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

Scientific Session • Diffusion MRI - Novel Insights into the Brain

Wednesday 3 June 2015

Constitution Hall 107

16:00 - 18:00


Susie Yi Huang, M.D., Ph.D., Xiaohong Joe Zhou, Ph.D., D.A.B.R.

16:00 0721.   Heritability of structural connections from HCP diffusion MRI data
Stamatios N Sotiropoulos1, Xu Chen2, Stephen M Smith1, David C Van Essen3, Timothy E Behrens1, Thomas E Nichols2, and Saad Jbabdi1
1FMRIB Centre, University of Oxford, Oxford, United Kingdom, 2Department of Statistics, University of Warwick, Coventry, United Kingdom, 3Department of Anatomy & Neurobiology, Washington University, St Louis, MO, United States

There is great interest in understanding population variability of brain connectivity patterns, and the genetic contributions to this variability. Heritability, the proportion of variability attributable to genetic sources, is a quantitative measure that allows the identification of phenotypes. In this work, we examine the heritability of structural connections using diffusion MRI data from the HCP. We compute whole-brain structural connectivity matrices and infer on heritability using permutation testing. Importantly, we localise regions with most heritable connections across different cortical parcellations and compare to heritability trends of cortical morphological features.

16:12 0722.   Motor and non-motor territories of the human dentate nucleus: Mapping the topographical connectivity of the cerebellar cortex with in-vivo sub-millimeter diffusion imaging
Christopher J. Steele1, Alfred Anwander1, Pierre-Louis Bazin1, Robert Trampel1, Andreas Schaefer1, Robert Turner1, Narender Ramnani2, and Arno Villringer1
1Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Sachsen, Germany, 2Royal Holloway University of London, Egham, Surrey, United Kingdom

The cortico-cerebellar loops form one of the largest systems in the brain, yet we have virtually no knowledge about cerebellar anatomical connectivity in humans. We acquired sub-mm cerebellar diffusion images and applied highly specific tractography to understand the cortico-cerebellar loops and provide insight on the influence of motor and non-motor dentate nucleus territories on the brain. We found the first structural evidence that the human dentate nucleus contains a motor/non-motor topographical organisation and, crucially, present novel evidence that the relative influence of non-motor functions of the cerebellum may have increased relative to that of our primate cousins.

16:24 0723.   
Contralateral cortico-ponto-cerebellar pathways with prominent involvement of associative areas in humans in vivo
Andrea De Rinaldis1,2, Fulvia Palesi2,3, Gloria Castellazzi1,2, Fernando Calamante4,5, Nils Muhlert6,7, J Donald Tournier4,5, Giovanni Magenes1, Egidio D'Angelo2,8, and Claudia AM Wheeler-Kingshott6
1Department of Electrical, Computer and Biomedical Engineering, University of Pavia, Pavia, PV, Italy, 2Brain Connectivity Center, C. Mondino National Neurological Institute, Pavia, PV, Italy, 3Department of Physics, University of Pavia, Pavia, PV, Italy, 4The Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, Heidelberg, Victoria, Australia, 5Department of Medicine, Austin Health and Northern Health, University of Melbourne, Heidelberg, Victoria, Australia, 6NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, England, United Kingdom, 7Department of Psychology, Cardiff University, Cardiff, Wales, United Kingdom, 8Department of Brain and Behavioral Sciences, University of Pavia, Pavia, PV, Italy

Cerebellar involvement in cognition is becoming increasingly evident; this is thought to occur through the cerebello-cortical loop, composed of two main pathways: an efferent cerebello-thalamo-cortical pathway and an afferent cortico-ponto-cerebellar pathway. The former has already been reconstructed in vivo using probabilistic tractography. We applied the same method to reconstruct the latter pathway and to describe it both anatomically and quantitatively. The main finding is that most of the cortico-ponto-cerebellar streamlines connect cerebral associative areas with their cerebellar cognitive counterpart. This result improves our understanding of cerebello-cortical connections and provide a plausible pathway through which the cerebellum can influence cognition.

16:36 0724.   Age-related changes of the human brain: Insights from double-wave vector imaging
Marco Lawrenz1,2, Stefanie Brassen1,2, and Jürgen Finsterbusch1,2
1Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Hamburg, Germany, 2Neuroimage Nord, University Medical Centers Hamburg-Kiel-Lübeck, Hamburg-Kiel-Lübeck, Hamburg-Kiel-Lübeck, Germany

Double-wave-vector diffusion-weighting experiments with two weighting periods applied successively offer access to microscopic tissue. Rotationally invariant measures of the microscopic diffusion anisotropy such as the MA index may yield additional information complementary to DTI. Recent studies showed that MA can be determined in the living human brain, and normal values and their variation in a group of young healthy volunteers have been reported. In this study, DWV and DTI measurements were performed in a group of old, healthy volunteers in order to detect age-related changes of the FA and MA.

16:48 0725.   The dynamics of short-term plasticity through water maze training
Shir Hofstetter1 and Yaniv Assaf1,2
1Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel, Israel, 2Neurobiology, Tel Aviv University, Israel, Israel

This study investigates the initial temporal and spatial progression of neuroplasticity using the Morris water maze training. We looked at the evolution of plasticity at different stages of the learning process as well as the effect of the overall time of the task on these changes. Results provide a first demonstration of an order to the progression of neuroplasticity. Few minutes of training can cause changes in the tissue, and the extent of this effect modifies through the progression of the training. Moreover, it seems some regions are also influenced by the overall time of the experience.

17:00 0726.   Differentiating Low- and High-Grade Pediatric Brain Tumors Using a Continuous Random Walk Diffusion Model at High b-Values
Muge Karaman1, Yi Sui1,2, He Wang3, Richard L Magin2, Yuhua H Li4, and Xiaohong Joe Zhou1,5
1Center for MR Research, University of Illinois at Chicago, Chicago, IL, United States, 2Bioengineering, University of Illinois at Chicago, Chicago, IL, United States, 3Philips Research China, Shanghai, China, 4Radiology, Xinhua Hospital, Shanghai, China, 5Departments of Radiology, Neurosurgery, and Bioengineering, University of Illinois at Chicago, Chicago, IL, United States

Differentiation of low-grade and high-grade brain tumors with the use of non-invasive imaging methods is important for the planning of optimal treatment, especially for the pediatric brain tumors that can be difficult to biopsy. Diffusion heterogeneity that reflects the underlying tissue structures may not be accurately captured by a simple diffusion imaging technique that uses a mono-exponential diffusion model to produce an ADC value. In this study, we show that the diagnostic accuracy of differentiating low-grade and high-grade pediatric brain tumors can be improved by using continuous random walk diffusion model that provides a more complete description of heterogeneous structures.

17:12 0727.   Diffusion Tensor Imaging in Patients with Glioblastoma Multiforme using the Supertoroidal Model
Choukri Mekkaoui1, Fabricio Pereira2, William J Kostis3, and Marcel P Jackowski4
1Harvard Medical School - Massachussetts General Hospital, Boston, MA, United States, 2CHU Nîmes, France, 3Harvard Medical School-Massachusetts General Hospital, Boston, MA, United States, 4University of São Paulo, São Paulo, Brazil

Diffusion Tensor Imaging (DTI) has been used extensively for the diagnosis and prognosis of cerebral lesions as well as for surgical planning. Traditional tensor representations, however, have difficulties in differentiating tumor-infiltrated regions and peritumoral edema. In this work, we employ the supertoroidal model of the diffusion tensor and the toroidal volume (TV) in the characterization of Glioblastoma multiforme (GBM). We show that the supertoroidal model is better suited to identifying the heterogeneity of structure in GBMs and that the nonlinear response of TV can enhance differentiation of gliomas from surrounding edema and normal brain parenchyma.

17:24 0728.   Stretched-exponential model DWI (SEM-DWI) as a potential imaging biomarker in grading gliomas and assessment of proliferative activity
Jingjing Jiang1 and Wenzhen Zhu1
1Tongji hospital, tongji medical college, huazhong university of science and technology, Wuhan, Hubei, China

Diffusion wighted imaging (DWI) is one of the advanced neuroimaging techniques in the evaluation of brain tumors. Stretched exponential model DWI (SEM-DWI) is one of them which can properly describe the signal intensity decay when b-factor exceeds 1000 s/mm2. Proliferating cell nuclear antigen (PCNA) and Ki-67 are two of the common nuclear markers in proliferation activity evaluation. In this study, we will assess the feasibility of SEM-DWI in grading gliomas and to find the correlation between DWI parameters and PCNA and Ki-67 labeling index (LI) thus to evaluate DWI as a noninvasive technique for evaluating the proliferative characteristics of gliomas.

17:36 0729.   Multi-shell Diffusion MRI Provides Better Performance in Discriminating Parkinson’s Disease
Silvia De Santis1, Nicola Toschi2,3, Derek K Jones1, Claudio Lucetti4, Stefano Diciotti5, Marco Giannelli6, and Carlo Tessa7
1CUBRIC Cardiff University, Cardiff, United Kingdom, 2Medical Physics Section, Department of Biomedicine and Prevention, Faculty of Medicine, University of Rome “Tor Vergata”, Italy, 3Department of Radiology, A.A. Martinos Center for Biomedical Imaging, MGH and Harvard Medical School, Boston, MA, United States, 4Division of Neurology Unit, Versilia Hospital, Lido di Camaiore (Lu), Italy, 5Department of Electrical, Electronic, and Information Engineering “Guglielmo Marconi”, University of Bologna, Cesena, Italy, 6Unit of Medical Physics, Pisa University Hospital “Azienda Ospedaliero-Universitaria Pisana”, Pisa, Italy, 7Division of Radiology Unit, Versilia Hospital, Lido di Camaiore (Lu), Italy

Parkinson's disease (PD) is associated with the death of dopamine-generating cells in the substantia nigra. We apply the composite hindered and restricted model of diffusion (CHARMED) and the stretched exponential model (SEM) to test the ability of multi-shell methods to differentiate between Parkinson's Disease (PD) patients and healthy controls. We found that multi-shell diffusion MRI provides significantly higher sensitivity and specificity to microstructural WM alterations in PD when compared to conventional DTI. Employing more advanced models such as CHARMED or SEM to study neurodegenerative pathologies may aid the interpretation of otherwise aspecific differences which can be detected with DTI.

17:48 0730.   In-vivo measurements of axon density and axon diameter in the Corpus Callosum in Multiple Sclerosis
Torben Schneider1, Wallace Brownlee1, Jonathan Clayden2, Olga Ciccarelli3, David H Miller1, Daniel C Alexander4, and Claudia A M Wheeler-Kingshott1
1NMR Research Unit, Department of Neuroinflammation, Queen Square MS Centre, UCL Institute of Neurology, London, United Kingdom, 2UCL Institute of Child Health, Imaging & Biophysics Unit, London, United Kingdom, 3Brain Repair & Rehabilitation, UCL Institute of Neurology, London, United Kingdom,4Centre of Medical Image Computing, Department of Computer Science, University College London, London, United Kingdom

It is known that microstructural changes in the Corpus Callosum are associated with disability in Multiple Sclerosis. Here, we have used a novel diffusion MRI protocol and analysis method to measure axon density and diameter in the Corpus Callosum in MS in-vivo and on a standard clinical scanner. Our preliminary results suggest a regional decrease of axon density and increase in axon diameter both in normal appearing white matter and lesion tissue, which is consistent with findings from ex vivo histology.