High-Resolution Diffusion Tensor Imaging (DTI) of the Human Head at 7T: First Results with a 70 MT/m Whole Body Gradient System

Ralf Luetzkendorf¹, Oliver Speck², John Grinstead³, Joerg Stadler⁴, Johannes Bernarding¹

High resolution DTI at ultra-high fields is advantageous as the initially higher signal-to-noise ratio allows to increase the resolution while simultaneously counteracting the according signal losses. Stronger gradients will also enable to apply larger diffusion-weighting at still acceptable TE times. We aimed to reduce TE to overcome the disadvantages of ultra high field conditions such as increased distortions and shortened T2 values. To this purpose we used a new 70 mT/m whole body gradient system for a 7T MR scanner and an improved DTI sequence with a single refocusing pulse to acquire isotropic DTI images with a resolution of (1.4 mm) 3.