特发性肺纤维化以外的系统性硬化症患者的肺血管形态与气体交换相关。

Pulmonary Vascular Morphology Associated With Gas Exchange in Systemic Sclerosis Without Lung Fibrosis.

机构信息

Departments of Radiology, Division of Image Processing.

Pulmonology.

出版信息

J Thorac Imaging. 2019 Nov;34(6):373-379. doi: 10.1097/RTI.0000000000000395.

DOI:10.1097/RTI.0000000000000395

PMID:30817504

Abstract

PURPOSE

Gas exchange in systemic sclerosis (SSc) is known to be affected by fibrotic changes in the pulmonary parenchyma. However, SSc patients without detectable fibrosis can still have impaired gas transfer. We aim to investigate whether pulmonary vascular changes could partly explain a reduction in gas transfer of SSc patients without fibrosis.

MATERIALS AND METHODS

We selected 77 patients whose visual computed tomography (CT) scoring showed no fibrosis. Pulmonary vessels were detected automatically in CT images, and their local radii were calculated. The frequency of occurrence for each radius was calculated, and, from this radius histogram, 2 imaging biomarkers (α and β) were extracted, wherein α reflects the relative contribution of small vessels compared with large vessels, and β represents the vessel tree capacity. Correlations between imaging biomarkers and gas transfer [single-breath diffusion capacity for carbon monoxide corrected for hemoglobin concentration (DLCOc) %predicted] were evaluated with Spearman correlation. Multivariable stepwise linear regression was performed with DLCOc %predicted as the dependent variable and age, BMI, sPAP, FEV1 %predicted, TLC %predicted, FVC %predicted, α, β, voxel size, and CT-derived lung volume as independent variables.

RESULTS

Both α and β were significantly correlated with gas transfer (R=-0.29, P-value=0.011 and R=0.32, P-value=0.004, respectively). The multivariable stepwise linear regression analysis selected sPAP [coefficient=-0.78; 95% confidence interval (CI)=-1.07, -0.49; P-value<0.001], β (coefficient=8.6; 95% CI=4.07, 13.1; P-value<0.001), and FEV1% predicted (coefficient=0.3; 95% CI=0.12, 0.48; P-value=0.001) as significant independent predictors of DLCOc %predicted (R=0.71, P-value<0.001).

CONCLUSIONS

In SSc patients without detectable pulmonary fibrosis, impaired gas exchange is associated with alterations in pulmonary vascular morphology.

摘要

目的

已知系统性硬皮病（SSc）的气体交换会受到肺实质纤维化改变的影响。然而，没有可检测到纤维化的 SSc 患者仍然可能存在气体转移受损。我们旨在研究肺血管变化是否可以部分解释无纤维化 SSc 患者气体转移减少的原因。

材料和方法

我们选择了 77 名视觉计算机断层扫描（CT）评分显示无纤维化的患者。在 CT 图像中自动检测肺血管，并计算其局部半径。计算每个半径的出现频率，并从该半径直方图中提取 2 个成像生物标志物（α和β），其中α反映小血管与大血管相比的相对贡献，β代表血管树容量。使用 Spearman 相关性评估成像生物标志物与气体转移[血红蛋白校正后一氧化碳单呼吸弥散量（DLCOc）%预测值]之间的相关性。使用多元逐步线性回归，以 DLCOc %预测值为因变量，年龄、BMI、sPAP、FEV1 %预测值、TLC %预测值、FVC %预测值、α、β、体素大小和 CT 衍生的肺容积为自变量。

结果

α和β均与气体转移显著相关（R=-0.29，P 值=0.011 和 R=0.32，P 值=0.004）。多元逐步线性回归分析选择 sPAP[系数=-0.78；95%置信区间（CI）=-1.07，-0.49；P 值<0.001]、β（系数=8.6；95%CI=4.07，13.1；P 值<0.001）和 FEV1%预测值（系数=0.3；95%CI=0.12，0.48；P 值=0.001）为 DLCOc %预测值的显著独立预测因子（R=0.71，P 值<0.001）。