RESUMEN
There have been over 481 million cases of Coronavirus Disease-19 (COVID-19), caused by the SARS-CoV-2 virus worldwide since December 2019 [1]. One of the hallmark features of acute COVID-19 pneumonia is pulmonary vascular involvement, most commonly manifesting as pulmonary artery thrombosis (PAT) [2, 3]. Post-mortem data in ten patients with COVID-19 pneumonia shows their central pulmonary arteries were free of thrombosis but all patients had small, firm thrombi in the peripheral parenchyma [4]. These findings raise the possibility that the CT finding of isolated subsegmental PAT may reflect "the tip of the iceberg”;that small segmental thrombi may reflect downstream in situ thrombosis in the microvasculature. In patients with severe COVID-19 pneumonitis, Dual-Energy CTPA (DECTPA) has been used to demonstrate reduced pulmonary perfusion in the absence of any visible central thromboembolism [5, 6], further supporting the view that microscopic PAT is prevalent [6].