081210 ENRS Improving Brachial Plexus Imaging Neurography
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Transcript of 081210 ENRS Improving Brachial Plexus Imaging Neurography
Improving Brachial Plexus Imaging: Is
Neurography the Answer?
Jason JohnsonTrevor Andrews
Diego LemosChristopher Filippi
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Disclosures
• Nothing to disclose
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Why image the brachial
Plexus?
• Trauma• Primary neural tumors• Metastatic disease• Pancoast tumor• Post radiation injury• Radiculopathy• Bony abnormalities
such as cervical ribs• Degenerative diseases• Etc...
Versalius
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Traditional Brachial Plexus Imaging
• Pros
• Familiar
• High signal contrast
• No post-processing
• Cons
• Indirect nerve visualization
• 2D, not well amenable to MIP
• Issues with inadequate/non-uniform fat suppression
• Pulsation and flow related artifacts in the adjacent vessels
• Anatomy not well visualized in orthogonal planes
Multiplanar 2D sequences, typically T1, T2 and T2 STIR
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Brachial Plexus Neurography
• MR neurography - techniques to improve the identification and to generate tissue specific images of nerves.
• Two major types:
• T2-based (water) neurography
• Diffusion neurographyIR-EPI; Zhang, Et al.
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T2-based Neurography
• Neurography has been described using T2-weighted STIR, IR EPI and DW imaging.
• Each sequence has pros and cons.
Oblique Coronal IR-EPI MIP
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Coronal Oblique IR-EPI MIP7
T2 Neurography Limitations
• Slow
• Post Processing
• Motion susceptible
• Not actually imaging the nerve
• Poor SNR
Cor IR-EPI MIP8
Diffusion Neurography / Tractography
• Based on DWI/DTI.
• DTI provides information beyond the resolution of conventional anatomic MR techniques.
• Mean fractional anisotropy (FA) and apparent diffusion coefficient (ADC) map values may reflect microstructural changes in some pathological conditions.
• Potential uses of DTI include monitoring the effects of radiation and/or chemotherapeutics on the brachial plexus. DW MIP Slab
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Diffusion Neurography Limitations
• Slow
• Post Processing
• Motion susceptible
• Validation DWIBS MIPs
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Future of Brachial Plexus Imaging
• Ideal imaging sequence for brachial plexus not yet identified.
• Current research focus appears to revolve around neurography and tractography.
• Future advances in brachial plexus should improve monitoring disease of the PNS and may also be useful in surgical planning and medical decision making.
• Need collaboration with clinicians to assess and improve our imaging techniques.
Neurography likely to be integral part of brachial plexus imaging in the future.
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References• Doi et al. Cervical nerve root avulsion in brachial plexus injuries: magnetic resonance imaging classification and
comparison with myelography and computerized tomography myelography. J Neurosurg (2002) vol. 96 (3 Suppl) pp. 277-84
• Filler et al. MR neurography and muscle MR imaging for image diagnosis of disorders affecting the peripheral nerves and musculature. Neurol Clin (2004) vol. 22 (3) pp. 643-82, vi-vii
• Siqueira et al. Management of brachial plexus region tumours and tumour-like conditions: relevant diagnostic and surgical features in a consecutive series of eighteen patients. Acta Neurochir (2009) vol. 151 (9) pp. 1089-1098
• Smith et al. Magnetic resonance neurography in children with birth-related brachial plexus injury. Pediatr Radiol (2008) vol. 38 (2) pp. 159-63
• Takahara et al. Diffusion-weighted MR neurography of the brachial plexus: feasibility study. Radiology (2008) vol. 249 (2) pp. 653-60
• Vargas et al. Diffusion tensor imaging (DTI) and tractography of the brachial plexus: feasibility and initial experience in neoplastic conditions. Neuroradiology (2010) vol. 52 (3) pp. 237-245
• Viallon et al. High-resolution and functional magnetic resonance imaging of the brachial plexus using an isotropic 3D T2 STIR (Short Term Inversion Recovery) SPACE sequence and diffusion tensor imaging. Eur Radiol (2008) vol. 18 (5) pp. 1018-23
• Zhang et al. Segmented echo planar MR imaging of the brachial plexus with inversion recovery magnetization preparation at 3.0T. J Magn Reson Imaging (2008) vol. 28 (2) pp. 440-4
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