To assess pulmonary vascular metrics about chest CT of COVID-19 patients, and their correlation with pneumonia extent (PnE) and outcome, we analyzed COVID-19 patients with an available previous chest CT, excluding those performed for cardiovascular disease. were found in 29/45 patients, GGOs with consolidations in 15/45, consolidations alone in 1/45. All but one patient had bilateral pneumonia, 9/45 minimal, 22/45 mild, 9/45 moderate, and 5/45 severe PnE. PA diameter (median 31 mm, IQR 28C33 mm) was larger than before (26 mm, IQR 25C29 mm) (P 0.001), PA/Ao ratio (median 0.83, IQR 0.76C0.92) was higher than before (0.76, IQR 0.72C0.82) (P 0.001). Patients with adverse outcome (death) had higher PA diameter (P=0.001), compared to discharged ones. Only weak correlations were found between PA or PA/Ao and PnE (0.453, Framycetin P0.032), with 4/45 cases with moderate-severe PnE and minimal increase in PA metrics. In conclusion, enlarged PA diameter was associated to death in COVID-19 patients, a finding deserving further investigation as a potential driver of therapy decision-making. (2): 0% (absent); 1C25% (minimal); 26C50% (mild); 51C75% (moderate); over 75% (severe). Perilesional vascular enlargement, defined as presence/absence of enlargement of pulmonary vessels next to lung parenchymal opacities, was qualitatively assessed (4). Finally, as described by Wells (9), the PA maximum diameter at the level of its bifurcation and the Ao maximum diameter were assessed in a single slice (test and the 2 2 test were used to compare vascular metrics and PnE between groups with different outcomes. Statistical analysis was performed using SPSS v.22.0 (IBM SPSS Inc., Chicago, IL, USA), and P values 0.05 were considered statistically significant. Results Population characteristics In the study timeframe, 374 patients underwent triage chest CT for suspected SARS-CoV-2 infection at Center 1, 298 patients at Center 2. A previous CT examination was available for 45 of subsequently confirmed COVID-19 patients (median age 75.2 years, IQR 66.0C81.0 years), twenty-eight of them (62%) being males. At ER Framycetin admission, 15 patients (33%) had both fever and dyspnea, 9 (20%) patients had both fever and cough, 13 (29%) only fever, 4 (9%) only dyspnea, 1 (2%) only cough, and 3 (7%) respiratory insufficiency. PaO2-Adm was available for 37 patients, with a median 70 mmHg (IQR 55C94 mmHg). Outcome data were available for 41/45 patients, 15/41 (37%) died after progression to severe ARDS and 26/41 (63%) discharged after a median 10 days hospitalization (IQR 0C20 days). The previous CT scans used as baseline examinations were performed a median 36 months before ER admission (IQR 12C72 months). Pulmonary parenchymal CT features All but one patient had bilateral pneumonia, GGOs without consolidation being found in 29 (65%) patients, both GGOs and consolidation in 15 (33%), consolidations alone in one patient only (2%). Only one patient had associated crazy-paving. PnE was categorized as minimal in nine patients (20%), mild in 22 (49%), moderate in 9 (20%), and severe Framycetin in 5 (11%). Pulmonary perilesional vascular enlargement was found in 10 patients (22%), 6 of Framycetin them with bilateral consolidations. Five patients had bilateral pleural effusion and three others showed mediastinum lymphadenopathies. Vascular metrics Median PApre diameter was 26 mm (IQR 25C29 mm), median PApost diameter was 31 mm (IQR 28C33 mm) (P 0.001, PApost-pre values showed Framycetin a significant but weak correlation with PnE (=0.321, P=0.032). PA/Aopost-pre values (This study was partially supported by Ricerca Corrente funding C13orf18 from Italian Ministry of Health to IRCCS Policlinico San Donato. Notes This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). Discover: https://creativecommons.org/licenses/by-nc-nd/4.0/. Footnotes All writers have finished the ICMJE standard disclosure type (offered by http://dx.doi.org/10.21037/qims-20-546). SS declares to become member of loudspeakers bureau for General Electric powered and to have obtained travel support from Bracco. FS declares to have obtained grants from or even to be person in speakers bureau/advisory panel for Bayer, General and Bracco Electric. The additional authors haven’t any conflicts appealing to declare..