ISMRM 23rd Annual Meeting & Exhibition 30 May - 05 June 2015 Toronto, Ontario, Canada

Focused Discussion Fusion with Diffusion
 

Wednesday 3 June 2015

Constitution Hall 107

10:00 - 12:00

Moderators:

Maxime Descoteaux, Ph.D., Karla L. Miller, Ph.D.

10:00 0562.   Fusing 3 and 7 tesla HCP datasets for improved brain connectivity analysis
Stamatios N Sotiropoulos1, Saad Jbabdi1, An T Vu2, Jesper L Andersson1, Steen Moeller2, Christophe Lenglet2, Essa Yacoub2, Kamil Ugurbil2, and Timothy Behrens1
1FMRIB Centre, University of Oxford, Oxford, United Kingdom, 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States

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10:20 0563.   Image quality transfer: exploiting bespoke high-quality data to enhance everyday acquisitions
Daniel C. Alexander1, Darko Zikic2, Viktor Wottschel3, Jiaying Zhang1, Hui Zhang1, and Antonio Criminisi2
1Dept. Computer Science, University College London, London, London, United Kingdom, 2Microsoft Research, Cambridge, United Kingdom, 3Institute of Neurology, University College London, London, United Kingdom

Learning the low-level structure of images from high-quality bespoke data sets can substantially improve the content of images reconstructed from more everyday acquisitions. The abstract presents a method that achieves this and demonstrates it using diffusion MRI data from the human connectome project.

10:40 0564.   
Improved diffusion tractography at the cortical boundary using HARDI acquisitions with high-b/low-k in white matter and low-b/high-k within and near the cortex
Qiuyun Fan1, Aapo Nummenmaa1, Thomas Witzel1, Susie Y. Huang1, Jonathan R. Polimeni1, Van J. Wedeen1, Bruce R. Rosen1, and Lawrence L. Wald1
1Massachusetts General Hospital, Charlestown, MA, United States

Mapping the cortico-cortical brain connections relies on the accurate characterization of the axonal structures in both deep white matter and cortical white/gray boundary regions where fibers can sharply curve from the white matter fascicles into the cortical ribbon. Thus, in the region near the cortex, we ideally want a lower b value but high spatial resolution (high-k). In contrast, structures in deep white matter need high b-values to resolve multiple fiber crossings and therefore need to give up some spatial resolution to preserve sensitivity. Thus, deep white matter voxels call for high-b/low-k acquisition. In this work, we acquired b=8000s/mm2 1.9mm isotropic resolution and b=1500s/mm2 1.0mm isotropic resolution diffusion data on the MGH-USC Connectom scanner. We demonstrated that different brain structures require different imaging parameters to be resolved, and diffusion tractography can be improved by fusing the two datasets.

11:00 0565.   Accurate Multi-resolution Discrete Search Method to Estimate the Number and Directions of Axon Packs from DWMRI
Ricardo Coronado-Leija1, Alonso Ramirez-Manzanares1, Jose Luis Marroquin1, and Rolando Jose Biscay1
1Computer Science Department, Centro de Investigacion en Matematicas, Guanajuato, Guanajuato, Mexico

We propose a Multi-resolution Discrete Search method to estimate white matter microstructure based on three key ideas: 1) A Multi-resolution Discrete Search to determine the Principal Diffusion Directions; 2) The parameter-free determination of the number of axon bundles using the Bayesian Information Criterion and 3) A Simultaneous Denoising and Fitting procedure to achieve robustness with respect to noise.

11:20 0566.   
Panchromatic sharpening of FOD-based DEC maps by structural T1 information
Thijs Dhollander1, David Raffelt1, Robert Elton Smith1, and Alan Connelly1,2
1The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia, 2The Florey Department of Neuroscience, University of Melbourne, Melbourne, Victoria, Australia

Diffusion weighted imaging (DWI) acquisitions typically suffer from a lower spatial resolution, compared to their T1 structural counterparts, but provide unique angular information. Researchers and clinical users may often find themselves switching back and forth between the "traditional" directionally-encoded colour (DEC) FA map and a T1 map to navigate anatomy, or try to overlay them using (partial) transparency. We propose a panchromatic sharpening approach tailored to (FOD-based) DEC and (T1) structural information to create a single fused image. The resulting contrast is striking and allows for easy identification of various anatomical structures beyond the resolution of the DWI data.

11:40 0567.   
Inversion Recovery DTI In Vivo at 7T in the Human Brain
Silvia De Santis1,2, Ben Jeurissen3, Derek K Jones1, Yaniv Assaf4, and Alard Roebroeck2
1CUBRIC Cardiff University, Cardiff, United Kingdom, 2Maastricht University, Maastricht, Netherlands, 3iMinds-Vision Lab, Dept. of Physics, University of Antwerp, Antwerp, Belgium, 4Tel Aviv University, Tel Aviv, Israel

The Inversion Recovery DTI technique was recently introduced to provide fibre-specific estimates of the relaxation time T1 and of the diffusion tensor in areas of crossing fibres, that characterise more than 90% of the human brain. Here, we demonstrate the feasibility of IR-DTI in vivo in the human brain, for the first time, and show that different fibre systems have distinct values of T1, reflecting their different myelination properties.