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Diffusion Imaging Group

Overall keywords:
Diffusion MRI
Diffusion Tensor Imaging (DTI)
Tractography

Tim Dyrby Lise Vejby Søgaard Ellen Garde
Tim B. Dyrby
(Engineer) BSc.EE, MSc, PhD
Research group leader
DRCMR

Active Imaging/Microstructure imaging
Tractography
Brain plasticity (maturation)
Histology and stereology
Lise Vejby Søgaard
(Physist), MSc, PhD
DRCMR

Gas diffusion in lungs

Ellen Garde
MD, PhD
DRCMR

Ageing
Dementia
White Matter
White matter lesions



Maurice Ptito  Matthew Liptrot
Maurice Ptito
MD, visiting professor
University of Montreal, Montreal Canada, DRCMR

Brain plasticity
Vision
Mark Burke
MD, PhD (external member)
University of Montreal, Montreal, Canada

Brain plasticity
Developmental neuroanatomy
Fetal alcohol syndrome
Histology and stereology
Matthew Liptrot (Engineer) BEng, MSc, PhD
DRCMR

Anatomical Connectivity
Microstructure measurements
Longitudinal and group analysis of structural connectivity changes
Visualization of diffusion data



Henrik Lundell Kristian Steen Jensen Tanja Kassuba
Henrik Lundell
(Engineer) MSc, PhD student
DRCMR, IFI

Spinal cord imaging
Motor function
Connectivity (describing function (clinical outcome, electrophysiology, fMRI) through anatomy (MRI, diffusion MRI))
Kristian Jensen
MD, Phd student
DRCMR, The Memory Disorders Research Group, Copenhagen University Hospital Rigshospitalet

Neurobehavioural aspects of cerebral white matter
Neurodegenerative diseases
Tanja Kassuba
(Psychologist) MSc, PhD student
DRCMR, University of Hamburg

Functional MRI
Transcranial magnetic stimulation (TMS)
Brain plasticity (sensory deprivation)
Cognitive processes (multisensory integration, object recognition)



Objectives
The group aims for understanding the brain on several levels ranging from isolated tissue compartments (cellular spaces, neuron, cell membranes) to visualisation and statistical analysis of whole brain connectivity networks. This knowledge is subsequently applied to clinical, pre-clinical and cognitive research projects as well as in the clinical settings. To fulfil this aim, expert knowledge from a broad range of research areas is essential and is established by through collaboration with colleagues within the DRCMR, external members as well as internationally collaboration with groups within diffusion MRI, scientific computing, and neuroanatomy.

DIG is closely linked to other research group at DRCMR: Aging, Brain plasticity, Multiple-sclerosis, Brain Maturation, Preclinical and the clinic.

Overall research areas
* Understanding of water diffusion in individual isolated tissue compartments such as cellular spaces, neurons, cell membranes (pre-clinical)
* Active Imaging of tissue microstructure – Verification and validation of new optimised diffusion MRI protocols to probe specific tissue microstructures (clinical, pre-clinical)
* Imaging pipelines for high-quality and high-resolution (ex vivo) diffusion MRI for studying tissue microstructure, method development and validation (pre-clinical)
* Tractography and mapping brain connectivity – improve and extend existing approaches and relate to functional data (fMRI, transcranial magnetic stimulation).
* Brain plasticity including diseases such as multiple-sclerosis and dementia (clinical and pre-clinical), brain maturation (pre-clinical), aging (clinical), and sensory deprivation as blindness and deafness (clinical)
* Mapping spinal cord functional anatomy. Combining diffusion MRI measurements in vivo/ex vivo with morphology from conventional spinal cord MRI and functional clinical and experimental methods (clinical and pre-clinical).

Resources
The DIG members have access to the following recourses:
MR scanners facilities:
*A pre-clinical 4.7T Varian MR-scanner equipped with 4 channels (parallel imaging) and strong gradients ranging up to 400mT/m. A wide range of RF coils are available, and the facilities to ensure high quality in vivo as well as ex vivo pre-clinical MRI data.
*Clinical 3T TRIO Siemens equipped with 8 channels, 40mT/m gradients

Computer facilities:
*High-performance Cluster (HPC), The Technical University of Denmark
*Terabytes of data storage for data processing of the extreme sized diffusion MRI datasets

Collaborations
Prof. Daniel C. Alexander, University London College (UCL), London, United Kingdom
Prof. Geoff JM Parker, Manchester University, Manchester, United Kingdom
Prof. Bente Pakkenberg, Copenhagen University Hospital Bispebjerg, Copenhagen, Denmark
Dr. Marc Tittgemeyer, Max Planck Institute for Neurological Research, Cologne, Germany


Selected publications
Dyrby TB, Baaré WFC, Alexander DC, Jelsing J, Garde E, Søgaard LV, An ex vivo imaging pipeline for producing high-quality and high-resolution diffusion weighted imaging datasets, Human Brain Mapping 2010, (in press)

Stavngaard T, Søgaard LV, Batz M, Schreiber LM, Dirksen A
Progression of emphysema evaluated by MRI using hyperpolarized 3He (HP 3He) measurements in patients with alpha-1 antitrypsin deficiency (A1AT), compared with CT and lung function tests
Acta Radiol. 2009, 50(9):1019-26

Sidaros A, Engberg AW, Sidaros K, Liptrot MG, Herning M, Petersen P, Paulson OB, Jernigan TL, Rostrup E. Diffusion tensor imaging during recovery from severe traumatic brain injury and relation to clinical outcome: a longitudinal study., Brain 2008, 131(Pt 2), 559-572

Dyrby TB, Sogaard LV, Parker GJ, Alexander DC, Lind NM, Baare WF, Hay-Schmidt A, Eriksen N, Pakkenberg B, Paulson OB, Jelsing J., Validation of in vitro probabilistic tractography., Neuroimage 2007, 37(4), 1267