Montesi Sydney B, Zhou Iris Y, Liang Lloyd L, Digumarthy Subba R, Mercaldo Sarah, Mercaldo Nathaniel, Seethamraju Ravi T, Rosen Bruce R, Caravan Peter
Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital, Boston, MA, USA.
Institute for Innovation in Imaging, Massachusetts General Hospital, Boston, MA, USA.
ERJ Open Res. 2021 Nov 8;7(4). doi: 10.1183/23120541.00907-2020. eCollection 2021 Oct.
Evidence suggests that abnormalities occur in the lung microvasculature in idiopathic pulmonary fibrosis (IPF). We hypothesised that dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) could detect alterations in permeability, perfusion and extracellular extravascular volume in IPF, thus providing regional functional information not otherwise available.
Healthy controls and IPF subjects underwent DCE-MRI of the thorax using a dynamic volumetric radial sampling sequence and administration of gadoterate meglumine at a dose of 0.1 mmol·kg at 2 mL·s. Model-free analysis of signal intensity time curves in regions of interest from a lower, middle and upper axial plane, a posterior coronal plane and the whole lung yielded parameters reflective of perfusion and permeability (peak enhancement and rate of contrast arrival (k)) and the extracellular extravascular space (rate of contrast clearance (k)). These imaging parameters were compared between IPF and healthy control subjects, and between fast/slow IPF progressors.
IPF subjects (n=16, 56% male, age (range) 67.5 (60-79) years) had significantly reduced peak enhancement and slower k in all measured lung regions compared to the healthy volunteers (n=17, 65% male, age (range) 58 (51-63) years) on unadjusted analyses consistent with microvascular alterations. k, as a measure of the extravascular extracellular space, was significantly slower in the lower lung and posterior coronal regions in the IPF subjects consistent with an increased extravascular extracellular space. All estimates were attenuated after adjusting for age. Similar trends were observed, but only the associations with k in certain lung regions remained statistically significant. Among IPF subjects, k rates nearly perfectly discriminated between those with rapidly progressive disease those with stable/slowly progressive disease.
DCE-MRI detects changes in the microvasculature and extravascular extracellular space in IPF, thus providing regional functional information.
有证据表明，特发性肺纤维化（IPF）患者的肺微血管存在异常。我们推测动态对比增强（DCE）磁共振成像（MRI）能够检测IPF患者的通透性、灌注及细胞外血管外容积的改变，从而提供其他方法无法获取的区域功能信息。
健康对照者和IPF患者采用动态容积径向采样序列，以2 mL·s的速率静脉注射0.1 mmol·kg的钆喷酸葡胺，进行胸部DCE-MRI检查。对下、中、上轴面、后冠状面及全肺感兴趣区的信号强度-时间曲线进行无模型分析，得出反映灌注和通透性的参数（峰值增强和对比剂到达速率（k））以及细胞外血管外间隙（对比剂清除速率（k））。比较IPF患者与健康对照者之间，以及快速/缓慢进展的IPF患者之间的这些成像参数。
未经校正的分析显示，与健康志愿者（n = 17，65%为男性，年龄（范围）58（51 - 63）岁）相比，IPF患者（n = 16，56%为男性，年龄（范围）67.5（60 - 79）岁）在所有测量的肺区域中峰值增强均显著降低，k值较慢，这与微血管改变一致。作为血管外细胞外间隙指标的k值，在IPF患者的下肺和后冠状区域显著较慢，这与血管外细胞外间隙增加一致。校正年龄后，所有估计值均减弱。观察到类似趋势，但仅某些肺区域与k值的关联仍具有统计学意义。在IPF患者中，k值几乎能完美区分快速进展性疾病患者和稳定/缓慢进展性疾病患者。
DCE-MRI可检测IPF患者微血管和血管外细胞外间隙的变化，从而提供区域功能信息。
