CT-derived measurements of pulmonary blood volume in small vessels and need for oxygen in COVID-19 patients

In contrast to early reports of conventional acute respiratory distress syndrome (ARDS) as the underlying pathophysiology of hypoxemic respiratory failure observed in patients with severe COVID-19, more recent findings implicate direct involvement of the pulmonary vasculature in giving rise to these symptoms. In earlier research, we demonstrated that patients with COVID-19 showed markedly reduced pulmonary blood volumes in pulmonary vessels <5 mm² in cross-sectional area visible on imaging (termed “BV5”), with attendant dilation of larger, more proximal vessels. Here, we present preliminary results in which reduced BV5 is shown to correlate significantly with increased need for supplemental oxygen and abnormal arterial blood gas measurements in hospitalized COVID-19 patients. We suggest a potential mechanistic link between observed clinical, pathological, and imaging findings, and outline how these may be helpful in clinical assessment as well as the development of novel therapies.