Implementation of a Lung Perfusion Only Imaging Protocol with SPECT or SPECT/CT in a Major Academic University Hospital Healthcare System in Adaption to the COVID-19 Pandemic.

Introduction: The COVID-19 pandemic has challenged medical institutions all over the world. The novel coronavirus can spread from person to person rapidly through respiratory droplets, which is the major cause for the global pandemic. Pulmonary embolism (PE) is a life threatening condition, however a common complication of COVID-19 can be sudden respiratory distress, which can also be seen with a diagnosis of pulmonary embolism. It is very important for nuclear medicine services to take prudent measures when dealing with aerosol-generating procedures, such as ventilation/perfusion (V/Q) scans to diagnose suspected pulmonary thromboembolism (PE), to reduce the potential aerosolization and spread of the virus. The incorporation of SPECT or SPECT/CT with Tc-99m-MAA perfusion only imaging can help improve the diagnostic accuracy of the exam in the absence of ventilation imaging. The development and adoption of a perfusion only imaging protocol with SPECT or SPECT/CT in a large healthcare system presents unique challenges.

Methods: Starting in March of 2020, University Hospitals of Cleveland Health System created a System Wide COVID-19 Taskforce to oversee development and implementation of protocols and policy in response to the global COVID-19 pandemic. With the oversight of the Taskforce and guidance of SNMMI guidelines, all 14 hospitals at University Hospitals of Cleveland Health System adopted a Tc-99m-MAA perfusion only lung scanning protocol with the addition of SPECT or SPECT/CT as official policy. The logic behind this initiative was the protection of staff and other non-COVID-19 patients, as well as the protection of Nuclear Medicine and Radiology imaging sites and System Medical Centers from the potential risks associated with the aerosolizing nature of the ventilation procedure.

Results: A total of 375 Tc-99m-MAA perfusion only exams were done during this period of time, of which 114 included SPECT and 261 included SPECT/CT imaging. The results were 240 low probability (64%), 22 intermediate probability (6%) and 113 high probability (30%).

Conclusions: The COVID-19 pandemic has forced medical institutions and health care systems all over the world to adapt to a rapidly changing environment with the challenge to deliver high quality health care while minimizing risk to staff and patients alike. This has presented a unique problem requiring both flexibility and innovativeness. Furthermore, there are the logistical challenges in policy implementation which are proportionally increased the larger the system is. Aerosol-generating procedures, such as ventilation scanning, inherently increase the risk of virus spread. The incorporation of SPECT or SPECT/CT with Tc-99m-MAA perfusion only imaging can help improve the diagnostic accuracy of the exam in the absence of ventilation imaging. SPECT scanning improves the delineation and distribution of perfusion defects through 3-D imaging. Low dose CT used in conjunction with SPECT is able to identify other non-embolic pulmonary pathologies (i.e. pneumonia, emphysematous changes, pleural effusions) responsible for nonspecific non-segmental perfusion defects thereby increasing the specificity in characterizing true segmental perfusion defects. We demonstrate the effective translation of a Tc-99m-MAA perfusion only imaging protocol with the routine incorporation of SPECT or SPECT/CT as policy within a large multi-center health system to meet the challenge to deliver high quality health care while minimizing risk to staff and patients.