Camino and DTI-TK: Advanced Diffusion MRI Pipeline for Traumatic

Report
UCL Centre for Medical Image Computing
Camino and DTI-TK: Advanced Diffusion MRI
Pipeline for Traumatic Brain Injury
Gary Hui Zhang, PhD
Microstructure Imaging Group
Centre for Medical Image Computing
Department of Computer Science
University College London
26th of June, 2013
Microstructure imaging with diffusion MRI
Diffusion MRI
Signal
Predict
Estimate
Diffusion MRI quantify
water mobility in tissue
Histology
Tissue
Cell size, shape, density
Membrane permeability
Orientation distribution
Axer, J. Neuro. Meth. 1999
Virtual
Histology
Tissue
Modeling
Model parameters are
the tissue microstructure
feature themselves!
Pipeline for advanced diffusion MRI analysis
Imaging
Inference
Localization
Normalization
Pipeline for advanced diffusion MRI analysis
Imaging
Inference
Localization
Normalization
Camino: a platform for advanced diffusion MRI
analysis
• Implements a rich hierarchy of analytic models for diffusion MRI
• Provides a robust framework for fitting diffusion MRI data to the models
• Delivers a sophisticated simulator for validating diffusion MRI models
Monte Carlo Diffusion Simulator (Hall and Alexander, IEEE
TMI 2009)
Displacement PDF
Diffusion MR Signal
Available Substrates
Simulation Pipeline
Diffusion Substrate
Gamma-Distributed Radii
Crossing Cylinders
Permeable Cylinders
Mesh-based substrates
Rich hierarchy of analytic models of diffusion MRI
(Panagiotaki et al, NeuroImage 2012)
Compartment Models
Stick
Cylinder
GDRCylinders
Ball
Zeppelin
Tensor
Multi-Compartment Models
Astrosticks
Astrocylinders
Sphere
Dot
ZeppelinStickAstrosticks
Mapping axon diameter and density in the living
human brain with ActiveAx (Alexander et al, NeuroImage 2010)
Fixed tissue:
• Vervet monkey
• 4.7T; 140mT/m
In vivo:
• human volunteer
• 3T; 60mT/m
Mapping neurite orientation dispersion and
density with NODDI (Zhang et al, NeuroImage 2012)
NODDI
DTI
Dominant
Orientation
Orientation
Dispersion
Fractional
Anisotropy
0
1
0
Neurite
Density
1
0
CSF
1
0
The acquisition protocol is simple to implement and clinically feasible.
1
Neurite density: a potential imaging marker for
brain recovery (Wang et al, PLoS One 2013)
NODDI enables the extension of this animal model study
to living human subjects.
Pipeline for advanced diffusion MRI analysis
Imaging
Inference
Localization
Normalization
Diffusion MRI supports superior anatomical
alignment of white matter structures
DTI
T1
?
Corpus Callosum
Optic Radiation
Arcuate Fasciculus
DTI-TK provides the state-of-the-art for aligning
diffusion MRI data
• Ranked the best performing tool of its kind (Wang et al, NeuroImage 2011)
• Supports unbiased longitudinal analysis of diffusion MRI data (Keihaninejad et al,
NeuroImage 2013)
The importance of tensor-based alignment for
longitudinal processing (Keihaninejad et al, NeuroImage 2013)
Tensor-based alignment improves specificity
The importance of tensor-based alignment for
longitudinal processing (Keihaninejad et al, NeuroImage 2013)
Tensor-based alignment improves sensitivity
Pipeline for advanced diffusion MRI analysis
Imaging
Inference
Localization
Normalization
Tract-specific analysis with DTI-TK (Yushkevich et al,
NeuroImage 2008; Zhang et al, Medical Image Analysis 2010)
• Evaluate specific a priori hypotheses (e.g., ALS impairs only motor tracts)
• Reduce confounding effect of neighboring structures
• Present findings in the context natural to the structure
Typical Voxelwise Analysis
Tract-Specific Analysis
Summary
• Camino provides a rigorous platform for
• developing and validating advanced diffusion MRI methods
• applying these methods to routine clinical research and practice
• DTI-TK supports population-based analysis of diffusion MRI data by
• implementing the state-of-the-art spatial normalization tool
• delivering a statistical inference tool tailored specifically for white matter
• Together, they deliver an end-to-end pipeline for advanced diffusion MRI
analysis
Acknowledgement
• Colleagues at
• CMIC and MIG (UCL)
• Penn Image Computing and Science Laboratory (U Penn)
• Camino funding support
• EU CONNECT consortium (www.brain-connect.eu)
• MS Society of Great Britain and Northern Ireland
• UCLH Biomedical Research Centre funded by NIHR
• DTI-TK funding support
• NIH-NIBIB R03-EB009321
• NIH-NINDS R01-NS065347

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