ARRS 2022 Abstracts

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E1610. Using Perfusion-Only Scintigraphy in the Diagnosis of Pulmonary Embolism in the Era of the COVID-19 Pandemic: One Institution’s Experience
Authors
  1. Ben Kaminski ; SUNY Upstate Medical University
  2. Leen Alkukhun; SUNY Upstate Medical University
  3. Marlon Coelho; SUNY Upstate Medical University
  4. Mary McGrath ; SUNY Upstate Medical University
Background
Ventilation-perfusion scintigraphy was developed in the 1960s and has since become useful in the diagnosis of pulmonary embolism (PE). The technique employs a number of radiopharmaceuticals, most commonly technetium-99m (99mTc) diethylene-triamine-pentaacetate (DTPA) in the ventilation portion and 99mTc macroaggregated albumin (MAA) in the perfusion portion, to depict alveolar and vascular function of the lungs. Patterns of matched and mismatched ventilation and perfusion are useful in diagnosing PE. Numerous studies including Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) and Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISAPED) have helped to establish criteria categorizing findings in ventilation and perfusion scintigraphy into varying likelihoods of PE. In March 2020, the Society of Nuclear Medicine and Molecular Imaging (SNMMI) warned of the increased risk of transmission of COVID-19 associated with the ventilation portion of ventilation-perfusion studies. Many institutions therefore transitioned to performing perfusion-only scans in cases of suspected PE. One study in 1992 found that in cases of high, low, or normal probability for PE, there was no significant difference in the interpretations of ventilation-perfusion and perfusion-only studies. Another study in 2008 concluded perfusion-only scintigraphy is adequately diagnostic for PE and can be the study of choice when unable to obtain a CTA of the chest.

Educational Goals / Teaching Points
We aim to provide a literature review on the utility of ventilation-perfusion scans versus perfusion-only scans in the diagnosis of PE; retrospectively investigate the results of perfusion only scans compared to a similar patient pool in which ventilation-perfusion scans were performed in the setting of PE diagnosis at one institution; explore the utility of perfusion-only scans compared to that of ventilation-perfusion scans in the diagnosis of PE; and potentially eliminate the need for ventilation thus reducing the spread of infectious disease in the healthcare setting, reduceing study time, and reducing radiation exposure.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This study retrospectively investigates the results of perfusion-only scans compared to a similar patient pool in which ventilation-perfusion scans were performed in the setting of PE diagnosis at one institution.

Conclusion
In a population of 128 patients who underwent either ventilation-perfusion or perfusion-only scintigraphy, no significant difference was detected for low, intermediate, and high probabilities of PE. If diagnostically equivalent, perfusion-only scans could potentially reduce transmission of infectious disease, reduce study time, and reduce radiation exposure.