False positive lung perfusion/ventilation scan due to rapidly resolved pulmonary abnormalities: Importance of SPECT/CT imaging

An eighty-year-old lady a with history of treated tuberculosis decades ago and polymerase chain reaction (PCR) proven COVID-19 pneumonia about four months ago was referred to our department for ventilation/perfusion scan due to deteriorating dyspnea to rule out P.E. Planar perfusion scan showed bilateral accentuated apical perfusion gradient and multiple segmental and non-segmental perfusion defects in both lungs, which were mismatched with relatively normal planar ventilation images. Perfusion SPECT images also showed multiple segmental, sub-segmental and semi-segmental perfusion defects, which proved to be concordant with consolidations, bilateral pleural effusion, right lung pneumothorax, and atelectasis which were consultant with CT findings. The ventilation SPECT/CT images also demonstrated uniform tracer activity throughout both lungs, with almost complete improvement in consolidations, lung pneumothorax, pleural effusion, and atelectasis. Our case highlights the importance of SPECT/CT imaging in avoiding false-positive interpretation of pulmonary embolism as well as the possibility for rapid resolution of the lung parenchymal abnormalities.