Young Hoon Cho1, Sang Min Lee2, Joon Beom Seo1, Namkug Kim1, Jang Pyo Bae1, Jae Seung Lee3, Yeon-Mok Oh3, Sang Do-Lee3. 1. Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul, 138-736, South Korea. 2. Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul, 138-736, South Korea. Electronic address: asellion@hanmail.net. 3. Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Poongnap-dong, Songpa-gu, Seoul, 138-736, South Korea.
Abstract
PURPOSE: Despite the high prevalence of pulmonary vascular alterations and their substantial impact on chronic obstructive pulmonary disease (COPD), tools for the direct in vivo assessment of pulmonary vascular alterations remain limited. Thus, the purpose of this study was to automatically extract pulmonary vessels from volumetric chest CT and evaluate the associations between the derived quantitative pulmonary vessel features and clinical parameters, including survival, in COPD patients. METHODS: This study included 344 adult COPD patients. Pulmonary vessels were automatically extracted from volumetric chest CT data. Quantitative pulmonary vessel features were obtained from various lung surface areas (LSAs), which are theoretical surface areas drawn at different depths from the pleural borders. The total number of vessels (Ntotal) and number of vessels with vessel area (VA) less than 5 mm2 (N<5mm) were counted as both robust values and as values per 10 cm2 of LSA (Ntotal/LSA; N<5mm/LSA). The average VA (VAmean) and percentage of measured VA in the corresponding LSA (%VA) were measured. Associations between quantitative pulmonary vessel features and clinical parameters, including survival and the pulmonary function test (PFT), were evaluated. RESULTS: The pulmonary vessels were automatically extracted with 100% technical success. Cox regression analysis showed Ntotal/LSA, N<5mm/LSA, VAmean, and %VA to be significant predictors of survival (hazard ratio (HR), 0.80, 0.75, 0.70, 0.49, respectively). Patients classified into high-risk groups by %VA18mm (cut-off = 3.258), chosen because it demonstrated the strongest statistical influence on survival in a univariate Cox analysis, were associated with worse overall survival before (HR, 4.83; p < 0.001) and after adjustment for patient age and BMI (HR, 2.18; p = 0.014). Of the quantitative pulmonary vessel features, Ntotal/LSA, N<5mm/LSA, and %VA were correlated with FEV1, FEV1/FVC, and DLCO in all LSAs. The strongest correlation with PFTs was noted at LSA9mm for both Ntotal (FEV1, r = 0.33; FEV1/FVC, r = 0.51) and N<5mm (FEV1, r = 0.35; FEV1/FVC, r = 0.52). For %VA, the association was most evident at LSA18mm (FEV1, r = 0.27; FEV1/FVC, r = 0.47). Significant moderate to strong correlations were consistently observed between the extent of emphysema and quantitative pulmonary vessel features (r = 0.44-0.66; all p < 0.001). CONCLUSIONS: The automated extraction of pulmonary vessels and their quantitative assessment are technically feasible. Various quantitative pulmonary vessel features demonstrated significant relationships with survival and PFT in COPD patients. Of the various quantitative features, the percentage of total VA measured at 18 mm depth from the pleural surface (%VA18mm) and the number of small vessels counted per 10 cm2 of LSA at 9 mm depth from the pleural surface (N<5mm/LSA9mm) had the strongest predictability for the clinical parameters.
PURPOSE: Despite the high prevalence of pulmonary vascular alterations and their substantial impact on chronic obstructive pulmonary disease (COPD), tools for the direct in vivo assessment of pulmonary vascular alterations remain limited. Thus, the purpose of this study was to automatically extract pulmonary vessels from volumetric chest CT and evaluate the associations between the derived quantitative pulmonary vessel features and clinical parameters, including survival, in COPDpatients. METHODS: This study included 344 adult COPDpatients. Pulmonary vessels were automatically extracted from volumetric chest CT data. Quantitative pulmonary vessel features were obtained from various lung surface areas (LSAs), which are theoretical surface areas drawn at different depths from the pleural borders. The total number of vessels (Ntotal) and number of vessels with vessel area (VA) less than 5 mm2 (N<5mm) were counted as both robust values and as values per 10 cm2 of LSA (Ntotal/LSA; N<5mm/LSA). The average VA (VAmean) and percentage of measured VA in the corresponding LSA (%VA) were measured. Associations between quantitative pulmonary vessel features and clinical parameters, including survival and the pulmonary function test (PFT), were evaluated. RESULTS: The pulmonary vessels were automatically extracted with 100% technical success. Cox regression analysis showed Ntotal/LSA, N<5mm/LSA, VAmean, and %VA to be significant predictors of survival (hazard ratio (HR), 0.80, 0.75, 0.70, 0.49, respectively). Patients classified into high-risk groups by %VA18mm (cut-off = 3.258), chosen because it demonstrated the strongest statistical influence on survival in a univariate Cox analysis, were associated with worse overall survival before (HR, 4.83; p < 0.001) and after adjustment for patient age and BMI (HR, 2.18; p = 0.014). Of the quantitative pulmonary vessel features, Ntotal/LSA, N<5mm/LSA, and %VA were correlated with FEV1, FEV1/FVC, and DLCO in all LSAs. The strongest correlation with PFTs was noted at LSA9mm for both Ntotal (FEV1, r = 0.33; FEV1/FVC, r = 0.51) and N<5mm (FEV1, r = 0.35; FEV1/FVC, r = 0.52). For %VA, the association was most evident at LSA18mm (FEV1, r = 0.27; FEV1/FVC, r = 0.47). Significant moderate to strong correlations were consistently observed between the extent of emphysema and quantitative pulmonary vessel features (r = 0.44-0.66; all p < 0.001). CONCLUSIONS: The automated extraction of pulmonary vessels and their quantitative assessment are technically feasible. Various quantitative pulmonary vessel features demonstrated significant relationships with survival and PFT in COPDpatients. Of the various quantitative features, the percentage of total VA measured at 18 mm depth from the pleural surface (%VA18mm) and the number of small vessels counted per 10 cm2 of LSA at 9 mm depth from the pleural surface (N<5mm/LSA9mm) had the strongest predictability for the clinical parameters.
Authors: Ju Gang Nam; Joseph Nathanael Witanto; Sang Joon Park; Seung Jin Yoo; Jin Mo Goo; Soon Ho Yoon Journal: Eur Radiol Date: 2021-05-19 Impact factor: 5.315
Authors: Anne-Noëlle Frix; François Cousin; Turkey Refaee; Fabio Bottari; Akshayaa Vaidyanathan; Colin Desir; Wim Vos; Sean Walsh; Mariaelena Occhipinti; Pierre Lovinfosse; Ralph T H Leijenaar; Roland Hustinx; Paul Meunier; Renaud Louis; Philippe Lambin; Julien Guiot Journal: J Pers Med Date: 2021-06-25