Rosetrees Interdisciplinary workshop on neurodegenerative diseases of the brain Feb 10, 2021 09:00 AM - 05:00 PM — Virtual Meeting (online)
iCAIRD, NHS GG&C and NVIDIA: AI in Healthcare Feb 25, 2021 09:00 AM - 12:15 PM — Virtual Meeting (online)
Medical Imaging Convention [rescheduled] Sep 15, 2021 - Sep 16, 2021 — National Exhibition Centre, Birmingham, England
Total Body PET 2021 conference [rescheduled] Sep 25, 2021 - Sep 27, 2021 — McEwan Hall, University of Edinburgh


SINAPSE experts from around Scotland have developed ten online modules designed to explain medical imaging. They are freely available and are intended for non-specialists.

Edinburgh Imaging Academy at the University of Edinburgh offers the following online programmes through a virtual learning environment:

Neuroimaging for Research MSc/Dip/Cert

Imaging MSc/Dip/Cert

PET-MR Principles & Applications Cert

Applied Medical Image Analysis Cert

Online Short Courses

Effects of random subject rotation on optimised diffusion gradient sampling schemes in diffusion tensor MRI

Author(s): Susana Munoz Maniega, Mark E. Bastin, Paul A. Armitage

The choice of the number (N) and orientation of diffusion sampling gradients required to measure accurately the water diffusion tensor remains contentious. Monte Carlo studies have suggested that between 20 and 30 uniformly distributed sampling orientations are required to provide robust estimates of water diffusions parameters. These simulations have not, however, taken into account what effect random subject motion, specifically rotation, might have on optimised gradient schemes, a problem which is especially relevant to clinical diffusion tensor MRI (DT-MRI). Here this question is investigated using Monte Carlo simulations of icosahedral sampling schemes and in vivo data. These polyhedra-based schemes, which have the advantage that large N can be created from optimised subsets of smaller N, appear to be ideal for the study of restless subjects since if scanning needs to be prematurely terminated it should be possible to identify a subset of images that have been acquired with a near optimised sampling scheme. The simulations and in vivo data show that as N increases, the rotational variance of fractional anisotropy (FA) estimates becomes progressively less dependent on the magnitude of subject rotation (alpha), while higher FA values are progressively underestimated as alpha increases. These data indicate that for large subject rotations the B-matrix should be recalculated to provide accurate diffusion anisotropy information.

Full version: Available here

Click the link to go to an external website with the full version of the paper

ISBN: 0730-725X
Publication Year: 2008
Periodical: Magn Reson Imaging
Periodical Number: 4
Volume: 26
Pages: 451-60
Author Address: