Joint Annual Meeting ISMRM-ESMRMB 2014 10-16 May 2014 Milan, Italy

Diffusion Applications

Monday 12 May 2014
Red 1 & 2  10:45 - 12:45 Moderators: Alexander Leemans, Ph.D., Claudia A. Wheeler-Kingshott, Ph.D.

10:45 0052.   Connectivity based segmentation of the periaqueductal grey matter in humans with diffusion tensor imaging
Martyn Ezra1, Olivia Kate Faull1, Saad Jbabdi2, and Kyle Thomas Shane Pattinson1
1Nuffield Department of Clinical Neuroscience, University of Oxford, Oxford, Oxfordshire, United Kingdom, 2Oxford Centre for Functional Magnetic Resonance Imaging of the Brain, University of Oxford, Oxford, Oxfordshire, United Kingdom

The periaqueductal gray matter (PAG) is involved in a number of key neurobiological functions. Animal research has identified four sub-divisional columns that differ in both connectivity and function. This study used high-resolution diffusion tensor imaging and probabilistic tractography to segment the human PAG based upon voxel connectivity profiles. While we identified four distinct subdivisions demonstrating spatial concordance with the columns of the animal model, the connectivity profiles of these subdivisions were different to those in animals. This is the first study to resolve subdivisions within the human PAG, and may aid stereotactic interventions and interpretation of functional imaging studies.

10:57 0053.   Imaging gray matter in human brainstem in vivo by high spatial resolution Diffusion Tensor Imaging at 7 Tesla
Marta Bianciardi1, Nicola Toschi1,2, Cornelius Eichner1, Kawin Setsompop1, Florian Beissner1, Vitaly Napadow1, Jonathan R Polimeni1, and Lawrence L Wald1
1Department of Radiology, A.A. Martinos Center for Biomedical Imaging, MGH, Harvard Medical School, Boston, MA, United States, 2Department of Medicine, University of Rome “Tor Vergata”, Rome, Italy

The human brainstem plays an important role in several vital functions, including sleep, and respiration. Our current knowledge of gray matter (GM) structure within the brainstem mostly derives from ex-vivo studies. Aim of this work was to develop novel in-vivo MRI-tools to identify GM-structure. We employed in-vivo high spatial-resolution DTI at 7Tesla, and scrutinized the contrast in DTI-maps, including fractional-anisotropy (FA). In single subject FA-maps, major clusters of brainstem-nuclei were visible with high contrast including the median-raphe-nucleus, the reticular-formation, and the vestibular/olivary/pontine nuclei. High-resolution DTI is a promising tool to delineate GM-structure in the brainstem in-vivo on a subject-by-subject basis.

Kaikai Shen1, Stephen Rose1, Jurgen Fripp1, Katie McMahon2, Greig de Zubicaray3, Nicholas Martin4, Paul Thompson5, Margaret Wright4, and Olivier Salvado1
1Australian e-Health Research Centre, CSIRO, Herston, Queensland, Australia, 2Centre for Advanced Imaging, University of Queensland, St Lucia, Queensland, Australia, 3School of Psychology, University of Queensland, St Lucia, Queensland, Australia, 4Queensland Institute of Medical Research, Herston, Queensland, Australia, 5Imaging Genetics Centre, University of Southern California, Los Angeles, California, United States

We aim to estimate the genetic influence on WM structures using Fibre Orientation Distrubution (FOD) based measurements. We hypothesize that because FOD resolves the crossing fibres, it will allow measuring genetic influence on intra-voxel fibre structures. We estimated the heritability of FOD measures over a twin cohort, by projecting the heritability of FOD onto fibre tracks, and estimating the genetic influence along fibre tracks.

11:21 0055.   Derivation and Evaluation of Amygdalo-Prefrontal Connections in Humans and Monkeys Using Diffusion Tractography
Longchuan Li1, Xiaoping Hu2, Jocelyne Bachevalier3, Warren Jones1, Sarah Shultz1, and Ami Klin1
1Department of Pediatrics, Marcus Autism Center, Children's HealthCare of Atlanta, Emory University, Atlanta, GA, United States, 2Department of Biomedical Engineering, Emory University School of Medicine, Atlanta, GA, United States, 3Yerkes National Primate Research, Emory University, GA, United States

Amygdala-cortical connections consist of major regions of “social brain” and mapping such a network may be critically informative of its roles in autism. In this study, diffusion tractography was used to delineate the connections between the amygdala and the prefrontal areas in macaque monkeys and humans. The results in monkeys were compared with the tracer literature and were also compared with those in humans. We found a generally similar pattern of connections between the tracer and tractography studies and between two species. Such work serves as the first step in realistically mapping amygdala network for the neural underpinnings of autism.

11:33 0056.   
Multi-centre reproducibility of diffusion MRI parameters for clinical sequences in the brain
Matthew Grech-Sollars1, Patrick W Hales1, Keiko Miyazaki2, Felix Raschke3, Daniel Rodriguez4,5, Martin Wilson6, Simrandip K Gill6, Tina Banks7, Dawn E Saunders7, Jonathan D Clayden1, Matt Gwilliam2, Thomas R Barrick3, Paul S Morgan4,5, Nigel P Davies8, James Rossiter9, Dorothee P Auer4,5, Richard Grundy5, Martin O Leach2, Franklyn A Howe3, Andrew C Peet6, and Chris A Clark1
1UCL Institute of Child Health, University College London, London, London, United Kingdom, 2CR UK and EPSRC Cancer Imaging Centre, Institute of Cancer Research and Royal Marsden Foundation Trust, Surrey, United Kingdom, 3Division of Clinical Sciences, St George's, University of London, London, United Kingdom, 4Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom, 5The Children‘s Brain Tumour Research Centre, University of Nottingham, Nottingham, United Kingdom, 6School of Cancer Sciences, University of Birmingham, Birmingham, United Kingdom,7Department of Radiology, Great Ormond Street Hospital for Children, London, United Kingdom, 8Imaging and Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom, 9Electrical & Computer Engineering, University of Birmingham, Birmingham, United Kingdom

The reproducibility of diffusion MRI parameters, and more specifically the apparent diffusion coefficient (ADC), intra-voxel incoherent motion (IVIM) parameters – the diffusion coefficient (D) and perfusion fraction (f), and diffusion tensor imaging (DTI) parameters – mean diffusivity (MD) and fractional anisotropy (FA), was analysed across multiple centres using standard clinical protocols. ADC, D, MD and FA were found to have a good reproducibility and research studies can benefit from incorporating multi-centre data without any loss of reproducibility compared to what would be achieved from a single scanner at a single site.

11:45 0057.   The effect of spatial registration algorithm on detection of white matter abnormalities in multiple sclerosis: a TBSS study.
Giovanni Giulietti1, Barbara Spano'1, Mara Cercignani2, Barbara Basile1, Carlo Caltagirone3,4, and Marco Bozzali1
1Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy, 2Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Brighton, United Kingdom, 3Clinical and Behavioural Neurology, Santa Lucia Foundation, Rome, Italy, 4Departement of Neuroscience, University of Rome "Tor Vergata", Rome, Italy

In the current study we compared the results obtained repeating twice the same FSL-TBSS analyses on the fractional anisotropy (FA) maps, belonging to patients with relapsing remitting multiple sclerosis and healthy subjects, only changing the spatial normalization algorithms. In particular, we tested the differences in using a cubic B-splines (FNIRT, used as default in FSL) and a diffeomorphic (ANTs) transformations algorithms, in terms of the produced skeleton layout and the results of the statistical group comparison. We found that the TBSS-ANTs analysis was able to reconstruct more WM tracts and to detect FA group differences in more brain regions.

11:57 0058.   
Preventing visual field deficits from neurosurgery using intraoperative MRI
Gavin P Winston1, Pankaj Daga2, Mark J White3,4, Caroline Micallef3,4, Anna Miserocchi5, Laura Mancini3,4, Marc Modat2, Jason Stretton1, Meneka K Sidhu1, Mark R Symms1, David J Lythgoe6, John Thornton3,4, Tarek A Yousry3,4, Sebastien Ourselin2, John S Duncan1, and Andrew W McEvoy5
1Epilepsy Society MRI Unit, Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London, England, United Kingdom, 2UCL Centre for Medical Image Computing, London, United Kingdom, 3Lysholm Department of Neuroradiology, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 4Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, London, United Kingdom, 5Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, United Kingdom, 6Centre for Neuroimaging Sciences, Institute of Psychiatry, Kings College London, England, United Kingdom

Anterior temporal lobe resection (ATLR) for refractory epilepsy may cause a visual field deficit (VFD) that precludes driving. We studied 21 patients undergoing ATLR in an intraoperative MRI (iMRI) suite. Preoperative tractography of optic radiation was displayed on the navigation and operating microscope displays either without (9 patients) or with (12 patients) correction for brain shift. Display of the optic radiation during surgery significantly reduced the degree of VFD and no patient developed a VFD that precluded driving (compared to 13% of a historical non-iMRI cohort). Outcome did not differ between iMRI guidance with and without brain shift correction.

12:09 0059.   Plasticity of the Human Visual Pathways Formed by Ocular Gene Therapy
Manzar Ashtari1, Gary Hui Zhang2, Laura Cyckowski1, Philip Cook3, Amanda Viands1, Kathleen Marshall4, James Gee3, Albert Maguire5, and Jean Bennett6
1Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, United States, 2Computer Science, University College London, London, United Kingdom,3Radiology, University of Pennsylvania, Philadelphia, PA, United States, 4CCMT, Children's Hospital of Philadelphia, Philadelphia, PA, United States,5Ophthalmology, University of Pennsylvania, PA, United States, 6Ophthalmology, University of Pennsylvania, Philadelphia, PA, United States

Visual deprivation and blindness are debilitating disorders with no available treatment. Recently, retinal gene therapy has successfully treated a group of patients with Leber's congenital amaurosis (LCA) and has profoundly affected the quality of their lives. Of all sensory systems, vision provides the most information to the brain and plays a central role in how we relate to and interact with the world. Thus, the success of this exciting treatment raises the question of the effect this therapy may have on the brain’s visual pathways. We have employed advanced functional and structural imaging to answer this question.

12:21 0060.   
Diffusion tensor MRI and tractography of the sacral plexus in children with spina bifida
Wieke Haakma1,2, Pieter Dik3, Bennie ten Haken4, Martijn Froeling1, Rutger Jan Nievelstein1, Jeroen Hendrikse1, Inge Cuppen5, Tom de Jong3, and Alexander Leemans6
1Radiology, University Medical Center Utrecht, Utrecht, Utrecht, Netherlands, 2Department of Forensic Sciences and Comparative Medicine Lab, Aarhus University, Aarhus, Central Denmark, Denmark, 3Pediatric Urology, University Medical Center Utrecht, Utrecht, Netherlands, 4Institute for Biomedical Technology & Technical Medicine, University of Twente, enschede, Overijssel, Netherlands, 5Pediatric Neurology, University Medical Center Utrecht, Utrecht, Netherlands, 6Image Science Institute, University Medical Center Utrecht, Utrecht, Netherlands

It is still largely unknown how neural tube defects in spina bifida (SB) affect the nerves at the level of the sacral plexus. Visualizing the sacral plexus in 3D could improve anatomical understanding regarding neurological problems. 10 SB patients underwent DTI on a 3 Tesla MRI. With tractography the microstructural properties of the nerves were investigated and were compared with 10 healthy controls. The sacral plexus of SB patients showed asymmetry, disorganization and lower diffusion values compared to healthy controls. We expect that this technology can provide a valuable contribution to a better analysis of these patients in the future.

12:33 0061.   Basal ganglia-cortical structural connectivity in Huntington’s disease
Marianne J U Novak1,2, Kiran K Seunarine3, Clare R Gibbard2,3, Bogdan Draganski4,5, Karl Friston1, Sarah J Tabrizi2,6, and Christopher A Clark3
1Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, London, United Kingdom, 2Department of Neurodegenerative Disease, UCL Institute of Neurology, London, United Kingdom, 3Imaging and Biophysics, UCL Institute of Child Health, London, United Kingdom, 4LREN, Département des Neurosciences Cliniques, Université de Lausanne, Switzerland, 5Max-Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany,6National Hospital for Neurology and Neurosurgery, London, United Kingdom

Huntington's disease (HD) is a genetic condition that affects both the white and grey matter of the brain. Striatal volume loss is the earliest and most characteristic structural abnormality seen using brain imaging in HD. In this work we present a statistical approach that allows us to quantitatively compare connectivity patterns of subcortical nuclei between groups. We apply our technique to a Huntington's disease cohort and find structured differences in patterns of connectivity compared to healthy controls. Conversely, we see no significant differences between premanifest HD patients and controls, which suggests progressive changes to patterns of connectivity with disease progression.