Alam Faiyza, Munidasa Samal, Zanette Brandon, Braganza Sharon, Li Daniel, Jensen Renee, Dumas Marie-Pier, Ratjen Felix, Santyr Giles
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada.
Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada.
J Cyst Fibros. 2025 May;24(3):593-600. doi: 10.1016/j.jcf.2024.09.021. Epub 2024 Sep 30.
Monitoring multiple-breath washout (MBW) of a xenon tracer using magnetic resonance imaging (MBW Xe-MRI) provides quantitative regional measures of gas washout (fractional ventilation, FV) and spatial ventilation heterogeneity (coefficient of variation, CoV) in pediatric CF lung disease, but has yet to be evaluated in an interventional setting.
12 pediatric CF participants (median age 15.3 ± 2 years) completed MBW Xe-MRI, pulmonary function tests (PFTs) (spirometry, N MBW for lung clearance index (LCI)) and single-breath Xe-MRI ventilation defect percent (VDP) measurements at baseline and 1-month post-initiation of elexacaftor/tezacaftor/ivacaftor (ETI) therapy. FV maps were calculated from MBW Xe-MRI washout images, and CoV maps were derived from FV maps. Significant changes between visits were determined using a paired Wilcoxon signed-rank test. For correlations between absolute changes, Pearson's correlation was used.
All measures changed significantly 1-month post-ETI therapy compared to baseline. For MRI metrics, median [IQR] VDP was significantly (P < 0.001) lower at 1 month (8.0 [3.7 12.4]) compared to baseline (17.8 [8.3 22.5]), FV was significantly (P < 0.05) higher at 1 month (0.42 [0.41 0.46]) compared to baseline (0.38 [0.33 0.44]), and CoV was significantly (P < 0.001) lower at 1 month (0.06 [0.05 0.07]) compared to baseline (0.09 [0.08 0.12]). Both absolute and relative differences in CoV and LCI were found to correlate highly (R = 0.92, P < 0.0001 and R = 0.91, P < 0.0001, respectively).
Functional information derived from MBW Xe-MRI, particularly CoV, can be used to assess regional lung function in pediatric CF patients in an interventional setting and may be complementary to VDP and pulmonary function tests.
使用磁共振成像监测氙示踪剂的多次呼吸洗脱（MBW）（MBW Xe-MRI）可提供小儿囊性纤维化（CF）肺病中气体洗脱的定量区域测量值（分数通气，FV）和空间通气异质性（变异系数，CoV），但尚未在干预环境中进行评估。
12名小儿CF参与者（中位年龄15.3±2岁）在基线时以及开始使用依列卡福/替扎卡福/依伐卡福（ETI）治疗1个月后，完成了MBW Xe-MRI、肺功能测试（PFTs）（肺活量测定、用于肺清除指数（LCI）的N次MBW）和单次呼吸Xe-MRI通气缺陷百分比（VDP）测量。从MBW Xe-MRI洗脱图像计算FV图，并从FV图导出CoV图。使用配对Wilcoxon符号秩检验确定访视之间的显著变化。对于绝对变化之间的相关性，使用Pearson相关性。
与基线相比，ETI治疗1个月后所有测量值均有显著变化。对于MRI指标，1个月时的中位[IQR]VDP（8.0[3.7 12.4]）与基线（17.8[8.3 22.5]）相比显著降低（P<0.001），1个月时的FV（0.42[0.41 0.46]）与基线（0.38[0.33 0.44]）相比显著升高（P<0.05），1个月时的CoV（0.06[0.05 0.0
