Neuroimaging in Multiple Sclerosis Kristin A. Linn Post-doctoral - - PowerPoint PPT Presentation

neuroimaging in multiple sclerosis
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Neuroimaging in Multiple Sclerosis Kristin A. Linn Post-doctoral - - PowerPoint PPT Presentation

Neuroimaging in Multiple Sclerosis Kristin A. Linn Post-doctoral researcher, University of Pennsylvania Personal Background 2004 - 2008 2009 - 2014 2014 - 2017 Recurse Center Structural MRI 3D array of voxels 2D Grayscale


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Neuroimaging in Multiple Sclerosis

Kristin A. Linn

Post-doctoral researcher, University of Pennsylvania

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Personal Background

2004 - 2008 2009 - 2014 2014 - 2017

Recurse Center

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SLIDE 3
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Structural MRI

Axial slice of a T1 image

  • 3D array of voxels
  • Grayscale intensities provide

contrast between different tissue types

  • Standard size approximately

256 x 256 x 176 voxels

pixel voxel 2D 3D

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Structural MRI in Multiple Sclerosis

  • Used to study lesion accumulation in brain and spinal cord

Inflammation

MS lesion dynamics

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Structural MRI in Multiple Sclerosis

  • Used to study lesion accumulation in brain and spinal cord

Tissue damage and demylenation Inflammation

MS lesion dynamics

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SLIDE 7

Structural MRI in Multiple Sclerosis

  • Used to study lesion accumulation in brain and spinal cord

Tissue repair and remylenation Tissue damage and demylenation Inflammation

MS lesion dynamics

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Structural MRI in Multiple Sclerosis

Tissue repair and remylenation Tissue damage and demylenation

MS lesion dynamics

Inflammation

  • Used to study lesion accumulation in brain and spinal cord
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SLIDE 9

Quantifying MS Treatment Efficacy

  • Do chronic lesions show evidence of repair in response to

treatment?

Pre-treatment Post-treatment

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Quantifying MS Treatment Efficacy

  • Do chronic lesions show evidence of repair in response to

treatment?

Pre-treatment Post-treatment

  • Initial comparison of average chronic lesion intensity before and

after treatment was highly significant

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SLIDE 11
  • Do chronic lesions show evidence of repair in response to

treatment?

Pre-treatment Post-treatment

  • Statistical challenges: confounding, automatic lesion

segmentation, image preprocessing

Quantifying MS Treatment Efficacy

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Preprocessing README

  • 12 steps before analysis
  • Current analysis is a t-test!
  • Each induces errors/uncertainty

that is not easy to account for

  • Typically, researchers ignore

preprocessing uncertainty

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Registration Error

  • Image alignment sometimes off by one slice

Pre- treatment: Post- treatment:

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Registration Error

Pre- treatment: Post- treatment: Leads to bias in favor of a treatment effect!

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Registration Error

Pre- treatment: Post- treatment:

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Registration Error

Pre- treatment: Post- treatment:

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Moving Forward

  • Many opportunities for statisticians to contribute in meaningful ways

to neuroimaging research

  • Need more sophisticated methods to account for preprocessing errors
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Moving Forward

  • Many opportunities for statisticians to contribute in meaningful ways

to neuroimaging research

  • Need more sophisticated methods to account for preprocessing errors
  • Steep learning curve (anatomy, physics, engineering)
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Moving Forward

  • Many opportunities for statisticians to contribute in meaningful ways

to neuroimaging research

  • Need more sophisticated methods to account for preprocessing errors
  • Steep learning curve (anatomy, physics, engineering)
  • Any methods/models we build must be fast with high-quality, well-

tested software

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Acknowledgements

Taki Shinohara, Ph.D.

Imaging and clinical collaborators: Post-doctoral Advisor:

Salim Chahin, M.D. (Penn) Gabrial Pilar, M.D. (Penn) Clyde Markowitz, M.D. (Penn) Matthew Schindler, M.D. (NIH) Emily Acton (Penn)

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Happy 75th Anniversary!