Figure 3From: Vibration response imaging: a novel noninvasive tool for evaluating the initial therapeutic effect of noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary diseaseCorrelation between clinical improvement and VRI image score in AECOPD group. The change of AVRIS (T2 vs T1) is positively correlated with the changes of PaCO2 (T3 vs T1).Back to article page