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Advanced Imaging in Degenerative Disc Disease

Greg Petermann, MD Marshfield Clinic, Wisconsin

USA

Advanced Imaging in Degenerative Disc Disease

Special thanks for material from: Meng Law MD, FRACR

Keck School of Medicine, University of Southern California Los Angeles, California

Lawrence Tanenbaum, MD Mount Sinai Hospital, New York, New York

Advanced Imaging of Degenerative Discs

•  Routine MRI items •  Discogram •  Diffusion and Diffusion tensor imaging of

the disc •  MR Spectroscopy of the disc •  DTI of the disc •  SPECT CT •  T1 rho •  IDEAL imaging

Current items to help in degenerative disc evaluation

•  On routine MRI : •  Type I endplate changes •  Extrusion vs protrusion •  Nerve root edema •  Facet edema and synovitis •  Muscle edema and atrophy

Type I endplate changes Type I endplate changes

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Type I endplate changes

T2 without T2 with Fat saturation T1

Protrusion vs Extrusion and Sx

80 % symptoms Modic et al

Nerve root edema

L5 S1

S1

T2 T1

Facet edema and synovitis

•  Responds well to facet injection if in isolation and…

•  Physical exam is point tender

Muscle edema and atrophy

•  What do we know about this area ?

•  Multifidus muscle and publications

•  Other muscles

CT imaging

•  Good for traumatic and insufficiency fractures

•  Facet and endplate degenerative changes

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SPECT CT imaging

SPECT/CT Imaging of the Lumbar Spine in Chronic Low Back Pain: A Case Report

Discogram

•  Direct study accessing types of disc pain

•  Is it the SAME pain ?

•  Can cause early degenerative disc problems later

Advanced imaging problems

•  Do you have available software programs •  Magnet strength 3T vs 1.5 T •  Enough experience to obtain reliable

repetitive images and data

•  Motion artifact issues in cord AND patient

Keshari et al, SPINE 2008

PG

Lactate

col

Painful Disc PG

Lactate

col

Non-Painful Disc

MR Spectroscopy Ex Vivo Surgical Samples (11T MRS)

Significantly lower proteoglycan (PG)/collagen and PG/lactate ratios, and a higher lactate/collagen ratio in specimens obtained from discogenic

pain patients.

Disc Degeneration – MR Spectroscopy

Sharmila Majumdar, Thomas M. Link, Lynne S. Steinbach, Serena Hu, John Kurhanewicz, Orthop Clin N Am 2011

Non-­‐Painful  L4/L5  Disc  

RAW  6ch  Avg  (3T  SIGNA)   PROCESSED  

Painful  L5/S1  Disc  

Non-­‐  Painful  

Painful  

- +

3T  spine-­‐MRS:  Novel  signal  processing  Nocimed  

Courtesy Larry Tannenbaum and James Peacock

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Diffusion Imaging of Disc

•  Use smaller FOV •  B= 500 and 1000

Comparison w Conventional ssEPI •  Zaharchuk G, Saritas EU, Andre JB, Chin CT, Rosenberg J, Brosnan TJ,

Shankaranarayanan A, Nishimura DG, Fischbein NJ. Reduced Field-of-View Diffusion Imaging of the Human Spinal Cord: Comparison with Conventional Single-shot Echo-Planar Imaging, AJNR. American journal of neuroradiology, 2011. 32(5): p. 813-20 .

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Results - Comparison with full-FOV EPI

rFOV Matrix 192 x 48

•  42 yo woman with left-sided weakness and disk protrusion. Full FOV

Same res 192 x 192 Full FOV Same readout time 96 x 96

DTI in Degenerative Discs

Zhang et al MRI 2012 Feb;30(2):181-8. Epub 2011 Nov 3.

Disc Degeneration T1 rho

Sharmila Majumdar, Thomas M. Link, Lynne S. Steinbach, Serena Hu, John Kurhanewicz Orthop Clin N Am 2011

Fat Fraction Fat Only Water Only

Characterization of early disc degenerative changes using IDEAL as an early indicator of disc space

instability and degeneration – Keck & Viterbi

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Fat Fraction Water Only

20 mm3 ROI

IDEAL Quantitation Of Disc and End Plate Water-Fat

Results: Disc Water Signal

•  Average water signal ratio for both groups decreases from T12/L1 to L4/L5 and then slightly increases at L5/S1

0.000

0.200

0.400

0.600

0.800

1.000

1.200

T12/L1 L1/2 L2/3 L3/4 L4/5 L5/S1

Wat

er S

igna

l Rat

io

Average Water Signal Ratio at each Disc

Patients

Normals

Chad Sarver, Houchun H. Hu, Alexander Lerner, Sam Valencerina, Krishna Nayak, Meng Law Viterbi & Keck USC

•  Advanced Imaging the Disc is a challenge •  Difficult to repeat – Bone causes inhomogenity of field •  Chemical Shift (Vertebral Body Lipids) and Fat Suppression •  Reimbursement

•  Advanced Imaging Techniques – MRS, DWI, DTI, Perfusion, Permeability fMRI, MEG or MMG, IDEAL fat quantitation, SWI, dynamic, flexion-extension. T1 rho, T2 mapping, discography

•  Remember to use the data we already have : •  Extrusion, root edema, development of type I endplate

changes, isolated facet edema, muscle edema and atrophy

Review