[Quantitative measurement of cross-sectional area of small pulmonary vessels in pulmonary embolism].

Abstract

Objective: The relationship between the percentage of total cross-sectional area (% CSA) of small pulmonary vessels for the lung area in CTPA and the right ventricular function parameters in patients with pulmonary embolism. Methods: 120 patients with PE and 72 healthy subjects underwent CTPA and all date were analyzed Retrospectively. The main pulmonary artery diameter (mPA), the ratio of the main pulmonary artery to the ascending aorta diameter (rPA), right ventricle/left ventricular diameter ratio (RVd/LVd), and the pulmonary artery obstruction index (PAOI) in the PE group were measured for all subjects. The %CSA<5 mm(2) and 5-10 mm(2) for the lung area (%CSA(<5) and %CSA(5-10)) of small pulmonary vessels were measured with Image J image-processing program. According to the risk stratification of the 2018 Guidelines for the Diagnosis and Treatment of Pulmonary Thromboembolism, PE patients were divided into medium-high risk group (RVd/LVd>1) and low-risk group (RVd/LVd<1). The indexes of PE in medium-high risk group, low risk group and control group were compared by ANOVA, and the indexes among PE subgroups were compared by independent sample t-test. Spearman correlation method was used to analyze the correlation between %CSA and right ventricular function parameters of PE patients. Results: %CSA(<5) of medium-high risk group, low-risk group and control group were (0.69±0.19)%, (0.95±0.27)% and (0.99±0.30)% (P<0.01), respectively. %CSA(5-10) of three groups were (0.63±0.15)%, (0.84±0.18)%, and (0.85±0.25)% (P<0.01), respectively; %CSA(<5) and %CSA(5-10) of medium-high risk group were lower than low-risk group and control group. %CSA(<5) and %CSA(5-10) in PE patients correlated negatively with RVd/LVd, rPA and mPA (r=-0.545/-0.549, -0.235/-0.352, -0.239/-0.298, respectively). Conclusion: The measurement of % CSA<(5) and %CSA (5-10) in CTPA were negatively correlated with RVd/LVd in patients with pulmonary embolism, which indirectly reflected the severity of the pulmonary embolism patients.