Re: Ventilation-Perfusion Scans During the Coronavirus Disease 2019 (COVID-19) Outbreak.

In complete agreement with the authors, the potential effects of the coronavirus disease 2019 (COVID-19) pandemic on nuclear medicine departments need to be addressed, because the nuclear medicine department staff are at high risk of exposure to COVID-19. In addition, contamination of the department equipment can initiate an outbreak within the health care facility. The virus is highly contagious, with the main route of transmission being respiratory droplets [1]. Chest CT scan could be normal in up to 15% of individuals with positive reverse transcription polymerase chain reaction for COVID-19, and therefore a normal chest CT scan cannot exclude the disease [2]. There have been reports of COVID-19 nosocomial outbreak; extra measures will be necessary for aerosol-generating procedures such as ventilation-perfusion scan.

First, the performance of pulmonary scintigraphy in patients suspicious for having COVID-19 pneumonia should be limited unless medically essential for management. CT angiography might be considered as the modality of choice during the COVID-19 pandemic unless contraindicated (eg, in patients who are pregnant or experiencing acute renal failure). According to a statement by the Society of Nuclear Medicine and Molecular Imaging [3], because the ventilation systems are difficult to thoroughly disinfect, some institutions are avoiding the ventilation phase of the scan and have only relied on the perfusion phase results for the diagnosis of acute pulmonary embolism. When the result of the perfusion scan is normal (ie, there is no perfusion defect), pulmonary thromboembolism is ruled out.

Second, if the scan is essential, apart from encouraging all the individuals sitting in the waiting area to adhere to social distancing, patients suspicious for disease should be placed in a separate waiting room.

Third, the number of the personnel in the unit should be minimized when there is an individual suspected to have COVID-19 pneumonia [4]. All the personnel should follow the recommended personal protective equipment for COVID-19 pneumonia, which includes N95 respirator or higher, medical mask, apron, gown, gloves, and eye protection with goggles.

Fourth, creating a negative airway pressure in the procedure room relative to the hallway is desirable. Finally, the scanner, the procedure equipment, the procedure room surfaces, and the viewing station should be decontaminated by professional environmental services staff immediately after each patient encounter [5].

In summary, limiting the acquisition of pulmonary ventilation-perfusion scans, eliminating the ventilation phase of the scan, appropriately using personal protective equipment throughout the department, using negative airway pressure in the procedure room, and thoroughly decontaminating the procedure room after each ventilation-perfusion scan can help the nuclear medicine department to minimize the impact of the COVID-19 pandemic on the staff, the equipment, and the health care facility.