Pathology Graduate Program, Federal University of Health Sciences of Porto Alegre - R. Sarmento Leite, 245, Porto Alegre, 90050170, Brazil.
Medical Imaging Research Lab, LABIMED, Department of Radiology, Pavilhão Pereira Filho Hospital, Irmandade Santa Casa de Misericórdia de Porto Alegre - Av, Independência, 75, Porto Alegre, 90020160, Brazil.
Sci Rep. 2018 Nov 22;8(1):17267. doi: 10.1038/s41598-018-35387-3.
This study was conducted to evaluate the presence of air trapping in patients with idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases (ILDs) (non-IPF), showing the radiological pattern of usual interstitial pneumonia (UIP). Retrospectively, we included 69 consecutive patients showing the typical UIP pattern on computed tomography (CT), and 15 final diagnosis of IPF with CT pattern "inconsistent with UIP" due to extensive air trapping. Air trapping at CT was assessed qualitatively by visual analysis and quantitatively by automated-software. In the quantitative analysis, significant air trapping was defined as >6% of voxels with attenuation between -950 to -856 HU on expiratory CT (expiratory air trapping index [ATIexp]) or an expiratory to inspiratory (E/I) ratio of mean lung density >0.87. The sample comprised 51 (60.7%) cases of IPF and 33 (39.3%) cases of non-IPF ILD. Most patients did not have air trapping (E/I ratio ≤0.87, n = 53, [63.1%]; ATIexp ≤6%, n = 45, [53.6%]). Air trapping in the upper lobes was the only variable distinguishing IPF from non-IPF ILD (prevalence, 3.9% vs 33.3%, p < 0.001). In conclusion, air trapping is common in patients with ILDs showing a UIP pattern on CT, as determined by qualitative and quantitative evaluation, and should not be considered to be inconsistent with UIP. On subjective visual assessment, air trapping in the upper lobes was associated with a non-IPF diagnoses.
这项研究旨在评估特发性肺纤维化（IPF）和其他间质性肺疾病（ILDs）（非 IPF）患者中空气潴留的存在情况，这些患者表现出普通间质性肺炎（UIP）的放射学模式。我们回顾性地纳入了 69 例连续患者，这些患者的计算机断层扫描（CT）显示典型的 UIP 模式，其中 15 例最终诊断为 IPF，但 CT 模式“不符合 UIP”，原因是广泛的空气潴留。通过视觉分析和自动软件对 CT 上的空气潴留进行定性评估和定量评估。在定量分析中，空气潴留被定义为呼气 CT 上衰减值在-950 至-856 HU 之间的体素（呼气空气潴留指数 [ATIexp]）大于 6%，或平均肺密度的呼气与吸气（E/I）比值大于 0.87。该样本包括 51 例（60.7%）IPF 患者和 33 例（39.3%）非 IPF ILD 患者。大多数患者没有空气潴留（E/I 比值≤0.87，n=53，[63.1%]；ATIexp≤6%，n=45，[53.6%]）。上叶空气潴留是唯一能区分 IPF 和非 IPFILD 的变量（患病率分别为 3.9%和 33.3%，p<0.001）。总之，通过定性和定量评估，CT 显示 UIP 模式的 ILD 患者中空气潴留很常见，不应认为与 UIP 不一致。在主观视觉评估中，上叶空气潴留与非 IPF 诊断相关。
