But My Back Hurts Only
When I’m Standing !
Axial Loading for Spinal Canal Stenosis
Matthew Cham, MD; Akio Hiwatashi, MD; Per-Lennart Westesson, MD, PhD, DDS
Division of Diagnostic and Interventional Neuroradiology, Department of Radiology,
University of Rochester Medical Center, Rochester, NY 14620
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 1 of 29
Spinal Canal Stenosis
! Progressive narrowing
of the central canal,
lateral recesses, and
neural foramina most
commonly due to
degenerative disease
! In the United States,
majority of individuals
over 60 years old are
affected
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
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Symptoms of Lumbar Stenosis
! Most commonly presents
as midline back pain
aggravated by standing
or walking
! Improved by leaning
forward
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
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Purpose
! To review the role of axial-loading in MRI
for the diagnosis of spinal canal stenosis
! To learn how axial-loading in MRI can be
performed during conventional supine MRI
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Effect of Positioning
! Myelography may
demonstrate
worsening of
spinal stenosis
during extension
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Axial Load
Axial Loading
! Some individuals are
symptomatic only in the
upright position
! May be secondary to axial
load exerted by bodyweight
on the spine, making spinal
stenosis worse in the
standing position
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 6 of 29
Effects of Axial Loading
! MRI is typically
performed in the
supine position with
no axial load
! Surgically treatable
spinal stenosis may
become hidden during
supine MRI
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 7 of 29
Axial Loading Device
! Device used to generate
axial loading
! Simulates the upright
standing position during
conventional supine MRI
! Consists of a harness
and a platform
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 8 of 29
Harness
! Harness comes
in several sizes
to fit various
body types
! Two nylon
straps fasten
the harness to
the foot platform
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Page 9 of 29
Foot Platform
! Foot platform applies an
adjustable tension to
the harness
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Page 10 of 29
Patient Interview
! Identify patients
who might benefit
from axial-loading
during MRI
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 11 of 29
Evaluation of Symptoms
! Patient may
My back hurts only
when I’m standing!
complain of pain that
occurs only when
standing
! Pain may be
relieved by lying
down
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 12 of 29
Evaluation of Prior MRI
! Prior MRI might show
no significant spinal
stenosis due to lack
of axial load
My back doesn’t
hurt lying down.
I have no pain at
all !
! Patient may have
been asymptomatic
during prior MRI due
to supine positioning
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 13 of 29
Using the Axial Loading Device
! Harness is worn
like a vest
! Vest is buckled in
place
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Using the Axial Loading Device
! The foot platform
is placed at
patient’s feet
! One size fits all
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Page 15 of 29
Using the Axial Loading Device
! Harness is
fastened to
the foot
platform with
two nylon
straps
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Using the Axial Loading Device
! Tension is applied to the
harness by adjusting two
large blue knobs
! As the two knobs are
turned, the axial load
increases
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 17 of 29
Using the Axial Loading Device
! Axial load (in pounds) is
indicated by two display gauges.
! Recommended total axial load is
50% of patient’s bodyweight
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 18 of 29
MRI with Axial Loading
! Patients usually become
symptomatic due to the
axial load
My back hurts!
It feels as if I
am standing!
! Patient should be given
reassurance
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 19 of 29
MRI with Axial Loading
No Pain!
No Axial Load
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Ouch!
With Axial Load
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Female 41y
! Neurogenic claudication
at L4-L5
No Axial Load
! Increasing central
stenosis with axial load
Axial Load
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Male 63y
! Neurogenic claudication
at L4-L5
No Axial Load
! Increasing disc
herniation and central
stenosis with axial load
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Axial Load
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Female 58y
! Neurogenic Claudication
at L4-L5
No Axial Load
! Increasing synovial cyst
bulge with axial load
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Axial Load
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Female 52y
! Neurogenic Claudication
at L4-L5
No Axial Load
! Increasing central
stenosis with axial load
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Axial Load
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Will it affect Management?
! The incremental increase in
diagnosis of operative spinal
canal stenosis with the use
of an axial-loading device is
currently under investigation.
! There is some evidence that
management could change
for some patients. (Hiwatashi, et
al. AJNR 2004; 25:170-174)
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 25 of 29
Is it safe?
! FDA-approved for both CT and MRI
! If patient cannot tolerate their back
pain, hip or knee flexion instantly
relieves the axial load
! Large display gauge allows MRI
technologist to see absence of axial
load in those situations
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Axial load is
relieved by
knee flexion
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What are other options?
!
Axial Loading Device
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
!
Upright MRI
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Conclusion
! Axial-loading during MRI can unmask operative
cases of spinal canal stenosis that may
otherwise appear inconsequential
! Axial-loading can be performed during
conventional supine MRI
! The incremental diagnostic yield of axial loading
for spinal canal stenosis is currently under
investigation
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
Page 28 of 29
References
!
!
!
!
!
Danielson BI, Willen J, Gaulitz A, et al. Axial loading of the spine during CT
and MR in patients with suspected lumbar spinal stenosis. Acta Radiol.
1998; 39(6):604-11.
Hiwatashi A, Danielson B, Moritani T. Axial loading during MRI imaging can
influence treatment decision for symptomatic spinal stenosis. AJNR 2004;
25:170-174.
Jinkins JR, Dworkin J. Upright, weight-bearing, dynamic-kinetic MRI of the
spine. Acta Clin Croat 2002; 41(Suppl):31-35.
Kimura S, Steinbach GC, Watenpaugh DE. Lumbar spine disc height and
curvature responses to an axial load. Spine 2001; 26:2596-2600.
Willen J, Danielson B. The diagnostic effect from axial loading of the lumbar
spine during computed tomography and magnetic resonance imaging in
patients with degenerative disorders. Spine 2001; 26(23):2607-14.
Presentation material is for education purposes only. All rights reserved. ©2004 URMC Radiology
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