Monday, January 7, 2019

Yet another breakthrough in gradient technology


The picture above looks like a usual T1-weighted MR image but it was in fact obtained from a highly unusual set of gradient coils which was recently invented by GE. Called Magnus, the gradient coil inserts into a clinical 3T whole-body scanner to boost the imaging speed and gradient encoding power dramatically compared to a conventional scanner. The formal performance metrics are: 200 mT/m and 500 T/m/s, which compare with 80 mT/m and 200 T/m/s for the most expensive clinical scanner available today. What is even more important is that the design of the gradient coil, targeting specifically human head imaging, allows operation near the design limit without human peripheral nerve stimulation, which is known to limit gradient performance in conventional designs. This remarkable achievement was made from a team at GE Global Research in Niskayuna, NY, under a grant from US Department of Defense, and is well on its way to define the next generation of MR neuroimaging hardware. On a brief demo run, the team has shown high b-value (at 2000 s/mm^2) whole-head diffusion imaging with TE of 36 milliseconds!, which compares with a typical TE of over 60 msec in conventional scanners. The new gradient coil is planned to be installed in Walter Reed Military Medical Center in Bethesda, MD (near Washington DC) in the summer.