ABSTRACT
Objective:To explore the diagnostic value of CT pulmonary vascular quantitative parameters in patients with chronic obstructive pulmonary disease (COPD) and high-risk groups.Methods:A retrospective study of 1 126 patients who underwent chest CT examination and pulmonary function test in Shanghai Tongji Hospital from January 2015 to August 2020. According to lung function, they were divided into COPD group (471 cases), high-risk group (454 cases), and normal control group (201 cases). Pulmonary vascular parameters on chest CT, including the total number of vessels (N total), the number cross-sectional area of vessels under 5 mm 2 (N CSA<5), lung surface area (LSA), number of pulmonary blood vessels per unit lung surface area (N total/LSA) and the total area of vessels (VA total) at a 9, 15, 21 mm depth from the pleural surface, and the total blood vessel volume (TBV), blood vessel volume under 5 mm 2 and 10 mm 2(BV5 and BV10) were measured quantitatively. Kruskal-Wallis H test was used to compare the differences of quantitative parameters of pulmonary vascular in the three groups; Spearman rank test was used to analyze the correlation between CT pulmonary vascular parameters and pulmonary function. Results:There were significant differences in N total/LSA at a 9, 15, 21 mm depth from the pleural surface among three groups ( P<0.05). There were significant differences in N CSA<5, N total at a 9 mm depth from the pleural surface among three groups ( P<0.05). There were significant differences in LSA at a 9 mm depth from the pleural surface, N CSA<5, N total, LSA, VA total at a 15, 21 mm depth from the pleural surface and TBV, BV5 and BV10 among three groups ( P<0.05). In high-risk group, there were positive correlation between N total/LSA, VA total at a 9 mm depth from the pleural surface and some pulmonary function parameters ( r=0.095-0.139, P<0.05). N CSA<5, N total, LSA, N total/LSA, TBV, BV5 and BV10 at different depth from pleural surface were negatively correlated with some pulmonary function parameters ( r=-0.110--0.215, P<0.05). In COPD group, number of vessels at a 9 mm depth from the pleural surface was positively correlated with the diffusion capacity for carbon monoxide of the lung single breath ( r=0.105, 0.103, P<0.05). In addition to N total/LSA were positively correlated with lung function parameters ( r=0.181-0.324, P<0.05), the remaining pulmonary vascular parameters were negatively correlated with some pulmonary function parameters ( r=-0.092--0.431, P<0.05). Conclusion:Quantitative chest CT imaging are able to effectively evaluate pulmonary vascular changes in COPD patients and high-risk groups, and the quantitative parameters of pulmonary vascular CT may distinguish COPD from high-risk groups, providing a novel means for early diagnosis of COPD and prediction of high-risk groups.