Olivia Viessmann

Secondment: MPIL (Histology and Neuroscience)

Project Description

Objectives: Small vessel disease (SVD) of the cerebrovasculature can cause cognitive and functional loss and is manifested in sub-cortical lesions such as lacunar infarcts and white matter lesions which can be assessed in MR neuroimaging. The underlying mechanisms and pathogenesis of SVD are not understood completely, for example the role of atherosclerosis. Due to its improved resolution UHF imaging opens the possibility to study the blood flow, lumen and wall of cerebral small vessels in vivo in more detail and tackle these questions using novel methods.

Tasks and methodology: Assessment of cerebrovascular health using different MR techniques at UHF. This will include optimizing and migrating existing methods for stroke imaging, such as T2 weighted FLAIR sequences for microinfarct assessment and T2* weighted GRE methods for microbleed imaging. We will also investigate whether 3D GRE data can be used to yield susceptibility-weighted images. Angiographic sequences, such as TOF will be used to depict the vessel structure and geometry.  Novel methods will be explored for vessel wall imaging. A new high-resolution black-blood sequence will be developed as well. The aim is to include the optimized sequences and methods in large scale studies, for example the already existing longitudinal OXVASC study, which has an existing patient pool that would be beneficial in terms of subject recruitment.

Results:On going: ESR trained to have experience in MR sequence design, testing for correctness and finally subject imaging.
6m: Literature studies of existing sequences and study of theory of new black-blood approach. Set up of simulation tools to predict signal behaviour in new sequence.
12 m: Assessment of optimised stroke imaging protocol at 7T in subjects. Set up of new pulse sequence on scanner and phantom testing.
24m: Testing of new sequence in subjects and finish of subject recruitment for large scale study.
36 m: Use data to determine the feasibility of neurovascular imaging at 7T for the assessment of SVD. Evaluation of its diagnostic value and its potential to depict the pathophysiology and alterations of the vasculature among patients.

Outreach: Brain Awareness Week 2014

Meetings Attended:PostgradBCISMRM 2014. Joint Annual Meeting ISMRM/ESMRMB 2014 (Milan)

Publications:High-Resolution Time-of-Flight Angiography of Lenticulostriate Arteries at 7T-Olivia Viessmann, Peter Rothwell and Peter Jezzard.BCISMRM 2014.

Imaging with Full Static Tissue Suppression for 3D Volume Rendered (VR) Intracranial Angiography: Application of DANTE-Prepared FLASH (3D-DASH) to Magnetic Resonance Angiography - Linqing Li, Olivia Viessmann, Thomas W. Okell, Francesca Galassi, and Peter Jezzard.ISMRM 2014.

7 Tesla MRI in cerebral small vessel disease: onlinelibrary.wiley.com/doi/10.1111/ijs.12490/abstract

Contact: olivia.viessmann@ndcn.ox.ac.uk

 CV:cv- Olivia