点所成角的度数(角1)、会厌根部、上切牙下牙槽嵴、声门中点三者以上切牙下缘为交点所成角的度数(角2)、下切牙上牙槽嵴、下颌骨下缘最远端、声门中点三者以下颌骨下缘最远端为交点所成角的度数(角3)、上切牙下牙槽嵴、硬腭后缘与会厌根部三者以硬腭后缘为交点所成角的度数(角4)、两侧下颌角的度数(角5)、下颌角两侧的下颌角点与颏部的颏顶点以颏顶点为交点所成角的度数(角6)；会厌尖端的气道截面积、口腔容积、腭咽腔容积、舌咽腔容积。上中切牙牙槽嵴至会厌根部距离、会厌根部至声门中点距离、下颌骨下缘至声门中点距离及上中切牙牙槽嵴、会厌根部、声门中点三者分别以会厌根部和上中切牙牙槽嵴为交点所成角的度数、会厌尖端的气道截面积和腭咽腔容积、舌咽腔容积等指标。根据Cormack-Lehane分级分为2组，喉镜暴露正常组20例，喉镜暴露困难组30例，建立喉镜暴露困难的决策树预测模型。结果:比较2组CT测量指标值，发现D4、D8、D10、D11、角3、角6以及口腔容积组间比较差异无统计学意义( P≥0.05)，其他指标组间比较差异有统计学意义( P<0.05)。会厌尖端气道截面积和腭咽腔容积对鉴别诊断皮罗氏序列征患儿喉镜暴露困难意义较大，并以此建立决策树模型。 结论:采用会厌尖端气道截面积和腭咽腔容积建立的决策树模型，有潜力预测皮罗氏序列征患儿喉镜暴露困难。

abstractsObjective:To analyze the characteristics of upper airway three-dimensional CT images in children with laryngoscope exposure.Methods:50 cases of Pierre Robin sequence who suffered mandibular distraction osteogenesis were included. Preoperation, Cone beam CT scan was performed to get upper airway anatomy information. Images were imported into medical engineering software Mimics for 3D reconstruction. The related anatomical parameters such as the cross-sectional area of the epiglottis tip, oral volume, palatopharynx volume, and glossopharyngeal volume were measured. The exposure of glottis was observed by direct laryngoscope after anaesthesia. According to Cormack-Lehane classification, 2 groups were divided into groups (group A, 30 cases), non exposure group (group B, 20 cases), and the difference of image data between the two groups was compared.Results:Comparing CT measurement index values of the two groups, it was found that there were no statistically significant differences in D4, D8, D10, D11, angle 3, angle 6 and oral volume between the two groups ( P≥0.05), while there were statistically significant differences in other indicators between the two groups ( P<0.05). The area of the airway at the tip of epiglottis and the volume of palatopharyngeal cavity are of great significance to the differential diagnosis of laryngoscopic exposure in children with Pierre Robin sequence, and the decision tree model was established accordingly. Conclusions:The decision tree model based on the area of the airway at the tip of epiglottis and the volume of the palatopharyngeal cavity can predict the difficulty of laryngoscopic exposure in children with Pierre Robin sequence.