Institute of Diagnostic and Interventional Radiology, Hannover Medical School, Carl-Neuberg-Str.1, 30625, Hannover, Germany.
Department of Radiology, Radboud University, Nijmegen, The Netherlands.
Eur Radiol. 2022 Sep;32(9):6046-6057. doi: 10.1007/s00330-022-08702-w. Epub 2022 Mar 31.
Idiopathic pulmonary fibrosis (IPF) is a disease with a poor prognosis and a highly variable course. Pathologically increased ventilation-accessible by functional CT-is discussed as a potential predecessor of lung fibrosis. The purpose of this feasibility study was to investigate whether increased regional ventilation at baseline CT and morphological changes in the follow-up CT suggestive for fibrosis indeed occur in spatial correspondence.
In this retrospective study, CT scans were performed at two time points between September 2016 and November 2020. Baseline ventilation was divided into four categories ranging from low, normal to moderately, and severely increased (C1-C4). Correlation between baseline ventilation and volume and density change at follow-up was investigated in corresponding voxels. The significance of the difference of density and volume change per ventilation category was assessed using paired t-tests with a significance level of p ≤ 0.05. The analysis was performed separately for normal (NAA) and high attenuation areas (HAA).
The study group consisted of 41 patients (73 ± 10 years, 36 men). In both NAA and HAA, significant increases of density and loss of volume were seen in areas of severely increased ventilation (C4) at baseline compared to areas of normal ventilation (C2, p < 0.001). In HAA, morphological changes were more heterogeneous compared to NAA.
Functional CT assessing the extent and distribution of lung parenchyma with pathologically increased ventilation may serve as an imaging marker to prospectively identify lung parenchyma at risk for developing fibrosis.
• Voxelwise correlation of serial CT scans suggests spatial correspondence between increased ventilation at baseline and structural changes at follow-up. • Regional assessment of pathologically increased ventilation at baseline has the potential to prospectively identify tissue at risk for developing fibrosis. • Presence and extent of pathologically increased ventilation may serve as an early imaging marker of disease activity.
特发性肺纤维化（IPF）是一种预后不良且病程高度多变的疾病。功能 CT 显示的病理性通气增加被认为是肺纤维化的潜在前兆。本可行性研究的目的是调查基线 CT 上区域性通气增加和随访 CT 上提示纤维化的形态变化是否确实存在空间对应关系。
在这项回顾性研究中，于 2016 年 9 月至 2020 年 11 月之间分两个时间点进行 CT 扫描。将基线通气分为低、正常、中度和重度增加四个类别（C1-C4）。在相应体素中，研究了基线通气与随访时体积和密度变化之间的相关性。使用具有显著性水平 p≤0.05 的配对 t 检验评估每个通气类别中密度和体积变化的差异显著性。分别对正常（NAA）和高衰减区（HAA）进行分析。
研究组包括 41 名患者（73±10 岁，36 名男性）。在 NAA 和 HAA 中，与正常通气（C2）相比，基线时通气严重增加（C4）的区域可见密度显著增加和体积损失（p<0.001）。与 NAA 相比，HAA 中的形态变化更为异质。
功能 CT 评估病理性通气增加的肺实质范围和分布，可作为一种影像学标志物，前瞻性地识别有发生纤维化风险的肺实质。
• 系列 CT 扫描的体素相关性表明基线时通气增加与随访时结构变化之间存在空间对应关系。• 基线时病理性通气增加的区域评估有可能前瞻性地识别有发生纤维化风险的组织。• 病理性通气的存在和程度可能是疾病活动的早期影像学标志物。
