振动反应成像技术在支气管哮喘患者中的应用价值

Exploration of vibration response imaging in evaluating airway resistance of asthmatics

目的初步探讨振动反应成像（VRI）检查对诊断支气管哮喘（简称哮喘）患者气流受限可逆性的价值。方法选择2007年北京协和医院呼吸内科门诊就诊的哮喘患者64例为哮喘组，COPD患者20例为对照组。VRI设备采用VRI^xp系统。按随访步骤（问诊、查体、肺功能检查、VRI检查）采集两组患者临床及VRI资料。应用符号秩和检验分别比较哮喘组和对照组应用支气管舒张剂前后VRI各变量的2次观测结果，并将其差值与FEV1改善率进行多元线性回归拟合。对拟合模型的预报结果进行受试者工作曲线（ROC曲线）分析，获得本试验诊断的敏感度和特异度并评价其准确性。结果哮喘组的VRI曲线异常、跳跃感、最大能量图（MEF）形态异常和干啰音单位计数4个变量，在应用支气管舒张剂前后2次观测结果的差异有统计学意义（M值分别为7．5、14．5、12．5和7．5，均P〈0．05），而对照组差异无统计学意义（M值分别为0．5、2．0、0．5和1．0，均P〉0．05）。所有受试者VRI4个变量在应用支气管舒张剂前后2次观测的差值x1、x2、x3、x4与FEV1改善率y之间应用多元线性回归模型拟合得出y=0．12784＋0．06767x1＋0．04723x2＋0．04919x3＋0．00391x4（F=10．16，P〈0．01）。ROC曲线分析提示本研究诊断气流受限可逆性的敏感度为81．3％，特异度为55．0％，ROC曲线下面积为0．704。结论VRI中曲线异常、跳跃感、MEF形态异常及干啰音单位计数这4个变量对诊断哮喘患者气流受限的可逆性有一定价值。

Objective To explore the value of vibration response imaging （VRI） system in evaluating airway resistance of asthmatics. Methods The asthmatic group had 64 patients with a FEV1 of （56 ±18）% predicted before bronehodilator, and a FEV1 of （69 ± 18）% predicted after bronchodilator. The control group had 20 patients with COPD with a FEV1 of （64 ± 17 ）% predicted before bronchodilator, and a FEV1 of （66 ± 19）% predicted after bronehodilator. All patients underwent VRI examination in close proximity of each spirometric recording before and after bronehodilator. VRI outcomes were evaluated to determine whether the VRI technology could detect changes in airway resistance in asthmatics. The statistical analysis in comparison between VRI outcomes before and after bronchodilator was performed using a matched pairs signed rank test. Linear regression was used to describe the relation between the improvements of VRI parameters and the increase in FEV1. ROC curve was used to evaluate the accuracy of this examination. Results After bronchodilator, VRI outcomes including flow graph characteristics, dynamic appearance, shape of the maximal energy frame and rale counts had significant improvements after bronchodilator （M =7.5, 14. 5, 12. 5, 7.5, respectively, all P 〈 0. 05）. Outcomes in the control group showed no significant improvements （M = 0. 5, 2. 0, 0. 5, 1.0, respectively, all P 〉 0. 05 ）. y = 0. 127 84 ＋ 0. 067 67x1 ＋ 0. 047 23x2 ＋ 0. 049 19x3 ＋ 0. 003 91x4 was the model of the linear regression between improvements of VRI parameters （x1 , x2, x3, x4 ） and the observed changes in FEV1 （y） , F = 10. 16, P 〈 0. 01. According to the bronchodilation test, the sensitivity was 81.3% , and the specificity was 55.0%. The area under the ROC curve was 0. 704. Conclusion VRI outcomes including graph characteristics, dynamic appearance, shape of the MEF and rale counts may be a promising method to evaluate changes of airway resistance in asthmatics.