Ventilation/perfusion SPECT/CT findings in different lung lesions associated with COVID-19: a case series

Abstract

Purpose: The aim of this series of cases is to show the aspects of ventilation/perfusion single-photon emission computed tomography combined with computed tomography (V/Q SPECT/CT) in patients hospitalized for COVID-19 pneumonia, with the worsening of respiratory symptoms raising the suspicion of a pulmonary embolism. Patients did not benefit from CT angiography for various reasons: a contraindication, unavailability of the CT angiography, or a low clinical probability for pulmonary embolism. Methods: We retrospectively describe the results of the V/Q SPECT/CT of five patients hospitalized for COVID-19 pneumonia in the nuclear medicine departments of the Centre Cardiologique du Nord and of the Delafontaine hospital in Saint-Denis (Ile-de-France, France) between April 2, 2020, and April 10, 2020. These patients had persistent dyspnea or chest pain suggesting pulmonary embolism. Results: The V/Q SPECT/CT allowed to diagnose a pulmonary embolism in one of these five patients. We also noted several characteristics of the perfusion and ventilation depending on the lung lesions on the CT scan. The areas affected by COVID-19 were most often responsible for ventilatory anomalies with a relatively preserved perfusion. In more advanced cases of pneumonia, with alveolar fillings, the perfusion was also reduced or absent in accordance with large ventilation defects. In addition, the healthy parenchyma appeared to benefit from an uptake in ventilation and perfusion. Conclusion: V/Q SPECT/CT can play a role in the management of patients hospitalized for COVID-19 for the diagnosis of embolic complications with meticulous hygienic precautions. The different characteristics of the ventilatory and perfusion anomalies related to COVID-19 pneumonia will be confirmed with the next cases. In addition, in this pandemic context and facing a significant infectious risk, the utility of ventilation will also have to be specified.