High-resolution chest CT angiography of patients with COVID-19 pneumonia: A longitudinal prospective study

Background: Vascular findings in coronavirus disease 2019 (COVID-19) are not systematically described using 384-row state-of-the-art chest CT angiography (CTA). The relationship between CT-CTA features and arterial blood gas (ABG) parameters is not fully understood. Methods: Chest CT images were acquired with Dual Source 384-slice (2×192) CT (Siemens SOMATOM Force). Quantitative volumetric assessment of lung lesions and the CT severity score were calculated by using a deep learning algorithm trained on COVID-19 pneumonia and correlated with ABG parameters. Assessment of pulmonary vascular tree was performed on CTA images. Statistical analysis included Mann-Whitney U test and non-parametric Spearman’s Rho test, with significance threshold at P<0.05. Results: Out of the 36 patients referred to the Covid Center, 30.6% (11/36) were admitted to the intensive care unit (ICU) and 69.4% (25/36) to the non-ICU low-cure Covid Medicine. We found a significant inverse relationship between the P/F ratio and lung lesion volume relative percentages (r=–0.52; 95% CI: –0.72, –0.23; P=0.001), absolute volume (r=–0.58; 95% CI: –0.76, –0.31; P<0.001) and the CT severity score (r=–0.60; 95% CI: –0.77, –0.34; P<0.001) at day 0. At day 7, CTA showed pulmonary embolism in 2/10 patients (20%). In 9/10 patients (90%) CTA detected vascular wall thickening/irregularity and stenoses of segmental and/or subsegmental branches of pulmonary artery. CTA demonstrated subsegmental tubular vessel dilation in all cases (100%) and the presence of subsegmental focal vessel dilations in 6/10 patients (60%). Conclusions: In conclusion, 384-row Chest CTA is able to capture the full spectrum of vascular pathology in COVID-19, comprising pulmonary embolism and stenoses together with tubular and focal dilations of segmental and/or subsegmental branches of pulmonary artery.