Radiology Section - Positional Magnetic Resonance Imaging (MRI)

IMPORTANT REMINDER

This Medical Policy has been developed through consideration of medical necessity, generally accepted standards of medical practice, and review of medical literature and government approval status.

Benefit determinations should be based in all cases on the applicable contract language. To the extent there are any conflicts between these guidelines and the contract language, the contract language will control.

The purpose of medical policy is to provide a guide to coverage. Medical Policy is not intended to dictate to providers how to practice medicine. Providers are expected to exercise their medical judgment in providing the most appropriate care.

Description

Conventional magnetic resonance imaging (MRI) systems acquire images with the patient in the horizontal, lying position.  Recently, a new fully open MRI system, the upright or positional MRI, has been developed which allows multiple positions in addition to horizontal imaging.  This system allows partial or full weight bearing, as well as simultaneous movement or positioning of the patient’s whole body or individual body parts.

It is theorized that imaging the body in positions related to the central loading of the spine, which occurs when standing upright or sitting or in the specific position related to the patient’s clinical symptoms, may lead to more accurate diagnosis. This is being evaluated in patients with suspected nerve root compression and in some cases of spondylolisthesis and may be particularly relevant in cases where disease is not visible on a horizontal MRI.

FONAR Corporation has 510(k) marketing clearance from the U.S. Food and Drug Administration (FDA) for an MRI system that performs positional MRI scans.

Policy/Criteria

Positional or upright MRI for the diagnosis and management of any condition, including but not limited to cervical, thoracic or lumbosacral back pain, is considered investigational.

Position Summary

It is uncertain if positional MRI is useful in the diagnosis and clinical management of patients with cervical, thoracic, or lumbosacral back pain.

In evaluating positional MRI, it is important to first determine if this approach results in additional findings that impact and improve clinical management of the patient.  Studies have reported that positional MRI may show abnormalities in patients which were not seen with conventional MRI; however, no studies indicated how these results changed or affected the patient’s treatment plan. (3-12)

More studies, preferably from randomized trials, are needed to determine the following:

• Characteristics of patients who might benefit from positional MRI studies;
• Clinical benefit of basing treatment decisions, including surgery, on these additional findings; and
• How this technique might replace current diagnostic tests, such as myelography.

References

1. BlueCross BlueShield Association Medical Policy Reference Manual,  Positional Magnetic Resonance Imaging, Draft Policy No. 6.01.48, February 2007
2. Weishaupt D, Schmid MR, Zanetti M et al.  Positional MR imaging of the lumbar spine:  does it demonstrate nerve root compromise not visible at conventional MR imaging?  Radiology 2000;215(1):247-53
3. Vitaz TW, Shields CB, Raque GH et al.  Dynamic weight-bearing cervical magnetic resonance imaging:  technical review and preliminary results.  South Med J 2004;97(5):456-61
4. Jinkins JR, Dworkin JS, Damadian RV.  Upright, weight-bearing, dynamic-kinetic MRI of the spine: initial results.  Eur Radiol 2005;15(9):1815-25
5. Karadimas EJ, Siddiqui M, Smith FW et al.  Positional MRI changes in supine versus sitting postures in patients with degenerative lumbar spine.  J Spinal Disord Tech. 2006;19(7):495-500
6. Weishaupt D, Boxheimer L.  Magnetic resonance imaging of the weight-bearing spine.  Semin Musculoskelet Radiol 2003;7(4):277-86
7. Jinkins JR, Dworkin J. Proceedings of the State-of-the-Art Symposium on Diagnostic and Interventional Radiology of the Spine, Antwerp, September 7, 2002 (Part two). Upright, weight-bearing, dynamic-kinetic MRI of the spine: pMRI/kMRI.  JBR-BTR  2003;86(5):286-93
8. Zamani AA, Moriarty T, Hsu L, et al.  Functional MRI of the lumbar spine in erect position in a superconducting open-configuration MR system: preliminary results.  J Magn Reson Imaging 1998;8(6):1329-33
9. Wildermuth S, Zanetti M, Duewell S et al.  Lumbar spine: quantitative and qualitative assessment of positional (upright flexion and extension) MR imaging and myelography.  Radiology 1998;207(2):391-8
10. Schmid MR, Stucki G, Duewell S et al.  Changes in cross-sectional measurements of the spinal canal and intervertebral foramina as a function of body position: in vivo studies on an open-configuration MR system.  AJR Am J Roentgenol 1999;172(4):1095-102
11. Zamani AA, Moriarty T, Hsu L et al.  Functional MRI of the lumbar spine in erect position in a superconducting open-configuration MR system: preliminary results.  J Magn Reson Imaging 1998;8(6):1329-33

Cross References

None

Radiology Section Table of Contents