Conventional Supine MRI With a Lumbar Pillow—An Alternative to Weight-bearing MRI for Diagnosing Spinal Stenosis?: A Cross-sectional Study

STUDY DESIGN.Cross-sectional study. OBJECTIVE.To investigate if adding a lumbar pillow in supine position during magnetic resonance imaging (MRI) is superior to standing positional MRI for diagnosing lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA.The upright standing position and especially extension of the lumbar spine seem to worsening symptoms of LSS. However, it is unclear whether a forced lumbar extension by a pillow in the lower back during conventional supine MRI may improve the diagnostics of LSS compared to standing MRI. METHODS.Patients suspected for LSS and referred to conventional MRI were included to an additional positional MRI scan (0.25T G-Scan) performed in1) conventional supine 2) standing 3) supine with a lumbar pillow in the lower back. LSS was evaluated for each position in consensus on a 0–3 semi-quantitative grading scale. Independently, L2-S1 lordosis angle, Spinal Cross-Sectional Diameter (SCSD), Dural Cross-Sectional Diameter (DCSD) and Dural Cross-Sectional Diameter (DCSA) were measured. The smallest dural diameter was defined as stenosis level and the largest control level for comparison. RESULTS.Twenty-seven patients (60.6 years; ± 9.4) were included. The lordosis angle increased significantly from supine to standing (3.2° CI1.2–5.2) and with the lumbar pillow (12.8° CI10.3–15.3). One-way ANOVA showed significant differences between positions (P