Computed Tomography Vascular Tree-in-Bud: A Novel Prognostic Imaging Biomarker in COVID-19?

Eddy and Sin discuss the study by Patel and colleagues on pulmonary vasculature on CT imaging and its physiologic and hematologic correlates in mechanically ventilated patients with severe COVID-19 pneumonia. This retrospective study included 39 consecutive patients with acute COVID-19 respiratory failure who showed increased physiologic dead space as evidenced by reduced dynamic compliance (mean, 33.7 ml/cm H2O) and elevated ventilatory ratio (mean, 2.6), in agreement with previous results and suggestive of marked vascular involvement. Pulmonary vascular abnormalities were assessed by the presence of dilated peripheral vessels, identified as a vascular "tree-in-bud" pattern, as well as pulmonary perfusion abnormalities in a subset of 18 patients who were able to undergo dual-energy CT imaging.