Respiratory Medicine Department, School of Medicine, University of Nottingham,Queen's Medical Centre Campus, Nottingham, UK; NIHR Nottingham Biomedical Research Centre, Queen's Medical Centre, Nottingham, UK.
The Translational Medicine Program, The Hospital for Sick Children, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada.
Respir Med. 2021 Apr-May;180:106368. doi: 10.1016/j.rmed.2021.106368. Epub 2021 Mar 13.
Pulmonary function tests (PFTs) are the main objective measures used to assess asthma in children. However, PFTs provide a global measure of lung function. Hyperpolarised xenon-129 magnetic resonance imaging (129Xe-MRI) can assess lung function spatially. This cross-sectional cohort study aimed to evaluate the use of 129Xe-MRI in detecting ventilation abnormalities in children with well-controlled severe asthma pre- and post-bronchodilator (BD).
Six healthy children (aged 11 ± 3) and six with well-controlled severe asthma (14 ± 1) underwent spirometry, multiple breath washout (MBW), and 129Xe-MRI. These tests were repeated post-BD in the asthma cohort. Image analysis was performed in MATLAB. Wilcoxon signed-rank test, repeated measures analysis of variance (ANOVA), and Spearman's rank correlation coefficient were used for statistical analysis.
A significantly higher number of ventilation defects were found in the asthma cohort pre-BD compared to the healthy participants and post-BD within the asthma cohort (p = 0.02 and 0.01). A greater number of wedge-shaped defects were detected in the asthma cohort pre-BD compared to healthy participants and post-BD within the asthma cohort (p = 0.01 and 0.008, respectively). 129Xe ventilation defect percentage (VDP) and coefficient of variation (CoV) were significantly higher in the asthma cohort pre-BD compared to the healthy cohort (p = 0.006 for both). VDP and CoV were reduced significantly post-BD in the asthma cohort, to a level where there was no longer a significant difference between the two cohorts.
129Xe-MRI is a sensitive marker of ventilation inhomogeneity in paediatric severe asthma and may potentially be used as a biomarker to assess disease progression and therapeutic response.
肺功能测试（PFTs）是评估儿童哮喘的主要客观测量方法。然而，PFT 提供了肺功能的整体测量。超极化氙-129 磁共振成像（129Xe-MRI）可以对肺功能进行空间评估。这项横断面队列研究旨在评估 129Xe-MRI 在检测支气管扩张剂（BD）前后，对控制良好的重度哮喘儿童的通气异常的作用。
六名健康儿童（年龄 11 ± 3 岁）和六名控制良好的重度哮喘儿童（14 ± 1 岁）接受了肺活量测定、多次呼吸洗脱（MBW）和 129Xe-MRI 检查。哮喘组在 BD 后重复了这些检查。图像分析在 MATLAB 中进行。采用 Wilcoxon 符号秩检验、重复测量方差分析（ANOVA）和 Spearman 秩相关系数进行统计学分析。
在 BD 前，哮喘组的通气缺陷数量明显高于健康组，且哮喘组在 BD 后也高于自身（p = 0.02 和 0.01）。BD 前，哮喘组的楔形缺陷数量明显多于健康组，BD 后哮喘组内也多于健康组（p = 0.01 和 0.008，分别）。BD 前，哮喘组的 129Xe 通气缺陷百分比（VDP）和变异系数（CoV）明显高于健康组（p = 0.006）。BD 后，哮喘组的 VDP 和 CoV 显著降低，两组间不再有显著差异。
129Xe-MRI 是儿童重度哮喘通气不均质性的敏感标志物，可能作为评估疾病进展和治疗反应的生物标志物。
