Abstract
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Objectives: Ventilation and perfusion lung scans are a common study in nuclear medicine departments. The COVID-19 pandemic has changed the way these scans are performed because of recommendations to limit the use of aerosol generating procedures, including the ventilation portion of lung scans. Prior to the COVID-19 pandemic, the protocol at our facility was to perform a ventilation study on every patient, followed by perfusion imaging. This study looked at lung scans performed during the COVID pandemic without the option of ventilation images, to evaluate if performing ventilation scans on every patient is beneficial as a practice.
Methods: Patients for this study were selected at random over a seven month period. All patients underwent a perfusion only lung scan for the indication of suspected pulmonary embolism. Patients' results were retrieved from their electronic medical record and the radiologist’s impression was classified into four groups, normal/very low probability, low probability, intermediate probability, and high probability of pulmonary embolism.
Results: Perfusion scans from 180 patients were evaluated for this study. Of those patients, 72 (40%) were classified as normal/very low probability, 73 (40.56%) as low probability, 30 (16.67%) as moderate probability, and 5 (2.78%) as high probability.
Conclusions: This study showed that in 80.56% of patients, ventilation images were not required to indicate a very low or low probability of pulmonary embolism. In 19.44% of patients, perfusion only images indicated either intermediate or high probability of a pulmonary embolism. WIthout the aerosol generating procedure limits during the COVID-19 pandemic, ventilation scans could have been obtained after the perfusion images for additional information in this moderate or high probability group. This study indicates that performing ventilation imaging on every patient may not be beneficial to the majority of patients. Performing ventilation scans on all patients has several drawbacks for the patient, including increased time and discomfort during the test, increased radiation exposure, and increased expense. An additional consideration is the impact the COVID-19 pandemic may have had on the results of this study. Due to the guidelines surrounding aerosol generating procedures physicians may have chosen to utilize different imaging modalities for the evaluation of pulmonary embolism due to the limitations on nuclear medicine lung scans.