Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.


WIN Wednesday Works In Progress

Synaptic Health in Neurodegeneration (SHINE)

Presented by Cara Alcock

Abstract: Synapses are the vital connections between neurons that enable cortical communication. In Alzheimer’s Disease (AD), damage to synapses can be observed prior to more established pathological indicators—such as protein aggregation and atrophy—and seem to better reflect the progressive cognitive decline experienced by those affected. However, most evidence derives from disease models and post-mortem brains. SHINE aims to address this by monitoring synaptic markers in vivo in older adults with and without AD pathology, then comparing their predictive validity for cognitive outcomes to other known markers. Advanced neuroimaging techniques SV2a-PET and E/MEG will enable us to visualise synapses and their function within the living human brain, while MRI will provide structural information and blood/CSF investigations will detect microscopic products of neurodegeneration (e.g. amyloid, tau). We are particularly interested in whether MEG signatures could offer unique diagnostic information that might improve the early detection of AD. Participants will be asked to attend the following visits at baseline: clinical screening and venepuncture; lumbar puncture; PET (London); E/MEG; and MRI and neuropsychological testing. The patient (AD) group will repeat all these procedures after 12 months, whereas controls will only repeat the clinical and neuropsychological questionnaires. Finally, after 24 months, these questionnaires will be repeated once more for all participants. Data will be collected and analysed across the Universities of Oxford and Cambridge in collaboration with local NHS sites.

 

 

 

WIN Wednesday Works In Progress

 Fast and robust measurement of cerebral oxygen metabolism

 Presented by Joseph Woods. 

Abstract: Measurements of cerebral blood flow (CBF) and oxygen extraction fraction (OEF) are key markers of tissue health and can aid the understanding of neurodegenerative and cerebrovascular disease diagnosis, prognosis, and treatment planning. 

While regional CBF can be accurately and non-invasively mapped in under five minutes using arterial spin labelling MRI, regional measurement of OEF using MRI typically requires long scan times and physiological challenges (e.g. gas challenges) or complicated modelling with many assumptions.

TRUST, a simple phase-contrast T2-based method, can provide a single whole-brain-average measurement of OEF in ~1 minute, but extending this approach to spatially map OEF across the brain leads to clinically unfeasible scans times (13 minutes per 2D slice). Recently, a T2*-based method enabled whole-brain OEF mapping in 20 minutes.

In this WIP, I will describe how I will further improve on this T2*-based approach by improving SNR, correcting off-resonance effects, and greatly accelerating the acquisition to reduce the scan time.

 

 

WIN Wednesday Methods Series

 

How to make a Sandwich: A new angle on B1+ Mapping

Presented by James Kent

Abstract: Ultra-high field MRI (>7T) promises superior SNR over conventional clinical field strengths. However, as the field strength increases, so does the inhomogeneity in the transmit field (B1+). This leads to a spatial distribution of flip angles and hence undesirable image contrast. In order to correct for this, we typically perform a scan to obtain the B1+ field and we use this to calibrate the scanner. However, B1+ mapping comes with its own challenges. This talk will explain what B1+ mapping is, why we need it and some of the challenges faced when trying to acquire B1+ maps in the body. I will then introduce our new pulse sequence for B1+ mapping ('Sandwich') that is going to be released as the standard B1+ mapping sequence for Siemens ultra-high field systems.