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Axial loading in MR imaging for spinal canal stenosis 2007

General Spine

Malin C Cesarz, MD
Matthew Cham, M.D., Non ASSR Member
Akio Hiwatashi, M.D., Non ASSR Member
Per-Lennart Westesson, M.D., Ph.D., D.D.S., ASSR Member

Scientific Poster

Exhibit Panels: 1

Purpose

Background:
Spinal canal stenosis is a common disease involving narrowing of the central spinal canal neural foramen, lateral recess and neural foramina. It is most often due to degenerative disease. Many patients have their most prominent symptoms while standing up or walking. Many are less symptomatic when lying down and some may even be asymptomatic in the supine position. We traditionally image patients in the supine position and it is not uncommon that the imaging findings do not match the patients' symptoms. Clinicians and researchers have postulated that some of these false negative imaging results may be due to the lack of axial loading during supine imaging. There is now a FDA approved device for inducing axial loading during supine position.

Methods & Materials

Objectives:
1. Review the role of axial loading in diagnosis of spinal canal stenosis using MRI.
2. Demonstrate the differences in the spinal canal during conventional supine MR imaging versus when axial loading is used.
3. Demonstrate how axial loading can be performed on supine patients.
4. Summarize our experience of axial loading during MR, CT and post myelography imaging.

Conclusion

Learning points:
1. Conventional supine imaging without axial loading can lead to false negatives in the diagnosis of canal stenosis.
2. Axial loading can simulate the gravitational forces on the spine and permit diagnosis of additional symptomatic cases of stenosis.
3. There is evidence that axial loading during imaging can influence surgical treatment decisions.