METHODS: After institutional review board approval and informed consent and in compliance with HIPAA regulations, we performed chest CT, pulmonary function tests (PFTs), and 129Xe MRI in 10 UIP subjects and 10 healthy controls.
RESULTS: The 129Xe MRI detected highly heterogeneous abnormalities within individual UIP subjects as compared to controls. Subjects with UIP had markedly impaired ventilation (ventilation defect fraction: UIP: 30 ± 9%; healthy: 21 ± 9%; p = 0.026), a greater amount of 129Xe dissolved in the lung interstitium (tissue-to-gas ratio: UIP: 1.45 ± 0.35%; healthy: 1.10 ± 0.17%; p = 0.014), and impaired 129Xe diffusion into the blood (RBC-to-tissue ratio: UIP: 0.20 ± 0.06; healthy: 0.28 ± 0.05; p = 0.004). Most MRI variables had no correlation with the CT and PFT measurements. The elevated level of 129Xe dissolved in the lung interstitium, in particular, was detectable even in subjects with normal or mildly impaired PFTs, suggesting that this measurement may represent a new method for detecting early fibrosis.
CONCLUSIONS: The hyperpolarized 129Xe MRI was highly sensitive to regional functional changes in subjects with UIP and may represent a new tool for understanding the pathophysiology, monitoring the progression, and assessing the effectiveness of treatment in UIP.
方法:在机构审查委员会批准和知情同意后,并符合HIPAA法规,我们做了胸部CT,肺功能测试(PFTs),10名UIP受试者和10名健康对照者的129XeMRI。
结果:与对照组相比,129XeMRI在单个UIP受试者中检测到高度异质性异常。UIP患者的通气功能明显受损(通气缺陷分数:UIP:30±9%;健康:21±9%;p=0.026),更大量的129Xe溶解在肺间质中(组织-气体比:UIP:1.45±0.35%;健康:1.10±0.17%;p=0.014),129Xe扩散到血液中(红细胞与组织的比率:UIP:0.20±0.06;健康:0.28±0.05;p=0.004)。大多数MRI变量与CT和PFT测量值没有相关性。升高的129Xe溶解在肺间质中,特别是,即使在PFT正常或轻度受损的受试者中也能检测到,这表明这种测量可能代表了一种检测早期纤维化的新方法。
结论:超极化129XeMRI对UIP患者的区域功能变化高度敏感,可能是了解病理生理学的新工具,监测进展,并评估UIP治疗的有效性。