Axial loading during supine MRI for improved assessment of lumbar spine: comparison with standing MRI

摘要

Background There are no studies comparing the morphologic changes of lumbar spines between supine axial-loaded and 90 degrees standing magnetic resonance imaging (MRI) examinations of patients with spinal stenosis. Purpose To determine whether axial-loaded MRI using a compression device demonstrated similar morphology of intervertebral disc, dural sac, and spinal curvature as those detected by 90 degrees standing MRI in individuals with suspected spinal stenosis. Material and Methods A total of 54 individuals suspected of having spinal stenosis underwent both axial-loaded and standing MRI studies. The outcome measures included seven radiologic parameters of the lumbar spine: measures of the intervertebral disc (i.e. cross-sectional area DA, disc height DH, and anteroposterior distance DAP), dural sac (cross-sectional area DCSA), spinal curvature (i.e. lumbar lordosis LL and L1-L3-L5 angle LA), and total lumbar spine height (LH). Results For agreement between the two methods, intraclass correlation coefficient (ICC) >= 0.8 was found for all seven radiologic parameters. Supine axial-loaded MRI underestimated LL but remained correlated (ICC = 0.83) with standing MRI. Minor differences between the two methods (<= 5.0) were observed in DA, DCSA, DAP, LA, and LH, while a major difference was observed in LL (8.1). Conclusion Using a compression device with the conventional supine MRI to simulate weight-bearing on the lumbar spine generated MRI morphology, which was strongly correlated with those from a standing MRI.