Clinical trials of the triple combination cystic fibrosis transmembrane conductance regulator (CFTR) modulator therapy elexacaftor/tezacaftor/ivacaftor (ETI) demonstrated unprecedented clinical benefits including improvements in lung function, respiratory symptoms and nutritional outcomes in patients with cystic fibrosis (CF) aged ≥2 years with at least one copy of the F508del allele [1–11]. Despite the emergence of highly effective CFTR modulator therapy, chronic progressive lung disease remains the main cause of morbidity and mortality in patients with CF; however, early intervention with CFTR-directed therapeutics in children with CF now provides an opportunity to delay or even prevent irreversible lung damage. Because of the limited sensitivity of percentage predicted forced expiratory volume in 1 s (FEV₁) to capture response to therapy in CF children with preserved spirometry [12, 13], more sensitive outcome measures such as multiple-breath washout (MBW) and lung imaging by computed tomography (CT) and magnetic resonance imaging (MRI) have been established [14–25]. A number of studies demonstrated that the LCI derived from MBW is sensitive to detect response to therapeutic interventions including CFTR modulators in children with CF with normal spirometry [9–15, 18].

三联囊性纤维化跨膜电导调节器 (CFTR) 调节剂疗法 elexacaftor/tezacaftor/ivacaftor (ETI) 的临床试验证明了前所未有的临床益处，包括改善 2 岁以上囊性纤维化 (CF) 患者的肺功能、呼吸系统症状和营养结果至少有一个F508del等位基因拷贝的年份 [1-11]。尽管出现了高效的 CFTR 调节剂疗法，但慢性进行性肺病仍然是 CF 患者发病和死亡的主要原因；然而，对CF儿童进行CFTR定向治疗的早期干预现在提供了延迟甚至预防不可逆肺损伤的机会。由于预测 1 秒用力呼气量百分比 (FEV ₁ ) 的敏感性有限，无法捕捉保留肺量计的 CF 儿童对治疗的反应 [12, 13]，因此更敏感的结果测量，例如多次呼吸冲洗 (MBW) 和肺计算机断层扫描（CT）和磁共振成像（MRI）成像技术已经建立[14-25]。大量研究表明，MBW 衍生的 LCI 对于检测肺量测定正常的 CF 儿童对治疗干预措施（包括 CFTR 调节剂）的反应很敏感 [9-15, 18]。