Abstract：
BACKGROUND: Cystic Fibrosis (CF) progresses through recurrent infection and inflammation, causing permanent lung function loss and airway remodeling. CT scans reveal abnormally low-density lung parenchyma in CF, but its microstructural nature remains insufficiently explored due to clinical CT limitations. To this end, diffusion-weighted 129Xe MRI is a non-invasive and validated measure of lung microstructure. In this work, we investigate microstructural changes in people with CF (pwCF) relative to age-matched, healthy subjects using comprehensive imaging and analysis involving pulmonary-function tests (PFTs), and 129Xe MRI.
METHODS: 38 healthy subjects (age 6-40; 17.2 ± 9.5 years) and 39 pwCF (age 6-40; 15.6 ± 8.0 years) underwent 129Xe-diffusion MRI and PFTs. The distribution of diffusion measurements (i.e., apparent diffusion coefficients (ADC) and morphometric parameters) was assessed via linear binning (LB). The resulting volume percentages of bins were compared between controls and pwCF. Mean ADC and morphometric parameters were also correlated with PFTs.
RESULTS: Mean whole-lung ADC correlated significantly with age (P < 0.001) for both controls and CF, and with PFTs (P < 0.05) specifically for pwCF. Although there was no significant difference in mean ADC between controls and pwCF (P = 0.334), age-adjusted LB indicated significant voxel-level diffusion (i.e., ADC and morphometric parameters) differences in pwCF compared to controls (P < 0.05).
CONCLUSIONS: 129Xe diffusion MRI revealed microstructural abnormalities in CF lung disease. Smaller microstructural size may reflect compression from overall higher lung density due to interstitial inflammation, fibrosis, or other pathological changes. While elevated microstructural size may indicate emphysema-like remodeling due to chronic inflammation and infection.
METHODS: 38 healthy subjects (age 6-40; 17.2 ± 9.5 years) and 39 pwCF (age 6-40; 15.6 ± 8.0 years) underwent 129Xe-diffusion MRI and PFTs. The distribution of diffusion measurements (i.e., apparent diffusion coefficients (ADC) and morphometric parameters) was assessed via linear binning (LB). The resulting volume percentages of bins were compared between controls and pwCF. Mean ADC and morphometric parameters were also correlated with PFTs.
RESULTS: Mean whole-lung ADC correlated significantly with age (P < 0.001) for both controls and CF, and with PFTs (P < 0.05) specifically for pwCF. Although there was no significant difference in mean ADC between controls and pwCF (P = 0.334), age-adjusted LB indicated significant voxel-level diffusion (i.e., ADC and morphometric parameters) differences in pwCF compared to controls (P < 0.05).
CONCLUSIONS: 129Xe diffusion MRI revealed microstructural abnormalities in CF lung disease. Smaller microstructural size may reflect compression from overall higher lung density due to interstitial inflammation, fibrosis, or other pathological changes. While elevated microstructural size may indicate emphysema-like remodeling due to chronic inflammation and infection.
摘要：
背景：囊性纤维化（CF）通过反复感染和炎症发展，导致永久性肺功能丧失和气道重塑。CT扫描显示CF中异常低密度的肺实质，但是由于临床CT的局限性，其微观结构性质仍未得到充分探索。为此,扩散加权129Xe磁共振成像是一种非侵入性的、经过验证的肺微结构测量方法。在这项工作中,我们调查了CF（pwCF）患者相对于年龄匹配的微观结构变化，健康受试者使用包括肺功能测试（PFTs）的综合成像和分析，和129XeMRI。
方法：38名健康受试者（年龄6-40岁；17.2±9.5岁）和39名pwCF（年龄6-40岁；15.6±8.0岁）接受了129Xe扩散MRI和PFT。扩散测量的分布(即，通过线性分级（LB）评估表观扩散系数（ADC）和形态参数）。在对照和pwCF之间比较所得的箱的体积百分比。平均ADC和形态参数也与PFTs相关。
结果：对照组和CF的全肺平均ADC值与年龄显着相关（P<0.001），PFTs(P<0.05)特别是pwCF。尽管对照组和pwCF之间的平均ADC没有显着差异（P=0.334），年龄调整后的LB表明显著的体素水平扩散(即ADC和形态参数）与对照组相比，pwCF的差异（P<0.05）。
结论：129Xe扩散MRI显示CF肺病的微结构异常。较小的微结构尺寸可能反映了由于间质性炎症引起的整体较高的肺密度的压迫，纤维化，或其他病理变化。虽然增加的微结构尺寸可能表明由于慢性炎症和感染引起的肺气肿样重塑。
方法：38名健康受试者（年龄6-40岁；17.2±9.5岁）和39名pwCF（年龄6-40岁；15.6±8.0岁）接受了129Xe扩散MRI和PFT。扩散测量的分布(即，通过线性分级（LB）评估表观扩散系数（ADC）和形态参数）。在对照和pwCF之间比较所得的箱的体积百分比。平均ADC和形态参数也与PFTs相关。
结果：对照组和CF的全肺平均ADC值与年龄显着相关（P<0.001），PFTs(P<0.05)特别是pwCF。尽管对照组和pwCF之间的平均ADC没有显着差异（P=0.334），年龄调整后的LB表明显著的体素水平扩散(即ADC和形态参数）与对照组相比，pwCF的差异（P<0.05）。
结论：129Xe扩散MRI显示CF肺病的微结构异常。较小的微结构尺寸可能反映了由于间质性炎症引起的整体较高的肺密度的压迫，纤维化，或其他病理变化。虽然增加的微结构尺寸可能表明由于慢性炎症和感染引起的肺气肿样重塑。
