Müller R A, Klimeš F, Voskrebenzev A, Behrendt L, Kaireit T F, Wernz M, Zubke M, Kern A L, Prince M R, Shen W, Cooper C B, Barr R G, Hohlfeld J M, Vogel-Claussen J
Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Hannover, Germany.
Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
COPD. 2025 Dec;22(1):2502671. doi: 10.1080/15412555.2025.2502671. Epub 2025 Jun 13.
Hyperinflation in chronic obstructive pulmonary disease (COPD) patients worsens on exertion/exercise when breathing frequency increases. Fast breathing, paced at 40 breaths per minute using a metronome (metronome-paced tachypnea, MPT), induces dynamic hyperinflation (DH) and can be performed during MRI. MPT in combination with phase-resolved functional lung (PREFUL) MRI can be used to assess stress-driven ventilation dynamics globally and regionally. A 90 s time series of one coronal slice centered to the trachea was acquired for PREFUL MRI during 60 s of resting tidal breathing (RTB) and 30 s of MPT at 40 breaths per minute in COPD patients and healthy volunteers. MPT detected DH in 12 out of 15 COPD patients and in 1 out of 15 healthy controls. During MPT, the global fractional ventilation decreased by 20% in healthy subjects ( = 0.01) and by 48% in COPD patients ( < 0.001). The end-expiratory lung area remained stable in healthy subjects and increased significantly by 7% in COPD patients over the course of MPT ( = 0.004). Younger, healthy volunteers adapted to increase breathing frequency by reducing tidal volume (global fractional ventilation), while older healthy volunteers showed less tidal volume reduction ( = 0.036). The MPT-induced change of regional ventilation homogeneity (flow volume loop cross-correlation, FVL-CC) increased with age in healthy volunteers ( = 0.039) likely due to the development of compensatory dystelectasis in younger volunteers leading to reduced homogeneity during MPT. In the future, the MPT test during MR imaging may be used for COPD treatment analysis and disease monitoring.
慢性阻塞性肺疾病（COPD）患者在运动时，随着呼吸频率增加，肺过度充气会加重。使用节拍器以每分钟40次呼吸的频率进行快速呼吸（节拍器控制的呼吸急促，MPT）会诱发动态肺过度充气（DH），并且可以在磁共振成像（MRI）期间进行。MPT与相位分辨功能肺（PREFUL）MRI相结合，可用于整体和局部评估应激驱动的通气动力学。在COPD患者和健康志愿者静息潮气呼吸（RTB）60秒和MPT每分钟40次呼吸30秒期间，获取以气管为中心的一个冠状面的90秒时间序列用于PREFUL MRI。15例COPD患者中有12例通过MPT检测到DH，15例健康对照中有1例检测到DH。在MPT期间，健康受试者的整体通气分数下降了20%（=0.01），COPD患者下降了48%（<0.001）。在MPT过程中，健康受试者的呼气末肺面积保持稳定，而COPD患者的呼气末肺面积显著增加了7%（=0.004）。年轻健康志愿者通过减少潮气量（整体通气分数）来适应呼吸频率增加，而老年健康志愿者潮气量减少较少（=0.036）。在健康志愿者中，MPT诱导的区域通气均匀性变化（流量容积环互相关，FVL-CC）随年龄增加（=0.039），这可能是由于年轻志愿者出现代偿性肺不张，导致MPT期间均匀性降低。未来，MR成像期间的MPT测试可能用于COPD治疗分析和疾病监测。
