Karmali D, Afanador-Castiblanco S, Ötvös T, Aguilar G, Hossen S, Eikelis N, Nilsen K, Punjabi N M, Siddharthan T, Kirkness J P
Department of Pulmonary, Critical Care & Sleep Medicine, School of Medicine, University of Miami, Miami, Florida, United States.
4DMedical, Melbourne, Victoria, Australia.
J Appl Physiol (1985). 2025 Mar 1;138(3):731-738. doi: 10.1152/japplphysiol.00676.2024. Epub 2025 Feb 12.
Noninvasive assessments of lung volume distribution often require inhaled contrast and are limited by low regional resolution. We aimed to examine a noncontrast imaging method of spatial lung volume displacement, adapted to assess changes with noninvasive positive pressure ventilation (NIPPV). This study evaluated regional lung volume displacement in nine healthy volunteers (6 males and 3 females; ages 29-55 yr; body mass index 20.2-31.3 kg/m) using X-ray velocimetry (XV). Participants were assessed during tidal breathing and, also with 15 cmHO inspiratory and 5 cmHO expiratory pressures in a supine position. Regional specific ventilation (SV) was measured during tidal breathing and NIPPV. Mean specific ventilation (MSV, mL/mL), low-volume region (LVR; % < 0.1 mL/mL), and high-volume region (HVR; % > 0.3 mL/mL) were calculated as output variables. Images were segmented into lobar as well as central and peripheral zones. Two-way ANOVA and paired tests were used to determine regional differences within individuals and the effect of NIPPV. NIPPV increased MSV in both peripheral ( = 0.01) and central ( = 0.02) lung regions compared with tidal breathing. High-volume regions increased in both peripheral ( = 0.04) and central regions ( = 0.04) during NIPPV. This study demonstrates that noncontrast imaging techniques can assess regional lung ventilation and redistribution of lung volumes on NIPPV. Heterogeneous responses to NIPPV may be associated with a distinct distribution of ventilation, and further work is needed to ascertain differential responses to NIPPV due to lung pathology among those with respiratory disease. Noninvasive positive pressure ventilation (NIPPV) is a commonly utilized intervention for acute and chronic respiratory failure. In this study, we use functional lung imaging to describe changes in regional lung ventilation and redistribution of lung volume with NIPPV. These results offer insight into the regional effects of NIPPV on volume expansion with the use of functional imaging.
肺容积分布的无创评估通常需要吸入造影剂，且受限于低区域分辨率。我们旨在研究一种用于空间肺容积移位的无造影成像方法，以评估无创正压通气（NIPPV）引起的变化。本研究使用X射线测速法（XV）评估了9名健康志愿者（6名男性和3名女性；年龄29 - 55岁；体重指数20.2 - 31.3 kg/m）的区域肺容积移位。在潮式呼吸期间对参与者进行评估，并且在仰卧位时还施加15 cmH₂O吸气压力和5 cmH₂O呼气压力进行评估。在潮式呼吸和NIPPV期间测量区域比通气量（SV）。计算平均比通气量（MSV，mL/mL）、低容积区域（LVR；% < 0.1 mL/mL）和高容积区域（HVR；% > 0.3 mL/mL）作为输出变量。图像被分割为肺叶以及中央和外周区域。使用双向方差分析和配对检验来确定个体内的区域差异以及NIPPV的影响。与潮式呼吸相比，NIPPV使外周（P = 0.01）和中央（P = 0.02）肺区域的MSV增加。在NIPPV期间，外周（P = 0.04）和中央区域（P = 0.04）的高容积区域均增加。本研究表明，无造影成像技术可评估NIPPV时的区域肺通气和肺容积再分布。对NIPPV的异质性反应可能与通气的独特分布有关，并且需要进一步开展工作以确定呼吸系统疾病患者中因肺部病理情况导致的对NIPPV的不同反应。无创正压通气（NIPPV）是急性和慢性呼吸衰竭常用的干预措施。在本研究中，我们使用功能性肺成像来描述NIPPV时区域肺通气和肺容积再分布的变化。这些结果为使用功能性成像深入了解NIPPV对容积扩张的区域影响提供了依据。
