Investigation of Whole Spine MRI in the Emergency Department at Two Large Tertiary Care Academic Medical Centers in the United States

Abstract

Rationale and ObjectivesThe impact of emergent whole spine magnetic resonance imaging (WS-MRI) on patient management has not been extensively studied to date. Here, we explore indications, results, and outcomes associated with WS-MRI performed through the emergency departments (EDs) of 2 large tertiary care, academic medical centers in the Northeastern United States. We hypothesize that given a relatively low barrier to entry, coupled with lack of appropriateness guidelines, a sizeable proportion of WS-MRI studies performed emergently do not result in spine findings necessitating inpatient admission for immediate treatment. Materials and MethodsWe retrospectively studied 335 adult patients (≥18 years) who underwent WS-MRI through the ED between 2016 and 2019. The demographic data collected included, age, sex, chief complaint, history of spine disease, and date and type of last spine imaging prior to ED presentation. Data compiled from the time of ED visit included WS-MRI result and patient disposition, including reason for hospital admission, by which patients were categorized into groups to allow for ease of comparisons. Hypergeometric tests were used to determine statistically significant associations between random discrete variables. ResultsTrauma was the most frequent chief complaint, comprising 35% (n = 117) of all presentations, followed by pain (25%, n = 84), motor deficit (16%, n = 55), sensory disturbance (12%, n = 41), bowel, and/or bladder dysfunction (9%, n = 30), and subjective or objective fevers with suspicion for spine infection (2%, n = 8). The largest proportion of WS-MRI studies revealed degenerative disc disease (DDD) as the principal result (41%, n = 139). 52% of all patients were either discharged directly from the ED (41%) or admitted for a non-spine issue after WS-MRI (11%); of these numbers, 61% underwent WS-MRI and no other imaging study in the ED. In patients who presented with a chief complaint of pain, DDD was often the principal WS-MRI finding (54%), albeit this association was not statistically significant. DDD, nonetheless, was positively associated with a discharge from the ED (P <0.001). Trauma was positively associated with fracture or ligamentous/soft tissue injury (P <0.001) on WS-MRI and hospital admission for a spine issue (P <0.01). ConclusionThat just under half of patients in our study were admitted for spine-related pathology suggests that WS-MRI is valuable in the emergent setting. At the same time, however, that over half of patients were not subsequently admitted for a spine-related issue points to the possibility of further refining which patients would benefit most from WS-MRI. WS-MRI may be less helpful in patients presenting with pain, though may be higher-yield in those with trauma, motor deficits, and bowel/bladder complaints. Although MRI is highly sensitive in ruling out emergent central nervous system pathology, given the resource-intensive nature of the test, it is prudent to carefully select which patients should undergo emergent WS-MRI, especially in instances when more cost-effective, alternative diagnostic approaches, including detailed neurological exam, computed tomography, or localized/targeted MRI, are possible.