Correlations of Computed Tomography Measurement of Distal Pulmonary Vascular Pruning with Airflow Limitation and Emphysema in COPD Patients

Guoyan Tang; Fengyan Wang; Zhenyu Liang; Cuixia Liang; Jinling Wang; Yuqiong Yang; Wanyi Tang; Weijuan Shi; Guoqiang Tang; Kai Yang; Zihui Wang; Qiasheng Li; Hualin Li; Jiaxuan Xu; Deyan Chen; Rongchang Chen

doi:10.2147/COPD.S362479

Correlations of Computed Tomography Measurement of Distal Pulmonary Vascular Pruning with Airflow Limitation and Emphysema in COPD Patients

Int J Chron Obstruct Pulmon Dis. 2022 Sep 14:17:2241-2252. doi: 10.2147/COPD.S362479. eCollection 2022.

Authors

Guoyan Tang^#¹, Fengyan Wang^#¹, Zhenyu Liang^#¹, Cuixia Liang^#², Jinling Wang^#³, Yuqiong Yang¹, Wanyi Tang^{1

4}, Weijuan Shi¹, Guoqiang Tang³, Kai Yang⁵, Zihui Wang¹, Qiasheng Li¹, Hualin Li¹, Jiaxuan Xu¹, Deyan Chen², Rongchang Chen⁵

Affiliations

¹ State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Health, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
² Neusoft Medical Systems Co., Ltd, Shenyang, People's Republic of China.
³ Qingyuan Chronic Disease Prevention Hospital, Qingyuan Occupational Disease Prevention Hospital, Qingyuan, People's Republic of China.
⁴ Qingyuan People's Hospital, the Sixth Affiliated Hospital of Guangzhou Medical University, Guangzhou, People's Republic of China.
⁵ Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Southern University of Science and Technology, Second Clinical Medical College of Jinan University, Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, People's Republic of China.

^# Contributed equally.

Abstract

Background: Pulmonary vascular alteration is an important feature of chronic obstructive pulmonary disease (COPD), which is characterized by distal pulmonary vascular pruning in angiography. We aimed to further investigate the clinical relevance of pulmonary vasculature in COPD patients using non-contrast computed tomography (CT).

Methods: Seventy-one control subjects and 216 COPD patients completed the questionnaires, spirometry, and computed tomography (CT) scans within 1 month and were included in the study. Small pulmonary vessels represented by percentage of cross-sectional area of pulmonary vessels smaller than 5 mm² or 5-10 mm² to the total lung fields (%CSA<5 or %CSA5-10, respectively) were measured using ImageJ software. Spearman correlation was used to investigate the relationship between %CSA<5 and airflow limitation. A receiver operating characteristic (ROC) curve was built to evaluate the value of %CSA<5 in discriminating COPD patients from healthy control subjects. Segmented regression was used to analyze the relationship between %CSA<5 and %LAA-950 (percentage of low-attenuation areas less than -950 HU).

Results: We found a significant correlation between %CSA<5 and forced expiratory volume in one second (FEV1) percentage of predicted value (%pred) (r = 0.564, P < 0.001). The area under the ROC curve for the value of %CSA<5 in distinguishing COPD was 0.816, with a cut-off value of 0.537 (Youden index J, 0.501; sensitivity, 78.24%; specificity, 71.83%). Since the relationship between %CSA<5 and %LAA-950 was not constant, performance of segmented regression was better than ordinary linear regression (adjusted R², 0.474 vs 0.332, P < 0.001 and P < 0.001, respectively). As %CSA<5 decreased, %LAA-950 slightly increased until an inflection point (%CSA<5 = 0.524) was reached, after which the %LAA-950 increased apparently with a decrease in %CSA<5.

Conclusion: %CSA<5 was significantly correlated with both airflow limitation and emphysema, and we identified an inflection point for the relationship between %CSA<5 and %LAA-950.

Keywords: airflow limitation; chronic obstructive pulmonary disease; computed tomography; emphysema; pulmonary vascular pruning.

MeSH terms

Emphysema*
Forced Expiratory Volume
Humans
Lung
Pulmonary Disease, Chronic Obstructive* / diagnostic imaging
Pulmonary Emphysema* / diagnostic imaging
Pulmonary Emphysema* / etiology
Tomography, X-Ray Computed / methods
Vital Capacity

Grants and funding

National Key R&D Program of China (2017YFC1310600, 2018YFC1311900); Medical Scientific Research Foundation of Guangdong Province (C2019001, A2019459); National Natural Science Foundation of China (82170042); the Shenzhen Science Technology and Innovative commission (KCXFZ202002011008256); Science and Technology Program of Guangzhou (202201020451).