Magnetic Resonance Imaging Utilization in an Emergency Department Observation Unit

INTRODUCTION: Emergency department observation units (EDOUs) are a valuable alternative to inpatient admissions for ED patients needing extended care. However, while the use of advanced imaging is becoming more common in the ED, there are no studies characterizing the use of magnetic resonance imaging (MRI) examinations in the EDOU. METHODS: This institutional review board-approved, retrospective study was performed at a 999-bed quaternary care academic Level I adult and pediatric trauma center, with approximately 114,000 ED visits annually and a 32-bed adult EDOU. We retrospectively reviewed the EDOU patient database for all MRI examinations done from October 1, 2013, to September 30, 2015. We sought to describe the most frequent uses for MRI during EDOU admissions and reviewed EDOU length of stay (LOS) to determine whether the use of MRI was associated with any change in LOS. RESULTS: A total of 22,840 EDOU admissions were recorded during the two-year study period, and 4,437 (19%) of these patients had a least one MRI examination during their stay; 2,730 (62%) of these studies were of the brain, head, or neck, and an additional 1,392 (31%) were of the spine. There was no significant difference between the median LOS of admissions in which an MRI study was performed (17.5 hours) and the median LOS (17.7 hours) of admissions in which an MRI study was not performed [p=0.33]. CONCLUSION: Neuroimaging makes up the clear majority of MRI examinations from our EDOU, and the use of MRI does not appear to prolong EDOU LOS. Future work should focus on the appropriateness of these MRI examinations to determine potential resource and cost savings.