Axial Loading During MR Imaging can influence treatment decision for Symptomatic Spinal Stenosis, Akio Hiwatashi, Barbro Danielson, Toshio Moritani, Rober S. Bakos, Thomas G. Rodenhause, Webster H. Pilcher and Per-Lennart Westesson, American Journal of Neuroradiology 25:170-174, February 2004.

Three experienced neurosurgeons reviewed non-axially loaded MRI images of 20 patients with narrowing of the spinal canal and then subsequently reviewed axially loaded MRI images of those same 20 patients.

• All three neurosurgeons changed their treatment decisions from conservative management to decompressive surgery for 5 of the 20 patients;

• Two of the three neurosurgeons changed their treatment decisions for 7 of the 20 patients;

• One of the three neurosurgeons changed his treatment decision for 11 of the 20 patients.

Dynamic Effects on the Lumbar Spinal Canal: Axially Loaded CT-Myelography and MRI in patients with Sciatica and/or Neurogenic Claudiction, Jan Willen, M.D., Ph.D; Arne Gaulitz, M.D.; Thomas Niklason; Nils Schonstrom, M.D., Ph.D; Tommy Hansson, M.D., Ph.D, SPINE 1997, Volume 22, Number 24, pp 2968-76.

• 79% of patients experienced a significant reduction of the dural sac cross-sectional area during axial compression;

• 35% of patients passed the borderlines for relative (100mm2) or absolute stenosis ( 75mm2);

• 36% of patients experienced a narrowing of the lateral recess during axial compression.

This study recommends axial loading of the lumbar spine in computed tomographic scanning and magnetic resonance imaging and concludes that the diagnostic specificity of spinal stenosis will increase considerably when a patient is subject to axial load.

Study presented at the 2002 American Society of Nueroradiology (ANSR) 40th Annual Meeting and Symposium. Presented by S. Kahn, J.F. Hemmer, W.K. Earley, J.F. Seeger of the University of Arizona Health Science Center.

• 33% of patients examined progressed from a non-critical to critical stenosis of the theca sac with axial loading.

• There was an AP diameter reduction in 50% of levels in sagittal scans and a cross-sectional area reduction in 64% of axial scans at all disc levels imaged.

• 25% of patients with one critical stenotic level developed a second critically stenotic level under axial loading.

• Previously undetected synovial cysts of diverticulae developed at 20 levels during axial loading of 50 patients.