Introduction to the
Spinal Cord Toolbox
Updated: 2019-08-06
Julien Cohen-Adad, PhD
Associate Professor, Ecole Polytechnique de Montreal
Associate Director, Functional Neuroimaging Unit, University of Montreal
Canada Research Chair in Quantitative Magnetic Resonance Imaging
SCT course
August 8th, 2019, Beijing, China
Outline
1. Image analysis with the Spinal Cord Toolbox
2. Standardize image acquisition: Spine Generic Protocol
3. Let’s communicate!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
2
Outline
1. Image analysis with the Spinal Cord Toolbox
2. Standardize image acquisition: Spine Generic Protocol
3. Let’s communicate!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
3
Why do we need spinal cord imaging?
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Clinico-radiological paradox
5 Collaboration A.L. Oaklander, B. Buchbinder, MGH, Boston
No abnormality above
and below lesion with
conventional MRI…


is it healthy tissue?
• 30 y.o. patient
• Needle injury during corticosteroid injection
at C6 level (malpractice)
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
What it “Quantitative MRI”?
6
Quantitative
MRI of the
Spinal Cord
Edited by
Julien Cohen-Adad
Claudia A. M. Wheeler-Kingshott
Neuronal activity
fMRI
Metabolism
Spectroscopy
F T1
Microstructure NODDIDTI_FADTI_MDqMT_kfMTsatB1+ MWF T2* MTR
What is qMRI used for?
•Diagnosis/prognosis traumas, neurological
diseases, cancers
•Objective biomarkers for testing new drugs
Problem: These quantitative MRI data require complex data analysis
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Analysis software for spinal cord
8
problem: no standard processing tool for spinal cord
brain
data
?spinal cord
data
solution: SCT
https://github.com/neuropoly/spinalcordtoolbox
“SCT (Spinal Cord Toolbox) is a comprehensive and
open-source library of analysis tools for multi-
parametric MRI of the spinal cord.”
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Overview of SCT
9De Leener, Neuroimage 2016
Atlas-based analysis
• 2D slice-by-slice
• Regularized across
slices & time
• Robust for DWI
(group-wise)
Motion correction
and many more
features…
Template and atlas
C1
C3
C5
T1
Registration framework
Segmentation
T2w
T1w
SCT
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
PAM50: template of the spinal cord
10
De Leener, Neuroimage 2017 —> PAM50
Fonov, NeuroImage 2014 —> Methods for template creation
Taso, MAGMA 2014 —> white matter probabilistic template
Taso, NeuroImage 2015 —> white matter probabilistic template (new version)
Lévy, NeuroImage 2015 —> white matter atlas
T2-weighted template
spinothalamic
spinocerebellar
corticospinal
cuneatus
gracilis
C1
C5
T1
C3
gray matter
white matter
cerebrospinal fluid
0 1
0 1
Probabilistic structure White matter atlasT2-weighted template
spinothalamic
spinocerebellar
corticospinal
cuneatus
gracilis
C1
C5
T1
C3
gray matter
white matter
cerebrospinal fluid
0 1
0 1
Probabilistic structure White matter atlasSpinal cord & brainstem templates in ICBM space
Benjamin
De Leener
Simon
Lévy
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Deep learning for segmentation
11
Spinal cord segmentation
• Models trained on ~3000 subjects from
~30 centers
• Robust towards various pathologies
Charley Gros
Patient with cord
compression
Gros et al., Neuroimage:1805.06349
invivoexvivo
Perone et al. Sci Rep 2018
Gray matter segmentation
Christian Perone
4676 axial slices @ 100 μm isotropic
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Applications (150+ citations)
Functional MRI
• Kong et al. Intrinsically organized resting state networks in the human spinal cord. PNAS 2014
• Vahdat et al. Simultaneous Brain–Cervical Cord fMRI Reveals Intrinsic Spinal Cord Plasticity during Motor Sequence Learning. PLOS Biology 2015
• Eippert F. et al. Investigating resting-state functional connectivity in the cervical spinal cord at 3T. BioRxiv 2016
• Weber K.A. et al. Functional Magnetic Resonance Imaging of the Cervical Spinal Cord During Thermal Stimulation Across Consecutive Runs. Neuroimage 2016
• Eippert et al. Denoising spinal cord fMRI data: Approaches to acquisition and analysis. Neuroimage 2016
Quantitative structural MRI (diffusion, MT, etc.)
• Taso et al. A reliable spatially normalized template of the human spinal cord — Applications to automated white matter/gray matter segmentation…. Neuroimage 2015
• Weber et al. Lateralization of cervical spinal cord activity during an isometric upper extremity motor task with functional magnetic resonance imaging. Neuroimage 2016
• Samson et al., ZOOM or non-ZOOM? Assessing Spinal Cord Diffusion Tensor Imaging protocols for multi-centre studies. PLOS One 2016 (in press)
• Taso et al.Tract-specific and age-related variations of the spinal cord microstructure: a multi-parametric MRI study using diffusion tensor imaging (DTI) and ihMT. NMR Biomed 2016
• Massire A. et al. High-resolution multi-parametric quantitative magnetic resonance imaging of the human cervical spinal cord at 7T. Neuroimage 2016
• Duval et al. g-Ratio weighted imaging of the human spinal cord in vivo. Neuroimage 2016
Application in patients
• Yiannakas et al. Fully automated segmentation of the cervical cord from T1-weighted MRI using PropSeg: Application to multiple sclerosis. NeuroImage: Clinical 2015
• Castellano et al., Quantitative MRI of the spinal cord and brain in adrenomyeloneuropathy: in vivo assessment of structural changes. Brain 2016
• Grabher et al., Voxel-based analysis of grey and white matter degeneration in cervical spondylotic myelopathy. Sci Rep 2016;6:24636.
• Talbott JF, Narvid J, Chazen JL, Chin CT, Shah V. An Imaging Based Approach to Spinal Cord Infection. Seminars in Ultrasound, CT and MRI. 2016
• Martin et al. A Novel MRI Biomarker of Spinal Cord White Matter Injury: T2*-Weighted White Matter to Gray Matter Signal Intensity Ratio. AJNR 2017
• David et al. The efficiency of retrospective artifact correction methods in improving the statistical power of between-group differences in spinal cord DTI. Neuroimage 2017
• Peterson et al. Test-Retest and Interreader Reproducibility of Semiautomated Atlas-Based Analysis of Diffusion Tensor Imaging Data in Acute Cervical Spine Trauma in Adult Patients
• Grabher et al. Neurodegeneration in the Spinal Ventral Horn Prior to Motor Impairment in Cervical Spondylotic Myelopathy. Journal of Neurotrauma 2017
• Smith et al. Lateral corticospinal tract damage correlates with motor output in incomplete spinal cord injury. Archives of Physical Medicine and Rehabilitation 2017
• McCoy et al. MRI Atlas-Based Measurement of Spinal Cord Injury Predicts Outcome in Acute Flaccid Myelitis. AJNR 2016
• Grabher et al., Voxel-based analysis of grey and white matter degeneration in cervical spondylotic myelopathy. Sci Rep 2016
• Hori et al., Application of Quantitative Microstructural MR Imaging with Atlas-based Analysis for the Spinal Cord in Cervical Spondylotic Myelopathy. Scientific Reports. 2018
12
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Integration into clinical workflow?
13
MRI PACS Server Clinician
Workstation
running SCT
Dicom images Dicom images + quantitative metrics from SCT
Example of clinical
users or SCT:
Example applications of SCT
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Multi-center DTI study
15Samson, PLOS One 2016
Vanderbilt MontrealLondon
A
P
R
b=0FA
0.1 0.9
L
Template
Atlas
London
Vanderbilt
M
ontreal
FA in fasciculus
gracilis
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
L R L R L R
• 3 sites
• 5 subjects per site
• Two MRI brands (Philips, Siemens)
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
SCT in patients
16
T2*-w WM atlas
Syringo. @3T
Cord seg
CSA=77.4 mm2
WM/GM seg
CSA=60.4/16.0
CSM @3T
CSA=77.9 mm2 CSA=61.9/15.4
Martin & Fehlings
Toronto Western Hospital
CSM @3T
CSA=65.3 mm2 CSA=54.2/12.9
Martin & Fehlings
Toronto Western Hospital
MS @7T
CSA=70.6 mm2 CSA=58.9/11.7
Mainero
MGH, Boston
ALS @7T
CSA=73.9 mm2 CSA=61.3/12.2
Atassi
MGH, Boston
SCI @7T
CSA=71.5 mm2 CSA=61.0/11.8
Oaklander
MGH, Boston
De Leener, Neuroimage 2016
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Gray matter atrophy in ALS
17Paquin, AJNR 2017 Collaboration: PF Pradat (Pitié-Salpêtrière, Paris)
p-value:
p=0.0041
p-value:
p=0.0203
A.
B.
0.0065 0.0116 0.0024 0.0707
0.0045 0.0530 0.0337 0.0412
GM atrophy is a good biomarker
for ALS diagnosis
ALSFRS-R1year
PredictionError
Clinical
predictors
Clinical
predictors
+ SCCSA
Clinical predictors
+ GMCSA
+ WM/GMCSA
Mean error
(Best value: 0.0)
2.05 ± 12.97 1.80 ± 8.67 1.63 ± 8.42
Prediction at 1 year
Charley
Gros
Marie-Eve
Paquin
Spinal cord Gray Matter
segmentation
We need better biomarkers of motoneuron degeneration for
earlier diagnosis and treatment monitoring
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Mapping MS lesions in the cord
18Kearney, Nat Rev Neuroscience 2015
Charley GrosDominique Eden
brain
spinal cord
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Mapping MS lesions in the cord
19Eden et al. Brain 2019
R. Bakshi (USA)
C. Mainero (USA)
T. Shepherd (USA)
S. Smith (USA)
J. Talbott (USA)
D. Reich (USA)
O. Ciccarelli (UK)
E. Bannier (France)
V. Callot (France)
OFSEP (France)
M. Filippi (Italy)
T. Granberg (Sweden)
M. Hori (Japan)
K. Kamiya (Japan)
Y. Tachibana (Japan)
J. Talbott (USA)
T. Granberg (Sweden)
A. Badji (Canada)
J. Maranzano (Canada)
R. Zhuoquiong (China)
SCTSpinal Cord Toolbox
Charley GrosDominique Eden
• 12 MS clinical centers

—> 600 patients
• 8 MD/neuroradiologists who
segmented lesions
• Automatic analysis with SCT
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Mapping MS lesions in the cord
20Eden et al. Brain 2019
Charley GrosDominique Eden
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
ProbabilisticdensityofMSlesions(%)
Vertebral Level
Mapping MS lesions in the cord
21Eden et al. Brain 2019
Vertebral Level
ProbabilisticdensityofMSlesions(%)
Lesion Probability Map (N=600)
Charley GrosDominique Eden
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Lesion segmentation with deep learning x
22Gros, Neuroimage 2018
Charley Gros
Dice: 63.1
Dice: 70.1
Dice: 76.6 Dice: 63.1
Dice: 77.3
T2*-w axial
orientations
T2-w sagittal
orientations
Raw Manual Auto Raw Manual Auto
• Results:
• Robust to image contrast and orientation.
• Overall good sensitivity (85%) but 30% false positive rate (i.e. spurious lesions)
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Shape analysis of cord compression
23Martin et al. BMJ Open 2018 Collaboration: Drs. Allan Martin & Michael Fehlings (U Toronto)
• SCT provides tools to automatically analyze the shape of the
spinal cord in the axial plane
• Relevant metrics include antero-posterior and right-left
dimensions.
• Particularly interesting for studying traumatic and non-traumatic
cord compression
Patient with degenerative cervical myelopathy
A-Pdiameter
(mm)
4
5
6
7
8
9
Area(mm2)
30
40
50
60
70
Eccentricity
0.7
0.75
0.8
0.85
0.9
0.95
Symmetry
0.9
0.92
0.94
0.96
0.98
1
Orientation
-10
-5
0
5
10
Superior-inferior direction
(Slice #)
R-Ldiameter
(mm)
7
9
11
13
Metrics of spinal cord shape sensitive for cord compression
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Detecting anomalies in stroke patients
24
Outline
1. Image analysis with the Spinal Cord Toolbox
2. Standardize image acquisition: Spine Generic Protocol
3. Let’s communicate!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
25
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
qMRI: What protocol to use?
26
If a researcher not familiar with qMRI was to
start a project involving spinal cord imaging,
what sequence and parameters to choose?
qMTMTR
MT_sat
MWF
CHARMED
NODDI
DTI
DKI
g-ratio
ultra-short TE
T1
T2*
T2
PD
This can become overwhelming!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
“Spine Generic Protocol” initiative
27Alley et al., ISMRM 2018 ; “white paper” in preparation
• Solution: Establish a consensus set of qMRI acquisition
parameters for the spinal cord at 3T. [Alley18]
• Similar to NINDS-CDE initiative, but focusing on qMRI
metrics and not specific to particular diseases
• 21 international sites involved in the optimization
• Protocol available for GE, Philips and Siemens at: 

www.spinalcordmri.org/protocols
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
“Spine Generic Protocol” initiative
28Alley et al., ISMRM 2018 ; “white paper” in preparation
Total acquisition time: 20-30 minutes
Diffusion Tensor Imaging
- Demyelination in WM
- Axon degeneration
Magnetization Transfer
- Demyelination in WM
2D multi-echo GRE
- Gray matter atrophy
3D T1w 1mm
- Brain & Spine
assessment
3D T2w 0.8mm
- Cord atrophy
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Multi-site, multi-subjects
29
Goals
• assessing efficacy (i.e. best of the best) vs. efficiency (in situ usage)
• Provide publicly-available database: could be used for generating normative
values, developing new analysis methods (train models, organize challenges, etc.)
Dataset
• ~6 subjects (3 males, 3 females), 20-40 y.o.
• # sites: 32 acquired, 4 confirmed, 5 maybe —> ~250 subjects
• It is not too late to participate! Drop me an email if you are interested.
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Open access
• Each subject is 25-40 MB
• Total size: 6.8 GB (207 subjects)
30
Data available at: https://openneuro.org/datasets/ds001919/
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Data structure: BIDS
31Gorgolewski et al. Sci Data 3, 160044 ; [2] https://github.com/bids-standard/bep001
http://bids.neuroimaging.io/ spineGeneric_multiSubjects
!"" dataset_description.json
!"" participants.json
!"" participants.tsv
!"" sub-ucl01
!"" sub-ucl02
!"" sub-ucl03
!"" sub-ucl04
!"" sub-ucl05
#"" sub-ucl06
   !"" anat
   $   !"" sub-ucl06_T1w.json
   $   !"" sub-ucl06_T1w.nii.gz
   $   !"" sub-ucl06_T2star.json
   $   !"" sub-ucl06_T2star.nii.gz
   $   !"" sub-ucl06_T2w.json
   $   !"" sub-ucl06_T2w.nii.gz
   $   !"" sub-ucl06_acq-MToff_MTS.json
   $   !"" sub-ucl06_acq-MToff_MTS.nii.gz
   $   !"" sub-ucl06_acq-MTon_MTS.json
   $   !"" sub-ucl06_acq-MTon_MTS.nii.gz
   $   !"" sub-ucl06_acq-T1w_MTS.json
   $   #"" sub-ucl06_acq-T1w_MTS.nii.gz
   #"" dwi
   !"" sub-ucl06_dwi.bval
   !"" sub-ucl06_dwi.bvec
   !"" sub-ucl06_dwi.json
   #"" sub-ucl06_dwi.nii.gz
What is BIDS?
BIDS is a convention for organizing neuroimaging
data files and folders
Why BIDS?
Easier to share data and to process them with
BIDS-compatible processing pipelines.
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Processing
• Full analysis pipeline + documentation: https://spine-generic.rtfd.io
• Processing of 207 subjects done in ~6h (2.2GHz x 64, 512 GB RAM)
32
(*)
T8
T1w
T2w
Cord & CSF
WM & GM
WM atlas
PAM50
Template
Cord CSA
Cord CSA
GM CSA
MTR
MTsat
T1
(*) Powered by multiple open-source libraries,
incl. ANTs, dipy, nibabel, numpy, scipy, etc.
FA
MD
RD
…
T1w Seg
Vert. labeling
Warping
field
Coregistration
ME-GRE
MTon
MToff
T1w Seg WM
T2w
WMSeg
DWI
Motion
correction
DWI
GM Seg
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Processing: QC (Live example)
34
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Manual correction
35https://github.com/sct-pipeline/spine-generic/blob/master/README.md#quality-control-rapid
• Number of subjects that needed
corrections:
• T1w seg: 17 (8%)
• T2w seg: 2 (1%)
• T2star GM seg: 15 (7%)
• T1w_ax: 8 (4%)
• Vertebral labeling (on T1w): 25 (12%)
• SOP for manual correction after
QC [1]
Results of the multi-subject spine generic protocol (*)
(*) To reproduce:
Data: https://openneuro.org/datasets/ds001919/versions/1.0.0
Processing pipeline (include manual corrections): https://github.com/sct-pipeline/spine-generic/releases/tag/1.0.0
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
T1w: Image quality
37
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
T1w: Cord CSA
38
Cord cross-sectional
area (CSA) averaged
between C2-C3
A
P
R
1 mm isotropic
L
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
T2w: Image quality
39
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
T2w: Cord CSA
40
A
P
R L
0.8 mm isotropic
Cord cross-sectional
area (CSA) averaged
between C2-C3
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Diffusion MRI: Data quality
41
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Diffusion MRI (Fractional Anisotropy)
42
A
P
R L
0.9 x 0.9 x 5 mm3
Fractional Anisotropy
(FA) averaged in WM
between C2-C5
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Magnetization Transfer: Data Quality
43
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Magnetization Transfer Ratio (MTR)
44
A
P
R L
0.9 x 0.9 x 5 mm3
MTR averaged in WM
between C2-C5
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Next steps & Perspectives
Next steps?
• Finalize data collection
• 35 sites: processed & shared
• 5 sites: recently added (processing todo)
• New sites?
• Finalize manuscript
What can this project be useful for?
• Normative values could be used for clinical studies
• Neuroscientific investigations: normalizing CSA, effect of sex and age on CSA and
other qMRI metrics, etc.
• Ground truth spinal cord segmentations can be used for training novel deep-learning
algorithms
45
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Limitation of deep-learning in medical imaging
46Perone & Cohen-Adad, Journal of Medical Artificial Intelligence 2019
People are different… but not that much!
Imaging parameters, MRI model, etc. create the largest variability:
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
S ∝
sin(α) . (1 − e−TR/T1) . e−TE/T2*
1 − cos(α) . e−TR/T1
• Bloch equation (for gradient echo):
Deep-learning informed by MR physics
47
we know we don’t know (model
will learn)
• Problem: How to introduce 

this equation in the architecture?
param_T1{} param_T2{} param_T2-IR{}
Segmentations
Modular DL
Architecture
• Idea: Learn image features based on
acquisition parameters that have an
impact on the contrast (TR, TE, etc.)
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
FiLM: Visual Reasoning with General Conditioning Layer
48Perez, arXiv:1709.07871, 2018
Input
Image
Output
Segmentation
ConvolutionalLayer
ConvolutionalLayer
…
ReLU
ReLU
Convolutional Neural NetworkConvolutional Neural NetworkConvolutional Neural Network
Collaboration with J.P. Cohen (Mila)
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
FiLM: Visual Reasoning with General Conditioning Layer
49Perez, arXiv:1709.07871, 2018
Input
Image
Output
Segmentation
ConvolutionalLayer
ConvolutionalLayer
…
ReLU
ReLU
FiLMLayer
Convolutional Neural NetworkConvolutional Neural NetworkConvolutional Neural Network
modulated by acquisition parameters
FiLMLayer
• Flip Angle
• Echo Time
• Repetition Time
• …
Input
Acquisition Parameters
FiLM Generator
(γ,β)
(γ,β)
(γ,β)
FiLM(x)=γ(z)⊙x+β(z).
x: Feature map z: conditioning input γ, β: FiLM parameters
Collaboration with J.P. Cohen (Mila)
Results using the “Spine Generic” database
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
FiLM: Results
51
Charley
Gros
Christian
Perone
Benoit
Sauty-de-Chalon
Valentine
Louis-Lucas
Training
MTSMToff MTon T2star T1w
Data from 144 subjects, scanned at 24 sites, with 5 contrasts (~10k 2D images)
Testing
Data from 24 subjects, scanned in 4 unseen sites,
with 1 unseen contrast:
T2w
Dice Precision Recall
Unet 95.1 96.4 95.8
FiLMedUnet 96.2 97.0 95.5
Results (preliminary)
Collaboration with J.P. Cohen (Mila)
Outline
1. Image analysis with the Spinal Cord Toolbox
2. Standardize image acquisition: Spine Generic Protocol
3. Let’s communicate!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
52
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
How to foster clinical translation?
53
problem:
• Despite efforts in open science, these
advanced acquisition/processing
techniques are difficult to translate because
they require expert knowledge to use them
• Publishing articles is not enough
• How to make them available to a larger pool
of clinics worldwide?
solution:
Communication &
Training!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
www.spinalcordmri.org
54
You can find my
slides there!
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
www.spinalcordmri.org
55
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Spinal Cord MRI Workshops
56
Would you like to be on the
mailing list or sponsor the event?
Visit: www.spinalcordmri.org
Toronto’15
45 attendees
Spinal cord MR software
Singapore’16
65 attendees
Gray matter segmentation
Spinal Cord MR Hack
Organizers:
PaulSummersUniMoRE,Modena,Italy
CarloPorroUniMoRE,Modena,Italy
JulienCohen-AdadPolyMTL,Montreal,Canada
Registrationviaemail:paul.summers@unimore.it
EventsponsoredbytheInternationalSpinalResearchTrust.
Friday 16 May, 2014
12:00 – 18:00
Enterprise Hotel
Corso Sempione 91
Milan, Italy
Milan’14
35 attendees
Standardize protocols across vendors
Hawaii’17
70 attendees
Paris’18
70 attendees
London’19
60 attendees
Montreal’19
65 registered
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
What’s next?
• Next year: London, January 21-22, 2020
• Organizers: Ferran Prados, Julien Cohen-Adad
• Concept: Abstract submission, then we pick 4-6 to present
• Topics:
• Killer applications for 7T
• Atrophy (GM, whole cord, longitudinal)
• Diseases (MS, SCI)
• Lower cord applications and challenges
• Histopatology
• Certificate/diploma for attendees
57
Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Conclusion
Analysis tools for spinal cord MRI —> promote reproducibility
• Standardize analysis tools: more transparent, enable cross-validation of published studies.
• Automatic pipelines: prevent user bias (e.g., manual delineation of ROIs), leverage large multi-center studies
• Open-source analysis tools for spinal cord MRI: SCT, spinalfmri8, JIM, etc.

List of software: http://www.spinalcordmri.org/software/
Spine Generic Protocol —> promote replicability, dissemination of knowledge
• Minimize wasted time & $$$ spent on pilot scans for optimization
• Minimize variability in multi-site, multi-vendor studies
• Images are well suited for analysis with SCT
• “One-fit-all” protocol: should be adapted to specific needs
• Already implemented in ~50 clinical sites, multicenter initiatives: INSPIRED (Wheeler-Kingshott), CanProCo
(Kolind), NAIMS (paper under revision), NINDS-CDE (Flanders)
Communication
• Discussions about unmet needs between physicists, clinicians and MRI vendors is key!
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Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT)
Acknowledgements
59
*** Open Positions! Send me an email ***
Pierre Bellec
Carollyn Hurst
André Cyr
Michael Fehlings
Allan Martin
Ali Akbar
Claudia Gandini Wheeler-Kingshott
Ferran Prados
Becky Samson
Joseph Paul Cohen
Christopher Pal
Yoshua Bengio
Shigeki Aoki
Masaaki Hori
Akifumi Hagiwara
Gerald Moran
Bart Schraa
Guillaume Gilbert
Suchandrima
Banerjee
Nikola Stikov
Agah Karakuzu
Aldo Zaimi
Alexandru Foias
Atef Badji
Aurélien Gilliot
Benjamin De Leener
B. Sauty-de-Chalon
Charley Gros
Christian Perone
Dominique Eden
Gabriel Mangeat
Grégoire Germain
Harris Nami
Ilana Leppert
Jennifer Campbell
Lucas Rouhier
Matthieu Parizet
Mathieu Boudreau
Mélanie Lubrano
Nibardo Lopez-Rios
Nicolas Pinon
Oumayma Bounou
Ryan Topfer
Tanguy Duval
Tommy Boshkovski
Valentine Louis-Lucas

SCT course

  • 1.
    Introduction to the SpinalCord Toolbox Updated: 2019-08-06 Julien Cohen-Adad, PhD Associate Professor, Ecole Polytechnique de Montreal Associate Director, Functional Neuroimaging Unit, University of Montreal Canada Research Chair in Quantitative Magnetic Resonance Imaging SCT course August 8th, 2019, Beijing, China
  • 2.
    Outline 1. Image analysiswith the Spinal Cord Toolbox 2. Standardize image acquisition: Spine Generic Protocol 3. Let’s communicate! Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT) 2
  • 3.
    Outline 1. Image analysiswith the Spinal Cord Toolbox 2. Standardize image acquisition: Spine Generic Protocol 3. Let’s communicate! Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT) 3
  • 4.
    Why do weneed spinal cord imaging?
  • 5.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Clinico-radiological paradox 5 Collaboration A.L. Oaklander, B. Buchbinder, MGH, Boston No abnormality above and below lesion with conventional MRI… 
 is it healthy tissue? • 30 y.o. patient • Needle injury during corticosteroid injection at C6 level (malpractice)
  • 6.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) What it “Quantitative MRI”? 6 Quantitative MRI of the Spinal Cord Edited by Julien Cohen-Adad Claudia A. M. Wheeler-Kingshott Neuronal activity fMRI Metabolism Spectroscopy F T1 Microstructure NODDIDTI_FADTI_MDqMT_kfMTsatB1+ MWF T2* MTR What is qMRI used for? •Diagnosis/prognosis traumas, neurological diseases, cancers •Objective biomarkers for testing new drugs
  • 7.
    Problem: These quantitativeMRI data require complex data analysis
  • 8.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Analysis software for spinal cord 8 problem: no standard processing tool for spinal cord brain data ?spinal cord data solution: SCT https://github.com/neuropoly/spinalcordtoolbox “SCT (Spinal Cord Toolbox) is a comprehensive and open-source library of analysis tools for multi- parametric MRI of the spinal cord.”
  • 9.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Overview of SCT 9De Leener, Neuroimage 2016 Atlas-based analysis • 2D slice-by-slice • Regularized across slices & time • Robust for DWI (group-wise) Motion correction and many more features… Template and atlas C1 C3 C5 T1 Registration framework Segmentation T2w T1w SCT
  • 10.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) PAM50: template of the spinal cord 10 De Leener, Neuroimage 2017 —> PAM50 Fonov, NeuroImage 2014 —> Methods for template creation Taso, MAGMA 2014 —> white matter probabilistic template Taso, NeuroImage 2015 —> white matter probabilistic template (new version) Lévy, NeuroImage 2015 —> white matter atlas T2-weighted template spinothalamic spinocerebellar corticospinal cuneatus gracilis C1 C5 T1 C3 gray matter white matter cerebrospinal fluid 0 1 0 1 Probabilistic structure White matter atlasT2-weighted template spinothalamic spinocerebellar corticospinal cuneatus gracilis C1 C5 T1 C3 gray matter white matter cerebrospinal fluid 0 1 0 1 Probabilistic structure White matter atlasSpinal cord & brainstem templates in ICBM space Benjamin De Leener Simon Lévy
  • 11.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Deep learning for segmentation 11 Spinal cord segmentation • Models trained on ~3000 subjects from ~30 centers • Robust towards various pathologies Charley Gros Patient with cord compression Gros et al., Neuroimage:1805.06349 invivoexvivo Perone et al. Sci Rep 2018 Gray matter segmentation Christian Perone 4676 axial slices @ 100 μm isotropic
  • 12.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Applications (150+ citations) Functional MRI • Kong et al. Intrinsically organized resting state networks in the human spinal cord. PNAS 2014 • Vahdat et al. Simultaneous Brain–Cervical Cord fMRI Reveals Intrinsic Spinal Cord Plasticity during Motor Sequence Learning. PLOS Biology 2015 • Eippert F. et al. Investigating resting-state functional connectivity in the cervical spinal cord at 3T. BioRxiv 2016 • Weber K.A. et al. Functional Magnetic Resonance Imaging of the Cervical Spinal Cord During Thermal Stimulation Across Consecutive Runs. Neuroimage 2016 • Eippert et al. Denoising spinal cord fMRI data: Approaches to acquisition and analysis. Neuroimage 2016 Quantitative structural MRI (diffusion, MT, etc.) • Taso et al. A reliable spatially normalized template of the human spinal cord — Applications to automated white matter/gray matter segmentation…. Neuroimage 2015 • Weber et al. Lateralization of cervical spinal cord activity during an isometric upper extremity motor task with functional magnetic resonance imaging. Neuroimage 2016 • Samson et al., ZOOM or non-ZOOM? Assessing Spinal Cord Diffusion Tensor Imaging protocols for multi-centre studies. PLOS One 2016 (in press) • Taso et al.Tract-specific and age-related variations of the spinal cord microstructure: a multi-parametric MRI study using diffusion tensor imaging (DTI) and ihMT. NMR Biomed 2016 • Massire A. et al. High-resolution multi-parametric quantitative magnetic resonance imaging of the human cervical spinal cord at 7T. Neuroimage 2016 • Duval et al. g-Ratio weighted imaging of the human spinal cord in vivo. Neuroimage 2016 Application in patients • Yiannakas et al. Fully automated segmentation of the cervical cord from T1-weighted MRI using PropSeg: Application to multiple sclerosis. NeuroImage: Clinical 2015 • Castellano et al., Quantitative MRI of the spinal cord and brain in adrenomyeloneuropathy: in vivo assessment of structural changes. Brain 2016 • Grabher et al., Voxel-based analysis of grey and white matter degeneration in cervical spondylotic myelopathy. Sci Rep 2016;6:24636. • Talbott JF, Narvid J, Chazen JL, Chin CT, Shah V. An Imaging Based Approach to Spinal Cord Infection. Seminars in Ultrasound, CT and MRI. 2016 • Martin et al. A Novel MRI Biomarker of Spinal Cord White Matter Injury: T2*-Weighted White Matter to Gray Matter Signal Intensity Ratio. AJNR 2017 • David et al. The efficiency of retrospective artifact correction methods in improving the statistical power of between-group differences in spinal cord DTI. Neuroimage 2017 • Peterson et al. Test-Retest and Interreader Reproducibility of Semiautomated Atlas-Based Analysis of Diffusion Tensor Imaging Data in Acute Cervical Spine Trauma in Adult Patients • Grabher et al. Neurodegeneration in the Spinal Ventral Horn Prior to Motor Impairment in Cervical Spondylotic Myelopathy. Journal of Neurotrauma 2017 • Smith et al. Lateral corticospinal tract damage correlates with motor output in incomplete spinal cord injury. Archives of Physical Medicine and Rehabilitation 2017 • McCoy et al. MRI Atlas-Based Measurement of Spinal Cord Injury Predicts Outcome in Acute Flaccid Myelitis. AJNR 2016 • Grabher et al., Voxel-based analysis of grey and white matter degeneration in cervical spondylotic myelopathy. Sci Rep 2016 • Hori et al., Application of Quantitative Microstructural MR Imaging with Atlas-based Analysis for the Spinal Cord in Cervical Spondylotic Myelopathy. Scientific Reports. 2018 12
  • 13.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Integration into clinical workflow? 13 MRI PACS Server Clinician Workstation running SCT Dicom images Dicom images + quantitative metrics from SCT Example of clinical users or SCT:
  • 14.
  • 15.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Multi-center DTI study 15Samson, PLOS One 2016 Vanderbilt MontrealLondon A P R b=0FA 0.1 0.9 L Template Atlas London Vanderbilt M ontreal FA in fasciculus gracilis 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 L R L R L R • 3 sites • 5 subjects per site • Two MRI brands (Philips, Siemens)
  • 16.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) SCT in patients 16 T2*-w WM atlas Syringo. @3T Cord seg CSA=77.4 mm2 WM/GM seg CSA=60.4/16.0 CSM @3T CSA=77.9 mm2 CSA=61.9/15.4 Martin & Fehlings Toronto Western Hospital CSM @3T CSA=65.3 mm2 CSA=54.2/12.9 Martin & Fehlings Toronto Western Hospital MS @7T CSA=70.6 mm2 CSA=58.9/11.7 Mainero MGH, Boston ALS @7T CSA=73.9 mm2 CSA=61.3/12.2 Atassi MGH, Boston SCI @7T CSA=71.5 mm2 CSA=61.0/11.8 Oaklander MGH, Boston De Leener, Neuroimage 2016
  • 17.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Gray matter atrophy in ALS 17Paquin, AJNR 2017 Collaboration: PF Pradat (Pitié-Salpêtrière, Paris) p-value: p=0.0041 p-value: p=0.0203 A. B. 0.0065 0.0116 0.0024 0.0707 0.0045 0.0530 0.0337 0.0412 GM atrophy is a good biomarker for ALS diagnosis ALSFRS-R1year PredictionError Clinical predictors Clinical predictors + SCCSA Clinical predictors + GMCSA + WM/GMCSA Mean error (Best value: 0.0) 2.05 ± 12.97 1.80 ± 8.67 1.63 ± 8.42 Prediction at 1 year Charley Gros Marie-Eve Paquin Spinal cord Gray Matter segmentation We need better biomarkers of motoneuron degeneration for earlier diagnosis and treatment monitoring
  • 18.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Mapping MS lesions in the cord 18Kearney, Nat Rev Neuroscience 2015 Charley GrosDominique Eden brain spinal cord
  • 19.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Mapping MS lesions in the cord 19Eden et al. Brain 2019 R. Bakshi (USA) C. Mainero (USA) T. Shepherd (USA) S. Smith (USA) J. Talbott (USA) D. Reich (USA) O. Ciccarelli (UK) E. Bannier (France) V. Callot (France) OFSEP (France) M. Filippi (Italy) T. Granberg (Sweden) M. Hori (Japan) K. Kamiya (Japan) Y. Tachibana (Japan) J. Talbott (USA) T. Granberg (Sweden) A. Badji (Canada) J. Maranzano (Canada) R. Zhuoquiong (China) SCTSpinal Cord Toolbox Charley GrosDominique Eden • 12 MS clinical centers
 —> 600 patients • 8 MD/neuroradiologists who segmented lesions • Automatic analysis with SCT
  • 20.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Mapping MS lesions in the cord 20Eden et al. Brain 2019 Charley GrosDominique Eden
  • 21.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) ProbabilisticdensityofMSlesions(%) Vertebral Level Mapping MS lesions in the cord 21Eden et al. Brain 2019 Vertebral Level ProbabilisticdensityofMSlesions(%) Lesion Probability Map (N=600) Charley GrosDominique Eden
  • 22.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Lesion segmentation with deep learning x 22Gros, Neuroimage 2018 Charley Gros Dice: 63.1 Dice: 70.1 Dice: 76.6 Dice: 63.1 Dice: 77.3 T2*-w axial orientations T2-w sagittal orientations Raw Manual Auto Raw Manual Auto • Results: • Robust to image contrast and orientation. • Overall good sensitivity (85%) but 30% false positive rate (i.e. spurious lesions)
  • 23.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Shape analysis of cord compression 23Martin et al. BMJ Open 2018 Collaboration: Drs. Allan Martin & Michael Fehlings (U Toronto) • SCT provides tools to automatically analyze the shape of the spinal cord in the axial plane • Relevant metrics include antero-posterior and right-left dimensions. • Particularly interesting for studying traumatic and non-traumatic cord compression Patient with degenerative cervical myelopathy A-Pdiameter (mm) 4 5 6 7 8 9 Area(mm2) 30 40 50 60 70 Eccentricity 0.7 0.75 0.8 0.85 0.9 0.95 Symmetry 0.9 0.92 0.94 0.96 0.98 1 Orientation -10 -5 0 5 10 Superior-inferior direction (Slice #) R-Ldiameter (mm) 7 9 11 13 Metrics of spinal cord shape sensitive for cord compression
  • 24.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Detecting anomalies in stroke patients 24
  • 25.
    Outline 1. Image analysiswith the Spinal Cord Toolbox 2. Standardize image acquisition: Spine Generic Protocol 3. Let’s communicate! Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT) 25
  • 26.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) qMRI: What protocol to use? 26 If a researcher not familiar with qMRI was to start a project involving spinal cord imaging, what sequence and parameters to choose? qMTMTR MT_sat MWF CHARMED NODDI DTI DKI g-ratio ultra-short TE T1 T2* T2 PD This can become overwhelming!
  • 27.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) “Spine Generic Protocol” initiative 27Alley et al., ISMRM 2018 ; “white paper” in preparation • Solution: Establish a consensus set of qMRI acquisition parameters for the spinal cord at 3T. [Alley18] • Similar to NINDS-CDE initiative, but focusing on qMRI metrics and not specific to particular diseases • 21 international sites involved in the optimization • Protocol available for GE, Philips and Siemens at: 
 www.spinalcordmri.org/protocols
  • 28.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) “Spine Generic Protocol” initiative 28Alley et al., ISMRM 2018 ; “white paper” in preparation Total acquisition time: 20-30 minutes Diffusion Tensor Imaging - Demyelination in WM - Axon degeneration Magnetization Transfer - Demyelination in WM 2D multi-echo GRE - Gray matter atrophy 3D T1w 1mm - Brain & Spine assessment 3D T2w 0.8mm - Cord atrophy
  • 29.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Multi-site, multi-subjects 29 Goals • assessing efficacy (i.e. best of the best) vs. efficiency (in situ usage) • Provide publicly-available database: could be used for generating normative values, developing new analysis methods (train models, organize challenges, etc.) Dataset • ~6 subjects (3 males, 3 females), 20-40 y.o. • # sites: 32 acquired, 4 confirmed, 5 maybe —> ~250 subjects • It is not too late to participate! Drop me an email if you are interested.
  • 30.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Open access • Each subject is 25-40 MB • Total size: 6.8 GB (207 subjects) 30 Data available at: https://openneuro.org/datasets/ds001919/
  • 31.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Data structure: BIDS 31Gorgolewski et al. Sci Data 3, 160044 ; [2] https://github.com/bids-standard/bep001 http://bids.neuroimaging.io/ spineGeneric_multiSubjects !"" dataset_description.json !"" participants.json !"" participants.tsv !"" sub-ucl01 !"" sub-ucl02 !"" sub-ucl03 !"" sub-ucl04 !"" sub-ucl05 #"" sub-ucl06    !"" anat    $   !"" sub-ucl06_T1w.json    $   !"" sub-ucl06_T1w.nii.gz    $   !"" sub-ucl06_T2star.json    $   !"" sub-ucl06_T2star.nii.gz    $   !"" sub-ucl06_T2w.json    $   !"" sub-ucl06_T2w.nii.gz    $   !"" sub-ucl06_acq-MToff_MTS.json    $   !"" sub-ucl06_acq-MToff_MTS.nii.gz    $   !"" sub-ucl06_acq-MTon_MTS.json    $   !"" sub-ucl06_acq-MTon_MTS.nii.gz    $   !"" sub-ucl06_acq-T1w_MTS.json    $   #"" sub-ucl06_acq-T1w_MTS.nii.gz    #"" dwi    !"" sub-ucl06_dwi.bval    !"" sub-ucl06_dwi.bvec    !"" sub-ucl06_dwi.json    #"" sub-ucl06_dwi.nii.gz What is BIDS? BIDS is a convention for organizing neuroimaging data files and folders Why BIDS? Easier to share data and to process them with BIDS-compatible processing pipelines.
  • 32.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Processing • Full analysis pipeline + documentation: https://spine-generic.rtfd.io • Processing of 207 subjects done in ~6h (2.2GHz x 64, 512 GB RAM) 32
  • 33.
    (*) T8 T1w T2w Cord & CSF WM& GM WM atlas PAM50 Template Cord CSA Cord CSA GM CSA MTR MTsat T1 (*) Powered by multiple open-source libraries, incl. ANTs, dipy, nibabel, numpy, scipy, etc. FA MD RD … T1w Seg Vert. labeling Warping field Coregistration ME-GRE MTon MToff T1w Seg WM T2w WMSeg DWI Motion correction DWI GM Seg
  • 34.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Processing: QC (Live example) 34
  • 35.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Manual correction 35https://github.com/sct-pipeline/spine-generic/blob/master/README.md#quality-control-rapid • Number of subjects that needed corrections: • T1w seg: 17 (8%) • T2w seg: 2 (1%) • T2star GM seg: 15 (7%) • T1w_ax: 8 (4%) • Vertebral labeling (on T1w): 25 (12%) • SOP for manual correction after QC [1]
  • 36.
    Results of themulti-subject spine generic protocol (*) (*) To reproduce: Data: https://openneuro.org/datasets/ds001919/versions/1.0.0 Processing pipeline (include manual corrections): https://github.com/sct-pipeline/spine-generic/releases/tag/1.0.0
  • 37.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) T1w: Image quality 37
  • 38.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) T1w: Cord CSA 38 Cord cross-sectional area (CSA) averaged between C2-C3 A P R 1 mm isotropic L
  • 39.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) T2w: Image quality 39
  • 40.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) T2w: Cord CSA 40 A P R L 0.8 mm isotropic Cord cross-sectional area (CSA) averaged between C2-C3
  • 41.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Diffusion MRI: Data quality 41
  • 42.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Diffusion MRI (Fractional Anisotropy) 42 A P R L 0.9 x 0.9 x 5 mm3 Fractional Anisotropy (FA) averaged in WM between C2-C5
  • 43.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Magnetization Transfer: Data Quality 43
  • 44.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Magnetization Transfer Ratio (MTR) 44 A P R L 0.9 x 0.9 x 5 mm3 MTR averaged in WM between C2-C5
  • 45.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Next steps & Perspectives Next steps? • Finalize data collection • 35 sites: processed & shared • 5 sites: recently added (processing todo) • New sites? • Finalize manuscript What can this project be useful for? • Normative values could be used for clinical studies • Neuroscientific investigations: normalizing CSA, effect of sex and age on CSA and other qMRI metrics, etc. • Ground truth spinal cord segmentations can be used for training novel deep-learning algorithms 45
  • 46.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Limitation of deep-learning in medical imaging 46Perone & Cohen-Adad, Journal of Medical Artificial Intelligence 2019 People are different… but not that much! Imaging parameters, MRI model, etc. create the largest variability:
  • 47.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) S ∝ sin(α) . (1 − e−TR/T1) . e−TE/T2* 1 − cos(α) . e−TR/T1 • Bloch equation (for gradient echo): Deep-learning informed by MR physics 47 we know we don’t know (model will learn) • Problem: How to introduce 
 this equation in the architecture? param_T1{} param_T2{} param_T2-IR{} Segmentations Modular DL Architecture • Idea: Learn image features based on acquisition parameters that have an impact on the contrast (TR, TE, etc.)
  • 48.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) FiLM: Visual Reasoning with General Conditioning Layer 48Perez, arXiv:1709.07871, 2018 Input Image Output Segmentation ConvolutionalLayer ConvolutionalLayer … ReLU ReLU Convolutional Neural NetworkConvolutional Neural NetworkConvolutional Neural Network Collaboration with J.P. Cohen (Mila)
  • 49.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) FiLM: Visual Reasoning with General Conditioning Layer 49Perez, arXiv:1709.07871, 2018 Input Image Output Segmentation ConvolutionalLayer ConvolutionalLayer … ReLU ReLU FiLMLayer Convolutional Neural NetworkConvolutional Neural NetworkConvolutional Neural Network modulated by acquisition parameters FiLMLayer • Flip Angle • Echo Time • Repetition Time • … Input Acquisition Parameters FiLM Generator (γ,β) (γ,β) (γ,β) FiLM(x)=γ(z)⊙x+β(z). x: Feature map z: conditioning input γ, β: FiLM parameters Collaboration with J.P. Cohen (Mila)
  • 50.
    Results using the“Spine Generic” database
  • 51.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) FiLM: Results 51 Charley Gros Christian Perone Benoit Sauty-de-Chalon Valentine Louis-Lucas Training MTSMToff MTon T2star T1w Data from 144 subjects, scanned at 24 sites, with 5 contrasts (~10k 2D images) Testing Data from 24 subjects, scanned in 4 unseen sites, with 1 unseen contrast: T2w Dice Precision Recall Unet 95.1 96.4 95.8 FiLMedUnet 96.2 97.0 95.5 Results (preliminary) Collaboration with J.P. Cohen (Mila)
  • 52.
    Outline 1. Image analysiswith the Spinal Cord Toolbox 2. Standardize image acquisition: Spine Generic Protocol 3. Let’s communicate! Cohen-Adad: Introduction to the Spinal Cord Toolbox (SCT) 52
  • 53.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) How to foster clinical translation? 53 problem: • Despite efforts in open science, these advanced acquisition/processing techniques are difficult to translate because they require expert knowledge to use them • Publishing articles is not enough • How to make them available to a larger pool of clinics worldwide? solution: Communication & Training!
  • 54.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) www.spinalcordmri.org 54 You can find my slides there!
  • 55.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) www.spinalcordmri.org 55
  • 56.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Spinal Cord MRI Workshops 56 Would you like to be on the mailing list or sponsor the event? Visit: www.spinalcordmri.org Toronto’15 45 attendees Spinal cord MR software Singapore’16 65 attendees Gray matter segmentation Spinal Cord MR Hack Organizers: PaulSummersUniMoRE,Modena,Italy CarloPorroUniMoRE,Modena,Italy JulienCohen-AdadPolyMTL,Montreal,Canada Registrationviaemail:paul.summers@unimore.it EventsponsoredbytheInternationalSpinalResearchTrust. Friday 16 May, 2014 12:00 – 18:00 Enterprise Hotel Corso Sempione 91 Milan, Italy Milan’14 35 attendees Standardize protocols across vendors Hawaii’17 70 attendees Paris’18 70 attendees London’19 60 attendees Montreal’19 65 registered
  • 57.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) What’s next? • Next year: London, January 21-22, 2020 • Organizers: Ferran Prados, Julien Cohen-Adad • Concept: Abstract submission, then we pick 4-6 to present • Topics: • Killer applications for 7T • Atrophy (GM, whole cord, longitudinal) • Diseases (MS, SCI) • Lower cord applications and challenges • Histopatology • Certificate/diploma for attendees 57
  • 58.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Conclusion Analysis tools for spinal cord MRI —> promote reproducibility • Standardize analysis tools: more transparent, enable cross-validation of published studies. • Automatic pipelines: prevent user bias (e.g., manual delineation of ROIs), leverage large multi-center studies • Open-source analysis tools for spinal cord MRI: SCT, spinalfmri8, JIM, etc.
 List of software: http://www.spinalcordmri.org/software/ Spine Generic Protocol —> promote replicability, dissemination of knowledge • Minimize wasted time & $$$ spent on pilot scans for optimization • Minimize variability in multi-site, multi-vendor studies • Images are well suited for analysis with SCT • “One-fit-all” protocol: should be adapted to specific needs • Already implemented in ~50 clinical sites, multicenter initiatives: INSPIRED (Wheeler-Kingshott), CanProCo (Kolind), NAIMS (paper under revision), NINDS-CDE (Flanders) Communication • Discussions about unmet needs between physicists, clinicians and MRI vendors is key! 58
  • 59.
    Cohen-Adad: Introduction tothe Spinal Cord Toolbox (SCT) Acknowledgements 59 *** Open Positions! Send me an email *** Pierre Bellec Carollyn Hurst André Cyr Michael Fehlings Allan Martin Ali Akbar Claudia Gandini Wheeler-Kingshott Ferran Prados Becky Samson Joseph Paul Cohen Christopher Pal Yoshua Bengio Shigeki Aoki Masaaki Hori Akifumi Hagiwara Gerald Moran Bart Schraa Guillaume Gilbert Suchandrima Banerjee Nikola Stikov Agah Karakuzu Aldo Zaimi Alexandru Foias Atef Badji Aurélien Gilliot Benjamin De Leener B. Sauty-de-Chalon Charley Gros Christian Perone Dominique Eden Gabriel Mangeat Grégoire Germain Harris Nami Ilana Leppert Jennifer Campbell Lucas Rouhier Matthieu Parizet Mathieu Boudreau Mélanie Lubrano Nibardo Lopez-Rios Nicolas Pinon Oumayma Bounou Ryan Topfer Tanguy Duval Tommy Boshkovski Valentine Louis-Lucas