Diagnostic Imaging Usage by Physician Assistants in Emergency Medicine: An Observational Study

Background: Diagnostic imaging is an essential and frequently utilized tool in emergency departments across Canada. With the ongoing increase in demand for emergency care and the growing workload faced by emergency physicians, exploring alternative strategies to support and optimize the use of diagnostic imaging is imperative. This study aims to describe how physician assistants (PAs) currently utilize diagnostic imaging in emergency medicine within a Canadian healthcare setting, providing valuable insights into their role and practices. Methods: This retrospective, multi-centre observational study employed participant observations to gather data on emergency PAs and their diagnostic imaging utilization from November 2022 to March 2025. Deductive thematic analysis was conducted, focusing on key areas such as chief complaints prompting imaging, PA interpretation of images, and PA imaging autonomy. Data analysis was performed using Delve: Qualitative Data Analysis Software. Results: Emergency PAs use all imaging modalities in practice, but most frequently utilize x-ray, followed by CT, in which they often interpret results prior to a radiology report. They investigate a variety of chief complaints requiring imaging that are routinely gastrointestinal, orthopedic, cardiovascular, neurologic, respiratory, and skin-related in nature. Common diagnoses made through diagnostic imaging include fractures, pneumonia, osteomyelitis, kidney stones, and appendicitis. They also frequently rule out brain bleeds. Overall, the diagnostic imaging scope of practice was similar for urban and rural PAs. However, the rural PAs had greater imaging responsibility due to limited radiologist access overnight, requiring them to formally interpret x-rays and head CTs during this timeframe. Conclusions: Emergency PAs order and interpret diagnostic imaging to diagnose and treat low and moderate acuity patients. With this greater understanding of how emergency PAs can be utilized as it relates to diagnostic imaging, this evidence helps to assists emergency physicians and ultimately, improve the quality of emergency care delivered to patients in Canada.