Rubidium-82 PET/CT in COVID-19.

A 56-year-old man presented to the emergency department with shortness of breath during the COVID-19 pandemic. Chest computed tomography angiography (CTa) showed bilateral peripheral ground-glass opacifications classified as CO-RADS 5, but no pulmonary embolism. To analyze the possibility of CTa-undetectable pulmonary microthrombi and to rule out cardiac perfusion abnormalities, we decided to perform a rubidium-82 (Rb) PET/CT. Rb PET/CT imaging in this patient yielded uptake in the pulmonary areas of ground-glass opacification and showed corresponding findings between Rb PET/CT and CTa imaging without any signs of microthrombi despite the elevated d-dimer. Even in the areas of profound groundglass opacifications, the increased Rb uptake indicates that perfusion is adequate to acquire Rb uptake in the pulmonary cells. Rb PET/CT is a promising imaging technique and might extend the diagnostic potential of conventional nuclear and radiological imaging in detecting pulmonary microthrombi or other minor perfusion defects.