Quick Project Snapshot

Novel MRI methods to study dynamic brain connectivity

MRI provides a powerful means to study structural and functional brain connectivity non-invasively. Interest in the study of connectivity is growing, particularly in understanding the dynamics of the structural/functional relation and how these two distinct forms of connectivity relate to each other. Within the field of functional connectivity, there is also growing interest in characterising dynamic changes (so-called dynamic functional connectivity), with recent studies demonstrating that dynamic characterizations of functional connectivity provide a more comprehensive description of functional brain networks. However, how these dynamic fluctuations influence the adaptive properties of neural information processing remains an open question that requires the development and application of new methods for time-resolved analysis. One of the research interests of our group is in the development of novel ways to investigate dynamic brain connectivity. For example, we recently developed the technique of track-weighted dynamic functional connectivity (TW-dFC), which fuses structural/functional connectivity data into a 4D image, providing a new approach to investigate dynamic connectivity. The structural connectivity information effectively ‘constrains’ the extremely large number of possible connections in the functional connectivity data (i.e. each voxel’s connection to each other), thus providing a way of reducing the problem’s dimensionality, while still maintaining key data features. Our Lab will continue to develop and optimise novel methods to characterise dynamic connectivity, as well as to assess their role in various neurological disorders.

Reference:
Calamante F, Smith RE, Liang X, Zalesky A, Connelly A. Track-weighted dynamic functional connectivity (TWdFC): a new method to study dynamic connectivity. In Proc. Annual Meeting of the Intl. Soc. Mag. Reson. Med. (ISMRM) 24 (2016), Singapore, p. 308.
 

(a) Seven illustrative TW-dFC time-frames (shown by the numbers). (b) 95% confidence interval of temporal variations in TW-dFC. (c) Track-weighted static functional connectivity (TW-sFC), i.e. without modelling temporal variations. (d) Super-resolution directionally-encoded track-density image (DEC-TDI) showing anatomy; colour-coding corresponds to local fibre orientation (red: left-right, green: anterior-posterior, blue: inferior-superior).

MRI Blood Flow and Brain Connectivity Laboratory

Recent advances in MRI have revolutionised the way we investigate brain structure, brain function, and brain network connectivity. Our lab's main research interests include the development and application of MRI methods to measure cerebral blood flow (Perfusion MRI), super-resolution MRI methods based on diffusion MRI fibre-tracking (Super-Resolution Track-Weighted Imaging), as well as the role of these methods to study brain structural and functional connectivity. 

In particular, we specialise in the development of the two main Perfusion MRI techniques: Dynamic Susceptibility Contrast MRI (DSC-MRI) and Arterial Spin Labelling (ASL). The former is playing a key role in many clinical applications (e.g. stroke, tumours), while the latter provides a powerful quantitative tool to characterise functional connectivity.  

Super-Resolution Track-Weighted Imaging provides a means to exploit the information from whole-brain diffusion MRI fibre-tracking to achieve image resolution not previously possible in the human brain in vivo. This method not only can generate images with exquisite image detail, but also provides a unique framework to combine structural and functional connectivity information, and therefore investigate the structural-function relationships in brain networks. Given that the pathophysiological basis of many brain disorders is related to abnormalities in the structural and/or functional connections, this method is expected to have a major role in clinical neuroscience.

All Projects by this Lab

Perfusion MRI: novel methods to image cerebral blood flow and brain functionSuper-resolution MRI methods for the Human Brain ConnectomeMapping myeloarchitecture using diffusion MRIMRI brain parcellation based on data-driven methodsMapping cerebral haematocrit using MRINovel MRI methods to study dynamic brain connectivity

Imaging

The Florey is a world-leader in neuroimaging development and applied research. Both the Imaging and Epilepsy divisions specialise in advanced magnetic resonance imaging (MRI) methods development, especially related to diffusion MRI, perfusion MRI, and methods to study brain functional and structural connectivity. Functional MRI (fMRI) and simultaneous fMRI and electroencephalography (fMRI-EEG) methods development and application are also a major priority. Neuroimaging is also a crucial component of several studies undertaken in the Stroke division.

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All Labs that operate in this Division

Advanced MRI Development GroupImaging and EpilepsyMRI Blood Flow and Brain Connectivity Laboratory