Ventilation-perfusion mismatches in the lungs contribute to hypoxaemia in patients with COVID-19, researchers report.

Doctors from Massachusetts General Hospital in Boston, US, used dual-energy CT imaging to characterise lung perfusion in three patients with COVID-19 who presented with elevated concentrations of D-dimer and clinical suspicion of pulmonary emboli.

No pulmonary emboli were observed but there were “striking perfusion abnormalities that have not been previously described”.

“In addition to the typical CT features of COVID-19 pneumonia, we observed considerable proximal and distal pulmonary vessel dilatation and tortuoisty, predominately within, or surrounding, areas of lung opacities.”