Transcript Imaging of Facet Joint Pathology

Interventional Pain
Management from a Diagnostic
Imaging Point of View
Arthur S. Watanabe, MD, FIPP
Friday, Sept 13, 2013
Washington Assn of Nurse Anesthetists
Art Watanabe, M.D., Pharm.D.
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Medical Director
Open MRI Diagnostics
Spinal Diagnostics, PLLC
Clinical Assistant
Professor of Radiology
University of Washington
Spokane, Washington
www.openmridiagnostics.com
Spinal Diagnostics, PLLC
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Disclaimer
• Medical Director, Spinal Diagnostics and Open
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MRI
Assistant Clinical Professor, Radiology, University
of Washington School of Medicine
Board Certified
– ABR
– ABIPP
Member: ASIPP, ISIS, ASSR, ASNR, NASS
Past Board Member, ASIPP
President, Washington Society of Interventional
Pain Physicians
Proctor for Advanced Neuromodulation Systems,
Boston Scientific
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Lecture Objectives:
• Description of various
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aspects of imaging of
the spine
Radiography
Myelography
Computed
Tomography
SPECT Scans
Imaging for Interventional Pain Physicians
Modality Physics Target
Xray
Xray
CT
Xray
Bone
RF
Waves
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Bone, ST ++++
Nucl Med Photons Physiology
MRI
Spatial Contrast
ST, Bone
Mx
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Imaging for Interventional Pain Physicians
Modality
Indication
Information
Xray
Localization, R/O
Fx, Mets
Bony anatomy
CT
Fx,Bony anatomy,
Stenosis
Bony & ST
anatomy
Nucl Med
Fx, inflammation,
arthrosis
Active osseous
process
MRI
DDD, Stenosis, Fx, ST & Mx anatomy
arthrosis
Radiography
Radiography Physics – X-ray
• Conversion electron
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K.E.  E.M.R.
Electrons boiled off xray tube hit Tungsten
anode  X-ray
X-rays generated by 2
processes:
– General radiation
– Characteristic radiation
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Lumbar Radiography Advantages
• High spatial resolution
• Good bone contrast resolution
• Wide availability
• Fast, easy imaging
• Non-claustrophobic
• Inexpensive
Lumbar Radiography Weaknesses
• Poor-fair soft tissue contrast resolution
• Only four densities
– Fat, water, air, bone
• Radiation dose
• Variation in techniques by facility
Lumbar Facet with Gadolinium
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Vertebral Cement Augmentation
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Myelography
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Myelography
• Radio-opaque contrast is injected into the thecal sac
to assss its contents, e.g. spinal cord, nerve roots.
• Approx 350,000 myelograms/year in U.S.
• 1913 – Luckett incidentally
noted vetricular system was
visualized on a posttraumatic skull x-ray.
• 1918 – Walter Dandy, MD
Johns Hopkins neurosurgeon
air myelography
and air
encephalography.
Lumbar Myelography Strengths
• Problem solving tool
– Nerve roots
– Intradural lesions
– Arachnoiditis
• Alternative for patients unable to have
MRI
Myelography Weaknesses
• Intradural imaging
• Invasive with attendant risks
• Radiation
• Variation in techniques by facility
• Variation in readings by radiologists
Myelography Technique
• Fluoroscopic guidance
• 25 or 26 G 3 ½ in
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Quincke tip
L2/3 interlaminar space
Bevel medial or lateral
Check lateral fluoro
12-15 cc nonionic
iodinated contrast 240M
Lumbar Myelography Complications
• Spinal headache
• Pneumocephalus
• Nerve root damage
• Contrast reaction
• Infection, hematoma
Computed Tomography
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CT Scan - Evolution
• CT one of the greatest
radiology innovations since
the discover of X-rays.
• X-sectional imaging provided
diagnostic information
improved visualization of
disease.
• Godfrey Hounsfield, British
electronics engineer with EMI
Company, builds a CT scanner
between 1969 and 1972.
• Allan Cormack, South African
nuclear physicist, in 1963
described the mathematical
basis for constructing a CT
scanner.
Spiral CT Imaging
– Volume Scanning
– Patient table translates thru scan gantry while xray tube rotates 360º continuously.
– X-ray produces a spiral path thru the body
resulting in a data volume acquisition of three
dimensional picture elements, i.e. voxels.
CT Lumbar Spine: Strengths
• High spatial resoln
• Good bone contrast
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resoln
Wide availability
Fast, easy imaging
Non-claustrophobic
Multiplanar, 3D
reformations
CT Spine: Weaknesses
• Fair soft tissue
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contrast resolution
Radiation dose
Variation in
techniques by facility
Variation in readings
by radiologists
CT Scan - Image Processing
• Axial cross-sectional images
– stored in digital form
– processed immediately.
• CT measurement of geometrical
parameters
– E.g., distance, area, angle, volume and
density.
• Geometrical parameters
– more accurately defined with CT than in
conventional radiography
– superimposition and distortion not
present
Magnetic Resonance Imaging
MRI Scan - Evolution
• 1972 Damadian files patent for a NMR body scanner
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entitled Apparatus and Method for Detecting Cancer in
Tissue.
1974 Damadian receives U.S. Patent #3,789,832.
1977 Dr. Damadian develops
the first MRI scanner of the
human body
– Indomitable
– installed in the Smithsonian Institution.
MRI Scan - Evolution
• 1977 the Indomitable produced the first human MRI
image.
MRI Sequences
• What is fat doing?
• What is CSF doing?
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MRI Sequences
• T1
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Fat Bright
H2O Dark
• C T2
– Fat Dark
– H2O Bright
• FSE T2
– Fat, H2O bright
• STIR
– Only H2O bright
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Imaging the Spectrum of
Facet Joint Pathology
Normal Facet Joints
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Joint Space
Joint Margins
Articular cartilage
Periarticular soft
tissues
Advanced Facet Disease
• Articular cartilage loss
• Subchondral bony
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eburnation
Marginal hypertrophic
changes, spurring
Effusion
Atrophy of multifidi
and erector spnae
muscles
Advanced Facet Disease
• Absence of cartilage
• Bone on Bone
• Marginal hypertrophic
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changes
Deconditioning of
multifidi and erector
spinae m.
Unilateral Facet Disease
• Left side normal
• Right side
– Articular cartilage loss
– Joint effusion
Facet Synovitis
• Prominent effusion
• Note: medial
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ligamentum flavum
hypertrophy
Paraspinous muscles
preservered
Paravertebral Soft Tissue
• Gadolinium contrast
enhancement
– Periarticular soft tissue
– Medullary bone
marrow
• High clinical
correlation with pain
generator
Unilateral Facet inflammation
• Articular cartilage
• Gadolinium contrast
enhancement
– Medullary bone
marrow
– Periarticular soft
tissues
Facet Marrow Edema
• Medullary bone
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marrow edema
Indicator of
inflammation
High clinical
correlation with pain
generator
The positive predictive value of
isotope lumbar SPECT scans to
RF rhizhtomy response
Unpublished Study
Study Design and MR
• Retrospective chart review study
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Initial assessment with diagnosis of lumbosacral arthrosis
Lumbar SPECT scan
Facet block: (0.4 cc 0.5% Marcaine, 0.4 cc Depo)
MBB block: (ea branch 0.4 cc 0.5% Marcaine)
RF Rhizhotomy (85 Degrees 105 sec) x 3
– Follow up
• Methods
– Total: 57 patients
– Age: Range: 32 – 80 yrs, Mean: 67 yrs
– Sex: M 30
F 27
Preliminary Results: SPECT
Preliminary Results: Clinical Exam
Preliminary Conclusion
• Concordant positive lumbar spine bone
scans are predictive of good clinical
response to RF rhizhotomy.
• Clinical diagnosis of facet pain generator
just as sensitive as lumbar spect scans
• Lumbar spect scans while predictive may
be unnecesary imaging and costs.
ANYBODY MISS THIS GUY?
• 'Government's
view of the
economy could be
summed up in a
few short phrases:
If it moves, tax it.
If it keeps moving,
regulate it. And if it
stops moving,
subsidize it' Ronald Reagan
Spinal Imaging: Caveats
• High tech physical
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•
•
exam
It’s just an image
Doesn’t tell you
where the pain is
coming from
Lots of false
positives and false
negatives
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Spinal Imaging: Caveats
• High tech physical
•
•
•
exam
It’s just an image
Doesn’t tell you
where the pain is
coming from
Lots of false
positives and false
negatives
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The truth about imaging
• The pictures lie
• The pictures rarely
tell you what the
pain generator is
• Over reliance on
imaging = false
sense of security
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Which is the more important
imaging modality here?
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Only the needle knows…
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In summary, my take home
messages
• Imaging are just pictures
• Images don’t necessarily tell you what is
the pain generator
• The patient’s finger may be more useful
and cost effective and accurate than any
x-ray, CT, MRI or bone scan
• Get comfortable looking at the images you
order
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Let me leave you with one
important thought at the very
end…
Obama-Care
• “We have to
pass the bill so
that you can find
out what’s in it.”
– N. Pelosi, 3/9/2010
"all animals are equal, but some animals are more equal than others."
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Obamacare:
How could they possibly do this?
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Answer:
• “In my many years I have come to a conclusion that one
useless man is a shame, two is a law firm and three or
more is a congress.”
-- John Adams
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so …
• “Remember,
politicians and
diapers need to
be changed
frequently and
for the same
reason.”

Robin
Williams,
Man of the
Year
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Arthur Watanabe, M.D.
Spinal Diagnostics, PLLC
Spokane, WA
•Thanks
for
listening!
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