Inflammatory and functional imaging aspects of COVID-19: analysis of PET/CT and pulmonary perfusion scintigraphy imaging findings

COVID-19 disease caused by the new coronoavirus (SARS-CoV-2) has killed almost 2.5 million people worldwide, 250 thousand of which registered in Brazil, and the discovery of new mutations is indicative that pandemic condition is expected to last in the coming months. Clinical picture and outcome of COVID-19 patients are very heterogeneous and studies on functional imaging, inflammatory and coagulation profile are justified. There is evidence that COVID-19 patients may develop disseminated intravascular coagulation, with prothrombotic nature and high risk of venous thromboembolism, especially pulmonay (PTE), which has a substantial impact on evolution and increases mortality. D-dimer, fibrinogen and thrombin time assessments may contribute to minimize the consequences of PTE. In addition, a prospective study of functional imaging such as pulmonary perfusion scintigraphy and 18F-FDG PET/CT will be able to evaluate the validity of these methods for detecting PTE in small vessels and early changes in lungs and other organs affected by the disease. Therefore, the major objective of this work is to assess the sensitivity of pulmonary perfusion scintigraphy in detecting early lung involvement, in particular PTE, and the sensitivity of 18F-FDG PET/CT in detecting early inflammatory changes in the lungs (and others organs) of these patients. We believe that this study may have a relevant impact on the management of COVID-19 patients.