Xray prediction of MRI in low back pain.

Abstract: Magnetic resonance imaging (MRI) use in low back pain (LBP) management can be associated with added costs and increased surgical interventions. Lumbar Xray findings predicting MRI results were assessed in patients with LBP, excluding post-surgical, red flag, or spinal stenosis history. At an outpatient Pain clinic, one hundred patients were selected (sequentially) from 12/1/2021-3/15/2022 that had lumbar Xrays within 1 year prior to lumbar MRI. Xray and MRI reports were analyzed by 2 readers. Forty-six patients had moderate facet hypertrophy on Xray, 35 (76.1%) also had moderate facet hypertrophy on MRI (Spearman's rank correlation Rs = 0.386, p < 0.0001). Thirty-eight patients had moderate multilevel degenerative changes on Xray, 34 (89.5%) also had moderate disc bulge on MRI (Spearman's Rs = 0.360, p < 0.001). Eighteen patients that had moderate disc height loss on Xray, 14 (77.8%) also had moderate disc desiccation, height loss, or space narrowing on MRI (Spearman's Rs = 0.554, p < 0.00000001). Forty-three patients had a listhesis on Xray, 20 (46.5%) also had a listhesis on MRI (Spearman's Rs = 0.458, p < 0.0001). Lumbar Xray is a reasonable study in the setting of axial and subacute radicular LBP, where red flags are absent, predicting moderate pathology on MRI > 75% of the time, and being more sensitive for listhesis.