Emergent spinal MRI in IVDU patients presenting with back pain: do we need an MRI in every case?

PURPOSE: Spinal MRI is the exam of choice for the workup of patients with suspected spinal infection. In this retrospective study, we assess the value of obtaining contrast-enhanced spinal MRI for patients presenting to the emergency department (ED) with acute back pain and a history of intravenous drug use (IVDU).

METHODS: A retrospective IRB-approved, HIPAA compliant review of the imaging findings, reports and electronic charts of 167 consecutive IV drug-using patients (M/F = 96:71, mean age = 40 years) that presented to the ED with acute back pain over a 55-month period and underwent contrast-enhanced spinal MRI within 24 h. Fisher's exact test was used to identify statistically significant (p < 0.05) associations with MRI findings.

RESULTS: Evidence of infectious spondylitis was demonstrated on the spinal MRIs of 39.5% (n = 66) of 167 patients, all of whom were admitted, and nearly half (48.5%; 32/66) underwent surgical or percutaneous intervention. Statistically significant differences in the decision to admit, blood cultures, and the type of treatment was demonstrated in patients with findings of spinal infection on MRI (p < 0.05).

CONCLUSION: Use of emergent spinal MRI in the workup of IVDU patients with acute back pain is justified despite the resultant pressure on MRI scanner, technologist, and interpretation time.