Philipp Dammann1, Oliver Kraff, Stefan
Maderwald, Elke Gizewski2, Mark Ladd, Thomas Gasser3
1Neurosurgery, University of
Duisburg-Essen, Germany and Erwin L. Hahn Institute for Magnetic Resonance
Imaging, Essen, NRW, Germany; 2Department for Diagn. and Interv.
Radiology and Neuroradiology, University of Duisburg-Essen, Germany; 3Department
of Neurosurgery, University of Duisburg-Essen, Germany
In
this study we assess geometrical distortion over a head-sized phantom at
ultra-high-field MRI (7 Tesla). As field inhomogenity is proportional to B0,
system-related distortions of spatial encoding are expected to increase with
the field strength. This may interfere with potential image-guided
applications in ultra-high-field MRI. This study revealed that distortion is
lower than expected, showing no significant difference in distortion at 7
Tesla compared to lower field strength within a range of 91 mm from the
magnetic center. Image distortion correction reduced local distortion maxima
but didn`t significantly reduce mean distortion over the whole volume.