Whole-Spine MRI in the Emergency Department: Diagnostic Yield Versus Clinical Impact

Purpose: Whole-spine MRI (WS-MRI) is often ordered in the emergency department (ED) to uncover spinal pathology when initial evaluation is inconclusive, particularly in patients with high-risk features. However, it remains unclear how actionable findings on WS-MRI correspond to the patient’s clinical course. This study examines the association between actionable WS-MRI findings (findings that could warrant further workup) and subsequent inpatient admission and intervention.

Methods/Materials: This is a retrospective cohort analysis of MRI findings for patients from 2018 through 2023 who received the entire spine MRI protocol (T1, T2, and STIR sagittal sequences) at Valleywise Hospital Systems in the acute care setting. The primary endpoint of this study is to assess the likelihood of finding actionable findings when the protocol is used and whether those findings necessitate further management and workup in an inpatient setting.

Results: Among 663 patients, 293 (44.7%) demonstrated actionable pathology on WS-MRI. In this group, 179 (61.1%) required inpatient admission. Of patients without acute findings, 145 (39.7%) were admitted, and 225 (61.5%) were discharged from the ED. Scans demonstrating significant actionable findings had a relative risk of 1.56, representing a 56% higher risk of admission compared to patients with no actionable findings on imaging. Furthermore, 72 (40.2%) of the patients admitted underwent invasive intervention. Finally, WS-MRI had a number needed to image (NNI) of 5, indicating that for every 5 patients displaying actionable findings on imaging, one additional hospital admission occurs.

Conclusions: WS-MRI is a time- and resource-intensive modality often reserved for ambiguous clinical presentations. Despite WS-MRI’s impressive diagnostic yield, its clinical impact is more modest; less than a third of the patients who underwent this study were admitted, with even fewer requiring intensive workup. Moreover, a large number of patients who didn’t demonstrate actionable findings were still admitted. As such, the presence of significant findings does not necessarily alter clinical management, and WS-MRI should be used judiciously to minimize unnecessary time and resource utilization.