关键词: 腭咽闭合不全, 动态磁共振成像, 腭咽结构, 手术决策模型, 多元回归分析

Abstract: Objective    To assess the differences in velopharyngeal structures between adult patients with velopharyngeal insufficiency（VPI）and normal volunteers using dynamic magnetic resonance imaging（MRI），and to develop a surgical decision-making model. Methods    A total of 38 adult patients with VPI（study group）and 30 volunteers with normal velopharyngeal closure（control group），who were treated at Peking Union Medical College Hospital from September 2021 to January 2025，were enrolled in this study. MRI was used to measure velopharyngeal structural parameters at rest and during phonation. Differences between the two groups were compared. Parameters with significant differences were incorporated into a multiple regression model to construct a surgical decision-making model. The accuracy of the model was evaluated using 4-fold cross-validation and follow-up data. Results    At rest，the angle between the bilateral levator veli palatini（LVP）muscles and the cranial base，as well as the velopharyngeal area，were significantly greater in the study group than in the control group. During phonation，the right LVP thickness，velar elevation ratio，velopharyngeal closure ratio，velar length，velar thickness，effective velar length/（effective velar length plus pharyngeal depth），palatal length，the angle between the trajectory of the LVP insertion point into the soft palate and the sella-nasion（SN） plane，and the displacement distance of the LVP insertion point into the soft palate were significantly smaller in the study group than in the control group，whereas the angle between the left LVP and the cranial base，the velopharyngeal area，and pharyngeal depth were significantly greater in the study group. All differences were statistically significant（P < 0.05）. No statistically significant differences were observed between the two groups in bilateral LVP length and velar height at rest and during phonation，bilateral LVP thickness and velar thickness at rest，or left LVP thickness，the angle between the right LVP and the cranial base，and effective velar length during phonation（P > 0.05）. Based on the discriminating variables and considering multicollinearity among the variables，five indices，namely，velar elevation ratio during phonation（X1），velopharyngeal closure ratio（X2），the angle between the trajectory of the LVP insertion point into the soft palate and the SN plane（X3），the displacement distance of the LVP insertion point into the soft palate（X4），and effective velar length/（effective velar length plus pharyngeal depth）（X5），were ultimately included in a multiple regression analysis. The resulting surgical decision model was：Y = 2.161 + 1.718 X1 - 0.381 X2 - 1.025 X3 - 0.681 X4 - 1.279 X5（R2 = 0.504，P = 0.006）. A Y value tending toward 1 suggested that surgical intervention was indicated，whereas a Y value tending toward 0 suggested that speech therapy was sufficient and surgery was not required. This VPI surgical decision model was validated using dynamic MRI data from 30 newly recruited patients with VPI，and the results demonstrated a significant correlation with expert opinion（χ2 = 12.805，P < 0.001）. Conclusion     Based on the assessment indices of velopharyngeal structures derived from dynamic MRI，this study has successfully developed a predictive model for surgical decisionmaking in VPI. The model can provide an objective and accurate evaluation system for the clinical formulation of treatment strategies for VPI.

Key words: velopharyngeal insufficiency, dynamic magnetic resonance imaging, velopharyngeal structures, surgical decision-making model, multiple regression analysis