Dept of Medical Physics, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA.
Dept of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin - Madison, Madison, WI, USA.
Eur Respir J. 2022 Oct 13;60(4). doi: 10.1183/13993003.02058-2021. Print 2022 Oct.
The objective of this work was to apply quantitative and semiquantitative dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) methods to evaluate lung perfusion in idiopathic pulmonary fibrosis (IPF).
In this prospective trial 41 subjects, including healthy control and IPF subjects, were studied using DCE-MRI at baseline. IPF subjects were then followed for 1 year; progressive IPF (IPF) subjects were distinguished from stable IPF (IPF) subjects based on a decline in percent predicted forced vital capacity (FVC % pred) or diffusing capacity of the lung for carbon monoxide ( % pred) measured during follow-up visits. 35 out of 41 subjects were retained for final baseline analysis (control: n=15; IPF: n=14; IPF: n=6). Seven measures and their coefficients of variation (CV) were derived using temporally resolved DCE-MRI. Two sets of global and regional comparisons were made: control IPF groups and control IPF IPF groups, using linear regression analysis. Each measure was compared with FVC % pred, % pred and the lung clearance index (LCI % pred) using a Spearman rank correlation.
DCE-MRI identified regional perfusion differences between control and IPF subjects using first moment transit time (FMTT), contrast uptake slope and pulmonary blood flow (PBF) (p≤0.05), while global averages did not. FMTT was shorter for IPF compared with both IPF (p=0.004) and control groups (p=0.023). Correlations were observed between PBF CV and % pred (r= -0.48, p=0.022) and LCI % pred (r= +0.47, p=0.015). Significant group differences were detected in age (p<0.001), % pred (p<0.001), FVC % pred (p=0.001) and LCI % pred (p=0.007).
Global analysis obscures regional changes in pulmonary haemodynamics in IPF using DCE-MRI in IPF. Decreased FMTT may be a candidate marker for IPF progression.
本研究旨在应用定量和半定量动态对比增强磁共振成像（DCE-MRI）方法评估特发性肺纤维化（IPF）患者的肺灌注。
本前瞻性研究共纳入 41 例受试者，包括健康对照者和 IPF 患者，于基线时行 DCE-MRI 检查。然后对 IPF 患者进行为期 1 年的随访，根据随访过程中预测的用力肺活量（FVC % pred）或一氧化碳弥散量（DLCO % pred）下降情况，将其分为进展性 IPF（IPF）和稳定性 IPF（IPF）。41 例患者中，35 例完成最终基线分析（对照组：n=15；IPF 组：n=14；IPF 组：n=6）。采用时间分辨 DCE-MRI 得出 7 个指标及其变异系数（CV）。分别采用线性回归分析进行两组间（对照组与 IPF 组，对照组与 IPF 组、IPF 组）的全局和局部比较，并用 Spearman 秩相关分析每个指标与 FVC % pred、DLCO % pred 和肺清除指数（LCI % pred）的相关性。
DCE-MRI 检测到特发性肺纤维化患者的局部灌注存在差异，具体表现为第一时相过渡时间（FMTT）、对比摄取斜率和肺血流量（PBF）的差异（p≤0.05），但全局平均值未显示出差异。与 IPF 组和对照组相比，IPF 组的 FMTT 更短（p=0.004 和 p=0.023）。PBF CV 与 DLCO % pred（r= -0.48，p=0.022）和 LCI % pred（r= +0.47，p=0.015）呈负相关。两组间的年龄（p<0.001）、DLCO % pred（p<0.001）、FVC % pred（p=0.001）和 LCI % pred（p=0.007）均存在显著差异。
DCE-MRI 检测到 IPF 患者存在区域性肺血流动力学变化，但全局分析结果可能被掩盖。FMTT 缩短可能是特发性肺纤维化进展的候选标志物。
